Non-equal-diameter hollow shaft inner hole defect detection device

Abstract

The invention discloses a non-equal-diameter hollow shaft inner hole defect detection device, which comprises a mechanical arm, an electromagnetic array eddy current sensor, a linear Hall sensor and an intelligent eddy current detector, and is characterized in that the linear Hall sensor judges the distance from the electromagnetic array eddy current sensor to the inner wall of a hollow shaft by acquiring the magnetic induction change of an induction coil; then the position of the electromagnetic array eddy current sensor is adjusted according to the mechanical arm, so that the electromagnetic array eddy current sensor is tightly attached to the inner wall of the hollow shaft, and the detection sensitivity is improved; meanwhile, the linear Hall sensor adopts an elastic piece structure, it is ensured that the electromagnetic array eddy current sensor can be tightly attached to the interior of the hollow shaft, and due to the fact that the hollow shaft of a non-equal-diameter inner hole structure is scanned, compared with a traditional single-point type eddy current probe, high detection efficiency and detection precision are achieved, and operation is more flexible.

Description

Technical Field

[0001] This application relates to the technical field of inner hole detection of hollow shafts, and specifically to a non-uniform diameter hollow shaft inner hole defect detection device. Background Technique

[0002] Hollow shafts have high corrosion resistance and are suitable for environments such as water, chemical substances, and other easily oxidizable environments. Their lightweight design reduces the overall weight while ensuring strength, and they are widely used in aeroengines, automotive drive systems, wind turbines, and industrial equipment.

[0003] In traditional non-destructive testing methods, ultrasonic waves are the main flaw detection method currently in use. If there are small surface defects on the inner wall of the hollow shaft, ultrasonic detection is prone to blind spots, resulting in missed detections. For the detection of inner wall defects of hollow shafts, as one of the five conventional non-destructive testing methods, eddy current testing is based on the principle of electromagnetic induction, does not require a coupling agent, has high sensitivity, can detect tiny surface defects of the test piece, and the data can be immediately fed back, making it suitable for on-site real-time detection of hollow shafts.

[0004] CN202122818101.8 discloses a hollow shaft inner hole array eddy current flaw detection device, including a skeleton, a connecting rod, a connecting sleeve, a telescopic member, an array coil, and an array channel, where: a first hollow cavity is opened in the connecting rod; a hollow cavity is provided inside the connecting sleeve, one end of the connecting sleeve is sleeved and installed on the outer wall of the connecting rod, and the other end of the connecting sleeve is used to be installed on the control platform; the array coil includes a first wiring terminal; a second hollow cavity is opened in the skeleton, a groove is opened on the outer side wall of the skeleton, and the array coil is wound on the groove; the telescopic member includes a first fixed end and a second fixed end, the first fixed end is installed on the skeleton and can be telescopically moved along the length direction of the connecting rod, and the second fixed end is installed on the control platform; the array channel includes a second wiring terminal and a third wiring terminal, and the second wiring terminal is connected to the first wiring terminal.

[0005] The detection method is as follows: The PC is connected to the array eddy current detector and the scanning push-pull device. The scanning push-pull device drives the probe through a chain and automatically extends into the inner hole of the hollow shaft along the guide sleeve. The motor drives the probe to move smoothly forward and backward in the inner hole. The probe covers the entire inner wall of the hollow shaft, and defect signals on the inner hole surface are collected during the process of withdrawing from the inner hole of the hollow shaft. The array eddy current detector is responsible for collecting the defect signals transmitted by the probe and performing signal processing, and finally obtaining the information of the inner hole surface defects, which is transmitted to the PC, thus completing the detection of the inner hole surface defects of the hollow shaft.

