Welding seam nondestructive testing equipment and method for high-precision pressure vessel

Abstract

The invention provides welding seam nondestructive testing equipment and method for a high-precision pressure vessel, and relates to the technical field of welding seam detection, the welding seam nondestructive testing equipment comprises a flaw detector main body, a data line, a probe and a fixed ring, two ends of the data line are respectively connected with the flaw detector main body and the probe, a movable frame is slidably mounted on one side of the fixed ring, and an adjustable track is mounted on the fixed ring. According to the nondestructive testing equipment and method for the welding seam of the high-precision pressure container, through the arrangement of the flaw detector main body, the data line, the probe, the fixed ring, the movable frame, the movable frame, the mounting frame, the adjustable track and the buffer structure, the wavelength of the adjustable track can be adjusted according to the width of the welding seam on the pressure container, so that the welding seam area is better covered, and the welding seam detection accuracy is improved. The device is simple and convenient to operate, in addition, it can be ensured that the probe can be better attached to a weld joint to conduct scanning operation, in the scanning process, the effect of buffering and protecting the external force borne by the probe can be well achieved, and damage to the probe is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of weld detection, and in particular to a weld nondestructive detection device and method for a high-precision pressure vessel. Background Art

[0002] High-precision pressure vessels refer to pressure vessels that have very strict requirements on various technical indicators of the container during the design, manufacturing and use process to ensure that they have extremely high safety, reliability and accuracy; such containers are usually used in some fields with extremely high pressure control requirements, such as chemical, petroleum, energy and other industries. They need to have precise dimensions, good sealing performance, stable structural strength and the ability to accurately control parameters such as pressure and temperature. At the same time, advanced processes and testing methods need to be used in the manufacturing process to ensure that their quality and performance meet high standards. The shape of high-precision pressure vessels is mainly cylindrical, which has the advantages of simple structure and easy production. After the sealing welding of both ends of the high-precision pressure vessel is completed, the welds need to be inspected to ensure the quality of welding and the sealing performance, safety and reliability of the container. When conducting weld quality inspection, the weld position needs to be polished and cleaned first, and then the handheld detection probe is attached to the weld position for scanning and flaw detection. Usually, a zigzag motion trajectory is used to scan the weld position of the container. At present, the technical means of weld flaw detection are usually manual or automated. Most of the automated methods are operated by robotic arms, but in actual situations, the purchase cost of automated equipment is relatively high, and manual operation will hinder the scanning work when scanning the trajectory of circular welds, affecting the accuracy of the weld detection results. Summary of the invention

[0003] Based on the technical problems existing in the background technology, the present invention proposes a high-precision non-destructive testing device and method for welds of pressure vessels.

[0004] The present invention proposes a high-precision pressure vessel weld nondestructive testing equipment and method, including a flaw detector body, a data line, a probe and a fixed ring, the two ends of the data line are respectively connected to the flaw detector body and the probe, a moving frame is slidably installed on one side of the fixed ring, an adjustable track is installed on the fixed ring, the moving frame can move along the track of the adjustable track, a moving frame is installed on the moving frame, a movable groove is opened through the moving frame, a mounting frame is installed in the movable groove, a buffer structure is installed between the moving frame and the mounting frame, the buffer structure is used to drive the mounting frame to fit the weld of the container, a mounting groove is opened through the mounting frame, and the probe is detachably installed in the mounting groove.

[0005] Preferably, the adjustable track comprises an elastic track No. 1, an elastic track No. 2 and an adjustment component; the number of the elastic track No. 1 and the number of the elastic track No. 2 are both multiple, and the multiple elastic tracks No. 1 and the multiple elastic tracks No. 2 are staggered in sequence and adjacent to each other end to end to form a ring shape, the elastic track No. 1 and the elastic track No. 2 are slidably matched, the middle section of the elastic track No. 1 is fixedly mounted on the fixed ring through a bracket, and the adjustment component is used to adjust the bending of the elastic track No. 2.

