An automatic detection device for drill pipe threads

Abstract

The present invention discloses an automatic detection device for drill pipe threads, which includes a rotating frame. A rotating shaft is inserted through the rotating frame. A gear set is arranged on one side of the rotating frame. A perforated slip ring is arranged between the gear set and the rotating frame. The perforated slip ring is sleeved outside the rotating shaft. A motor is arranged below the perforated slip ring. A bolt positioning component is arranged at one end of the rotating shaft away from the gear set. The present invention is applicable to the technical field of oil drilling. It does not require manual scanning, improves the detection efficiency and detection quality. It adopts a scheme of bolt fixation and probe rotation. The introduction of the bolt positioning component makes bolt positioning more convenient and accurate. By adjusting the inclination angle of the guide rail beam, the inspection of bolts with different tapers can be realized. By adjusting the lift height of the floating probe, the inspection of bolts with different outer diameters can be realized. Different coil structures can be selected for the tooth bottom and tooth feet. During the scanning process, the probe can always closely fit along the spiral line of the tooth groove, avoiding noise caused by left and right shaking.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil drilling, and specifically relates to an automatic detection device for drill pipe threads. Background Art

[0002] In the oil drilling industry, during the use of drill pipe threads, due to long-term bearing of alternating forces and being in a harsh working environment, it is very likely that processing defects and wear defects will occur at the root of the tubing threads. To ensure the safe use of equipment, it is necessary to detect the threads of the drill pipe to ensure that the screw threads are defect-free. This is of great significance for reducing the sticking and failure accidents of drill pipes and lowering the oil production cost.

[0003] Currently, there are only two non-destructive testing methods for tubular threads specified in the internationally common standards for oil country tubular goods, "Casing and Tubing" and "Drill Pipe Specification", namely visual inspection method and wet fluorescent magnetic particle inspection method [1]. The visual inspection method has poor reliability and can only be detected when the wear, cracks, and deformations are relatively serious; the fluorescent magnetic particle inspection is currently the most widely used non-destructive testing method for tubular thread areas. Under the irradiation of ultraviolet light, the fluorescent substances on the surface of the fluorescent magnetic particles can show the shape and position of the defects. By photographing the shape formed by the magnetic particles, the damage condition of the tested part can be distinguished. However, this method also has relatively large limitations: ① It is necessary to carefully clean the tested threads before detection, and the workload is relatively large; ② It is difficult to detect near-surface defects of threads and difficult to evaluate the depth of defects; ③ The identification of defects often also depends on visual inspection. Generally speaking, the traditional eddy current defect detection method for drill pipe threads mainly relies on the naked eye observation of inspectors, with cumbersome operations, low detection efficiency, and a high degree of dependence on the experience of inspectors. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide an automatic detection device for drill pipe threads.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] An automatic detection device for drill pipe threads, including a rotating frame, a rotating shaft is inserted through the rotating frame, a gear set is arranged on one side of the rotating frame, a perforated slip ring is arranged between the gear set and the rotating frame, the perforated slip ring is sleeved outside the rotating shaft, a motor is arranged below the perforated slip ring, and a bolt positioning component is arranged at one end of the rotating shaft away from the gear set;

[0007] On the top of the rotating frame, on the side away from the gear set, there is a guide rail beam and a knob for adjusting the position and angle of the guide rail beam. A clamping device is arranged on the guide rail beam, a floating probe is arranged on the clamping device, and guide rods are arranged on both sides of the floating probe.

[0008] Preferably, the rotor of the perforated slip ring is fixed on the rotating shaft, and the rotor is connected to the floating probe.

[0009] Preferably, the front end of the bolt positioning component adopts a chuck structure, and the test equipment is fixed by pressing the inner hole with three jaws, so as to realize the accurate positioning of the bolt.

[0010] Preferably, the axial center line of the bolt positioning component coincides with the rotation center line of the rotating frame.

