A liquid immersion automatic ultrasonic testing system for small diameter metal rods

Abstract

The utility model discloses a kind of liquid immersion automatic ultrasonic detection systems of small diameter metal bar, it is related to metal bar ultrasonic detection technical field, the ultrasonic detection system includes: detection water tank, for carrying the liquid of submerged detection workpiece;Supporting mechanism is set in detection water tank, supporting mechanism includes supporting indexing drive part, shaft and nylon cover, the output end of supporting indexing drive part is connected with shaft in transmission, shaft is set in pairs, the rotation direction of the shaft set in pairs is same, shaft is fixedly provided with nylon cover, detection workpiece is horizontally placed on nylon cover;Ultrasonic detector, with electrically connected with probe, probe is set above detection workpiece, probe is used for scanning detection detection workpiece;Space coordinate displacement mechanism is set on detection water tank, the output end of space coordinate displacement mechanism is provided with probe, and space coordinate displacement mechanism is used for adjusting the space coordinate position of probe;The ultrasonic detection system can realize the automatic flaw detection of bar.

Description

Technical Field

[0001] This utility model belongs to the field of ultrasonic testing technology for metal rods, specifically relating to an automatic ultrasonic testing system for small-diameter metal rods through liquid immersion. Background Technology

[0002] After the raw material bar supplier delivers the products, the bars need to undergo ultrasonic testing for re-inspection at the factory. If the test is passed, the bars are then threaded (for example, to produce double-ended studs made of 20Cr13 steel). Therefore, the bars returned to the factory are processed to a shorter length, ranging from 200mm to 300mm, and the diameter is also smaller (Ф18mm). Each batch inspection involves approximately 500 pieces. This presents difficulties for the equipment manufacturer in inspecting the dimensions and quantity of the existing raw materials.

[0003] Therefore, traditional testing methods often employ ultrasonic testing, which should be implemented and accepted according to the requirements of the NB / T20003.2-2010 standard. However, there are many problems with using conventional manual contact methods for ultrasonic testing of bars of this diameter and quantity. The main problem is that the application of coupling agent and the movement of the probe on the coupling agent cause continuous changes in the thickness of the coupling agent (especially serious for probes used for testing thinner materials), resulting in unstable display waveforms that are difficult to determine whether they indicate defects. In this case, it is necessary to manually and repeatedly confirm the position of the unstable waveform, which slows down the testing speed and increases the risk of missed defects. In addition, the stability of the entire manual testing system is not high, as it is difficult to manually control the movement speed of the probe and the rotation range of the workpiece during testing, making it impossible to determine whether 100% testing has been performed. Therefore, the testing of bars of this size and quantity is not suitable for conventional manual contact methods; targeted, specific ultrasonic testing methods are required. Utility Model Content

[0004] The purpose of this invention is to provide an automatic ultrasonic testing system for small-diameter metal rods with a simple structure and reasonable design in order to solve the above problems.

[0005] This utility model achieves the above objectives through the following technical solutions:

[0006] An automated ultrasonic testing system for liquid immersion of small-diameter metal rods includes:

[0007] The testing water tank is used to hold the liquid that immerses the workpiece under testing.

[0008] The support mechanism is installed in the testing water tank. The support mechanism includes a support indexing drive, a rotating shaft and a nylon sleeve. The output end of the support indexing drive is connected to the rotating shaft. The rotating shafts are arranged in pairs and rotate in the same direction. A nylon sleeve is fixedly installed on the rotating shaft. The test workpiece is horizontally placed on the nylon sleeve.

[0009] An ultrasonic testing instrument, electrically connected to a probe, which is positioned above the workpiece to be tested and is used to scan and test the workpiece.

[0010] A spatial coordinate shifting mechanism is installed on the detection water tank. A probe is installed at the output end of the spatial coordinate shifting mechanism, which is used to adjust the spatial coordinate position of the probe.

[0011] As a further optimization of this utility model, the plurality of nylon sleeves are evenly distributed along the axial direction of the rotating shaft, and the distance between the nylon sleeves at both ends of the rotating shaft matches the maximum scanning stroke of the probe.

[0012] As a further optimization of this utility model, the supporting indexing drive component includes a synchronous transmission belt, a driving transmission wheel, a driven transmission wheel, and an indexing motor. The output end of the indexing motor is connected to the driving transmission wheel, and the input end of the rotating shaft is fixedly connected to the driven transmission wheel. The synchronous transmission belt is sleeved on the driving transmission wheel and the driven transmission wheel.

[0013] As a further optimization of this utility model, the spatial coordinate shifting mechanism includes an X-axis adjustment module, a slide block, and a Z-axis adjustment module. The output end of the X-axis adjustment module is drivenly connected to the slide block, and the X-axis adjustment module is used to adjust the axial displacement of the slide block along the rotating shaft. The slide block is provided with a Z-axis adjustment module, and the output end of the Z-axis adjustment module is drivenly connected to a probe. The Z-axis adjustment module is used to adjust the distance between the probe and the detection surface of the workpiece.

[0014] As a further optimization of this utility model, the output end of the Z-axis adjustment module is also provided with a probe adjustment module. The output end of the probe adjustment module is provided with a probe. The probe adjustment module is used to adjust the displacement of the probe in the clearance direction, wherein the clearance direction is perpendicular to the vertical direction and the axial direction of the rotating shaft.

[0015] As a further optimization of this utility model, the probe adjustment module includes a rotation frame and a rotation drive component. The rotation drive component is located at the output end of the Z-axis adjustment module, and the output end of the rotation drive component is connected to the rotation frame. The probe is arranged on the side of the rotation frame facing the detection water tank.

