Bolt detection method, device and equipment based on pulse reflection ultrasound

Abstract

The invention provides a bolt detection method, device and equipment based on pulse reflection ultrasound. The method comprises the steps that a bolt test block is manufactured, the bolt test block is provided with a plurality of preset cutting grooves, and the placement angle of a target detector is determined based on the bolt detection range; detecting the preset cutting groove based on the placement angle to obtain the flaw detection sensitivity of the bolt test block; the flaw detection sensitivity is a correlation curve of the ultrasonic reflection signal and time, the ultrasonic reflection signal of the preset cutting groove changes suddenly, a first change trend of the flaw detection sensitivity is determined according to the sudden change amplitude of the ultrasonic reflection signal of the preset cutting groove scanned by the target detector in sequence, and the to-be-detected bolt is detected based on the target detector; and comparing the obtained actually measured wave band with the flaw detection sensitivity, and determining the detection result of the to-be-detected bolt. The pulse reflection ultrasound-based bolt detection method, device and equipment provided by the invention are used for accurately and reliably detecting bolts.

Description

Technical Field

[0001] The present application relates to the field of ultrasonic testing technology, and in particular to a bolt testing method, device and equipment based on pulse reflection ultrasound. Background Art

[0002] Bolts are important fasteners in pressure-bearing equipment and are widely used. In pressure piping systems and fixed pressure vessels, a large number of bolts are used as fasteners, such as the connection between the pipe box and the shell of a large heat exchanger, the connection between the manhole cover and the seat ring of a large container, and the connection between the container pipe and the pressure pipe, etc., all of which play an important connecting role. Therefore, once fatigue cracks or breaks occur in the bolts, it will cause danger or disaster in the factory.

[0003] The existing bolt detection method relies on magnetic particle detection, penetration testing and other detection technologies after removing the bolts. After cleaning the studs one by one, check their damage and cracks, focus on checking whether there are circumferential cracks in the threads and transition parts, and perform non-destructive testing when necessary. This method is cumbersome, and in the process of removing and installing bolts, if the operation is improper, a gap will be generated between the bolts and the bolt holes, which will increase the probability of damage during use, resulting in a reduced service life and even threatening the safe operation of pressure-bearing equipment. During the removal of the bolts, the threads that need to be tested by magnetic particles and penetration have the problem that the roots are difficult to clean, and the rust in the grooves is also difficult to remove and will have a great impact on the detection. In the process of removing bolts from large equipment, certain high-altitude operations will occur, threatening personal safety. In addition, the process of removing bolts for detection requires the factory to stop production, and the number of bolts is large, which will lead to a long detection time and affect the company's benefits. It cannot meet the requirements for bolt detection in actual production. Summary of the invention

[0004] In view of this, the present application provides a bolt detection method, device and equipment based on pulse reflection ultrasound to accurately and reliably detect bolts.

[0005] Specifically, the present application is implemented through the following technical solutions:

[0006] In a first aspect, the present application provides a bolt detection method based on pulse reflection ultrasound, the method comprising:

[0007] Making a bolt test block, wherein the bolt test block is provided with a plurality of preset grooves, each of the preset grooves being non-parallel to a side wall of the bolt test block;

[0008] The placement angle of the target detector is determined based on the bolt detection range; the target detector has a longitudinal wave oblique probe, the oblique probe and the center line of the target detector form a first angle, the first angle is less than or equal to 10°, the placement angle is the angle between the center line of the target detector and the side wall of the bolt, at the placement angle, the longitudinal wave reflection intensity emitted by the target detector is the maximum;

[0009] The preset groove is detected based on the placement angle to obtain the flaw detection sensitivity of the bolt test block; the flaw detection sensitivity is a correlation curve between the ultrasonic reflection signal and time, the ultrasonic reflection signal of the preset groove undergoes a sudden change, and a first change trend of the flaw detection sensitivity is determined according to the sudden change amplitude of the ultrasonic reflection signal of the preset groove sequentially scanned by the target detector, and the flaw detection sensitivity is generated according to the first change trend;

[0010] Based on the target detector detecting the bolt to be tested, the obtained measured wave band is compared with the flaw detection sensitivity to determine the detection result of the bolt to be tested.

[0011] The second aspect of the present application provides a bolt detection device based on pulse reflection ultrasound, the device comprising a manufacturing module, a determination module, an acquisition module and a detection module; wherein,

[0012] The manufacturing module is used to manufacture a bolt test block, wherein the bolt test block is provided with a plurality of preset grooves, and each of the preset grooves is not parallel to a side wall of the bolt test block;

[0013] The determination module is used to determine the placement angle of the target detector based on the bolt detection range; the target detector has a longitudinal wave oblique probe, the oblique probe and the center line of the target detector form a first angle, the first angle is less than or equal to 10°, the placement angle is the angle between the center line of the target detector and the side wall of the bolt, at the placement angle, the longitudinal wave reflection intensity emitted by the target detector is the maximum;

[0014] The acquisition module is used to detect the preset groove based on the placement angle to obtain the flaw detection sensitivity of the bolt test block; the flaw detection sensitivity is a correlation curve between the ultrasonic reflection signal and time, the ultrasonic reflection signal of the preset groove undergoes a sudden change, and a first change trend of the flaw detection sensitivity is determined according to the sudden change amplitude of the ultrasonic reflection signal of the preset groove sequentially scanned by the target detector, and the flaw detection sensitivity is generated according to the first change trend;

[0015] The detection module is used to detect the bolt to be tested based on the target detector, compare the obtained measured wave band with the flaw detection sensitivity, and determine the detection result of the bolt to be tested.