[0011] Preferably, the floating probe is connected to the eddy current detection device through a network cable, and the eddy current detection device includes a control module, an excitation module, a receiving module, a mechanical control module and an alarm module.

[0012] Preferably, the control module includes a host computer and a microcontroller. The host computer completes the human-computer interaction function, and the microcontroller controls the receiving module, the excitation module and the mechanical module;

[0013] The excitation module amplifies the power of the given-frequency sine wave and drives the eddy current coil;

[0014] The receiving module receives the two-channel differential signal, filters and amplifies it, and through the acquisition circuit, the signal is collected into the host computer for further digital signal processing and analysis;

[0015] The mechanical control module controls the servo motor to make the probe position controllable;

[0016] The differential probe module uses a differential coil to receive, improves the signal-to-noise ratio of the detection signal and suppresses the influence caused by the change of the lift-off distance generated by vibration;

[0017] The alarm module uses a warning light to alarm the conditioned suspected defect signal, which is convenient for the defect detection process in the industrial field.

[0018] Preferably, before detection, the detection device is calibrated with a standard specimen. The host computer determines the defect signal threshold through human-computer interaction, and the microcontroller sets the threshold. During detection, when the detection signal exceeds the threshold, the warning light flashes to remind, so as to realize the warning function for actual defects.

[0019] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

[0020] ① There is no need for hand-held scanning, which improves the detection efficiency and detection quality.

[0021] ② The scheme of fixing the bolt and rotating the probe is adopted, which is convenient for inspecting bolts that are heavy and difficult to rotate, or bolts with obvious deformation of the screw during use. The introduction of the bolt positioning component makes the bolt positioning more convenient and accurate.

[0022] ③Eddy current inspection can be carried out on the trapezoidal external threads of drill pipes with different thread specifications in the range of NC31-41 to NC70-100 that meet the relevant requirements of API Spec7-1 and API Spec7-2. By adjusting the inclination angle of the guide rail beam, the inspection of different taper bolts can be realized, and by adjusting the lift-off height of the floating probe, the inspection of bolts with different outer diameters can be realized.

[0023] ④For different coil structures at the root and flank of the tooth, there are options. During the scanning process, the probe can always closely fit along the tooth groove and travel along the helix, avoiding left-right shaking and generating noise. Description of the Drawings

[0024] Figure 1 is a schematic diagram of the overall structure of an automatic drill pipe thread inspection device of the present invention;

[0025] Figure 2 is a schematic diagram of the positional relationship of Coil Structure I in an automatic drill pipe thread inspection device of the present invention;

[0026] Figure 3 is a schematic diagram of the positional relationship of Coil Structure II in an automatic drill pipe thread inspection device of the present invention;

[0027] Figure 4 is a side view of Coil Structure II in an automatic drill pipe thread inspection device of the present invention;

[0028] Figure 5 is a schematic diagram of the structure of the floating probe in an automatic drill pipe thread inspection device of the present invention;

[0029] Figure 6 is a schematic diagram of the structure of the eddy current inspection device in an automatic drill pipe thread inspection device of the present invention;

[0030] Figure 7 is a connection relationship diagram of the eddy current inspection device and the floating probe in an automatic drill pipe thread inspection device of the present invention.

[0031] Reference Numerals: 1. Floating probe; 2. Clamping device; 3. Guide rod; 4. Guide rail beam; 5. Knob; 6. Bolt positioning component; 7. Motor; 8. Gear set; 9. Rotating frame; 10. Perforated slip ring; 11. Excitation coil; 12. Probe body; 13. Probe head; 14. Tooth flank; 15. Eddy current inspection device; 16. Receiving coil; 17. Trapezoidal thread groove; 18. Network cable; 19. PCB board; 20. Coil. Detailed Embodiment

[0032] The following is combined with the attached Figure 1-7, further illustrate the specific implementation of an automated drill pipe thread detection device of the present invention. The automated drill pipe thread detection device of the present invention is not limited to the description of the following embodiments.

