Pulsed eddy current detection device for outer wall defects of small-diameter pressure pipeline

Abstract

The utility model discloses a pulsed eddy current detection device for outer wall defects of a small-diameter pressure pipeline. The pulsed eddy current detection device comprises a bottom plate and a mark driving assembly, a single-chip microcomputer is arranged at the right end of the upper surface of the bottom plate, a pulsed eddy current detection probe is fixedly mounted in the middle of the upper surface of the bottom plate through symmetrically arranged fixing plates, the output end of the pulsed eddy current detection probe is electrically connected with the input end of the single-chip microcomputer, and mounting bases are arranged at the left end and the right end of the upper surface of the bottom plate; the left end and the right end of the upper surface of the bottom plate are slidably connected with arc-shaped supporting seats, the arc-shaped supporting seats are located on the right sides of the adjacent mounting seats, portal frames are arranged on the upper surfaces of the mounting seats, and fixing seats are arranged on the inner walls of the portal frames in an annular array mode. The small-diameter pressure pipeline is automatically conveyed, the defects of the outer wall of the small-diameter pressure pipeline are marked, later searching and processing by operators are facilitated, and the working efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of pulse eddy current detection, in particular to a pulse eddy current detection device for outer wall defects of a small-diameter pressure pipeline. Background Art

[0002] Pulse eddy current is a branch of eddy current testing. Its basic principle is to cut off the current at the moment of probe loading to stimulate a rapidly decaying pulse magnetic field. This magnetic field can pass through a certain thickness of protective layer and insulation layer to induce eddy current on the surface of the inspected component. The induced eddy current will diffuse from the upper surface to the lower surface. At the same time, a secondary magnetic field in the opposite direction of the exciting magnetic field will be generated during the eddy current diffusion process. This induced voltage will be output in the receiving sensor of the probe. If there is a defect on the pipeline, it will affect the pulse eddy current condition on the loading pipeline, and then affect the induced voltage on the receiving sensor.

[0003] Currently, when workers use the pulsed eddy current detection probe on the market, they need to keep moving the pulsed eddy current detection probe, or manually transport the pressure pipe inside the pulsed eddy current detection probe. When a defect on the outer wall of the pressure pipe is detected, the defect position is manually marked with a pen, and then the next round of detection is carried out. However, small-diameter pressure pipes are usually long, which makes the detection operation time-consuming and laborious. For this reason, we propose a pulsed eddy current detection device for defects on the outer wall of small-diameter pressure pipes. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the existing defects and provide a pulse eddy current detection device for the outer wall defects of a small-diameter pressure pipeline, which automatically transports the small-diameter pressure pipeline, reduces the manual workload, and automatically marks the defects on the outer wall of the small-diameter pressure pipeline, which is convenient for operators to find and process later, improves work efficiency, and can effectively solve the problems in the background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a pulsed eddy current detection device for defects on the outer wall of a small-diameter pressure pipeline, comprising a base plate and a marking drive assembly;

[0006] Base plate: A single-chip microcomputer is provided at the right end of its upper surface. In the middle of the upper surface of the base plate, pulsed eddy current detection probes are fixedly installed through symmetrically arranged fixing plates. The output end of the pulsed eddy current detection probe is electrically connected to the input end of the single-chip microcomputer. Mounting seats are provided at both the left and right ends of the upper surface of the base plate. Arc-shaped support seats are slidably connected to both the left and right ends of the upper surface of the base plate. The arc-shaped support seats are respectively located on the right side of the adjacent mounting seats. Gantry frames are provided on the upper surfaces of the mounting seats. Fixed seats are annularly arranged on the inner walls of the gantry frames. A first rotating shaft is rotatably connected to the middle of the inner end of each fixed seat. The outer arc surfaces of the first rotating shafts are rotatably connected to fixing plates through shaft sleeves. A second rotating shaft is rotatably connected to the right end of each fixing plate. Positioning wheels are provided on the middle outer arc surfaces of the second rotating shafts. Positioning rings are provided on the inner arc surfaces of the arc-shaped support seats. Diagonal struts are rotatably connected to the inner arc surfaces of the positioning rings in an annular array. The left ends of the diagonal struts are respectively rotatably connected to the middle of the left adjacent fixing plates through pin shafts. A U-shaped seat is provided in the middle of the upper surface of the base plate;

