A defect recording method and related device for ultrasonic flaw detector

Abstract

The present application relates to the technical field of ultrasonic flaw detection, and discloses a defect recording method and related device of an ultrasonic flaw detector. The ultrasonic flaw detector includes a distance measuring device and an angle measuring device; the distance measuring device includes a sliding member and an encoder, and the encoder is used to record the movement distance of the sliding member; the angle measuring device includes a support seat, a roller, a reset spring, a bracket, an angle sensor and a flaw detection probe; the top of the support seat is connected to the sliding member, and a bracket extends from the bottom, and rotating blocks are hinged on both sides of the bracket, and the rotating blocks rotate in the direction toward or away from the support seat, and angle sensors are arranged between the rotating blocks, and the angle sensors are used to measure the angle between the rotating blocks; the rotating blocks are connected to the bracket through compression springs, and each rotating block is provided with two pairs of rollers, and the flaw detection probe is arranged on a rotating block. The present application has the advantages of solving the problems caused by encoder side slip and poor probe fitting, and improving the applicability and measurement accuracy of the flaw detector.

Description

Technical Field

[0001] The present application relates to the technical field of ultrasonic flaw detection, and in particular to a defect recording method and related device of an ultrasonic flaw detector. Background Art

[0002] Ultrasonic flaw detector is a commonly used non-destructive testing equipment, which mainly judges whether there are defects inside the object and the location, size and nature of the defects by emitting ultrasonic waves into the object and receiving its reflected signals, and analyzing the time difference and intensity of the reflected signals. Due to its high detection accuracy and wide range of applications, ultrasonic flaw detectors are widely used in quality inspection and safety assessment in industrial fields such as pipelines and metal components.

[0003] The basic structure of a traditional ultrasonic flaw detector usually includes a probe, an encoder and a mobile platform. The flaw detector is usually directly connected to a trolley through a connecting rod. An encoder is installed at the bottom of the trolley to record the distance the trolley moves. During operation, the probe slides along the surface of the pipe being tested, and the encoder records the distance the trolley moves in a straight line. This method is suitable for detecting straight pipes, especially pipes with regular diameters and smooth surfaces.

[0004] However, in actual applications, the pipeline may not be completely straight and often has certain bends. When the trolley slides along the curved pipeline, the linear movement distance recorded by the encoder may deviate from the actual path due to the existence of the bend. This deviation mainly comes from the inconsistency between the encoder's side sliding or rolling direction and the movement direction of the pipeline surface, resulting in errors in the measurement position. In addition, when the pipeline has a large bend, the fit between the probe and the pipeline surface may be weakened, further affecting the effective propagation and reception of ultrasonic signals.

[0005] Therefore, although the traditional method is simple, it is difficult to ensure the accuracy of position recording under actual complex working conditions because it cannot effectively deal with curved pipes. Summary of the invention

[0006] In order to solve the problems caused by encoder side slip and poor probe fitting and improve the applicability and measurement accuracy of the flaw detector, the present application provides a defect recording method and related devices for an ultrasonic flaw detector.

[0007] In a first aspect, the present application provides an ultrasonic flaw detector, which adopts the following technical solution:

[0008] An ultrasonic flaw detector comprises a distance measuring device and a rotation angle measuring device;

[0009] The distance measuring device comprises a sliding member whose bottom surface can conform to the plane movement, and an encoder located on the bottom surface of the sliding member, wherein the encoder is used to record the movement distance of the sliding member;

[0010] The rotation angle measuring device includes a support seat, a roller, a reset spring, a bracket, an angle sensor and a flaw detection probe; the top of the support seat is connected to the sliding member through a connecting rod, the bottom of the support seat is provided with a bracket extending away from the connecting rod, and the two sides of the bracket are respectively hinged with a first rotating block and a second rotating block, the first rotating block is used for the front end of the movement, the first rotating block and the second rotating block rotate in the direction toward or away from the support seat, an angle sensor is arranged between the first rotating block and the second rotating block, and the angle sensor is used to measure the angle between the first rotating block and the second rotating block; the first rotating block and the second rotating block are connected to the bracket through a compression spring at the end away from the bracket, and the first rotating block and the second rotating block are both provided with two pairs of rollers; the flaw detection probe is arranged on the second rotating block.