[0033] Embodiment 1:

[0034] This embodiment gives a specific implementation of an automated drill pipe thread detection device, as Figure 1-7 shown, including a rotating frame 9, a rotating shaft is inserted through the rotating frame 9, a gear set 8 is arranged on one side of the rotating frame 9, a perforated slip ring 10 is arranged between the gear set 8 and the rotating frame 9, the perforated slip ring 10 is sleeved outside the rotating shaft, a motor 7 is arranged below the perforated slip ring 10, and a bolt positioning member 6 is arranged at one end of the rotating shaft away from the gear set 8;

[0035] On the top of the rotating frame 9, on the side away from the gear set 8, there is a guide rail beam 4 and a knob 5 for adjusting the position and angle of the guide rail beam 4. A clamping device 2 is arranged on the guide rail beam 4, a floating probe 1 is arranged on the clamping device 2, and guide rods 3 are arranged on both sides of the floating probe 1.

[0036] Furthermore, the rotor of the perforated slip ring 10 is fixed on the rotating shaft, and the rotor is connected to the floating probe 1.

[0037] Furthermore, the front end of the bolt positioning member 6 adopts a chuck structure, and the inner hole is tightened by three jaws to fix the testing equipment, realizing accurate positioning of the bolt.

[0038] Furthermore, the axial center line of the bolt positioning member 6 coincides with the rotation center line of the rotating frame 9.

[0039] Furthermore, the floating probe 1 is connected to an eddy current detection device 15 through a network cable 18. The eddy current detection device 15 includes a control module, an excitation module, a receiving module, a mechanical control module and an alarm module.

[0040] Furthermore, the control module includes a host computer and a microcontroller. The host computer completes the human-machine interaction function, and the microcontroller controls the receiving module, the excitation module and the mechanical module;

[0041] The excitation module amplifies the power of a sine wave of a given frequency to drive the eddy current coil;

[0042] The receiving module receives two-channel differential signals, filters and amplifies them, and through an acquisition circuit, the signals are collected into the host computer for further digital signal processing and analysis;

[0043] The mechanical control module controls the servo motor to make the probe position controllable;

[0044] Differential probe module, which uses a differential coil for reception, improves the signal-to-noise ratio of the detection signal and suppresses the influence caused by the change in the lift-off distance due to vibration;

[0045] Alarm module, which uses a warning light to alarm the conditioned suspected defect signal, facilitating the defect detection process in the industrial field.

[0046] Furthermore, before detection, the detection device is calibrated using a standard specimen. The defect signal threshold is determined through human-computer interaction by the host computer, and the threshold is set by the microcontroller. During detection, when the detection signal exceeds the threshold, the warning light flashes to remind, thereby realizing the warning function for actual defects.

[0047] Embodiment 2:

[0048] This embodiment provides a specific implementation manner of an automated drill pipe thread detection device. As Figure 1-7 shown, other structures are similar to those in Embodiment 1. The coil structure of the floating probe 1 is Coil Structure I. For defects at the inner tooth bottom position of the thread, three coils form a differential structure, arranged in a straight line along the scanning direction. The relative position relationship is as Figure 2 shown. During use, the bottom surfaces of all three coils are parallel to the coil in the middle of the thread tooth bottom. The middle coil is the receiving coil 11, and the two coils on both sides form differential excitation coils 12.

[0049] Embodiment 3:

[0050] This embodiment provides a specific implementation manner of an automated drill pipe thread detection device. As Figure 1-7 shown, other structures are similar to those in Embodiment 1. The coil structure of the floating probe 1 is Coil Structure II. For defects at the inner tooth flank 14 position of the 17, trapezoidal thread groove 17, three coils form a differential structure, arranged in a straight line along the scanning direction. The relative position relationship is as Figure 3 and Figure 4 shown. During use, the positions of the three coils respectively correspond to the thread tooth bottom plane and the tooth flank 14 planes on both sides. The middle coil is the receiving coil, and the two coils on both sides form differential excitation coils.