[0016] The third aspect of the present application provides a bolt detection device based on pulse reflection ultrasound, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of any one of the methods provided in the first aspect of the present application are implemented.

[0017] The fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the methods provided in the first aspect of the present application.

[0018] The bolt detection method and device based on pulse reflection ultrasound provided in the present application can complete online detection and flaw detection without disassembling the bolts in the pressure-bearing equipment, avoiding the safety risks, cumbersome operation and problems affecting the normal operation of the equipment caused by disassembling the bolts in the traditional method. Further, when the probe bevel angle is set, the damaged groove in the bolt is usually difficult to be parallel to the bolt surface. Therefore, in order to maximize the reflected signal, the detection capability is improved. If the transverse wave is used for detection, two different reflected waves (transverse wave and longitudinal wave) will be obtained, and the longitudinal wave will interfere with the detection result. The method provided by the present invention sets the bevel angle, and the pure longitudinal wave is used for detection. The reflected wave obtained is also a pure longitudinal wave, without the interference of other reflected waves, and accurate detection results can be obtained. Further, by accurately controlling parameters such as the probe angle, moving speed and gain, the depth and position of the defect can be accurately measured, and the accuracy and reliability of the detection are improved. Further, the sensitivity curve can be directly compared with the measured band without other processing, which can greatly increase the simplicity of detection, that is, the bolt detection can be completed without other operations such as processing and conversion. At the same time, the detection sensitivity is obtained by using a bolt test block with a preset groove of a certain depth and angle to ensure the accuracy of the test results. In this way, the test results of the bolts to be tested can be obtained accurately and reliably by performing online testing on the bolts to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a flow chart of a bolt detection method based on pulse reflection ultrasound according to an exemplary embodiment of the present application;

[0020] Figure 2 A detection schematic diagram of a target detector shown as an exemplary embodiment of the present application;

[0021] Figure 3 A schematic diagram of flaw detection sensitivity shown in an exemplary embodiment of the present application;

[0022] Figure 4 A hardware structure diagram of a bolt detection device based on pulse reflection ultrasound in which the bolt detection device based on pulse reflection ultrasound of the present application is located;

[0023] Figure 5 This is a schematic structural diagram of Embodiment 1 of the bolt detection device based on pulse reflection ultrasound provided in the present application. DETAILED DESCRIPTION

[0024] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0025] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items.

[0026] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0027] The present application provides a bolt detection method, device and equipment based on pulse reflection ultrasound, which are used to accurately and reliably detect bolts.

[0028] Specific embodiments are given below to introduce the technical solution of the present application in detail.

[0029] Figure 1 This is a flowchart of a bolt detection method based on pulse reflection ultrasound, which is an exemplary embodiment of the present application. Figure 1 , the method provided in this embodiment may include:

[0030] S101, manufacturing a bolt test block, wherein the bolt test block is provided with a plurality of preset grooves, and each of the preset grooves is not parallel to a side wall of the bolt test block.

[0031] Specifically, the bolt test block is a test piece used to simulate the real bolt structure in order to conduct non-destructive testing experiments such as ultrasonic testing. It should be noted that the bolt test block has the same size, shape and material as the bolt to be tested, so as to simulate the sound wave propagation and reflection characteristics in the actual testing environment. In specific implementation, a new bolt of the same model as the bolt to be tested can be selected as the bolt test block.

[0032] Furthermore, the preset groove is a groove of a specific depth artificially processed on the bolt test block, which is used to simulate possible defects (such as cracks, fatigue damage, etc.) in the bolt. It should be noted that the specific position and number of the preset grooves are set according to actual needs, and this is not limited in this embodiment. In specific implementation, three preset grooves can be set, and the groove depth is 1.0 mm-3.0 mm.

[0033] It should be noted that the main defect to be detected is the circumferential crack at the root of the thread, so when making the preset groove, it can be made according to the pattern of the circumferential crack at the root of the thread.

[0034] Furthermore, in order to prevent the side wall of the bolt test block from interfering with the preset groove, the preset groove is set to be non-parallel to the side wall. It should be noted that the preset groove that is non-parallel to the side wall can better simulate the circumferential crack at the root of the bolt in the actual scene.

[0035] In specific implementation, in this step, according to the material properties of the bolt to be tested, a suitable bolt test block is selected, and a preset groove is processed on the bolt test block by mechanical processing or wire cutting and other technical means, and then the processed bolt test block is subjected to surface treatment, such as grinding and cleaning, to remove burrs, oil stains and other impurities generated during the processing. Ensure that the surface of the test block is flat and smooth to facilitate subsequent testing operations.

[0036] S102. Determine a placement angle of the target detector based on the bolt detection range; the target detector has a longitudinal wave oblique probe, the oblique probe forms a first angle with the center line of the target detector, the first angle is less than or equal to 10°, and the placement angle is the angle between the center line of the target detector and the side wall of the bolt. At the placement angle, the reflection intensity of the longitudinal wave emitted by the target detector is maximum.

[0037] Specifically, the bolt detection range is the area inside the bolt that can be covered by ultrasonic detection. The bolt detection range refers to the detection target area for effectively detecting defects inside the bolt. In specific implementation, the entire side wall thread of the bolt can be used as the bolt detection range.

[0038] Furthermore, the target detector is a device for ultrasonic detection of bolts, which integrates a longitudinal wave oblique probe and other necessary detection elements, and is capable of transmitting and receiving ultrasonic signals, thereby performing non-destructive detection on the bolts.