[0011] Optionally, the first rotating block and the second rotating block are rotatably connected to the bracket, and the end surfaces of the two rotating blocks close to each other are provided with a transmission mechanism, and the transmission mechanism is suitable for driving the end surfaces of the rotating blocks far away from each other to gather or disperse.

[0012] Optionally, the transmission mechanism includes a gear or a rack or a synchronous wheel or a sprocket.

[0013] Optionally, the rotating block is provided with a magnetic member for adsorbing the rotating block onto the steel pipe to be tested.

[0014] Optionally, a traction rope is provided on the support seat.

[0015] Optionally, the sliding member is provided with a sliding groove in a direction perpendicular to the required fitting plane, and the sliding groove is slidably connected to the connecting rod; the support seat is provided with a telescopic rod in the extension direction of the sliding groove, and a support ball is provided at one end of the telescopic rod away from the support seat.

[0016] Optionally, corresponding scales are provided on the slide groove and the telescopic rod, the telescopic rod is inserted into the support seat and is dampingly connected, and a limit bolt is sleeved on the telescopic rod, and the limit bolt can be screwed up and down in the length direction of the telescopic rod.

[0017] In a second aspect, the present application provides a defect recording method for an ultrasonic flaw detector, which adopts the following technical solution:

[0018] A defect recording method for an ultrasonic flaw detector, used for the above-mentioned ultrasonic flaw detector, comprises the following steps:

[0019] Place the distance measuring device on a flat surface, and attach the angle measuring device to the surface of the pipe to be measured;

[0020] Horizontally adjust the distance measuring device and the rotation angle measuring device;

[0021] Initialize the global coordinate system and set the initial coordinates, and define the angle accumulation variables;

[0022] In each calculation cycle Δt, the current angle value is read from the angle sensor and the angle accumulation variable is updated;

[0023] In the same calculation cycle Δt, the incremental moving distance of the support seat is read from the encoder:

[0024] Based on the micro-element operation, the moving distance increment of the support base is trigonometrically transformed with the current angle value to obtain the moving distance increment of the second rotating block;

[0025] Based on the differential operation, the moving distance increment of the second rotating block is trigonometrically transformed with the current angle value to obtain the moving distance increment of the first rotating block;

[0026] The rotation component of the flaw detection probe is calculated based on the distance from the flaw detection probe to the rotation center of the first rotating block and the current angle value, and the displacement of the rotation component of the flaw detection probe and the movement distance increment of the first rotating block in the movement direction of the second rotating block and the displacement of the flaw detection probe are orthogonally decomposed based on the angle accumulation variable to obtain the coordinate change of the flaw detection probe;

[0027] When the flaw detection probe obtains the flaw detection result, the coordinates of the flaw detection probe are recorded to obtain the real-time defect position coordinates.

[0028] In summary, the present application includes at least one of the following beneficial technical effects:

[0029] 1. Through the combination of the distance measuring device and the angle measuring device, the plane displacement and angle change of the pipeline can be accurately recorded, and the defect position of the flaw detection probe can be further calculated and located to improve the measurement accuracy of ultrasonic flaw detection.

[0030] 2. Using angle sensors instead of gyroscopes for angle measurement avoids the complicated operation of repeatedly calibrating the reference direction due to environmental changes, simplifies user steps, and improves operating efficiency.

[0031] 3. The structure adopts sawtooth meshing and multi-point force design to avoid deformation or damage of components caused by single-point force, and further reduces vibration and external force interference through damping connection to improve the durability and reliability of the equipment. Through the cooperation of double rotating blocks, the force balance of the device at the bend of the pipeline is ensured to avoid measurement errors caused by uneven spring compression, thereby ensuring the accuracy of the flaw detector data.

[0032] 4. The encoder is independently set on the sliding part to separate it from the angle measurement device, which is convenient for maintenance, replacement or calibration, reduces downtime and improves equipment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A bottom view of an ultrasonic flaw detector is shown in one embodiment of the present application.