[0007] Marking drive assembly: It is arranged in the middle of the U-shaped seat. Two C-shaped brackets are provided at the upper end of the marking drive assembly. Arc-shaped plates are provided between the two horizontal plates of each C-shaped bracket. Arc-shaped sponges are provided on the inner arc surfaces of the arc-shaped plates. The two arc-shaped sponges are arranged offset left and right. It automatically conveys small-diameter pressure pipes, reduces the manual workload, and automatically marks the defective parts on the outer wall of the small-diameter pressure pipes, facilitating the later search and processing by operators and improving work efficiency.

[0008] Further, the marking drive assembly includes a second motor, a gear, and a rack. The second motor is arranged in the middle of the lower surface of the horizontal plate of the U-shaped seat. The output shaft of the second motor is rotatably connected to the middle of the horizontal plate of the U-shaped seat. A gear is provided at the top of the output shaft of the second motor. The racks are respectively slidably connected to the front and rear ends of the upper surface of the U-shaped seat. The two racks are arranged offset left and right. The gears are respectively meshed with the two racks. C-shaped brackets are provided on the upper surfaces of the racks. The input ends of the second motors are electrically connected to the output ends of the single-chip microcomputer, driving the two arc-shaped sponges to move towards each other to mark the defective positions on the outer wall of the pressure pipe.

[0009] Further, dovetail grooves are symmetrically provided on the left and right sides of the upper surface of the U-shaped seat. Dovetail strips provided on the lower surface of the rack are respectively slidably connected to the inner walls of the vertically corresponding dovetail grooves to limit the rack and prevent it from separating and misaligning with the U-shaped seat.

[0010] Further, it further includes a pulley and a belt. The pulleys are respectively fixedly connected to the upper ends of the first rotating shaft and the second rotating shaft below. Adjacent pulleys are connected by belt drive. Clamping drive components are provided on the upper surfaces of the mounting seats. The clamping drive components are respectively fixedly connected to the lower ends of the two adjacent first rotating shafts vertically corresponding, driving the positioning wheels below to rotate, so as to convey small-diameter pressure pipes.

[0011] Further, the clamping drive component includes a first vertical plate, a transmission shaft, a first bevel gear, a connecting rod, a second bevel gear, a second vertical plate, a third bevel gear and a first motor. The first vertical plates are respectively symmetrically arranged at the front and rear ends of the upper surface of the mounting seat. A transmission shaft is rotatably connected between the two first vertical plates corresponding longitudinally. The first bevel gears are symmetrically arranged on the outer arc surfaces of the transmission shafts. The connecting rods are respectively fixedly connected to the lower ends of the four first rotating shafts below. The second bevel gears are provided at the lower ends of the connecting rods. The second vertical plates are respectively symmetrically arranged at the front and rear ends of the upper surface of the mounting seat. The third bevel gears are rotatably connected to the upper ends of the second vertical plates. The third bevel gears are respectively meshed with the adjacent first bevel gears and the second bevel gears. The first motors are respectively fixedly connected to the front surfaces of the front first vertical plates. The output shafts of the first motors are respectively fixedly connected to the front ends of the transmission shafts corresponding longitudinally. The input ends of the first motors are electrically connected to the output ends of the single-chip microcomputer, driving the two longitudinally corresponding first rotating shafts below to rotate synchronously, reducing the use of motors and reducing consumables.

[0012] Further, it further includes an ink bottle. The ink bottles are respectively threadedly connected to the inside of the horizontal plate bodies above the U-shaped brackets. The ink bottles are respectively arranged in cooperation with the arc-shaped sponges corresponding vertically, automatically replenishing the ink inside the arc-shaped sponges.