[0039] Furthermore, the longitudinal wave oblique probe can be a small-angle longitudinal wave oblique probe of organic glass wedge and transducer (wafer). When it is implemented, a pulse reflection ultrasonic flaw detector of model HS700 can be selected as the target detector. The size of the longitudinal wave oblique probe is 5-7 mm×5-7 mm.

[0040] It should be noted that the specific frequency of the sound wave emitted by the target detector is determined according to actual needs, and is not limited in this embodiment. In specific implementation, the specific frequency of the sound wave emitted by the target detector can be determined according to the depth of the bolt to be detected to prevent the bolt from being completely detected due to excessive frequency. For example, in one embodiment, the specific frequency of the sound wave emitted by the target detector is determined to be 5 MHz.

[0041] Furthermore, the longitudinal wave oblique probe can emit and receive longitudinal waves, and is responsible for converting electrical energy into ultrasonic energy and emitting it, while receiving ultrasonic reflection signals reflected from the inside of the bolt. It should be noted that the longitudinal wave oblique probe emits longitudinal waves to ensure the thread detection of the bolt. If shear wave detection is used, the shear wave will generate a large number of reflected waves on the side wall of the bolt, which will not only fail to detect the thread of the bolt, but also generate a large number of interference signals.

[0042] Furthermore, the first angle refers to the angle between the axis of the sound beam of the longitudinal wave oblique probe and the center line of the target detector. It should be noted that the size of the first angle will affect the propagation path and reflection effect of the ultrasonic wave inside the bolt. In specific implementation, the first angle is used to ensure that the ultrasonic wave can enter the bolt at a suitable angle and be effectively reflected back, thereby improving the accuracy and reliability of the detection. For example, in one embodiment, the first angle is set to be less than or equal to 10°.

[0043] In specific implementation, the target detector with adjusted angle is placed on the surface of the bolt test block, and the detection program is started. The target detector will emit ultrasonic signals into the bolt, and receive the reflected ultrasonic reflection signals for processing and analysis, so as to detect the situation inside the bolt test block.

[0044] Optionally, the frequency of the target detector is 2-10 MHZ, and the placement angle is 5°-8°.

[0045] A specific embodiment is given below to introduce the process of determining the placement angle in detail:

[0046] (1) Obtaining a distance interval between the bolt detection range and the top of the bolt test block, and determining a maximum angle based on the distance interval.

[0047] Specifically, the distance interval is the spatial distance range between the bolt detection range and the top of the bolt test block. The size of this interval determines the initial conditions that need to be considered when the ultrasonic probe emits sound waves.

[0048] In a specific implementation, the maximum angle is a maximum tilt angle determined to ensure that the sound wave can effectively cover the entire bolt detection range.

[0049] (2) Determining a minimum angle based on parameter information of the bolt to be tested; the parameter information at least includes thread parameter information of the bolt to be tested.

[0050] Specifically, the parameter information is all physical dimensions, structural features, material properties and other information related to the bolt test block, including but not limited to the bolt's diameter, length, thread specification, material, thread parameter information and the like.

[0051] In specific implementation, since the target detector detects from the top of the bolt test block to the bottom of the bolt test block, when the detection angle is too small, the sound wave will not be able to reach the thread of the bolt, causing the detection to fail.

[0052] (3) Selecting the placement angle based on the minimum angle and the maximum angle.

[0053] During specific implementation, the constraints of the maximum angle and the minimum angle, as well as the actual needs and effects of the detection are comprehensively considered, and a suitable angle is selected as the placement angle.

[0054] The pulse reflection ultrasound-based bolt detection method provided in this embodiment can ensure that the ultrasonic wave can effectively cover the detection range of the entire bolt by determining the maximum angle, avoiding missing areas, thereby improving the reliability of detection. Furthermore, when determining the minimum angle, the thread parameter information of the bolt is taken into account, which can avoid missing the thread by the sound wave during the detection process. In this way, the placement angle is determined by the maximum angle and the minimum angle, which ensures the reliability and accuracy of the bolt inspection.

[0055] Furthermore, by testing probes at different placement angles and comparing the height difference between the artificial defect reflection wave and the thread root reflection wave, the longitudinal wave oblique probe with a suitable angle was screened out. The results are shown in Table 1. Table 1 shows the detection range of oblique probes with different small angles:

[0056] Table 1

[0057]

[0058] Please continue to refer to Table 1. According to Table 1, it can be determined that among the three placement angles, the actual detection range of 6° is the largest.

[0059] Figure 2 This is a detection diagram of a target detector shown in an exemplary embodiment of the present application. Figure 2 , the target detector detects the threads of the bolts at three positions H1, H2, and H3 at a placement angle.

[0060] S103, detecting the preset groove based on the placement angle to obtain the flaw detection sensitivity of the bolt test block; the flaw detection sensitivity is a correlation curve between the ultrasonic reflection signal and time, the ultrasonic reflection signal of the preset groove undergoes a sudden change, and the first change trend of the flaw detection sensitivity is determined according to the sudden change amplitude of the ultrasonic reflection signal of the preset groove scanned sequentially by the target detector, and the flaw detection sensitivity is generated according to the first change trend.

[0061] Specifically, when the ultrasonic waves emitted by the target detector encounter different media (such as bolt materials and defects), reflection, refraction and other phenomena will occur. These reflected ultrasonic reflection signals are received by the probe and converted into electrical signals for processing and analysis to determine whether there are defects inside the bolt and their location and size.