[0034] Figure 2 It is used to show the overall schematic diagram of the rotation angle measuring device in a certain embodiment of the present application.

[0035] Figure 3 It is used to show the overall schematic diagram of the angle measuring device in a certain embodiment of the present application with part of the bracket removed.

[0036] Figure 4 It is used to illustrate the matching relationship between the first rotating block and the second rotating block in the support seat for transmitting the mechanism in a certain embodiment of the present application.

[0037] Figure 5 Used to show a front view of a distance measuring device in a certain embodiment of the present application.

[0038] Figure 6 A flowchart for illustrating a defect recording method of an ultrasonic flaw detector in a certain embodiment of the present application.

[0039] Reference numerals:

[0040] 1. Distance measuring device; 11. Sliding member; 12. Encoder; 13. Slide;

[0041] 2. Angle measuring device; 201. Support seat; 202. Roller; 203. Reset spring; 204. Bracket; 205. Angle sensor; 206. Flaw detection probe; 207. First rotating block; 208. Second rotating block; 209. Traction rope; 210. Transmission mechanism; 211. Magnetic member; 212. Telescopic rod; 213. Support ball; 214. Limit bolt;

[0042] 3. Connecting rod. DETAILED DESCRIPTION

[0043] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings.

[0044] In the description of this specification, the description with reference to the terms "certain embodiments", "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0045] The present application embodiment discloses an ultrasonic flaw detector, referring to Figure 1-5 , including a distance measuring device 1 and an angle measuring device 2. The two are connected to each other through a connecting rod 3. The distance measuring device 1 records the movement distance, and the angle measuring device 2 records the bending degree of the pipeline passed during the movement, so that the computer can calculate the defect position recorded by the flaw detection probe 206 based on these two sets of data.

[0046] The distance measuring device 1 is used to record the travel of the flaw detector along the plane, and it is usually placed on the plane for sliding. Its structure includes a sliding member 11 and an encoder 12. In different embodiments, the shape of the sliding member 11 can be different, and it can be in the shape of a trolley or a simple square shape. The bottom can be equipped with rollers or balls to ensure that it moves smoothly. The roller is suitable for a large area of ​​flat surface, and the ball structure is suitable for flexible movement in more directions. The encoder 12 is located on the bottom surface of the sliding member 11 and is used to record the movement distance of the sliding member 11 in real time. The sliding member 11 presses the encoder 12 against the ground so that the encoder 12 can accurately record the movement distance of the sliding member 11 without side slipping or idling.

[0047] It should be noted that the main function of the encoder 12 is to record the linear movement distance of the flaw detector, while the core task of the angle measuring device 2 is to record the angular change of the pipeline. These two types of measurement data belong to motion information of different dimensions. If the encoder 12 is combined with the angle measuring device 2, the measurement results of the two may be coupled, reducing the independence of the data. For example, when the angle measuring device 2 rotates at the bend of the pipeline, it may cause measurement errors of the encoder 12.

[0048] Moreover, if the encoder 12 is directly set on the angle measuring device 2, the angle measuring device 2 will be subjected to certain rotational forces and frictional forces when it is attached to the pipe surface. These forces may be transmitted to the encoder 12 through the mechanical connection, thereby affecting the accurate recording of the encoder 12. If the encoder 12 is independently installed on the sliding member 11, its measurement path is separated from the angle measuring device 2, which can avoid these interference factors. In addition, it is more convenient to maintain the encoder 12 independently on the sliding member 11. Once the encoder 12 fails or needs to be calibrated, the user can quickly replace or adjust it without affecting the use of the angle measuring device 2. If the encoder 12 is integrated with the angle measuring device 2, the entire angle measurement module may need to be disassembled for maintenance or replacement.

[0049] The rotation angle measuring device 2 is used to record the angle change of the flaw detector when it passes through the curved area of ​​the pipeline. The structural design is intended to meet the dynamic recording requirements of slightly undulating curved surfaces.