[0013] Further, it further includes a screw rod. The screw rods are respectively inside the lower ends of the two mounting seats. The screw rods are respectively threadedly connected to the middle parts of the two arc-shaped supporting seats, adjusting the relative movement of the arc-shaped supporting seats with respect to the mounting seats, so as to control the distance between the three positioning wheels and adapt to the conveying of pressure pipes with different diameters.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows: The pulse eddy current detection device for the outer wall defects of small-diameter pressure pipes has the following advantages:

[0015] 1. Manually adjust the screw rod. The screw rod drives two arc-shaped support seats to move to the left respectively. The arc-shaped support seats drive the right ends of the diagonal strut rods rotatably connected thereto to move to the left. The left end of the diagonal strut rod pushes the fixed plate to rotate along the axis of the first rotating shaft, so that three adjacent positioning wheels approach each other and fit on the outer wall of the small-diameter pressure pipeline. Start two first motors respectively through the single-chip microcomputer. The output shaft of the first motor drives the longitudinally corresponding transmission shaft to rotate. The transmission shaft drives the third bevel gear to rotate through the first bevel gear, and then drives the second bevel gear. The second bevel gear drives the lower first rotating shaft to rotate through the connecting rod. The first rotating shaft drives the lower positioning wheel to rotate through the transmission connection between the pulley and the belt. The lower positioning wheel drives the small-diameter pressure pipeline to move to the left through the friction force between it and the outer wall of the small-diameter pressure pipeline, eliminating the need for personnel to manually transport the small-diameter pressure pipeline, reducing the manual workload and improving the degree of automation.

[0016] 2. The pulsed eddy current detection probe detects the defects on the outer wall of the small-diameter pressure pipeline and sends the detection data to the single-chip microcomputer. When defects are detected on the outer wall of the small-diameter pressure pipeline, the single-chip microcomputer starts the internal timer to delay until the defect position of the small-diameter pressure pipeline moves between two arc-shaped sponges. The single-chip microcomputer starts the second motor to rotate forward and reverse once. When the second motor rotates forward, the output shaft of the second motor drives the gear to rotate clockwise. The gear drives two racks to move longitudinally towards each other, so that the U-shaped bracket drives the arc-shaped plate and the arc-shaped sponge to move. The inside of the arc-shaped sponge is filled with ink, which contacts the outer wall of the small-diameter pressure pipeline during the movement and marks the left and right of the defect position on the outer wall of the small-diameter pressure pipeline. Then the second motor rotates in reverse to drive the arc-shaped sponge to reset, automatically marking the defect on the outer wall of the small-diameter pressure pipeline, facilitating the later search and processing by the operators, simplifying the work process and improving the work efficiency. Brief Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of the present utility model;

[0018] Figure 2 It is a schematic structural diagram of the clamping and driving assembly of the present utility model;

[0019] Figure 3 It is a schematic structural diagram of the marking and driving assembly of the present utility model.

[0020] In the figure: 1 bottom plate, 2 single-chip microcomputer, 3 U-shaped seat, 31 dovetail groove, 4 pulsed eddy current detection probe, 5 arc-shaped support seat, 51 positioning ring, 6 diagonal strut, 7 clamping drive assembly, 71 first vertical plate, 72 transmission shaft, 73 first bevel gear, 74 connecting rod, 75 second bevel gear, 76 second vertical plate, 77 third bevel gear, 78 first motor, 8 fixed seat, 9 marking drive assembly, 91 second motor, 92 gear, 93 rack, 10 first rotating shaft, 11 fixing plate, 12 second rotating shaft, 13 positioning wheel, 14 mounting seat, 15 gantry, 16 C-shaped bracket, 17 arc-shaped plate, 18 arc-shaped sponge, 19 ink bottle, 20 screw, 21 pulley, 22 belt. Specific implementation manner

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] Please refer to Figure 1-3 , this embodiment provides a technical solution: a pulsed eddy current detection device for the outer wall defects of small-diameter pressure pipelines, including a bottom plate 1 and a marking drive assembly 9;