[0051] Embodiment 4:

[0052] This embodiment provides a specific implementation manner of an automated drill pipe thread detection device. As Figure 1-7 shown, other structures are similar to those in Embodiment 1. The shape of the probe head 13 is consistent with the thread profile angle, as Figure 5 shown. When the probe head 13 is in direct contact with and rubs against the bolt tooth bottom, to avoid deformation caused by wear during the detection process, the material of the probe head 13 is wear-resistant ceramic, and the probe head 13 is fixed to the probe body 12 by screws.

[0053] The coil 20 is connected to the wire core in the network cable 18 via the PCB board 19. The other end of the network cable 18 is connected to the eddy current detection device 15. The PCB board 19 is placed in the installation chamber of the probe body 13.

[0054] By adopting the above technical solution:

[0055] The floating probe 1 is fixed in the clamping device 2 by hand-tightening screws and the up-and-down position of the floating probe 1 can be manually adjusted. The guide rods 3 of the probe assembly are also installed on the clamping device 2, located on both sides of the floating probe. Due to the spring pressure, the guide rods on both sides are stably embedded in the threaded grooves, driving the test probe to move along the threaded grooves. The clamping device 2 can make a reciprocating motion along the guide rail beam 4 on the guide rail beam. The position and angle of the guide rail beam 4 can be adjusted by the knob 5 to match the taper of the bolt to be measured. The guide rail beam 4 is fixed on the rotating frame 9. The rotor of the slip ring 10 with a hole is fixed on the rotating shaft, and the rotor outgoing line is connected to the probe. The gear set 8 is connected to the motor 7. The micro-deceleration motor 7 drives the rotating frame 9 to rotate through the gear set 8, and then drives the guide rail beam 4 to rotate [As an alternative when the motor fails, or when manual fine-tuning is required, the manual wheel on the back panel of the gear set 8 can also be used to manually drive the gear set to rotate, achieving the same effect as the drive of the motor 7]. A bolt positioning component 6 is provided at the front end of the device. The rear end of the bolt positioning component 6 is in butt-joint connection with the front end of the threaded side of the bolt to be inspected. The front end of the bolt positioning component 6 is a clamping head, which tightens the inner hole through three clamping jaws, thereby fixing the entire testing device and achieving accurate positioning of the bolt. The axial center line of the bolt positioning component 6 coincides with the rotation center line of the rotating frame. The adjustment knob / nut of the clamping head is located on the back panel of the gear set 8. By tightening this knob, the three clamping jaws of the clamping head can be extended to tighten the inner hole of the drill pipe, automatically center and fix the device; after loosening, the clamping jaws can be retracted and the testing device can be removed.

[0056] The eddy current detection device 15 is composed of a control module, an excitation module, a receiving module, a mechanical control module and an alarm module. Among them, the control module is composed of a host computer and a microcontroller. The host computer completes the human-computer interaction function, and the microcontroller controls the receiving module, the excitation module and the mechanical module; the excitation module amplifies the power of the given-frequency sine wave and drives the eddy current coil; the receiving module receives the two-channel differential signal, filters and amplifies it, and through the acquisition circuit, the signal is collected into the host computer for further digital signal processing and analysis; the mechanical control module controls the servo motor to make the probe position controllable. The differential probe module uses differential coils to receive, improving the signal-to-noise ratio of the detection signal and suppressing the influence caused by the change of the lift-off distance due to vibration. The alarm module uses warning lights to alarm the conditioned suspected defect signals, facilitating the defect detection process in the industrial field.

[0057] Warning light: Before detection, the detection device is calibrated using a standard specimen. The defect signal threshold is determined through human-computer interaction on the host computer and set by the microcontroller. During actual detection, when the detection signal exceeds the threshold, the warning light flashes to give a reminder, thus realizing the warning function for actual defects.

[0058] The working principle is as Figure 1-7 shown:

[0059] 1. Place the bolt to be inspected on the support base.