[0050] The support seat 201 is the core support component of the rotation angle measuring device 2, and is connected to the sliding member 11 through the connecting rod 3; the bracket 204 extends downward from the bottom of the support seat 201, and serves as a fixed support point of the rotating assembly; the first rotating block 207 and the second rotating block 208 are connected to the bracket 204 through a hinge, and can rotate in the direction toward or away from the support seat 201. Two pairs of rollers 202 are provided on the side of the first rotating block 207 and the second rotating block 208, and move on the surface of the pipe through the rollers 202.

[0051] Specifically, the first rotating block 207 and the second rotating block 208 are rotatably connected to the bracket 204, and the end faces of the two rotating blocks close to each other are provided with a transmission mechanism 210, and the transmission mechanism 210 is suitable for driving the end faces of the rotating blocks away from each other to gather or disperse. Furthermore, the transmission mechanism 210 includes a gear or a rack or a synchronous wheel or a sprocket. For example, the cross-section of the end of the first rotating block 207 and the second rotating block 208 close to each other is semicircular, and the outer periphery of the semicircle is provided with saw teeth of the same specification, the saw teeth of the first rotating block 207 and the second rotating block 208 are meshed with each other, and the center of the end of the first rotating block 207 and the second rotating block 208 is rotatably connected to the support seat 201 through an axis.

[0052] The purpose of using two saw teeth to mesh closely together to build a stable platform is to form a constant angle relationship between the two rotating blocks. The core advantages of this design are: first, it provides a mechanically self-stabilizing structure. Through the meshing of the saw teeth, the two rotating blocks can rotate synchronously, which not only ensures the accuracy of the angle measurement, but also provides additional buffering function under dynamic conditions.

[0053] The traditional design method (such as direct hinge method) has obvious risks: since the ultrasonic flaw detector is often stored arbitrarily by the user, such as mixed with other tools in a tool bag, if the support base 201 and a single rotating block are directly hinged, the rotating block or the hinged part may be deformed due to external force, or cause the angle sensor 205 to drift zero. However, this solution disperses the stress through the close meshing of the saw teeth, making the device more durable when subjected to external force and not easily damaged due to excessive force on a single component.

[0054] In addition, the platform is fixed on two rotating blocks instead of a single rotating block because if the platform is only fixed on one rotating block, the force of the distance measuring device 1 will be concentrated on one rotating block during use, which will cause imbalance. When the other rotating block deflects, due to the different compression degrees of the two compression springs, the restoring force applied by the spring on the rotating block will also be different. This asymmetry of force will affect the motion trajectory of the flaw detector, thereby causing positioning errors. This error may affect the accuracy of defect detection in ultrasonic flaw detection applications, especially when operating on the curved area of ​​the pipeline.

[0055] The angle sensor 205 is arranged between the first rotating block 207 and the second rotating block 208, and its function is to record the relative angle between the two rotating blocks in real time. Such a design can intuitively reflect the angle change of the flaw detector when passing through the curved pipe, and deduce the actual angle of the pipe by recording the relative angle. In the initial state, the first rotating block 207 and the second rotating block 208 are in the same straight line position, and the angle is zero. This clear initial reference design makes the measurement of the angle sensor 205 more intuitive and accurate.

[0056] A key advantage of using the angle sensor 205 is that the structure is simple and reliable. Functionally, the angle sensor 205 can directly record changes in the angle of the pipeline, avoiding the complex operating problems that may occur when using other sensing devices (such as gyroscopes). For example, although a gyroscope can also provide angle information, it usually relies on changes in relative direction and requires recalibration of the reference direction under different usage environments. For a flaw detection device that needs to adapt to a variety of working conditions and is highly portable, this complex calibration process of the gyroscope will undoubtedly increase the difficulty of use and may also introduce human errors.

[0057] In contrast, the angle sensor 205 measures the angle directly based on the mechanical connection between the rotating blocks, and its output data can reflect the real physical state without additional calculation or calibration. This feature not only simplifies the use steps of the flaw detector, but also improves the applicability of the device in various environments. Especially when the user quickly switches the detection scene, the angle sensor 205 can be plug-and-play, reducing the time wasted due to calibration or initialization. In addition, from the perspective of reliability, the angle sensor 205 is closely integrated with the first rotating block 207 and the second rotating block 208, forming a more physical measurement method. It avoids the problem of the accuracy of the gyroscope being affected by external interference (such as magnetic field changes or vibrations).