[0023] Bottom plate 1: A single-chip microcomputer 2 is provided at the right end of its upper surface. In the middle of the upper surface of the bottom plate 1, a pulsed eddy current detection probe 4 is fixedly installed through symmetrically arranged fixing plates. The output end of the pulsed eddy current detection probe 4 is electrically connected to the input end of the single-chip microcomputer 2. Mounting seats 14 are provided at both the left and right ends of the upper surface of the bottom plate 1. Arc-shaped support seats 5 are slidably connected to both the left and right ends of the upper surface of the bottom plate 1. The arc-shaped support seats 5 are respectively located on the right side of the adjacent mounting seats 14. Gantries 15 are provided on the upper surfaces of the mounting seats 14. Fixed seats 8 are annularly and arrayedly provided on the inner walls of the gantries 15. A first rotating shaft 10 is rotatably connected to the middle of the inner end of each fixed seat 8. The outer arc surfaces of the first rotating shafts 10 are rotatably connected to fixing plates 11 through shaft sleeves. The right ends of the fixing plates 11 are rotatably connected to second rotating shafts 12. Positioning wheels 13 are provided on the middle outer arc surfaces of the second rotating shafts 12. Positioning rings 51 are provided on the inner arc surfaces of the arc-shaped support seats 5. Diagonal struts 6 are annularly and rotatably connected to the inner arc surfaces of the positioning rings 51. The left ends of the diagonal struts 6 are respectively rotatably connected to the middle of the left adjacent fixing plate 11 through pins. A U-shaped seat 3 is provided in the middle of the upper surface of the bottom plate 1;

[0024] The belt pulley 21 and the belt 22 are also included. The belt pulley 21 is fixedly connected to the upper ends of the rotating shaft 10 and the rotating shaft 12 below. The two adjacent belt pulleys 21 are connected by the belt 22. The upper surface of the mounting seat 14 is provided with a clamping drive assembly 7. The clamping drive assembly 7 is fixedly connected to the lower ends of the two vertically corresponding and adjacent rotating shafts 10, and drives the positioning wheel 13 below to rotate, so as to transport the small diameter pressure pipeline. The clamping drive assembly 7 includes a vertical plate 71, a transmission plate 72, and a transmission plate 73. The driving shaft 72, bevel gear 1 73, connecting rod 74, bevel gear 2 75, vertical plate 2 76, bevel gear 3 77 and motor 1 78, the vertical plate 1 71 is symmetrically arranged at the front and rear ends of the upper surface of the mounting seat 14, and the transmission shaft 72 is rotatably connected between the two vertical plates 1 71 corresponding to each other in the longitudinal direction, and the outer arc surface of the transmission shaft 72 is symmetrically provided with bevel gear 1 73, the connecting rod 74 is fixedly connected to the lower end of the four rotating shafts 10 below, and the lower end of the connecting rod 74 is provided with bevel gear 2 75, the vertical plate 2 76, the bevel gear 3 77 and the motor 1 78. 6 are symmetrically arranged at the front and rear ends of the upper surface of the mounting seat 14, and the upper ends of the vertical plate 2 76 are rotatably connected with bevel gear 3 77, and the bevel gear 3 77 is respectively meshed with the adjacent bevel gear 1 73 and gear 2 75, and the motor 1 78 is respectively fixedly connected to the front side of the vertical plate 1 71 on the front side, and the output shaft of the motor 1 78 is respectively fixedly connected to the front end of the corresponding transmission shaft 72 in the longitudinal direction, and the input end of the motor 1 78 is electrically connected to the output end of the single-chip computer 2, and the two motors 1 78 are respectively started by the single-chip computer 2, and the output shaft of the motor 1 78 drives the corresponding transmission shaft 72 in the longitudinal direction to rotate, and the transmission shaft 72 drives the bevel gear 3 77 to rotate through the bevel gear 1 73, and then drives the bevel gear 2 75, and the bevel gear 2 75 drives the lower rotating shaft 10 to rotate through the connecting rod 74, and the rotating shaft 10 drives the lower positioning wheel 13 to rotate through the transmission connection between the pulley 21 and the belt 22, and the lower positioning wheel 13 drives the small diameter pressure pipeline to move to the left through the friction between the small diameter pressure pipeline and the outer wall.