[0062] Furthermore, the flaw detection sensitivity is the ability of the target detector to detect the minimum defect size or reflection signal strength. In specific implementation, the flaw detection sensitivity can be expressed by the correlation curve between the ultrasonic reflection signal and time. The flaw detection sensitivity curve reflects the reflection of defects at different depths or positions to the ultrasonic wave.

[0063] It should be noted that in the flaw detection sensitivity, the horizontal axis is the time that the ultrasonic wave travels, which can be understood as the detection depth; the vertical axis is the size of the reflected wave. When the bolt has a defect, the wave height of the ultrasonic reflection signal is higher. If there is no defect, the ultrasonic reflection signal is only the reflection wave of the thread. The reflection wave of the thread gradually decreases from high to low, and there is a tip at the lowest point. If there is a crack in the middle of the bolt, when the ultrasonic reflection signal gradually decreases, one end will suddenly be very high. At the same time, the signal behind the crack will be blocked by the crack, and no ultrasonic reflection signal can be generated.

[0064] Furthermore, on a bolt test block with a preset groove, the trend of the time and amplitude of the sudden change of the ultrasonic reflection signal when scanning the preset groove is the first change trend, which reflects the propagation characteristics of the ultrasonic wave in the bolt material. When encountering a defect (such as a preset groove), the reflection signal will mutate, so that the location and size of the defect can be determined by analyzing these mutations, and then the sensitivity of the flaw detection can be determined.

[0065] A specific embodiment is given below to introduce the process of obtaining the flaw detection sensitivity in detail:

[0066] The first groove is detected based on the placement angle, the horizontal coordinate of the first groove is determined according to the detection time of the first groove, the vertical coordinate of the first groove is determined according to the sudden change amplitude value of the ultrasonic reflection signal of the first groove, the coordinate of the groove detected later is determined according to the vertical coordinate of the first groove, and each groove is connected in sequence to obtain the flaw detection sensitivity.

[0067] Another specific embodiment is given below to introduce the process of obtaining the flaw detection sensitivity in detail:

[0068] (1) Arranging the target detector according to the placement angle.

[0069] In specific implementation, the target detector is placed on the top of the bolt test block according to the preset placement angle, ensuring that the probe is in close contact with the bolt surface and applying a proper amount of coupling agent to reduce the attenuation and interference of the sound waves.

[0070] (2) Moving the target detector at a first speed.

[0071] Specifically, the first speed is the speed at which the target detector moves during the ultrasonic detection process. The first speed can ensure that the target detector can scan the bolt test block evenly and stably, thereby capturing the reflection signals of all preset grooves. It should be noted that the specific value of the first speed is pre-set according to actual needs and is not limited in this embodiment.

[0072] A specific embodiment is given below to introduce the process of obtaining the first speed in detail:

[0073] (1) Determining the echo time based on the detection parameters of the target detector.

[0074] Specifically, before performing ultrasonic testing, various detection parameters of the target detector need to be determined first.

[0075] In specific implementation, the time of sending ultrasonic waves to the bolt to be tested and receiving echo signals, i.e., echo time, is determined by detection parameters. This time reflects the propagation distance and speed of ultrasonic waves inside the bolt.

[0076] (2) A maximum moving speed is generated based on the echo time, and the target detector moves at a first speed for detection according to the placement angle, and the first speed is less than the maximum moving speed.

[0077] In specific implementation, the first speed can be set to be much smaller than the speed from the pulse signal being transmitted to the receiving speed. In this way, the first speed is prevented from being too fast and failing to receive the returned data of the pulse signal. For example, in one embodiment, the first speed can be set to 150 mm / s. For another example, in another embodiment, the first speed can be set to 100-150 mm / s.

[0078] The pulse reflection ultrasound-based bolt detection method provided in this embodiment uses the maximum moving speed calculated by the echo time to limit the moving speed of the probe during the detection process, avoiding the detection blind area or missed detection caused by moving too fast, and further improving the detection accuracy. Furthermore, under the premise of ensuring the detection accuracy, by reasonably setting the first speed of the probe, the detection time can be shortened and the detection efficiency can be improved.

[0079] (3) Detecting the ultrasonic reflection signal in the bolt test block and locating the reflected waves at the positions of the plurality of preset grooves.

[0080] Specifically, during the movement of the target detector, the ultrasonic probe emits ultrasonic waves and receives ultrasonic reflection signals. These ultrasonic reflection signals are processed in real time by the oscilloscope and converted into recognizable waveforms to be displayed on the oscilloscope screen. By analyzing these waveforms, the preset groove position and size inside the bolt test block can be preliminarily determined.

[0081] In specific implementation, the position where the waveform suddenly changes can be determined as the position where the preset groove is detected.

[0082] (4) Determining the display position of the subsequent preset groove in the coordinate axis based on the amplitude of the ultrasonic reflection signal corresponding to the first preset groove.

[0083] Specifically, the reflected wave of each preset groove is positioned in the coordinate axis.

[0084] In specific implementation, the reflection amplitude value of the first preset groove is used as the reference point to obtain the process of adjusting the reflection amplitude value of the first preset groove, and the reflection amplitude values ​​of all subsequent preset grooves are adjusted through the same adjustment process to determine the display position of all ultrasonic reflection signals in the coordinate axis.

[0085] A specific embodiment is given below to introduce in detail the process of determining the display position of the ultrasonic reflection signal:

[0086] Step 1: Determine the vertical axis of the coordinate axis based on the maximum display range of the display position, determine the horizontal axis of the coordinate axis based on the time of receiving the ultrasonic reflection signal, and construct the coordinate system.