[0058] The first rotating block 207 is used for the front end of the movement, and the flaw detection probe 206 is installed at the end of the first rotating block 207 away from the connecting rod 3, and is used to perform a flaw detection operation on the pipeline when the pipeline is fitted.

[0059] When using an ultrasonic flaw detector, the user needs to frequently pull or push the device to complete the measurement task. These actions will inevitably exert a certain external force on the angle measuring device 2, and improper force may cause the rotating block to slide or fall off the pipe surface. In order to avoid this problem, a certain embodiment of the present application adds a magnetic piece 211 to the rotating block, and the rotating block is adsorbed on the surface of the steel pipe by magnetic force. It utilizes the magnetic properties of the steel pipe itself, enhances the fit between the device and the pipeline, and makes it more stable in operations in various directions and angles. The addition of the magnetic piece 211 not only improves the anti-slip ability of the equipment, but also simplifies the user's operating requirements. Through magnetic adsorption, the user does not need to accurately control the force during operation to keep the device fit, which reduces the difficulty of operation. At the same time, the magnetic piece 211 can continuously provide a stable adsorption force, and even when the angle of the rotating block changes due to pipe bending, it can maintain a good fit and ensure measurement accuracy.

[0060] The magnetic part 211 is usually embedded or fixed at the bottom of the rotating block and is in direct contact with the pipe. For example, the magnetic part 211 can be directly embedded in the groove at the bottom of the rotating block and connected to the rotating block by bonding or threading. This design can keep the surface of the magnetic part 211 flush with the bottom surface of the rotating block to ensure the stability of the fitting surface. Alternatively, the magnetic part 211 is installed at the bottom of the rotating block through the metal bracket 204, and the bracket 204 and the rotating block are fixed by screws or welding. This method makes it easy to replace or adjust the position of the magnetic part 211.

[0061] For example, when inspecting a vertical pipeline, the flaw detector needs to be pushed upward along the pipeline. Due to gravity, the rotating block is easy to slide due to insufficient friction, and the adsorption force provided by the magnetic member 211 can significantly enhance the fit and ensure the smooth advancement of the device.

[0062] Furthermore, a traction rope 209 is provided on the support base 201. The traction rope 209 is provided on one side of the support base 201 where the first rotating block 207 is provided, and is used to pull the support base 201 to slide forward. When manual control of the moving path is required, the traction rope 209 can directly transfer the user's pulling force to the support base 201, thereby achieving precise control of the movement of the entire device. From the perspective of use, the addition of the traction rope 209 not only makes the operation of the device easier, but also increases the adaptability of the device in complex environments. For example, when detecting certain inclined or curved pipes, the user can apply a more stable control force to the flaw detector through the traction rope 209 without directly pushing the support base 201, thereby avoiding unstable movement of the device due to inconvenient operating angles or uneven external forces.

[0063] The design of the traction rope 209 also indirectly optimizes the overall structure of the device. By guiding the force application point from the side or top surface of the support base 201 to the fixing point of the traction rope 209, the interference of the user's operation on the balance of the device can be reduced, so that the support base 201 can maintain a stable posture during the sliding process, thereby improving the accuracy of the flaw detection measurement. In terms of connection method, the traction rope 209 can be connected to the support base 201 through a sturdy hook or fixed ring. The specific position is usually designed to be at the front end or upper side of the support base 201. This arrangement can keep the traction force consistent with the sliding direction of the support base 201, reducing the problem of tilting or side sliding caused by uneven force.