[0006] However, the probe used in the above-mentioned eddy current flaw detection device for the inner hole array of the hollow shaft is a single-point eddy current probe. The single-point eddy current probe has inherent technical limitations when dealing with the variable curvature pipe cavity structure. Since the hollow shaft adopts a non-uniform inner diameter design, the traditional single-point eddy current probe cannot ensure close contact with the inner wall of the hollow shaft, thus affecting the detection sensitivity and detection accuracy. Summary of the Invention

[0007] The purpose of this application is to provide a non-uniform inner diameter hollow shaft inner hole defect detection device to solve the problem that the traditional single-point eddy current probe cannot ensure close contact with the inner wall of the hollow shaft in the above-mentioned background technology, thereby affecting the detection sensitivity and detection accuracy.

[0008] To achieve the above purpose, this application provides the following technical solutions: A non-uniform inner diameter hollow shaft inner hole defect detection device includes a robotic arm, an electromagnetic array eddy current sensor, a linear Hall sensor, and an intelligent eddy current detector. The robotic arm is responsible for receiving control commands and adjusting the detection posture of the electromagnetic array eddy current sensor according to the control commands. The linear Hall sensor is detachably installed on the robotic arm and is used to detect the fitting state between the electromagnetic array eddy current sensor and the inner wall of the hollow shaft. The electromagnetic array eddy current sensor is axially movably arranged on the linear Hall sensor through a mounting component. The intelligent eddy current detector is arranged on one side of the robotic arm and is used to obtain the detection data of the electromagnetic array eddy current sensor and transmit the detection data to the host computer for imaging of the detection results; An elastic member is sleeved on the mounting component, and both ends of the elastic member are respectively abutted against the mounting component and the linear Hall sensor. In one embodiment, the electromagnetic array eddy current sensor includes an S-shaped array coil assembly. The S-shaped array coil assembly includes a four-element detection array and a three-element detection array, and the four-element detection array and the three-element detection array form a spatial phase difference distribution structure.

[0009] In one embodiment, the robotic arm is a six-degree-of-freedom robotic arm, and the six-degree-of-freedom robotic arm includes six rotating joints.

[0010] In one embodiment, the mounting component includes a mounting base and at least two support columns. The mounting base is fixedly or detachably installed on the electromagnetic array eddy current sensor. One end of the support column passes through the mounting base, and the other end is installed on the linear Hall sensor. The mounting base can slide along the support column. The elastic member is sleeved on the support column and both ends are respectively abutted against the mounting base and the linear Hall sensor.

[0011] In one embodiment, the mounting base and the two support columns are in interference fit.

[0012] In one embodiment, the elastic member is a spring.

[0013] In one embodiment, the linear Hall sensor is mounted on the robotic arm through a mounting tube, and the mounting tube is of a hollow structure.

[0014] In one embodiment, one end of the mounting tube has mounting holes, and there are two mounting holes, which are symmetrically arranged on the outer wall of one end of the mounting tube.

[0015] In one embodiment, the linear Hall sensor has a mounting portion, and a receiving hole is formed on the mounting portion. The mounting tube is inserted into the receiving hole. A fixing hole is formed on the mounting portion. When the mounting tube is inserted into the receiving hole, the fixing hole and the mounting hole are aligned and communicated with each other, and an external plug is sequentially inserted into the fixing hole and the mounting hole.

[0016] In one embodiment, one end of the robotic arm close to the mounting tube has a fixed bushing, and the fixed bushing is detachably mounted on the robotic arm, and the mounting tube is inserted on the fixed bushing.