[0087] Specifically, the maximum display range is the maximum signal strength range that the oscilloscope can display. This range is usually fixed and is used to standardize and compare the strength of different reflected signals.

[0088] Furthermore, when constructing the coordinate system, the maximum display range is used as the maximum value of the vertical axis. In specific implementation, since the display range of the oscilloscope is displayed as the wave height of the ultrasonic reflection signal, the vertical axis of the coordinate system is also the wave height of the ultrasonic reflection signal.

[0089] Furthermore, the time required for the ultrasonic wave to be emitted, reflected and returned to the probe is an important basis for determining the defect location. In specific implementation, when constructing the coordinate system, the time point of receiving the ultrasonic reflection signal is used as the horizontal axis reference of the coordinate axis to represent the depth of the defect in the bolt test block.

[0090] Step 2: Determine a gain supplement value based on the amplitude of the ultrasonic reflection signal corresponding to the first preset groove; the gain supplement value is the proportion that needs to be adjusted to adjust the ultrasonic reflection signal corresponding to the first preset groove to the preset value of the maximum display range.

[0091] Specifically, the specific value of the preset value is set according to actual needs, and is not limited in this embodiment. In specific implementation, for example, in one embodiment, the ultrasonic reflection signal corresponding to the first preset groove can be adjusted to 90% of the maximum display range. For another example, in another embodiment, the ultrasonic reflection signal corresponding to the first preset groove can be adjusted to 60-80% of the maximum display range.

[0092] In specific implementation, in this step, the amplitude of the ultrasonic reflection signal corresponding to the first preset groove is automatically gained to a preset value, and the gain amount to be increased or decreased is recorded to adjust the amplitude of the ultrasonic reflection signals of all other preset grooves according to this gain amount so as to be uniformly represented in the coordinate system.

[0093] Step three: Based on the gain supplement value, adjust the ultrasonic reflection signal corresponding to the subsequent preset groove to generate the display positions of all the preset grooves in the coordinate axis.

[0094] Specifically, the gain value corresponding to the first preset groove is used to adjust the amplitude of the ultrasonic reflection signal corresponding to the subsequent preset grooves.

[0095] Furthermore, the adjusted ultrasonic reflection signal amplitudes are mapped onto the vertical axis of the coordinate system, and their positions on the horizontal axis are determined based on the time when these reflection signals are received, thereby generating display positions of all preset grooves in the coordinate axis.

[0096] The pulse reflection ultrasound-based bolt detection method provided in this embodiment constructs a coordinate system and determines the vertical and horizontal axes, so that the ultrasonic reflection signals of all preset grooves can be represented and compared within a unified framework, which helps to standardize the detection process and improve the accuracy and repeatability of the detection results. Furthermore, by adjusting the gain supplement value, it is ensured that the reflection signal of the first preset groove can reach the preset display intensity on the display, which provides a reference benchmark for subsequent defect detection and helps to improve the detection sensitivity. In this way, through a unified processing and representation method, the influence of other factors on the detection results is reduced, making the display position more complete and reliable.

[0097] (5) Connecting the displayed positions of the preset grooves in the coordinate axis to obtain the flaw detection sensitivity.

[0098] In specific implementation, the display positions of each preset groove in the coordinate axis are connected with a smooth curve to obtain the flaw detection sensitivity. It should be noted that the flaw detection sensitivity curve reflects the reflection of the preset grooves of different depths or positions to the ultrasonic wave, which is an important basis for evaluating the bolt condition.

[0099] Figure 3 This is a schematic diagram of the flaw detection sensitivity of an exemplary embodiment of the present application. Figure 3 The bolt test block has three preset slots, and the corresponding three coordinates are obtained by smooth connection. Figure 3 Detection sensitivity shown.

[0100] The pulse reflection ultrasound-based bolt detection method provided in this embodiment performs detection without removing the bolts, thus avoiding damage and safety hazards that may be caused by removing and reinstalling the bolts, and also saving time and labor costs. Furthermore, detection at the first speed can ensure that the probe moves evenly and stably on the bolt test block or the actual bolt surface, thereby more accurately capturing the ultrasonic reflection signal, preventing incomplete signal capture or missing defects, and improving the precision and accuracy of detection. In this way, through the pulse reflection method longitudinal wave ultrasonic detection technology, combined with specific instrument settings and probe angles, it is possible to accurately and quickly locate the preset groove of the bolt test block, obtain the corresponding flaw detection sensitivity, and provide a guarantee for subsequent accurate bolt detection by ensuring the accuracy and reliability of the flaw detection sensitivity.

[0101] S104, detecting the bolt to be tested based on the target detector, comparing the obtained measured wave band with the flaw detection sensitivity, and determining the detection result of the bolt to be tested.

[0102] Specifically, the bolt to be tested refers to the bolt on the pressure-bearing equipment that needs to be non-destructively tested. In specific implementation, the bolt to be tested is the same model as the bolt test block, and the diameter of the bolt to be tested is usually greater than or equal to 36 mm.

[0103] Furthermore, the measured wave band is a wave band formed after the ultrasonic signal reflected from the inside of the bolt is processed when the bolt to be tested is detected by the target detector.

[0104] In specific implementation, place the target detector on the top of the bolt to be tested, ensure that the probe is in close contact with the bolt surface and apply an appropriate amount of coupling agent to reduce the attenuation and interference of the sound wave. The probe is placed on the top of the bolt to be tested, and the probe is swept back and forth in a zigzag shape in the direction of the outer arc, and the measured band is compared with the predetermined flaw detection sensitivity. If the signal strength of the measured band exceeds the flaw detection sensitivity, it means that there is a defect inside the bolt to be tested, and further analysis and confirmation of the location, size, shape and other information of the defect are required. If the signal strength of the measured band does not exceed the flaw detection sensitivity, it means that no obvious defects are found inside the bolt to be tested, and it can be considered to be in good condition.

