Variable-diameter pipeline pulsed eddy current detection device

Abstract

The invention belongs to the technical field of eddy current nondestructive testing, and discloses a variable-diameter pipeline pulsed eddy current testing device which comprises a main body support and a lift-off and testing structure, the main body support comprises a support left arm and a support right arm, the upper end of the main body support is connected with two variable-diameter guide frames, and the tail ends of the variable-diameter guide frames are inserted into the lift-off and testing structure. The lift-off and detection structure comprises a lift-off box, the lift-off box is connected with the body support, a lift-off motor is arranged on the upper portion of the lift-off box, the lift-off motor penetrates into a lift-off rod and is connected with the lift-off box, the terminal of the lift-off rod is connected with a probe box, an excitation coil and a detection coil are placed in the probe box, a wheel support is arranged at the tail end of the body support, and a magnetic wheel is connected to the tail end of the wheel support. The left side of the magnetic wheel is connected with an encoder, and the right side is connected with a driving motor. Corrosion defects of pipelines with different pipe diameters can be detected in real time, personal errors caused by manually moving the probe are reduced, and the detection accuracy is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of eddy current nondestructive testing, and in particular relates to a pulse eddy current testing device for variable-diameter pipelines. Background Art

[0002] In many industrial fields such as petroleum, natural gas, chemical industry, and electric power, pipelines are important facilities for conveying media, and their safety is directly related to the safety and efficiency of industrial production. As the use time of pipelines increases, the probability of defects such as corrosion and cracks increases, so regular inspection and maintenance of pipelines is essential. At present, pipeline inspection technologies mainly include ultrasonic inspection, X-ray inspection, magnetic particle inspection, and eddy current inspection. Among them, pulsed eddy current inspection technology has been widely used in the field of pipeline inspection due to its advantages such as non-destructive, high efficiency, and strong adaptability to the inspection environment.

[0003] However, the existing pulsed eddy current testing technology still has some limitations in practical applications. First, traditional eddy current testing equipment is usually designed for fixed wall thickness, which may lead to detection system errors for pipes with different curvatures and elbows; second, when the probe is manually moved for testing, due to differences in the operator's technical level and operating habits, human errors are prone to occur, further affecting the accuracy of the test results. Summary of the invention

[0004] In order to solve the defects of the prior art, the present invention provides a variable-diameter pipeline pulse eddy current detection device, which can automatically adapt to pipelines of different diameters and reduce human errors caused by manual adjustment of the probe; at the same time, the present invention also introduces an innovative curvature compensation method, which further improves the accuracy and reliability of detection by accurately calculating and compensating the influence of pipeline curvature on the detection signal.

[0005] In order to achieve the above object, the present invention is achieved through the following technical solutions:

[0006] The present invention is a pulse eddy current detection device for variable-diameter pipelines, comprising a main body support, the main body support comprising two parallel left arms connected at one end and two parallel right arms connected at one end, two variable-diameter guide frames are connected to the upper ends of the left arm and the right arm of the support, the lower ends of the variable-diameter guide frames are inserted into a lift-off box, the lift-off box is connected to the left arm and the right arm of the support, a lift-off motor is provided at the upper part of the lift-off box, the lift-off motor passes through a lift-off rod and is connected to the lift-off box, one end of the lift-off rod is connected to a probe box, an excitation coil and a detection coil are placed in the probe box, a wheel support is provided at one end of the left arm and the right arm of the support close to the pipeline, a magnetic wheel is connected to the end of the wheel support, an encoder is connected to the left side of the magnetic wheel, and a drive motor is connected to the right side of the magnetic wheel.

[0007] The further improvement of the present invention is that: the inner bottom surface of the probe box is provided with two circles of circular positioning grooves for placing the excitation coil and the detection coil, a probe box cover is provided on the top of the probe box, and a distance sensor is installed at the lower end of the probe box.

[0008] A further improvement of the present invention is that a rectangular groove is provided at the lower end of the right arm of the bracket, and a wire pressing slider is provided on the rectangular groove and slides along the rectangular groove.

[0009] A further improvement of the present invention is that a wireless transmission module is provided inside the lifting box.