[0064] In order to meet the different diameters and detection positions of the pipelines to be detected, the heights of the sliding member 11 and the support seat 201 need to be adjusted to ensure that the bottom surfaces of the connecting rod 3 and the sliding member 11 are perpendicular to the advancing direction of the sliding member 11. Specifically, the sliding member 11 is provided with a slide groove 13 in the direction of the sliding member 11 perpendicular to the required fitting plane, and the slide groove 13 is slidably connected to the connecting rod 3; the support seat 201 is provided with a telescopic rod 212 in the extending direction of the slide groove 13, and a support ball 213 is provided at one end of the telescopic rod 212 away from the support seat 201.

[0065] The slide groove 13 is arranged perpendicular to the direction of the fitting plane and is used for sliding connection with the connecting rod 3. This structure allows the connecting rod 3 to move up and down in the slide groove 13, thereby fine-tuning the vertical height of the device. The telescopic rod 212 connected to the slide groove 13 further expands this adjustment function. The telescopic rod 212 is arranged along the extension direction of the slide groove 13, and a support ball 213 is installed at its far end. This structure not only increases the support stability of the device, but also ensures the smooth movement of the device on a horizontal or inclined surface through the low friction characteristics of the ball.

[0066] The slide 13 and the telescopic rod 212 are provided with corresponding scales. The telescopic rod 212 is inserted into the support seat 201 and connected with damping. The telescopic rod 212 is provided with a limit bolt 214, which can be screwed up and down in the length direction of the telescopic rod 212. During operation, the user can quickly determine the relative position of the slide 13 and the telescopic rod 212 by observing the scale, thereby achieving fast and accurate height adjustment. At the same time, the damping connection between the telescopic rod 212 and the support seat 201 effectively increases the stability of the device, so that the telescopic rod 212 will not slide accidentally due to external interference. The function of the limit bolt 214 is to effectively limit the adjustment range of the telescopic rod 212. By screwing the limit bolt 214, the user can lock the length of the telescopic rod 212 to avoid misalignment due to vibration or external force during the flaw detection process.

[0067] Reference Figure 6The present application also discloses a defect recording method of an ultrasonic flaw detector, comprising the following steps:

[0068] S1. Place the distance measuring device 1 on a plane and fit the angle measuring device 2 on the surface of the pipe to be measured;

[0069] S2. The distance measuring device 1 and the angle measuring device 2 are adjusted horizontally;

[0070] S3. Initialize the global coordinate system and set the initial coordinates, and define the angle accumulation variable;

[0071] S4. In each calculation cycle Δt, the current angle value is read from the angle sensor 205, and the angle accumulation variable is updated;

[0072] S5. Within the same calculation cycle Δt, the moving distance increment of the support base 201 is read from the encoder 12:

[0073] S6. Based on the micro-element operation, the moving distance increment of the support base 201 is trigonometrically transformed with the current angle value to obtain the moving distance increment of the second rotating block 208;

[0074] S7. Based on the micro-element operation, the moving distance increment of the second rotating block 208 is trigonometrically transformed with the current angle value to obtain the moving distance increment of the first rotating block 207;

[0075] S8. Calculate the rotation component of the flaw detection probe 206 based on the distance from the flaw detection probe 206 to the rotation center of the first rotating block 207 and the current angle value, and perform orthogonal decomposition on the displacement of the rotation component of the flaw detection probe 206 and the moving distance increment of the first rotating block 207 in the movement direction of the second rotating block 208 based on the angle accumulation variable to obtain the coordinate change of the flaw detection probe 206;

[0076] S9. When the flaw detection probe 206 obtains the flaw detection result, the coordinates of the flaw detection probe 206 are recorded to obtain the real-time defect position coordinates.

[0077] Specifically, the first rotating block 207 and the second rotating block 208 are connected to each other and rotate around the rotation center point a, which is the midpoint of the projection of the two rotation axes of the first rotating block 207 and the second rotating block 208 on a vertical plane, that is, the contact point of the first rotating block 207 and the second rotating block 208. In the initial state, the two rotating blocks are on the same straight line and can rotate in the same rotation plane. With the rotation center as point a, no matter how the two rotating blocks rotate, the connecting rod 3 is always located on the bisector of the angle formed by the first rotating block 207 and the second rotating block 208 from point a. A point c is provided on the connecting rod 3, which is equipped with an encoder 12 to record the movement distance of point c.