[0006] Preferably, both ends of the No. 1 elastic track are provided with movement grooves that slidably cooperate with the No. 2 elastic track, the inner wall of the No. 2 elastic track is fixedly connected with an anti-slip sliding button, and the outer surfaces of both sides of the No. 1 elastic track are provided with anti-slip sliding grooves that slidably cooperate with the anti-slip sliding buttons.

[0007] Preferably, the adjustment assembly includes a stretching rod, an adjustment ring, a threaded gear ring and a driving gear; the number of the stretching rods is the same as the number of the No. 2 elastic track and they are arranged in one-to-one correspondence, one end of the stretching rod is fixedly connected to the middle section of the No. 2 elastic track, the other end of the stretching rod is fixedly connected to the adjustment ring, a displacement groove that slides with the adjustment ring is provided in the fixed ring, the threaded gear ring is installed in the displacement groove, the threaded gear ring is rotatably connected to a side of the adjustment ring away from the stretching rod, and the threaded gear ring is threadedly matched with the inner wall of the displacement groove, the driving gear is rotatably installed in the fixed ring, and the driving gear is meshed with the threaded gear ring.

[0008] Preferably, the buffer structure includes a movable ball, a slider, an elastic rod and a reset spring; a ball groove is provided on the outer periphery of the mounting frame for rotationally cooperating with the movable ball, the movable ball is rotatably installed in the ball groove, a buffer hole is provided on the inner wall of the movable groove for slidingly cooperating with the slider, one end of the elastic rod is fixedly connected to the movable ball, the other end of the elastic rod slides through the inner wall of the movable groove and extends into the buffer hole and is fixedly connected to the slider, the reset spring is located in the buffer hole, and the two ends of the reset spring respectively abut against the inner walls of the slider and the end of the buffer hole.

[0009] Preferably, the buffer structure further includes an anti-bending ball; the inner wall of the movable groove is provided with a rotating groove that cooperates with the anti-bending ball for rotation, the anti-bending ball is rotatably installed in the rotating groove, and the elastic rod slides through the anti-bending ball.

[0010] Preferably, the movable frame includes a straight rod, a sleeve and a clamping block; an annular electric slide rail is fixedly installed on the fixed ring, the straight rod is fixedly installed on the slider of the annular electric slide rail, the sleeve is slidably mounted on the straight rod, and the movable frame is fixedly installed on the end of the sleeve away from the straight rod. There are two clamping blocks, both of which are fixedly connected to the sleeve and are arranged at intervals between the two clamping blocks, and the two clamping blocks can clamp the adjustable track to slide.

[0011] A method for using a high-precision pressure vessel weld nondestructive testing device, the testing steps are as follows: Step 1, grinding and cleaning the weld of the pressure vessel; Step 2, putting the fixing ring on the pressure vessel and fixing it; Step 3: Apply coupling agent to the welding position of the pressure vessel, install the probe on the mounting frame, and drive the detection surface of the probe to fit the surface position of the weld of the pressure vessel under the action of the buffer structure; Step 4, the annular electric slide rail works to drive the probe to perform scanning operations at the weld of the pressure vessel; Step 5, observe the echo signal on the display screen of the flaw detector body, determine whether there is a defect, and record the defect location and characteristics; Step 6: Evaluate and classify defects according to inspection standards and specifications; Step 7: Organize the test data and results and write a test report.

[0012] Preferably, in step 4, the bending degrees of the first elastic track and the second elastic track in the adjustable track need to be adjusted according to the width of the weld.