[0017] Compared with the prior art, the beneficial effects of the present application are as follows: In the process of detecting internal defects of a hollow shaft by a traditional single-point eddy current probe, due to the non-uniform inner diameter design of the hollow shaft, the single-point eddy current probe cannot closely fit the inside of the hollow shaft during the detection process; therefore, the present application provides a non-uniform inner diameter hollow shaft inner hole defect detection device, including a robotic arm, an electromagnetic array eddy current sensor, a linear Hall sensor, and an intelligent eddy current detector. The linear Hall sensor judges the distance between the electromagnetic array eddy current sensor and the inner wall of the hollow shaft by obtaining the magnetic induction change of the induction coil, and then adjusts the position of the electromagnetic array eddy current sensor according to the robotic arm, so as to achieve the purpose of closely attaching the electromagnetic array eddy current sensor to the inner wall of the hollow shaft and improving the detection sensitivity; at the same time, the present application adopts an elastic member structure on the linear Hall sensor to ensure that the electromagnetic array eddy current sensor can be closely attached to the inside of the hollow shaft. Since the present application scans the hollow shaft with a non-uniform inner hole structure, compared with the traditional single-point eddy current probe, it has high detection efficiency and detection accuracy, and the operation is more flexible and convenient. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of a non-uniform inner diameter hollow shaft inner hole defect detection device in the present application; Figure 2 It is a schematic assembly structure diagram of an electromagnetic array eddy current sensor, a linear Hall sensor and a mounting tube of a non-uniform inner diameter hollow shaft inner hole defect detection device in the present application; Figure 3 It is a schematic assembly structure diagram of an electromagnetic array eddy current sensor and a linear Hall sensor of a non-uniform inner diameter hollow shaft inner hole defect detection device in the present application; Figure 4 It is a schematic structural diagram of an S-shaped array coil assembly of a non-uniform inner diameter hollow shaft inner hole defect detection device in the present application.

[0019] Reference numerals: robotic arm 1, electromagnetic array eddy current sensor 2, S-shaped array coil assembly 21, four-element detection array 211, three-element detection array 212, linear Hall sensor 3, mounting portion 31, accommodation hole 311, fixing hole 312, intelligent eddy current detector 4, mounting assembly 5, mounting base 51, two support columns 52, elastic member 6, mounting tube 7, mounting hole 71, fixed bushing 8. Detailed implementation manners

[0020] To make the above objects, features, and advantages of the present application more apparent and understandable, the following will describe the detailed implementation manners of the present application in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0021] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present. In contrast, when an element is referred to as being "directly" connected to another element, there is no intermediate element.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific implementation manners and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0023] As Figure 1 and Figure 2 shown: A non-uniform-diameter hollow shaft inner hole defect detection device includes a robotic arm 1, an electromagnetic array eddy current sensor 2, a linear Hall sensor 3, and an intelligent eddy current detector 4. The robotic arm 1 is responsible for receiving control instructions and adjusting the detection posture of the electromagnetic array eddy current sensor 2 according to the control instructions. The linear Hall sensor 3 is detachably mounted on the robotic arm 1 and is used to detect the fitting state between the electromagnetic array eddy current sensor 2 and the inner wall of the hollow shaft. The electromagnetic array eddy current sensor 2 is axially movably arranged on the linear Hall sensor 3 through a mounting assembly 5. The intelligent eddy current detector 4 is arranged on one side of the robotic arm 1 and is used to obtain the detection data of the electromagnetic array eddy current sensor 2 and transmit the detection data to the upper computer for imaging of the detection results; An elastic member 6 is sleeved on the mounting assembly 5, and both ends of the elastic member 6 are respectively abutted against the mounting assembly 5 and the linear Hall sensor 3.

[0024] The elastic member 6 is a spring, and the robotic arm 1 is a six-degree-of-freedom robotic arm, which includes six rotational joints.

[0025] Linear Hall sensors 3 are distributed above the electromagnetic array eddy current sensor 2, forming an integrated detection device. The host computer connects the electromagnetic array eddy current sensor 2 and the robotic arm 1. The servo motor controls the relative movement between the non-uniform hollow shaft and the integrated detection device, thus achieving eddy current detection.

[0026] The primary magnetic field excited by the electromagnetic array eddy current sensor 2 induces eddy currents on the inner wall surface of the hollow shaft. The magnetic field generated by the induced eddy currents reacts on the magnetic field of the S-type array coil assembly 21, causing the impedance of the S-type array coil assembly 21 to change, thereby causing the voltage in the S-type array coil assembly 21 to change. The intelligent eddy current detector 4 analyzes and processes the received changed voltage signal to obtain defect information.