[0010] A further improvement of the present invention is that the wireless transmission module transmits data to an external device, and the external device uses a curvature compensation formula to compensate for the error caused by the curvature of the pipeline. The compensation formula is:

[0011]

[0012] in, is the voltage signal detected by the probe on the flat test block with the same thickness. is the pipe radius, is the correction factor.

[0013] A further improvement of the present invention is that the upper end of the variable diameter guide frame is an arc-shaped notch, and grooves with equal distances are arranged on the left and right sides of the upper end of the arc-shaped notch, and numbers 1, 5, and 10 are engraved one by one from the right outer side above the groove to the inner side.

[0014] A further improvement of the present invention is that a right-handed thread is provided at the lower end of the lift-off rod to be connected to the probe box, and a left-handed thread is provided at the upper end of the lift-off rod to be threadedly connected to the lift-off motor and the lift-off box.

[0015] A further improvement of the present invention is that all of the bracket left arm, bracket right arm, diameter-changing guide frame, lift-off box, and wheel bracket are made of stainless steel.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention designs a unique variable diameter main body bracket, which adjusts the main body bracket through a variable diameter guide frame to adapt to pipes of different diameters. This design does not require manual movement of the probe, which significantly reduces the error in the detection process.

[0018] 2. The present invention introduces an innovative lifting and detection structure, which measures the distance between the probe and the pipe surface in real time through a screw motor combined with a distance sensor added to the bottom of the probe box, and automatically adjusts the lifting height of the probe. This design ensures that the probe is always in a reasonable position, eliminates the uncertainty of manual adjustment, and improves the accuracy of detection.

[0019] 3. A wireless transmission module is integrated inside the lift-off box, so that the detection data can be transmitted to external devices in real time. This function improves the efficiency of data collection, the operator can monitor the detection status at any time, and reduces the connection lines between devices, improving portability.

[0020] 4. The probes in the probe box are designed to be replaceable. Operators can flexibly replace appropriate probes according to on-site testing conditions. This innovation improves the adaptability of the equipment in different environments and ensures accurate detection of various defects.

[0021] 5. The present invention adds a driving motor to the magnetic wheel, and the device can realize automatic mobile detection by remote control. In the automatic mode, the operator only needs to remotely control the device, and the device can automatically move along the pipeline and perform detection. The device also retains the manual mode, and the operator can manually push the device for detection under special circumstances. The coexistence of automatic and manual detection modes increases the versatility of the device and the flexibility of use scenarios.

[0022] 6. Pipeline curvature error compensation mechanism: The present invention specifically derives a calculation formula for compensating the system error caused by pipeline curvature. The formula comprehensively considers the geometric characteristics of the pipeline and the physical principles of eddy current detection, and can perform accurate error calculation and correction, further improving the accuracy of the detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention.

[0024] Figure 2 It is a structural diagram of the variable diameter guide frame of the present invention.

[0025] Figure 3 It is a cross-sectional view of the right arm structure of the support of the present invention.

[0026] Figure 4 It is an exploded diagram of the lift-off and detection structure of the present invention.

[0027] In the figure: 1-left arm of the bracket; 2-right arm of the bracket; 3-reducing guide frame; 4-lift-off box; 5-lift-off motor; 6-probe box; 7-excitation coil; 8-detection coil; 9-wheel bracket; 10-magnetic wheel; 11-encoder; 12-wire pressing slider; 13-probe box cover; 14-lift-off rod; 15-butterfly nut; 16-distance sensor; 17-drive motor; 18-wire transmission module. DETAILED DESCRIPTION

[0028] The following will disclose the embodiments of the present invention with drawings. For the purpose of clear description, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present invention. That is, in some embodiments of the present invention, these practical details are not necessary. In addition, for the purpose of simplifying the drawings, some conventional structures and components will be depicted in a simple schematic manner in the drawings.