[0013] The high-precision pressure vessel weld nondestructive testing equipment and method proposed by the present invention have the following beneficial effects: through the provision of a flaw detector body, a data line, a probe, a fixing ring, a movable frame, a mounting frame, an adjustable track and a buffer structure, the wavelength of the adjustable track can be adjusted according to the width of the weld on the pressure vessel, so as to better cover the weld area, and the operation is simple and convenient. In addition, it can ensure that the probe can better fit the weld for scanning operations. During the scanning process, it can play a good buffering and protective role on the external force applied to the probe, thereby reducing damage to the probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the overall structure of a high-precision nondestructive testing device for welds of pressure vessels proposed by the present invention; Figure 2 A side view of a fixing ring in a high-precision nondestructive testing device for welds of a pressure vessel proposed by the present invention; Figure 3 A partial cross-sectional view of a fixing ring in a high-precision pressure vessel weld nondestructive testing device proposed by the present invention; Figure 4 This is a schematic diagram of the structure of a No. 1 elastic track in a high-precision nondestructive testing device for welds of pressure vessels proposed by the present invention; Figure 5 This is a schematic diagram of the structure of the second elastic track in a high-precision nondestructive testing device for welds of pressure vessels proposed by the present invention; Figure 6 A cross-sectional view of the position of the displacement groove in the fixing ring of a high-precision pressure vessel weld nondestructive testing device proposed by the present invention; Figure 7 This is a schematic diagram of the structure of a movable frame in a high-precision nondestructive testing device for welds of pressure vessels proposed by the present invention; Figure 8 This is a structural schematic diagram of a probe, a moving frame and a mounting frame in a high-precision pressure vessel weld nondestructive testing device proposed by the present invention; Fig. 9 A cross-sectional view of a probe, a moving frame and a mounting frame in a high-precision nondestructive testing device for welds of pressure vessels proposed by the present invention; Fig.10 A high-precision nondestructive testing device for welds of pressure vessels proposed by the present invention Fig. 9 Enlarged view of point A in the middle.

[0015] In the figure: 1. main body of flaw detector; 2. data line; 3. probe; 4. fixing ring; 5. moving frame; 51. straight rod; 52. sleeve; 53. clamping block; 6. moving frame; 7. installation frame; 8. elastic track No. 1; 9. elastic track No. 2; 10. anti-slip button; 11. anti-slip groove; 12. stretching rod; 13. adjustment ring; 14. threaded gear ring; 15. driving gear; 16. movable ball; 17. slider; 18. elastic rod; 19. reset spring; 20. anti-bend ball. DETAILED DESCRIPTION

[0016] Reference Figure 1-Figure 10The present invention proposes a high-precision pressure vessel weld nondestructive testing equipment, including a flaw detector body 1, a data line 2, a probe 3 and a fixed ring 4. The model of the flaw detector body 1 is a JUT800 digital ultrasonic flaw detector. The data line 2 and the probe 3 are both prior art. The two ends of the data line 2 are respectively connected to the flaw detector body 1 and the probe 3. The data line 2 is used for power supply of the probe 3 and transmission of detection data. The fixed ring 4 is a circle structure. A moving frame 5 is slidably installed on one side of the fixed ring 4. The axis of the moving track of the moving frame 5 coincides with the axis of the fixed ring 4. An adjustable track is installed on the fixed ring 4. The adjustable track can be adjusted into a wavy line shape. The moving frame 5 follows the adjustable track. When the track moves, the moving frame 5 can make a wavy line motion track on the outer surface of the pressure vessel. The adjustable track can adjust the "wavelength" of the adjustable track according to the width of the weld, so as to adapt to the width of the weld. At the same time, the wavy line scanning path has the following advantages compared with the zigzag scanning path, which improves the detection rate: the wavy line scanning can cover the weld area more comprehensively and reduce the possibility of missed detection; reduce interference: the wavy line scanning is relatively smoother, which can reduce the interference signal that may be caused by the zigzag track; more in line with the weld shape: the wavy line is more in line with the weld shape of the cylindrical container, which is conducive to more accurate detection of defects; the moving frame 5 can move along the track of the adjustable track The movable frame 6 is provided with a movable groove, and a mounting frame 7 is provided in the movable groove. A buffer structure is provided between the movable frame 6 and the mounting frame 7. The buffer structure is used to drive the mounting frame 7 to fit the weld of the container. The mounting frame 7 is provided with a mounting groove, and the probe 3 is detachably installed in the mounting groove. In specific operation, the probe 3 is installed in the mounting frame 7 so that the detection surface of the probe 3 protrudes from the mounting groove. When the fixing ring 4 is mounted on the pressure vessel, the detection surface of the probe 3 will abut against the weld position of the pressure vessel. When the buffer structure drives the mounting frame 7 and the probe 3 to abut against the weld of the pressure vessel, in actual conditions, the pressure vessel The thickness of the weld of the pressure vessel varies, and it is impossible to achieve a uniform thickness. Therefore, during scanning, the buffer structure ensures that the probe 3 is always attached to the weld on the pressure vessel. In addition, when the probe 3 touches a burr, the buffer structure will also reduce the impact force on the probe 3, thereby protecting the probe 3. The movable frame 5 slides on the side of the fixed ring 4, so that the probe 3 is attached to the weld of the pressure vessel and performs a circular motion. While performing the circular motion, the probe 3 performs a reciprocating wave-shaped motion, so that the weld on the pressure vessel can be comprehensively scanned and inspected, without the need for manual scanning by the staff, thereby reducing the labor intensity of the staff. At the same time, the structure is simple, the operation is convenient, and the purchase cost is low.