[0027] The linear Hall sensor 3 collects changes in the primary magnetic field in real time, thus determining the size of the induced eddy currents. As the fit between the electromagnetic array eddy current sensor 2 and the inner wall of the hollow shaft varies, the induced eddy currents differ, and their impact on the primary magnetic field also varies. Therefore, changes in the primary magnetic field are correlated to the fit between the electromagnetic array eddy current sensor 2 and the inner wall of the hollow shaft. The linear Hall sensor 3 detects changes in the primary magnetic field and outputs an analog voltage signal related to the distance. The output signal is processed through filtering, noise reduction, signal amplification and standardization, and analog-to-digital conversion (ADC). The output signal is then transmitted to the host computer, which analyzes the output signal to obtain the actual distance d between the linear Hall sensor 3 and the inner wall of the hollow shaft. 实际 , and the target distance d between the linear Hall sensor 3 and the inner wall of the hollow shaft when the detection device is tightly fitted to the hollow shaft 目标 , calculation error e(t)=d 目标 -d 实际 , the control variable u(t) is generated by the PID algorithm, the direction and amplitude of the robot arm 1 to move are determined, the smooth trajectory is planned by the inverse kinematics of the robot arm 1, and then the motor is used to drive the robot arm joint to move to the target angle. The encoder provides real-time feedback on the actual angle, and the actual angle is compared with the target angle for fine-tuning. Repeat the above steps until |d 目标 -d 实际 |<Specified error, thereby ensuring the fit between the electromagnetic array eddy current sensor 2 and the inner wall of the hollow shaft.

[0028] The hollow shaft is stably positioned by a dedicated clamping mechanism and driven to rotate uniformly around the central axis. With the help of the robotic arm 1, the integrated electromagnetic array eddy current sensor 2 and the linear Hall sensor 3 are accurately sent to the specified detection point inside the hollow shaft. The electromagnetic array eddy current sensor 2 detects the defect signal at the specified point and uploads the signal to the intelligent eddy current detector 4. After the hollow shaft completes a full rotation detection, the robotic arm 1 drives the integrated electromagnetic array eddy current sensor 2 and the linear Hall sensor 3 to gradually advance along the axial direction. The built-in linear Hall sensor 3 continuously obtains the distance information between the electromagnetic array eddy current sensor 2 and the inner wall of the hollow shaft, ensuring that the electromagnetic array eddy current sensor 2 always maintains a stable contact state with the inner wall of the hollow shaft in the variable-diameter hollow shaft pipeline.

[0029] The intelligent eddy current detector 4 is responsible for collecting the defect signals transmitted by the electromagnetic array eddy current sensor 2 and performing signal processing. Finally, the information on the defects on the inner hole surface of the hollow shaft is obtained and transmitted to the PC, thus completing the detection of the defects on the inner hole surface of the hollow shaft.

[0030] Repeat the above process to obtain the detection data of different regions on the inner wall of the hollow shaft in turn, and complete the defect inspection of the inner wall of the hollow shaft.

[0031] In this way, a non-uniform-diameter hollow shaft inner hole defect detection device, through the cooperative setting of the robotic arm 1, the electromagnetic array eddy current sensor 2, the linear Hall sensor 3, and the intelligent eddy current detector 4, in the process of detecting the internal defects of the hollow shaft by the traditional single-point eddy current probe, due to the non-uniform-diameter inner hole design of the hollow shaft, the single-point eddy current probe cannot closely fit the inside of the hollow shaft during the detection process; therefore, the linear Hall sensor 3 of the present application judges the distance between the electromagnetic array eddy current sensor 2 and the inner wall of the hollow shaft by obtaining the magnetic induction change of the induction coil, and then adjusts the position of the electromagnetic array eddy current sensor 2 according to the robotic arm 1, so as to make the electromagnetic array eddy current sensor 2 closely adhere to the inner wall of the hollow shaft, achieving the purpose of improving the detection sensitivity; at the same time, the present application adopts an elastic member structure on the linear Hall sensor to ensure that the electromagnetic array eddy current sensor can closely adhere to the inside of the hollow shaft. Since the detection device of the present application scans the hollow shaft with a non-uniform-diameter inner hole structure, compared with the traditional single-point eddy current probe, it has high detection efficiency and detection accuracy, and the operation is more flexible and simple.