[0105] A specific embodiment is given below to introduce the process of obtaining the detection result in detail:

[0106] (1) Determine the horizontal coordinate of the measured waveband on the coordinate axis based on the detection position and detection direction of the target detector.

[0107] Specifically, the detection position refers to the specific position of the probe of the target detector when scanning the top of the bolt to be tested. It should be noted that the detection position determines the specific point where the ultrasonic wave is incident on the inside of the bolt.

[0108] Furthermore, the detection direction refers to the direction in which the probe of the target detector moves on the end face of the bolt. It should be noted that this direction determines the propagation path and reflection path of the ultrasonic wave inside the bolt. In specific implementation, the direction of the target detector can be determined according to the placement angle, and then determined as the detection direction.

[0109] In a specific implementation, the horizontal coordinate of the coordinate axis corresponding to the detection position and the detection direction can be determined based on the data when the target detector detects the bolt test block.

[0110] (2) Detecting a measured waveband whose ordinate value is greater than the detection sensitivity, and determining a detection result of the bolt to be tested based on the abscissa of the measured waveband, the detection position, and the detection direction.

[0111] Specifically, the peak height of the measured band is compared with the value of the flaw detection sensitivity to determine the numerical values ​​of the two. In specific implementation, when the peak height of the measured band is greater than the flaw detection sensitivity, it is considered that the position of the bolt to be tested corresponding to the measured band has a defect.

[0112] Furthermore, after determining the measured waveband where the defect exists, the depth of the defect is calculated according to the horizontal coordinate, detection position and detection direction of the measured waveband. In specific implementation, the position of the defect is obtained by multiplying the product of the sound speed and the propagation time by the cosine value of the angle through parameters such as the sound speed, propagation time and the angle between the probe and the end face of the bolt. For example, in one embodiment, the depth of the defect is approximately the sound speed (5900 m / s) × the wave propagation time (t) of the oscilloscope screen × cosθ; where θ is the placement angle.

[0113] Furthermore, the damage position on the bolt for testing was prepared by wire cutting technology, and the defects of different depths were detected by using a 6° small angle longitudinal wave probe, and the difference between the measured position and the self-made position was compared (the position is expressed as the distance from the vertical direction of the defect to the end). The results are shown in Table 2, which compares the detection position of the 6° small angle oblique probe with the actual position:

[0114] Table 2

[0115]

[0116] The pulse reflection ultrasound-based bolt detection method provided in this embodiment can accurately locate the position of the internal defects of the bolt by accurately determining the detection position and detection direction of the probe and combining the horizontal coordinate information of the measured waveband. This precise positioning helps to reduce false positives and missed positives and improve the accuracy of detection. Furthermore, the defect depth is determined based on the horizontal coordinate, detection position and detection direction of the measured waveband, taking into account factors such as the speed of sound, propagation time and the angle between the probe and the end face of the bolt, and a more accurate defect depth value can be calculated, providing strong support for subsequent maintenance and replacement work.

[0117] Optionally, determining the detection result of the bolt to be tested includes:

[0118] Determine that the measured waveband is higher than the defect waveband of the flaw detection sensitivity;

[0119] Obtaining the wave transmission time corresponding to the defect band and the cosine value of the placement angle;

[0120] The product of the wave transmission time, the sound velocity and the cosine value is determined as the depth of the defect of the bolt to be tested.

[0121] Specifically, the portion of the measured band that is higher than the flaw detection sensitivity is the location where defects exist in the bolt to be tested, so this measured band can be determined as a defective band.

[0122] Furthermore, the wave propagation time corresponding to the defect band can be determined by the emission time of the defect band and the time of receiving the reflected wave.

[0123] The pulse reflection ultrasonic bolt detection method provided in this embodiment can directly perform nondestructive testing without disassembling the large-diameter bolts on the pressure-bearing equipment, greatly reducing the workload during the detection process and avoiding equipment downtime and production losses caused by disassembling and installing bolts. By adopting the pulse reflection method of longitudinal wave ultrasonic detection, defects inside the bolt, such as cracks, fatigue damage, etc., can be quickly and accurately located. By precisely controlling the moving speed and direction of the probe, combined with the setting of the flaw detection sensitivity, the accuracy and reliability of the detection results can be ensured.

[0124] Corresponding to the aforementioned embodiment of a bolt detection method based on pulse reflection ultrasound, the present application also provides an embodiment of a bolt detection device based on pulse reflection ultrasound.

[0125] The embodiment of a bolt detection device based on pulse reflection ultrasound in the present application can be applied to a bolt detection device based on pulse reflection ultrasound. The device embodiment can be implemented through software, or through hardware or a combination of software and hardware. Taking software implementation as an example, as a device in a logical sense, it is formed by the processor of the bolt detection device based on pulse reflection ultrasound reading the corresponding computer program instructions in the non-volatile memory into the memory and running them. From the hardware level, if Figure 4 As shown, it is a hardware structure diagram of the bolt detection device based on pulse reflection ultrasound in the present application, except Figure 4 In addition to the processor, memory, network interface, and non-volatile memory shown, the pulse reflection ultrasound-based bolt detection device in which the device in the embodiment is located may also include other hardware according to the actual function of the pulse reflection ultrasound-based bolt detection device, which will not be described in detail.