[0017] like Figure 2 , Figure 3 , Figure 4 and Figure 5As shown in FIG. , the adjustable track includes a first elastic track 8, a second elastic track 9 and an adjustment component; the shape of the first elastic track 8 is as shown in FIG. Figure 4 As shown in FIG. , the shape of the second elastic track 9 is as follows Fig. 9 As shown in, when connected, the two ends of the No. 2 elastic track 9 are respectively inserted into the ends of the two No. 1 elastic tracks 8. When the No. 2 elastic track 9 is bent, the two ends of the No. 2 elastic track 9 can drive the No. 2 elastic track 9 to bend at the same time, thereby forming a wavy linear structure. The number of the No. 1 elastic track 8 and the No. 2 elastic track 9 are both multiple, and the multiple No. 1 elastic tracks 8 and the multiple No. 2 elastic tracks 9 are staggered in sequence and adjacent to each other end to end to form a ring. The No. 1 elastic track 8 and the No. 2 elastic track 9 are slidably matched. The middle section of the No. 1 elastic track 8 is fixedly mounted on the fixing ring 4 through a bracket. The adjusting component is used to adjust the bending of the No. 2 elastic track 9. When the weld width of the pressure vessel is different, the bending degree of the No. 2 elastic track 9 can be adjusted by the adjusting component, thereby driving the No. 1 elastic track 8 to have a corresponding deformation, forming a wavy linear motion track, which has a simple structure and is easy to operate.

[0018] like Figure 4 and Figure 5 As shown in, both ends of the No. 1 elastic track 8 are provided with movement grooves that slide with the No. 2 elastic track 9, the inner wall of the No. 2 elastic track 9 is fixedly connected with an anti-slip slide button 10, and the outer surface of both sides of the No. 1 elastic track 8 is provided with anti-slip slide grooves 11 that slide with the anti-slip slide button 10. In actual conditions, when the No. 2 elastic track 9 undergoes elastic bending deformation, the distance between the middle position of the No. 2 elastic track 9 and the end of the No. 1 elastic track 8 will change. Therefore, it is necessary to slide between the end of the No. 2 elastic track 9 and the end of the No. 1 elastic track 8 to adapt to the deformation of the No. 2 elastic track 9. When sliding occurs between the No. 2 elastic track 9 and the No. 1 elastic track 8, the anti-slip slide button 10 slides in the anti-slip slide groove 11; it should be noted that when the No. 2 elastic track 9 is deformed, it is necessary to ensure that the end of the No. 2 elastic track 9 and the end of the No. 1 elastic track 8 remain in a fit state to ensure the smoothness of the sliding of the moving frame 5.