[0032] As Figure 4 shown, in one of the embodiments, the electromagnetic array eddy current sensor 2 includes an S-shaped array coil assembly 21. The S-shaped array coil assembly 21 includes a four-element detection array 211 and a three-element detection array 212. The four-element detection array 211 and the three-element detection array 212 form a spatial phase difference distribution structure.

[0033] In this way, the S-shaped array coil assembly 21 includes a four-element detection array 211 and a three-element detection array 212, forming a spatial phase difference distribution. A spiral progressive detection path is constructed by the embedded arrangement of the three-element detection array 212 in the gap of the four-element detection array 211. Each sensing unit on the three-element detection array 212 and the four-element detection array 211 adopts an equal-parameter design to ensure the consistency of the detection field strength. After the magnetic core is subjected to magnetic domain orientation treatment, the magnetic circuit is optimized.

[0034] As Figure 3 shown, in one embodiment, the mounting assembly 5 includes a mounting base 51 and at least two support columns 52. The mounting base 51 is fixedly or detachably mounted on the electromagnetic array eddy current sensor 2. One end of the support column 52 passes through the mounting base 51, and the other end is mounted on the linear Hall sensor 3. The mounting base 51 can slide along the support column 52. The elastic member 6 is sleeved on the support column 52 and abuts against the mounting base 51 and the linear Hall sensor 3 at both ends respectively; the mounting base 51 and the two support columns 52 are in interference connection. The support columns 52 can be 4, and are symmetrically arranged on the mounting base 51.

[0035] In this way, when the electromagnetic array eddy current sensor 2 detects inside the hollow shaft, the mechanical arm 1 drives the linear Hall sensor 3. The linear Hall sensor 3 always pushes the electromagnetic array eddy current sensor 2 to contact the inner wall of the hollow shaft through the mounting base 51 and at least two support columns 52, ensuring the detection sensitivity and detection accuracy. At the same time, the elastic member 6 is sleeved on the support column 52 and abuts against the mounting base 51 and the linear Hall sensor 3 at both ends respectively, avoiding the hard contact between the mounting base 51 and the linear Hall sensor 3, and also avoiding the hard contact between the electromagnetic array eddy current sensor 2 and the inner wall of the hollow shaft. When the electromagnetic array eddy current sensor 2 does not abut against the inner wall of the hollow shaft, the elastic member 6 can reset the electromagnetic array eddy current sensor 2 during the process of restoring deformation.

[0036] In one embodiment, the linear Hall sensor 3 is mounted on the mechanical arm through a mounting tube 7. The mounting tube 7 is a hollow structure; one end of the mounting tube 7 has a mounting hole 71, and there are two mounting holes 71, symmetrically arranged on the outer wall of one end of the mounting tube 7; the linear Hall sensor 3 has a mounting portion 31, and a receiving hole 311 is opened on the mounting portion 31. The mounting tube 7 is inserted into the receiving hole 311. A fixing hole 312 is opened on the mounting portion 31. When the mounting tube 7 is inserted into the receiving hole 311, the fixing hole 312 and the mounting hole 71 are aligned and communicated with each other, and an external plug-in member is sequentially inserted into the fixing hole 312 and the mounting hole 7; one end of the mechanical arm 1 close to the mounting tube 7 has a fixed shaft sleeve 8, and the fixed shaft sleeve 8 is detachably mounted on the mechanical arm 1, and the mounting tube 7 is inserted on the fixed shaft sleeve 8.