[0025] Wherein: it also includes a screw 20, the screw 20 is respectively connected to the lower end of the two mounting seats 14, the screw 20 is respectively threadedly connected to the middle part of the two arc-shaped support seats 5, the screw 20 is manually adjusted, the screw 20 drives the two arc-shaped support seats 5 to move to the left side, and the arc-shaped support seats 5 drive the right end of the diagonal support rod 6 rotatably connected thereto to move to the left side, and the left end of the diagonal support rod 6 pushes the fixed plate 11 to rotate along the axis of the rotating shaft 10, so that the three adjacent positioning wheels 13 are close to each other and fit on the outer wall of the small-diameter pressure pipeline, so as to adapt to the transportation of pressure pipelines with different diameters.

[0026] Marker driving component 9: It is arranged in the middle of the U-shaped seat 3. There are two C-shaped brackets 16 at the upper end of the marker driving component 9. Arc plates 17 are arranged between the two horizontal plates of the C-shaped bracket 16. Arc-shaped sponges 18 are arranged on the inner arc surfaces of the arc plates 17. The two arc-shaped sponges 18 are arranged with a left-right offset. The marker driving component 9 includes a second motor 91, a gear 92 and a rack 93. The second motor 91 is arranged in the middle of the lower surface of the horizontal plate of the U-shaped seat 3. The output shaft of the second motor 91 is rotatably connected to the middle of the horizontal plate of the U-shaped seat 3. A gear 92 is arranged at the top end of the output shaft of the second motor 91. The racks 93 are respectively slidably connected to the front and rear ends of the upper surface of the U-shaped seat 3. The two racks 93 are arranged with a left-right offset. The gear 92 is respectively meshed with the two racks 93. C-shaped brackets 16 are arranged on the upper surfaces of the racks 93. The input ends of the second motor 91 are respectively electrically connected to the output end of the single-chip microcomputer 2, driving the two arc-shaped sponges 18 to move towards each other to mark the defective position on the outer wall of the pressure pipeline. Dovetail grooves 31 are symmetrically arranged on the left and right sides of the upper surface of the U-shaped seat 3. The dovetail bars arranged on the lower surface of the rack 93 are respectively slidably connected to the inner walls of the vertically corresponding dovetail grooves 31 to limit the rack 93 to prevent separation and dislocation from the U-shaped seat 3. When defects are detected on the outer wall of the small-diameter pressure pipeline, the single-chip microcomputer 2 starts the internal timer to delay until the defective position of the small-diameter pressure pipeline moves between the two arc-shaped sponges 18. The single-chip microcomputer 2 starts the second motor 91 to rotate forward and backward once. When the second motor 91 rotates forward, the output shaft of the second motor 91 drives the gear 92 to rotate clockwise. The gear 92 drives the two racks 93 to move longitudinally towards each other, so that the C-shaped bracket 16 drives the arc plate 17 and the arc-shaped sponge 18 to move. The arc-shaped sponge 18 is filled with ink, which contacts the outer wall of the small-diameter pressure pipeline during the movement to mark the left and right of the defective position on the outer wall of the small-diameter pressure pipeline. Then the second motor 91 rotates backward to drive the arc-shaped sponge 18 to reset.

[0027] Wherein: It further includes an ink bottle 19. The ink bottles 19 are respectively threadedly connected to the inside of the horizontal plates above the C-shaped brackets 16. The ink bottles 19 are respectively arranged in cooperation with the vertically corresponding arc-shaped sponges 18. When the ink inside the arc-shaped sponge 18 decreases, the ink inside the ink bottle 19 automatically flows downward to supplement the inside of the arc-shaped sponge 18. When the ink inside the arc-shaped sponge 18 is in a saturated state, the tension of the ink between the voids inside the arc-shaped sponge 18 prevents the ink from dripping freely.

[0028] The working principle of a pulsed eddy current detection device for defects on the outer wall of a small-diameter pressure pipeline provided by the present utility model is as follows:

[0029] The end of the small-diameter pressure pipeline is passed through the positioning ring 51 on the right, the gantry 15, the pulsed eddy current detection probe 4, the positioning ring 51 on the left, and the inside of the gantry 15 on the left from right to left in sequence. Manually adjust the screw rod 20. The screw rod 20 drives the two arc-shaped support seats 5 to move to the left respectively. The arc-shaped support seats 5 drive the right ends of the inclined strut rods 6 rotatably connected thereto to move to the left. The left end of the inclined strut rod 6 pushes the fixed plate 11 to rotate along the axis of the first rotating shaft 10, so that three adjacent positioning wheels 13 approach each other and fit on the outer wall of the small-diameter pressure pipeline. The single-chip microcomputer 2 starts two first motors 78 respectively. The output shaft of the first motor 78 drives the longitudinally corresponding transmission shaft 72 to rotate. The transmission shaft 72 drives the third bevel gear 77 to rotate through the first bevel gear 73, and then drives the second bevel gear 75. The second bevel gear 75 drives the lower first rotating shaft 10 to rotate through the connecting rod 74. The first rotating shaft 10 drives the lower positioning wheel 13 to rotate through the transmission connection between the pulley 21 and the belt 22. The lower positioning wheel 13 drives the small-diameter pressure pipeline to move to the left through the friction force with the outer wall of the small-diameter pressure pipeline. The pulsed eddy current detection probe 4 detects the defects on the outer wall of the small-diameter pressure pipeline and sends the detection data to the single-chip microcomputer 2. When a defect is detected on the outer wall of the small-diameter pressure pipeline, the single-chip microcomputer 2 starts the internal timer to delay until the defect position of the small-diameter pressure pipeline moves between the two arc-shaped sponges 18. The single-chip microcomputer 2 starts the second motor 91 to rotate forward and backward once. When the second motor 91 rotates forward, the output shaft of the second motor 91 drives the gear 92 to rotate clockwise. The gear 92 drives the two racks 93 to move longitudinally towards each other, so that the U-shaped bracket 16 drives the arc-shaped plate 17 and the arc-shaped sponge 18 to move. The inside of the arc-shaped sponge 18 is filled with ink, and contacts with the outer wall of the small-diameter pressure pipeline during the movement, and marks the left and right of the defect position on the outer wall of the small-diameter pressure pipeline. Then the second motor 91 rotates reversely to drive the arc-shaped sponge 18 to reset. The pulsed eddy current detection probe 4 continues to detect the remaining part on the right side of the outer wall of the small-diameter pressure pipeline. Then the operator processes the small-diameter pressure pipeline according to the marked position.

[0030] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. A pulsed eddy current detection device for defects on the outer wall of a small-diameter pressure pipeline, characterized in that: It includes a bottom plate (1) and a marking driving assembly (9); Bottom plate (1): A single-chip microcomputer (2) is provided at the right end of its upper surface. In the middle of the upper surface of the bottom plate (1), a pulsed eddy current detection probe (4) is fixedly installed through symmetrically arranged fixing plates. The output end of the pulsed eddy current detection probe (4) is electrically connected to the input end of the single-chip microcomputer (2). Mounting seats (14) are provided at both the left and right ends of the upper surface of the bottom plate (1). Arc-shaped support seats (5) are slidably connected to both the left and right ends of the upper surface of the bottom plate (1). The arc-shaped support seats (5) are respectively located on the right side of the adjacent mounting seats (14). Gantry frames (15) are provided on the upper surfaces of the mounting seats (14). Fixed seats (8) are annularly arranged on the inner walls of the gantry frames (15). A first rotating shaft (10) is rotatably connected to the middle of the inner end of each fixed seat (8). The outer arc surfaces of the first rotating shafts (10) are rotatably connected to fixing plates (11) through shaft sleeves. The right ends of the fixing plates (11) are rotatably connected to second rotating shafts (12). Positioning wheels (13) are provided on the middle outer arc surfaces of the second rotating shafts (12). Positioning rings (51) are provided on the inner arc surfaces of the arc-shaped support seats (5). Oblique support rods (6) are annularly and rotatably connected to the inner arc surfaces of the positioning rings (51). The left ends of the oblique support rods (6) are respectively rotatably connected to the middle of the left adjacent fixing plates (11) through pins. A U-shaped seat (3) is provided in the middle of the upper surface of the bottom plate (1); Marking driving assembly (9): It is arranged in the middle of the U-shaped seat (3). Two C-shaped brackets (16) are provided at the upper end of the marking driving assembly (9). Arc-shaped plates (17) are provided between the two horizontal plate bodies of the C-shaped brackets (16). Arc-shaped sponges (18) are provided on the inner arc surfaces of the arc-shaped plates (17). The two arc-shaped sponges (18) are arranged in a left-right offset manner.