[0019] like Figure 2 , Figure 3 and Figure 6As shown in, the adjustment component includes a stretching rod 12, an adjustment ring 13, a threaded gear ring 14 and a driving gear 15; the number of the stretching rods 12 is the same as the number of the second elastic track 9 and is arranged one by one. When the second elastic track 9 is deformed, the stretching rod 12 pulls the middle section of the second elastic track 9, and the two ends of the second elastic track 9 are pulled by the ends of the two adjacent first elastic tracks 8, so that the second elastic track 9 undergoes elastic deformation. When the second elastic track 9 undergoes elastic deformation, the ends of the two adjacent first elastic tracks 8 are also elastically deformed, thereby changing the "wavelength" of the adjustable track wave line to adapt to the weld of appropriate width, so as to ensure a comprehensive scan of the weld, one end of the stretching rod 12 is fixedly connected to the middle section of the second elastic track 9, the other end of the stretching rod 12 is fixedly connected to the adjustment ring 13, a displacement groove is provided in the fixed ring 4 for sliding cooperation with the adjustment ring 13, the threaded gear ring 14 is installed in the displacement groove, and the threaded gear ring 14 and The adjusting ring 13 is rotatably connected to the side away from the stretching rod 12, and the threaded gear ring 14 cooperates with the inner wall thread of the displacement groove, and the driving gear 15 is rotatably installed in the fixed ring 4, and the driving gear 15 is meshed with the threaded gear ring 14. The driving gear 15 is driven by a motor. In actual operation, the weld width of the outer periphery of the pressure vessel is usually consistent, so the "wavelength" of the adjustable track can be adjusted to be consistent, and the motor needs to work. The motor drives the driving gear 15 to rotate, and the driving gear 15 drives the threaded gear ring 14 to rotate. When the threaded gear ring 14 rotates, it cooperates with the inner wall thread of the displacement groove, so that the threaded gear ring 14 slides in the displacement groove. Due to the sliding of the threaded gear ring 14 and the adjusting ring 13, the threaded gear ring 14 pulls the adjusting ring 13 to move synchronously in the displacement groove, and the adjusting ring 13 drives multiple stretching rods 12 to move synchronously. Multiple stretching rods 12 simultaneously pull multiple No. 2 elastic tracks 9 to bend and deform, thereby realizing the "wavelength" adjustment of the adjustable track, and the operation is simple and convenient.

[0020] like Fig. 9 and Fig.10As shown in the figure, the buffer structure includes an active ball 16, a slider 17, an elastic rod 18 and a reset spring 19; a ball groove is provided on the outer periphery of the mounting frame 7 for rotationally cooperating with the active ball 16, the active ball 16 is rotatably installed in the ball groove, a buffer hole is provided on the inner wall of the active groove for slidingly cooperating with the slider 17, one end of the elastic rod 18 is fixedly connected to the active ball 16, the other end of the elastic rod 18 slides through the inner wall of the active groove and extends into the buffer hole and is fixedly connected to the slider 17, the reset spring 19 is located in the buffer hole, and the two ends of the reset spring 19 are respectively connected to the active ball 16. The slider 17 and the inner wall of the end of the buffer hole are abutted, and the buffer structure also includes an anti-folding ball 20; the inner wall of the movable groove is provided with a rotating groove that cooperates with the anti-folding ball 20 for rotation, and the anti-folding ball 20 is rotatably installed in the rotating groove, and the elastic rod 18 slides through the anti-folding ball 20. In actual situations, when the elastic rod 18 is bent, the elastic rod 18 has irreversible deformation at the position where it contacts the inner wall of the movable groove. Therefore, the anti-folding ball 20 is designed to change the bending degree of the position where the elastic rod 18 contacts the inner wall of the movable groove. In actual situations, when the probe 3 is abutted When the probe 3 is placed against the weld of the pressure vessel, the probe 3 will be placed against the outer periphery of the pressure vessel. Due to the interaction of forces, the probe 3 and the mounting frame 7 will move synchronously in the movable groove. When the mounting frame 7 is displaced, the mounting frame 7 will drive the movable ball 16 to move synchronously. However, since the movable ball 16 will be pulled by the elastic rod 18, the movable ball 16 will rotate in the ball groove. At the same time, the elastic rod 18 cannot be stretched and deformed. The movable ball 16 drives the elastic rod 18 to move. At the same time, the elastic rod 18 will pull the slider 17 to slide in the buffer hole. The slider 17 When sliding in the buffer hole, the slider 17 will squeeze the reset spring 19. Due to the rebound effect of the reset spring 19, the reset spring 19 has a tendency to make the slider 17 slide and reset in the buffer hole. Therefore, the slider 17 has the function of pulling the elastic rod 18 and the movable ball 16 to reset, so that the movable ball 16 drives the mounting frame 7 and the probe 3 to be close to the weld surface of the pressure vessel. Since the buffer structure is arranged around the mounting frame 7, the probe 3 can play a buffering protection role when it is hit by external force in any direction, and plays a good protective role.