[0029] like Figure 1 As shown, the present invention is a variable diameter pulse eddy current detection device, comprising: a main body support, the main body support comprises two parallel and one-end connected support left arms 1 and two parallel and one-end connected support right arms 2, the upper end of the main body support is connected with two variable diameter guide frames 3; the end of the variable diameter guide frame 3 is inserted into a lift-off and detection structure, the lift-off and detection structure comprises a lift-off box 4, the lift-off box 4 is connected to the support left arm 1 and the support right arm 2, the upper part of the lift-off box 4 is provided with a lift-off motor 5, the lift-off motor 5 penetrates the lift-off rod 14 and is connected to the lift-off box 4, the terminal of the lift-off rod 14 is connected to the probe box 6, the probe box 6 is provided with an excitation coil 7 and a detection coil 8, the end of the main body support is provided with a wheel support 9, the end of the wheel support 9 is connected with a magnetic wheel 10, the left side of the magnetic wheel 10 is connected with an encoder 11, and the right side of the magnetic wheel 10 is connected with a drive motor 17, that is, the right end of the encoder 11 is fixedly connected to the magnetic wheel 10, and the right end of the magnetic wheel 10 is connected to the drive motor 17.

[0030] like Figure 1 As shown, a wireless transmission module is provided inside the lifting box 4, so that the detection data can be transmitted to the external device in real time. This function improves the efficiency of data collection, the operator can monitor the detection status at any time, and reduces the connection lines between devices, improving portability.

[0031] like Figure 2 The upper end of the variable diameter guide frame 3 shown is an arc-shaped notch, and the upper end of the notch is provided with equidistant grooves, which are used to cooperate with the screw rods to ensure that the screw rods can be accurately embedded in the grooves. The numbers 1, 5, and 10 are engraved on the upper end of the grooves to mark the groove positions and ensure that the screw rods on both sides of the variable diameter guide frame 3 are embedded in the same position. The above measures ensure that the main bracket is always in a vertical position during the diameter change process.

[0032] like Figure 3 A rectangular groove is provided at the lower end of the right arm 2 of the bracket shown in the figure, and a wire pressing slider 12 is provided on the rectangular groove which can slide along the rectangular groove. The signal lines of the excitation coil 7 and the detection coil 8 are connected to the encoder 11 from the groove. The wire pressing slider 12 ensures that the signal line can move freely and is not damaged during the diameter change process.

[0033] like Figure 4The lower end of the lifting rod 14 shown is provided with a right-handed thread connected to the probe box 6, and the upper end of the lifting rod 14 is provided with a left-handed thread connected to the lifting motor 5 and the lifting box 4. The two sets of threads in different directions on the lifting rod 14 ensure that the probe box 6 will not be separated from the lifting rod 14 during the lifting process. At the same time, the lifting height of the probe can be accurately adjusted by the lifting motor 5 and the distance sensor 16.

[0034] like Figure 4 The inner bottom surface of the probe box 6 is provided with two circles of circular positioning grooves for fixing the excitation coil 7 and the detection coil 8 provided inside the probe box 6. A distance sensor 16 is mounted at the lower end of the probe box 6.

[0035] like Figure 1 The magnetic wheel 10 is adsorbed on the surface of the structure to be tested, and the magnetic wheel is driven to move by the driving motor. The right end of the encoder 11 is fixedly connected to the magnetic wheel 10 to record the distance traveled by the magnetic wheel 10. The obtained data is transmitted to the external processing device through the wireless transmission module. The external processing device will use the curvature compensation formula to compensate for the error caused by the curvature of the pipeline to improve the detection accuracy.

[0036] The curvature compensation principle is to use simulation and experiments to obtain the voltage data of the detection coil of the same probe under different pipe diameters, take the peak value as the characteristic value, and then obtain the detection voltage of the same probe on the plate with the same thickness as the pipeline through simulation and experiments. The peak detection voltage obtained under different pipe diameters is subtracted from the peak detection voltage under the plate, and then the difference is curve fitted to obtain the compensation formula: , where is the voltage signal detected by the probe on the flat test block with the same thickness. is the pipe radius, is the correction coefficient. For the probe of the embodiment of the present application, the fitting parameters are: =24.973, =-0.02344, =5.81035E-5, =4.48077.