2. The pulsed eddy current detection device for outer wall defects of small diameter pressure pipelines according to claim 1 is characterized in that: The marking driving assembly (9) includes a second motor (91), a gear (92), and a rack (93). The second motor (91) is arranged in the middle of the lower surface of the horizontal plate body of the U-shaped seat (3). The output shaft of the second motor (91) is rotatably connected to the middle of the horizontal plate body of the U-shaped seat (3). A gear (92) is provided at the top of the output shaft of the second motor (91). The racks (93) are respectively slidably connected to the front and rear ends of the upper surface of the U-shaped seat (3). The two racks (93) are arranged in a left-right offset manner. The gear (92) is respectively meshed with the two racks (93). C-shaped brackets (16) are provided on the upper surfaces of the racks (93). The input ends of the second motor (91) are electrically connected to the output end of the single-chip microcomputer (2).

3. The pulsed eddy current detection device for outer wall defects of small diameter pressure pipes according to claim 2 is characterized in that: Dovetail grooves (31) are symmetrically provided on the left and right sides of the upper surface of the U-shaped seat (3). The dovetail strips provided on the lower surfaces of the racks (93) are respectively slidably connected to the inner walls of the vertically corresponding dovetail grooves (31).

4. The pulsed eddy current detection device for outer wall defects of small diameter pressure pipeline according to claim 1, characterized in that: It further includes a pulley (21) and a belt (22). The pulley (21) is fixedly connected to the upper ends of the lower rotating shafts one (10) and two (12) respectively. Adjacent pulleys (21) are all drivingly connected by a belt (22). The upper surfaces of the mounting seats (14) are all provided with clamping driving assemblies (7), and the clamping driving assemblies (7) are fixedly connected to the lower ends of two vertically corresponding and adjacent rotating shafts one (10) respectively.

5. The pulsed eddy current detection device for outer wall defects of small diameter pressure pipes according to claim 4, characterized in that: The clamping driving assembly (7) includes a first vertical plate (71), a transmission shaft (72), a first bevel gear (73), a connecting rod (74), a second bevel gear (75), a second vertical plate (76), a third bevel gear (77) and a first motor (78). The first vertical plates (71) are symmetrically arranged at the front and rear ends of the upper surface of the mounting seat (14) respectively. A transmission shaft (72) is rotatably connected between two longitudinally corresponding first vertical plates (71). The first bevel gears (73) are symmetrically arranged on the outer arc surface of the transmission shaft (72). The connecting rods (74) are fixedly connected to the lower ends of the four lower rotating shafts one (10) respectively. The lower ends of the connecting rods (74) are all provided with second bevel gears (75). The second vertical plates (76) are symmetrically arranged at the front and rear ends of the upper surface of the mounting seat (14) respectively. The upper ends of the second vertical plates (76) are all rotatably connected with third bevel gears (77). The third bevel gears (77) are meshed with the adjacent first bevel gears (73) and second bevel gears (75) respectively. The first motors (78) are fixedly connected to the front surfaces of the front first vertical plates (71). The output shafts of the first motors (78) are fixedly connected to the front ends of the longitudinally corresponding transmission shafts (72). The input ends of the first motors (78) are all electrically connected to the output ends of the single-chip microcomputer (2).

6. The pulsed eddy current detection device for outer wall defects of small diameter pressure pipeline according to claim 1, characterized in that: It further includes an ink bottle (19). The ink bottles (19) are respectively threadedly connected to the inside of the horizontal plate bodies above the U-shaped brackets (16). The ink bottles (19) are respectively arranged in cooperation with the vertically corresponding arc-shaped sponges (18).

7. The pulsed eddy current detection device for outer wall defects of a small diameter pressure pipeline according to any one of claims 1 to 6, characterized in that: It further includes a screw rod (20). The screw rods (20) are respectively inside the lower ends of the two mounting seats (14). The screw rods (20) are respectively threadedly connected to the middle parts of the two arc-shaped support seats (5).

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