[0037] In this way, one end of the installation pipe 7 is inserted into the fixed bushing 8 of the robotic arm 1, and the other end is inserted into the accommodation hole 311, so that the fixing hole 312 and the installation hole 71 are aligned and communicated with each other. The external plug-in is sequentially inserted into the fixing hole 312 and the installation hole 71. The linear Hall sensor 3 is detachably installed on the robotic arm 1. When it is necessary to disassemble the linear Hall sensor 3 from the robotic arm 1, the external plug-in can be pulled out from the fixing hole 312 and the installation hole 71 in sequence, and the disassembly and assembly are simple and convenient.

[0038] The above are only the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application, according to the technical solution and inventive concept of the present application, makes equivalent substitutions or changes, and should be covered within the protection scope of the present application.

Claims

1. A non-uniform diameter hollow shaft inner hole defect detection device, characterized in that: It includes a robotic arm, an electromagnetic array eddy current sensor, a linear Hall sensor, and an intelligent eddy current detector. The robotic arm is responsible for receiving control instructions and adjusting the detection posture of the electromagnetic array eddy current sensor according to the control instructions. The linear Hall sensor is detachably installed on the robotic arm and is used to detect the fitting state between the electromagnetic array eddy current sensor and the inner wall of the hollow shaft. The electromagnetic array eddy current sensor is axially movably arranged on the linear Hall sensor through a mounting assembly. The intelligent eddy current detector is arranged on one side of the robotic arm and is used to obtain the detection data of the electromagnetic array eddy current sensor and transmit the detection data to the upper computer for imaging of the detection results; An elastic member is sleeved on the mounting assembly, and both ends of the elastic member are respectively abutted against the mounting assembly and the linear Hall sensor.

2. The non-equal-diameter hollow shaft inner hole defect detection device according to claim 1, wherein: The electromagnetic array eddy current sensor includes an S-shaped array coil assembly. The S-shaped array coil assembly includes a four-element detection array and a three-element detection array, and the four-element detection array and the three-element detection array form a spatial phase difference distribution structure.

3. The non-uniform diameter hollow shaft inner hole defect detection device according to claim 1, characterized in that: The robotic arm is a six-degree-of-freedom robotic arm, and the six-degree-of-freedom robotic arm includes six rotating joints.

4. The non-equal-diameter hollow shaft inner hole defect detection device according to claim 1, characterized in that, The mounting assembly includes a mounting seat and at least two support columns. The mounting seat is fixedly or detachably installed on the electromagnetic array eddy current sensor. One end of the support column passes through the mounting seat, and the other end is installed on the linear Hall sensor. The mounting seat can slide along the support column. The elastic member is sleeved on the support column and both ends are respectively abutted against the mounting seat and the linear Hall sensor.

5. A non-uniform diameter hollow shaft inner hole defect detection device according to claim 4, characterized in that, The mounting seat and the two support columns are in interference connection.

6. The non-uniform diameter hollow shaft inner hole defect detection device according to claim 4, characterized in that The elastic member is a spring.

7. A non-uniform diameter hollow shaft inner hole defect detection device according to claim 1, characterized in that, The linear Hall sensor is installed on the robotic arm through a mounting tube, and the mounting tube is a hollow structure.

8. A non-equal-diameter hollow shaft inner hole defect detection device according to claim 7, characterized in that, One end of the mounting tube has mounting holes, and there are two mounting holes, which are symmetrically arranged on the outer wall of one end of the mounting tube.

9. The non-uniform diameter hollow shaft inner hole defect detection device according to claim 8, characterized in that, The linear Hall sensor has a mounting portion, and a receiving hole is opened on the mounting portion. The mounting tube is inserted into the receiving hole. A fixing hole is opened on the mounting portion. When the mounting tube is inserted into the receiving hole, the fixing hole and the mounting hole are aligned and communicated with each other, and an external plug-in member is sequentially inserted into the fixing hole and the mounting hole.

10. A non-uniform diameter hollow shaft inner hole defect detection device according to claim 9, characterized in that, One end of the robotic arm close to the mounting tube has a fixed shaft sleeve, and the fixed shaft sleeve is detachably installed on the robotic arm, and the mounting tube is inserted on the fixed shaft sleeve.

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