[0078] The first rotating block 207 and the second rotating block 208 can slide along the pipeline direction (the X-axis direction in the global coordinate system X-Y). Assume that the first rotating block 207 is in front and the second rotating block 208 is in the back. The position where the flaw detection probe 206 is installed at the front end of the first rotating block 207 is point b. The pipeline is generally straight, with slight bends in some areas.

[0079] The global coordinate system is set as a fixed coordinate system (X−Y), where the X-axis direction is the axial direction of the starting part of the pipeline, and the Y-axis direction is the direction perpendicular to the axis of the starting part of the pipeline in the rotation plane.

[0080] During the movement, the first rotating block 207 and the second rotating block 208 both translate along the X-axis. When the pipeline is slightly bent, they deflect during the forward movement, causing the front end to move closer to or deviate from the X-axis. Due to the front-to-back relationship, the first rotating block 207 deflects first, and the second rotating block 208 deflects later, so an angle Δθ is generated between the two. The cumulative rotation angle of the second rotating block 208 relative to the X-axis is , then the rotation angle of the first rotating block 207 relative to the X-axis is .

[0081] Since the connecting rod is always located on the bisector of the angle, when the two rotating blocks perform pure linear motion (no relative rotation), the connecting rod and the rotating blocks move synchronously (i.e., relatively stationary). When the first rotating block 207 rotates relative to the second rotating block 208, the angle between the two changes, and the corresponding bisector also changes, so that the connecting rod swings relative to the second rotating block 208. The swing angle is In the limit of Δθ→0 and Δt→0, the motion of the connecting rod can be approximately decomposed into two superimposed motions: the circular motion around the rotation center a and the translational motion with the first rotating block. The synthesis of the two is the distance corresponding to the change in encoder counts. Mathematically, the idea of ​​differential analysis can be used to approximate it to a very small sector.

[0082] For the encoder on the connecting rod (point c), since Δθ→0, the movement distance of the encoder is Decomposing this movement distance, the component of the encoder along the translation direction of the second rotating block 208 is:

[0083] .

[0084] Then the translation distance of the second rotating block 208 is:

[0085] .

[0086] At this time, the rotation center a has not yet moved to the position where the pipeline is offset, but the end (point b) of the first rotating block 207 has moved to the offset position, causing the connecting rod to rotate. Similar to the previous analysis, the movement of the first rotating block 207 away from the rotation center a can be regarded as first moving in the direction of movement of the second rotating block 208 ( The first rotating block 207 here will cause the coordinates of point b to change, while the swing of the sliding block in the above case will cause the sliding block to move horizontally and vertically, but this is different from the support base in the horizontal direction. Separate in direction of movement.

[0087] The movement distance of the end away from the rotation center (i.e. point b) in the movement direction of the second rotating block 208 is also:

[0088] .

[0089] exist The displacement in the direction is , the circular rotation displacement around the rotation center is , where r is the rotation radius of the point relative to the rotation center a. When Δθ→0, it can be approximated by as well as Small angle approximation of .

[0090] right and The synthetic displacement is orthogonally decomposed, with the global coordinate system as the reference, and its increment is as follows:

[0091] The increment in the X direction is:

[0092]

[0093] The increment in the Y direction is:

[0094]

[0095] By calculating the and By accumulating, we can get the integral of the coordinate change of point b in the global coordinate system over time:

[0096] ,

[0097] .