[0126] Figure 5 This is a schematic diagram of the structure of the first embodiment of the bolt detection device based on pulse reflection ultrasound provided by this application. Figure 5 The device provided in this embodiment includes a production module 510, a determination module 520, an acquisition module 530 and a detection module 540; wherein,

[0127] The manufacturing module 510 is used to manufacture a bolt test block, wherein the bolt test block is provided with a plurality of preset grooves, each of which is not parallel to a side wall of the bolt test block;

[0128] The determination module 520 is used to determine the placement angle of the target detector based on the bolt detection range; the target detector has a longitudinal wave oblique probe, the oblique probe and the center line of the target detector form a first angle, the first angle is less than or equal to 10°, the placement angle is the angle between the center line of the target detector and the side wall of the bolt, at the placement angle, the longitudinal wave reflection intensity emitted by the target detector is the maximum;

[0129] The acquisition module 530 is used to detect the preset groove based on the placement angle to obtain the flaw detection sensitivity of the bolt test block; the flaw detection sensitivity is a correlation curve between the ultrasonic reflection signal and time, the ultrasonic reflection signal of the preset groove undergoes a sudden change, and a first change trend of the flaw detection sensitivity is determined according to the sudden change amplitude of the ultrasonic reflection signal of the preset groove sequentially scanned by the target detector, and the flaw detection sensitivity is generated according to the first change trend;

[0130] The detection module 540 is used to detect the bolt to be tested based on the target detector, compare the obtained measured wave band with the flaw detection sensitivity, and determine the detection result of the bolt to be tested.

[0131] The device of this embodiment can be used to perform Figure 1 The steps, specific implementation principles and implementation processes of the method embodiment shown are similar and will not be repeated here.

[0132] Optionally, the acquisition module 530 is specifically configured to arrange the target detector according to the placement angle;

[0133] The acquisition module 530 is further specifically configured to move the target detector at a first speed;

[0134] The acquisition module 530 is further specifically used to detect the ultrasonic reflection signal in the bolt test block and locate the reflection wave at the positions of the plurality of preset grooves;

[0135] The acquisition module 530 is further specifically used to determine the display position of the subsequent preset groove in the coordinate axis based on the amplitude of the ultrasonic reflection signal corresponding to the first preset groove;

[0136] The acquisition module 530 is further specifically used to connect the display positions of each of the preset grooves in the coordinate axis to obtain the flaw detection sensitivity.

[0137] Optionally, the acquisition module 530 is further specifically configured to determine the vertical axis of the coordinate axis based on the maximum display range of the display position, determine the horizontal axis of the coordinate axis based on the time of receiving the ultrasonic reflection signal, and construct the coordinate system;

[0138] The acquisition module 530 is further specifically used to determine a gain supplement value based on the amplitude of the ultrasonic reflection signal corresponding to the first preset groove; the gain supplement value is the ratio of the ultrasonic reflection signal corresponding to the first preset groove to be adjusted to the preset value of the maximum display range;

[0139] The acquisition module 530 is further specifically configured to generate the display positions of all the preset grooves in the coordinate axis based on the ultrasonic reflection signal corresponding to the preset groove adjusted by the gain supplement value.

[0140] Optionally, the determination module 520 is specifically configured to obtain a distance interval between the bolt detection range and the top of the bolt test block, and determine a maximum angle based on the distance interval;

[0141] The determination module 520 is further specifically configured to determine the minimum angle based on parameter information of the bolt to be tested; the parameter information at least includes thread parameter information of the bolt to be tested;

[0142] The determination module 520 is further specifically configured to select the placement angle based on the minimum angle and the maximum angle.

[0143] Optionally, the detection module 540 is specifically configured to determine the horizontal coordinate of the measured waveband located on the coordinate axis based on the detection position and detection direction of the target detector;

[0144] The detection module 540 is further specifically used to detect a measured band whose ordinate value is greater than the flaw detection sensitivity, and determine the detection result of the bolt to be tested based on the abscissa of the measured band, the detection position and the detection direction.

[0145] Optionally, the detection module 540 is further specifically configured to determine the echo time based on the detection parameters of the target detector;

[0146] The detection module 540 is further specifically configured to generate a maximum moving speed based on the echo time, and the target detector moves at a first speed for detection according to the placement angle, and the first speed is less than the maximum moving speed.

[0147] Optionally, the frequency of the target detector is 2-10 MHZ, and the placement angle is 5°-8°.

[0148] Please continue to refer to Figure 4The present application also provides a bolt detection device based on pulse reflection ultrasound, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of any one of the methods provided in the first aspect of the present application are implemented.

[0149] The present application also provides a computer-readable storage medium having a computer program stored thereon, and when the program is executed by a processor, the steps of any one of the methods provided in the present application are implemented.

[0150] The implementation process of the functions and effects of each unit in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, and will not be repeated here.