[0021] like Figure 3 and Figure 6As shown in the figure, the mobile frame 5 includes a straight rod 51, a sleeve 52 and a clamping block 53; an annular electric slide rail is fixedly installed on the fixed ring 4, the straight rod 51 is fixedly installed on the slider of the annular electric slide rail, the sleeve 52 is slidably sleeved on the straight rod 51, and the mobile frame 6 is fixedly installed on the end of the sleeve 52 away from the straight rod 51. The number of the clamping blocks 53 is two, and the two clamping blocks 53 are fixedly connected to the sleeve 52, and the two clamping blocks 53 are arranged at intervals. The two clamping blocks 53 can clamp the adjustable track to slide. In specific operations When the straight rod 51 moves, it will drive the sleeve 52 to move synchronously. When the sleeve 52 rotates, the two clamping blocks 53 are always clamped on the adjustable track. Since the distances between each section of the adjustable track and the annular electric slide rail are different, the two clamping blocks 53 will follow the trajectory of the adjustable track, so that the clamping blocks 53 drive the sleeve 52 to move synchronously, thereby driving the probe 3 to move synchronously in a wave line to scan the welds on the pressure vessel.

[0022] The detection steps are as follows: Step 1, grinding and cleaning the weld of the pressure vessel; Step 2, put the fixing ring 4 on the pressure vessel and fix it, and select a fixing ring 4 of suitable size; Step 3, applying coupling agent to the welding position of the pressure vessel, installing the probe 3 on the mounting frame 7, and making the detection surface of the probe 3 fit the surface position of the weld of the pressure vessel under the action of the buffer structure; Step 4, the annular electric slide rail drives the probe 3 to scan the weld of the pressure vessel. The bending degree of the first elastic rail 8 and the second elastic rail 9 in the adjustable rail needs to be adjusted according to the width of the weld. Step 5, observe the echo signal on the display screen of the flaw detector body 1, determine whether there is a defect, and record the defect location and characteristics; Step 6: Evaluate and classify defects according to inspection standards and specifications; Step 7: Organize the test data and results and write a test report.

[0023] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-precision pressure vessel weld nondestructive testing equipment, characterized in that: The device comprises a flaw detector body (1), a data line (2), a probe (3) and a fixing ring (4), wherein two ends of the data line (2) are respectively connected to the flaw detector body (1) and the probe (3), a moving frame (5) is slidably mounted on one side of the fixing ring (4), an adjustable track is mounted on the fixing ring (4), the moving frame (5) can move along the track of the adjustable track, a moving frame (6) is mounted on the moving frame (5), a movable groove is formed through the moving frame (6), a mounting frame (7) is mounted in the movable groove, a buffer structure is mounted between the moving frame (6) and the mounting frame (7), the buffer structure is used to drive the mounting frame (7) to fit the weld of the container, a mounting groove is formed through the mounting frame (7), and the probe (3) is detachably mounted in the mounting groove.

2. The high-precision pressure vessel weld nondestructive testing equipment according to claim 1, characterized in that: The adjustable track comprises a first elastic track (8), a second elastic track (9) and an adjustment component; the first elastic track (8) and the second elastic track (9) are both multiple in number, the multiple first elastic tracks (8) and the multiple second elastic tracks (9) are staggered in sequence and adjacent to each other end to end to form a ring shape, the first elastic track (8) and the second elastic track (9) are slidably matched, the middle section of the first elastic track (8) is fixedly mounted on the fixing ring (4) through a bracket, and the adjustment component is used to adjust the bending of the second elastic track (9).

3. The high-precision pressure vessel weld nondestructive testing equipment according to claim 2, characterized in that: Both ends of the first elastic track (8) are provided with movement grooves that are slidably matched with the second elastic track (9); the inner wall of the second elastic track (9) is fixedly connected with an anti-slip button (10); and the outer surfaces of both sides of the first elastic track (8) are provided with anti-slip grooves (11) that are slidably matched with the anti-slip button (10).