[0098] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. An ultrasonic flaw detector, characterized in that: It comprises a distance measuring device (1) and a rotation angle measuring device (2); The distance measuring device (1) comprises a sliding member (11) whose bottom surface can move in a plane conforming thereto, and an encoder (12) located on the bottom surface of the sliding member (11), wherein the encoder (12) is used to record the movement distance of the sliding member (11); The rotation angle measuring device (2) comprises a support seat (201), a roller (202), a return spring (203), a bracket (204), an angle sensor (205) and a flaw detection probe (206); the top of the support seat (201) is connected to the sliding member (11) via a connecting rod (3); the bottom of the support seat (201) is provided with a bracket (204) extending in a direction away from the connecting rod (3); the two sides of the bracket (204) are respectively hinged with a first rotating block (207) and a second rotating block (208); the first rotating block (207) is used for the front end of the movement; the first rotating block (207) and the second rotating block (208) are respectively hinged. 8) rotating in a direction toward or away from the support seat (201), an angle sensor (205) is arranged between the first rotating block (207) and the second rotating block (208), and the angle sensor (205) is used to measure the angle between the first rotating block (207) and the second rotating block (208); the first rotating block (207) and the second rotating block (208) are connected to the bracket (204) through a compression spring at one end away from the bracket (204), and the flaw detection probe (206) is arranged on the second rotating block (208); the distance measuring device (1) and the angle measuring device (2) are connected through a connecting rod (3).

2. The ultrasonic flaw detector according to claim 1, characterized in that: The first rotating block (207) and the second rotating block (208) are rotatably connected to the bracket (204); the end surfaces of the first rotating block (207) and the second rotating block (208) that are close to each other are provided with a transmission mechanism (210); the transmission mechanism (210) is used to drive the end surfaces of the first rotating block (207) and the second rotating block (208) that are far away from each other to gather or disperse.

3. The ultrasonic flaw detector according to claim 2, characterized in that: The transmission mechanism (210) comprises a gear or a rack or a synchronous wheel or a sprocket.

4. The ultrasonic flaw detector according to claim 1, characterized in that: The first rotating block (207) and the second rotating block (208) are provided with magnetic parts (211) for adsorbing the rotating blocks onto the steel pipe to be tested.

5. The ultrasonic flaw detector according to claim 1, characterized in that: A traction rope (209) is arranged on the support seat (201).

6. The ultrasonic flaw detector according to claim 1, characterized in that: The sliding member (11) is provided with a sliding groove (13) in a direction perpendicular to the required fitting plane, and the sliding groove (13) and the connecting rod (3) are slidably connected; the support seat (201) is provided with a telescopic rod (212) in the extension direction of the sliding groove (13), and a supporting ball (213) is provided at one end of the telescopic rod (212) away from the support seat (201).

7. The ultrasonic flaw detector according to claim 6, characterized in that: The slide groove (13) and the telescopic rod (212) are provided with corresponding scales. The telescopic rod (212) is inserted into the support seat (201) and is damping-connected. A limiting bolt (214) is sleeved on the telescopic rod (212). The limiting bolt (214) can be screwed up and down in the length direction of the telescopic rod (212).

8. A defect recording method for an ultrasonic flaw detector, characterized in that: The ultrasonic flaw detector according to any one of claims 1 to 7 comprises the following steps: The distance measuring device (1) is placed on a plane, and the rotation angle measuring device (2) is attached to the surface of the pipeline to be measured; The distance measuring device (1) and the rotation angle measuring device (2) are adjusted horizontally; Initialize the global coordinate system and set the initial coordinates, and define the angle accumulation variables; In each calculation cycle Δt, the current angle value is read from the angle sensor (205) and the angle accumulation variable is updated; In the same calculation cycle Δt, the moving distance increment of the support base (201) is read from the encoder (12): Based on the micro-element operation, the moving distance increment of the support base (201) is trigonometrically transformed with the current angle value to obtain the moving distance increment of the second rotating block (208); Based on the differential operation, the moving distance increment of the second rotating block (208) is trigonometrically transformed with the current angle value to obtain the moving distance increment of the first rotating block (207) in the moving direction of the second rotating block (208); The rotation component of the flaw detection probe (206) is calculated based on the distance from the flaw detection probe (206) to the rotation center of the first rotating block (207) and the current angle value, and the displacement of the rotation component of the flaw detection probe (206) and the displacement of the first rotating block (207) in the moving direction of the second rotating block (208) are orthogonally decomposed based on the angle accumulation variable to obtain the coordinate change of the flaw detection probe (206); When the flaw detection probe (206) obtains the flaw detection result, the coordinates of the flaw detection probe (206) are recorded to obtain the real-time defect position coordinates.

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