[0151] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0152] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A bolt detection method based on pulse reflection ultrasound, characterized in that: The method comprises: Making a bolt test block, wherein the bolt test block is provided with a plurality of preset grooves, each of the preset grooves being non-parallel to a side wall of the bolt test block; The placement angle of the target detector is determined based on the bolt detection range; the target detector has a longitudinal wave oblique probe, the oblique probe and the center line of the target detector form a first angle, the first angle is less than or equal to 10°, the placement angle is the angle between the center line of the target detector and the side wall of the bolt, at the placement angle, the longitudinal wave reflection intensity emitted by the target detector is the maximum; The preset groove is detected based on the placement angle to obtain the flaw detection sensitivity of the bolt test block; the flaw detection sensitivity is a correlation curve between the ultrasonic reflection signal and time, the ultrasonic reflection signal of the preset groove undergoes a sudden change, and a first change trend of the flaw detection sensitivity is determined according to the sudden change amplitude of the ultrasonic reflection signal of the preset groove sequentially scanned by the target detector, and the flaw detection sensitivity is generated according to the first change trend; Based on the target detector detecting the bolt to be tested, the obtained measured wave band is compared with the flaw detection sensitivity to determine the detection result of the bolt to be tested.

2. The method according to claim 1, characterized in that The detecting the preset cut groove based on the placement angle to obtain the flaw detection sensitivity of the bolt test block includes: The first groove is detected based on the placement angle, the horizontal coordinate of the first groove is determined according to the detection time of the first groove, the vertical coordinate of the first groove is determined according to the sudden change amplitude value of the ultrasonic reflection signal of the first groove, the coordinate of the groove detected later is determined according to the vertical coordinate of the first groove, and each groove is connected in sequence to obtain the flaw detection sensitivity.

3. The method according to claim 1, characterized in that The detecting the preset cut groove based on the placement angle to obtain the flaw detection sensitivity of the bolt test block includes: Arranging the target detector according to the placement angle; moving the target detector at a first speed; Detecting the ultrasonic reflection signal in the bolt test block and locating the reflection waves at the positions of the plurality of preset grooves; Determining the display position of the subsequent preset groove in the coordinate axis based on the amplitude of the ultrasonic reflection signal corresponding to the first preset groove; The display positions of the preset grooves in the coordinate axis are connected to obtain the flaw detection sensitivity.

4. The method according to claim 3, characterized in that The step of determining the display position of the subsequent preset groove in the coordinate axis based on the amplitude of the reflected wave of the first preset groove comprises: Determine the vertical axis of the coordinate axis based on the maximum display range of the display position, determine the horizontal axis of the coordinate axis based on the time of receiving the ultrasonic reflection signal, and construct a coordinate system; Determine a gain supplement value based on the amplitude of the ultrasonic reflection signal corresponding to the first preset groove; the gain supplement value is the ratio of the ultrasonic reflection signal corresponding to the first preset groove to be adjusted to the preset value of the maximum display range; Based on the ultrasonic reflection signal corresponding to the preset groove after the gain supplement value adjustment, the display positions of all the preset grooves in the coordinate axis are generated.

5. The method according to claim 1, characterized in that The step of determining the placement angle of the target detector based on the bolt detection range includes: Obtaining a distance interval between the bolt detection range and the top of the bolt test block, and determining a maximum angle based on the distance interval; Determine the minimum angle based on parameter information of the bolt to be tested; the parameter information at least includes thread parameter information of the bolt to be tested; The placement angle is selected based on the minimum angle and the maximum angle.

6. The method according to claim 1, characterized in that The method of detecting the bolt to be tested based on the target detector, comparing the obtained measured wave band with the flaw detection sensitivity, and determining the detection result of the bolt to be tested includes: Determine the horizontal coordinate of the measured waveband on the coordinate axis based on the detection position and detection direction of the target detector; A measured waveband whose ordinate value is greater than the flaw detection sensitivity is determined, and a detection result of the bolt to be tested is determined based on the abscissa of the measured waveband, the detection position and the detection direction.

7. The method according to claim 1, characterized in that Determining the detection result of the bolt to be tested includes: Determine a defect band where the measured waveband is higher than the flaw detection sensitivity; Obtaining the wave transmission time corresponding to the defect band and the cosine value of the placement angle; The product of the wave transmission time, the sound velocity and the cosine value is determined as the depth of the defect of the bolt to be tested.

8. The method according to claim 1, characterized in that The detecting the bolt to be tested based on the target detector comprises: determining an echo time based on detection parameters of the target detector; A maximum moving speed is generated based on the echo time, and the target detector moves at a first speed for detection according to the placement angle, where the first speed is less than the maximum moving speed.

9. The method according to claim 1, characterized in that: The frequency of the target detector is 2-10 MHZ, and the placement angle is 5°-8°.

10. A bolt detection device based on pulse reflection ultrasound, characterized in that: The device includes a production module, a determination module, an acquisition module and a detection module; wherein, The manufacturing module is used to manufacture a bolt test block, wherein the bolt test block is provided with a plurality of preset grooves, and each of the preset grooves is not parallel to a side wall of the bolt test block; The determination module is used to determine the placement angle of the target detector based on the bolt detection range; the target detector has a longitudinal wave oblique probe, the oblique probe and the center line of the target detector form a first angle, the first angle is less than or equal to 10°, the placement angle is the angle between the center line of the target detector and the side wall of the bolt, at the placement angle, the longitudinal wave reflection intensity emitted by the target detector is the maximum; The acquisition module is used to detect the preset groove based on the placement angle to obtain the flaw detection sensitivity of the bolt test block; the flaw detection sensitivity is a correlation curve between the ultrasonic reflection signal and time, the ultrasonic reflection signal of the preset groove undergoes a sudden change, and a first change trend of the flaw detection sensitivity is determined according to the sudden change amplitude of the ultrasonic reflection signal of the preset groove sequentially scanned by the target detector, and the flaw detection sensitivity is generated according to the first change trend; The detection module is used to detect the bolt to be tested based on the target detector, compare the obtained measured wave band with the flaw detection sensitivity, and determine the detection result of the bolt to be tested.

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