4. The high-precision pressure vessel weld nondestructive testing equipment according to claim 3, characterized in that: The adjustment assembly comprises a stretching rod (12), an adjustment ring (13), a threaded gear ring (14) and a driving gear (15); the number of the stretching rods (12) is the same as the number of the second elastic track (9) and they are arranged in a one-to-one correspondence; one end of the stretching rod (12) is fixedly connected to the middle section of the second elastic track (9); the other end of the stretching rod (12) is fixedly connected to the adjustment ring (13); a displacement groove slidably matched with the adjustment ring (13) is provided in the fixing ring (4); the threaded gear ring (14) is installed in the displacement groove; the threaded gear ring (14) is rotatably connected to a side of the adjustment ring (13) away from the stretching rod (12); the threaded gear ring (14) is threadably matched with the inner wall of the displacement groove; the driving gear (15) is rotatably installed in the fixing ring (4); the driving gear (15) is meshed with the threaded gear ring (14).

5. The high-precision pressure vessel weld nondestructive testing equipment according to claim 1, characterized in that: The buffer structure comprises a movable ball (16), a slider (17), an elastic rod (18) and a reset spring (19); a ball groove for rotationally cooperating with the movable ball (16) is provided on the outer periphery of the mounting frame (7); the movable ball (16) is rotationally mounted in the ball groove; a buffer hole for slidingly cooperating with the slider (17) is provided on the inner wall of the movable groove; one end of the elastic rod (18) is fixedly connected to the movable ball (16); the other end of the elastic rod (18) slides through the inner wall of the movable groove and extends into the buffer hole to be fixedly connected to the slider (17); the reset spring (19) is located in the buffer hole, and the two ends of the reset spring (19) respectively abut against the slider (17) and the inner wall of the end of the buffer hole.

6. The high-precision pressure vessel weld nondestructive testing equipment according to claim 5, characterized in that: The buffer structure also includes an anti-folding ball (20); the inner wall of the movable groove is provided with a rotation groove that rotatably cooperates with the anti-folding ball (20); the anti-folding ball (20) is rotatably installed in the rotation groove; and the elastic rod (18) slides through the anti-folding ball (20).

7. The high-precision pressure vessel weld nondestructive testing equipment according to claim 1, characterized in that: The movable frame (5) comprises a straight rod (51), a sleeve (52) and a clamping block (53); an annular electric slide rail is fixedly mounted on the fixing ring (4); the straight rod (51) is fixedly mounted on a slider of the annular electric slide rail; the sleeve (52) is slidably sleeved on the straight rod (51); the movable frame (6) is fixedly mounted on an end of the sleeve (52) away from the straight rod (51); there are two clamping blocks (53); both of the two clamping blocks (53) are fixedly connected to the sleeve (52); the two clamping blocks (53) are spaced apart from each other; and the two clamping blocks (53) can clamp the adjustable track for sliding.

8. A method for using a high-precision pressure vessel weld non-destructive testing device, according to any one of claims 1 to 7, characterized in that: The detection steps are as follows: Step 1, grinding and cleaning the weld of the pressure vessel; Step 2, putting the fixing ring (4) on the pressure vessel and fixing it; Step 3, applying coupling agent to the welding position of the pressure vessel, installing the probe (3) on the mounting frame (7), and driving the detection surface of the probe (3) to fit the surface position of the weld of the pressure vessel under the action of the buffer structure; Step 4, the annular electric slide rail operates to drive the probe (3) to perform a scanning operation at the weld of the pressure vessel; Step 5, observing the echo signal on the display screen of the flaw detector body (1), determining whether there is a defect, and recording the defect location and characteristics; Step 6: Evaluate and classify defects according to inspection standards and specifications; Step 7: Organize the test data and results and write a test report.

9. The method for using the high-precision pressure vessel weld nondestructive testing device according to claim 8, characterized in that: In step 4, the bending degrees of the first elastic track (8) and the second elastic track (9) in the adjustable track need to be adjusted according to the width of the weld.

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