[0037] The working principle and use process of the present invention:

[0038] The staff measures the radius of the pipeline in advance, places the variable-diameter pulse eddy current probe device on the pipeline, slides the line pressing slider 12 downward, then loosens the butterfly nut 15 on the variable-diameter guide frame 3, pulls the left arm 11 and the right arm 2 of the bracket to the left and right, until the probe box 6 drops to a position close to the pipeline, confirms that the screws are embedded in the same groove through the digital mark on the variable-diameter guide frame 3, and tightens the butterfly nut 15. Turn on the lift-off motor 5 to fine-tune the lift-off rod 14 so that the probe box 6 is close to the pipeline surface, slides the slider 12 upward, presses the signal line, and remotely controls the variable-diameter pulse eddy current probe device to move and detect on the pipeline surface through the remote control. Input the measured pipeline radius into the external signal processing system, compensate for the curvature error, and obtain the test result.

[0039] The present invention can detect corrosion defects in pipelines with different diameters in real time, reduce human errors caused by manually moving the probe, and compensate for system errors caused by different pipeline curvatures through calculation formulas, thereby further improving detection accuracy.

[0040] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A pulsed eddy current detection device for variable diameter pipelines, comprising a main support and a lift-off and detection structure, characterized in that: The main support comprises two parallel support left arms (1) connected at one end and two parallel support right arms (2) connected at one end. The upper ends of the support left arms (1) and the support right arms (2) are connected to two variable diameter guide frames (3). The lower ends of the variable diameter guide frames (3) are inserted into a lift-off and detection structure. The lift-off and detection structure comprises a lift-off box (4). The lift-off box (4) is connected to the support left arm (1) and the support right arm (2). A lift-off motor (5) is provided on the upper part of the lift-off box (4). The lift-off motor (5) is 5) Insert a lifting rod (14) and connect it to a lifting box (4); one end of the lifting rod (14) is connected to a probe box (6); an excitation coil (7) and a detection coil (8) are placed in the probe box (6); a wheel bracket (9) is provided at one end of the left arm (1) and the right arm (2) of the bracket close to the pipeline; a magnetic wheel (10) is connected to the end of the wheel bracket (9); an encoder (11) is connected to the left side of the magnetic wheel (10); and a drive motor (17) is connected to the right side of the magnetic wheel (10).

2. A pulsed eddy current testing device for variable diameter pipelines according to claim 1, characterized in that: The inner bottom surface of the probe box (6) is provided with two circles of circular positioning grooves for placing the excitation coil (7) and the detection coil (8), a probe box cover (13) is provided on the top of the probe box (6), and a distance sensor (16) is installed at the lower end of the probe box (6).

3. The variable diameter pipeline pulse eddy current detection device according to claim 1 is characterized in that: A rectangular groove is provided at the lower end of the right arm (2) of the bracket, and a wire pressing slider (12) is provided on the rectangular groove and slides along the rectangular groove.

4. The variable diameter pipeline pulse eddy current detection device according to claim 1 is characterized in that: A wireless transmission module is provided inside the lift-off box (4).

5. The variable diameter pipeline pulse eddy current detection device according to claim 4, characterized in that: The wireless transmission module transmits data to an external device, and the external device uses a curvature compensation formula to compensate for the error caused by the pipe curvature. The compensation formula is: in, is the voltage signal detected by the probe on the flat test block with the same thickness. is the pipe radius, is the correction factor.

6. The variable diameter pipeline pulse eddy current detection device according to claim 1, characterized in that: The upper end of the variable diameter guide frame (3) is an arc-shaped notch, and grooves are provided at equal distances on the left and right sides of the upper end of the arc-shaped notch, and numbers 1, 5, and 10 are engraved one after another from the right outer side above the groove to the inner side.

7. The variable diameter pipeline pulse eddy current testing device according to claim 1 is characterized by: The lower end of the lift-off rod (14) is provided with a right-handed thread connected to the probe box (6), and the upper end of the lift-off rod (14) is provided with a left-handed thread threadedly connected to the lift-off motor (5) and the lift-off box (4).

8. The variable diameter pipeline pulse eddy current testing device according to claim 1, characterized in that: All of the bracket left arm (1), bracket right arm (2), diameter-changing guide frame (3), lift-off box (4), and wheel bracket (9) are made of stainless steel.

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