[0060] 2. Insert the bolt positioning component 6 into the inner hole of the bolt. The rear end of the bolt positioning component abuts and connects with the front end of the bolt to be inspected; the clamping head block at the front end of the positioning component 6 extends out and presses tightly against the inner hole of the bolt. Thus, the positioning and fixing of the bolt to be inspected are completed.

[0061] 3. Rotate the knob 5 to adjust the inclination angle of the guide rail beam 4 until it is consistent with the bolt taper.

[0062] 4. Install the guide rod 3 on the clamping device 2. Drive the motor through the control mechanism to drive the gear set to rotate, and then drive the rotating frame 9 and the guide rail beam 4 to rotate, so that the guide rod closely adheres to the root of the thread and moves along the thread groove for one circle to clean the possible foreign matters and dirt in the thread groove.

[0063] 5. Install the floating probe 1, adjust the height of the floating probe so that the coil part of the probe head 13 extends into the thread groove. Connect the floating probe 1 to the eddy current detection equipment. Drive the motor through the control mechanism to drive the gear set to rotate, and then drive the rotating frame 9 and the guide rail beam 4 to rotate, driving the floating probe to move in a spiral along the thread groove for scanning.

[0064] 6. Start the scan. When the signal is abnormal, the warning light lights up, indicating that there may be a crack here.

[0065] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, which should all be regarded as belonging to the protection scope of the present invention.

Claims

1. An automatic detection device for drill pipe threads, characterized in that, It includes a rotating frame (9) with a rotating shaft inserted therethrough. On one side of the rotating frame (9), there is a gear set (8). A perforated slip ring (10) is arranged between the gear set (8) and the rotating frame (9). The perforated slip ring (10) is sleeved outside the rotating shaft. Below the perforated slip ring (10), there is a motor (7). At one end of the rotating shaft away from the gear set (8), there is a bolt positioning component (6). On one side of the top of the rotating frame (9) away from the gear set (8), there is a guide rail beam (4) and a knob (5) for adjusting the position and angle of the guide rail beam (4). A clamping device (2) is arranged on the guide rail beam (4). A floating probe (1) is arranged on the clamping device (2). Guide rods (3) are arranged on both sides of the floating probe (1). The front end of the bolt positioning component (6) adopts a chuck structure. By tightening the inner hole with three jaws, the testing equipment is fixed to achieve accurate positioning of the bolt. The axial center line of the bolt positioning component (6) coincides with the rotation center line of the rotating frame (9).

2. The automatic detection device for drill pipe threads according to claim 1, characterized in that: The rotor of the perforated slip ring (10) is fixed on the rotating shaft and is connected to the floating probe (1).

3. The automatic detection device for drill pipe threads according to claim 1, wherein: The floating probe (1) is connected to an eddy current detection device through a network cable. The eddy current detection device includes a control module, an excitation module, a receiving module, a mechanical control module, and an alarm module.

4. The automatic detection device for drill pipe threads according to claim 3, characterized in that: The control module includes a host computer and a microcontroller. The host computer completes the human-machine interaction function, and the microcontroller controls the receiving module, the excitation module, and the mechanical module. The excitation module amplifies the power of a sine wave with a given frequency to drive the eddy current coil. The receiving module receives two-channel differential signals, filters and amplifies them, and through an acquisition circuit, the signals are sampled into the host computer for further digital signal processing and analysis. The mechanical control module controls the servo motor to make the position of the probe controllable. The differential probe module uses a differential coil to receive, improving the signal-to-noise ratio of the detection signal and suppressing the influence caused by the change in the lift-off distance due to vibration. The alarm module uses a warning light to alarm the suspected defect signal after conditioning, facilitating the defect detection process in the industrial field.

5. The automatic drill pipe thread detection device according to claim 4, characterized in that: Before detection, the detection device is calibrated using a standard specimen. The defect signal threshold is determined through human-machine interaction by the host computer and set by the microcontroller. During detection, when the detection signal exceeds the threshold, the warning light flashes to remind, thereby realizing the warning function for actual defects.

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