[0016] As a further optimization of this utility model, the X-axis adjustment module includes an X-axis adjustment motor, a slide rail, and a lead screw. The output end of the X-axis adjustment motor is connected to the lead screw, and both ends of the lead screw are rotatably mounted on the slide rail. The lead screw is threadedly connected to a slide block, and the slide block is slidably connected to the slide rail.

[0017] As a further optimization of this utility model, the liquid immersion automatic ultrasonic testing system also includes an electrical control box, on which a touch screen is installed.

[0018] As a further optimization of this utility model, a safety monitoring mechanism is also provided on one side of the electrical control box. The safety monitoring mechanism includes an emergency stop device and an instrument alarm device. The emergency stop device is used to switch the system from automatic adjustment state to manual adjustment state.

[0019] As a further optimization of this utility model, the water tank is fixedly mounted on the frame, and the lower end of the frame is provided with adjusting casters.

[0020] This utility model has at least the following beneficial effects: The automatic ultrasonic testing system for small-diameter metal rods disclosed in this utility model, by setting a support mechanism in the testing water tank, includes a support and rotation drive, a rotating shaft and a nylon sleeve. The rotating shafts in pairs drive their respective nylon sleeves to rotate in the same direction, so as to realize the uniform rotation of the test workpiece of the rod held on the nylon sleeve. Furthermore, the spatial coordinate position of the probe is adjusted by a spatial coordinate shifting mechanism to realize the probe moves at a uniform speed along the axis of the rotating shaft, so as to perform a comprehensive automatic scanning and detection of the surface of the test workpiece immersed in the liquid. The detection results are then displayed graphically by an ultrasonic testing instrument. This avoids the problems in the prior art where the uniformity of the coupling agent coating causes the coupling agent thickness to change continuously, and the accumulation of coupling agent around the probe when the probe moves during the detection process. These two situations cause the waveform display of false defect signals on the instrument's oscilloscope screen. It also solves the problem of the influence of human subjective factors on the detection results introduced by manually operating the focusing probe to adjust the moving speed and coverage scanning. In other words, it improves the detection sensitivity and facilitates the control of the moving speed.

[0021] Moreover, multiple nylon sleeves on the rotating shaft are evenly distributed along the axial direction of the rotating shaft, and the distance between the nylon sleeves at both ends of the rotating shaft matches the maximum scanning stroke of the probe. Thus, when the probe moves along the axial direction of the rotating shaft, the ultrasonic testing instrument will also simultaneously acquire the displacement of the probe. After the detection is completed, the staff can find the adjacent nylon sleeves according to the defect coordinate position displayed by the ultrasonic testing instrument to locate the position range of the defect on the workpiece and realize the positioning and marking function of the defect.

[0022] Furthermore, when shifting the probe's spatial coordinates using a spatial coordinate shifting mechanism, after determining the probe's vertical position using the Z-axis adjustment module, the probe adjustment module drives the rotation frame to shift the probe horizontally to a position directly above the workpiece's axis. Driven by the X-axis adjustment module, the probe moves at a uniform speed along the workpiece's axis to automatically and comprehensively scan the workpiece's surface. After the inspection is complete, the probe adjustment module drives the rotation frame to turn the probe to one side, facilitating the removal of the inspected workpiece and the placement of a new one. The removal and placement process does not interfere with the probe. Moreover, for the inspection of the same batch of workpieces, there is no need to readjust the Z-axis adjustment module; only the probe adjustment module needs adjustment, thus improving inspection efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model. Figure 1 ;

[0024] Figure 2 This is a schematic diagram of the overall structure of this utility model. Figure 2 ;

[0025] Figure 3 Figure 1 is a schematic diagram of the structure of a traditional test block, wherein (a) is a left view of the traditional test block and (b) is a front view of the traditional test block;

[0026] Figure 4 This is a schematic diagram of the structure of the optimized test block used in this utility model, wherein (c) is a front view of the optimized test block and (d) is a left view of the conventional test block;

[0027] Figure 5 This is the sensitivity calibration diagram for the liquid immersion method of this utility model;

[0028] Figure 6 This is a manual contact method calibration diagram for comparison with this utility model;

[0029] Figure 7 This is a sensitivity confirmation diagram for the liquid immersion method of this utility model.

[0030] In the diagram: 1. Electrical control box; 101. Control box door; 2. Touch screen; 3. Safety monitoring mechanism; 4. Protective cover; 5. Rotary shaft; 51. Synchronous transmission belt; 52. Indexing motor; 6. Nylon sleeve; 7. Workpiece to be inspected; 8. Frame; 9. Adjustable casters; 10. Inspection water tank; 11. Slide rail; 12. Z-axis adjustment module; 13. Probe adjustment module; 14. Ultrasonic testing instrument; 15. Probe; 16. Indexing frame; 17. Lead screw; 18. Slide block; 19. Limit switch; 20. X-axis adjustment motor. Detailed Implementation

[0031] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0032] In one embodiment, such as Figure 1 and Figure 2 As shown, the present invention provides an automatic ultrasonic testing system for liquid immersion of small-diameter metal rods, comprising:

[0033] The test water tank 10 is used to hold the liquid that immerses the test workpiece 7; for example, the liquid is water.

[0034] The support mechanism is installed in the testing water tank 10. The support mechanism includes a support indexing drive, a rotating shaft 5 and a nylon sleeve 6. The output end of the support indexing drive is connected to the rotating shaft 5. The rotating shafts 5 are arranged in pairs and the rotation directions of the paired rotating shafts 5 are the same. The nylon sleeve 6 is fixedly installed on the rotating shaft 5. The testing workpiece 7 is horizontally placed on the nylon sleeve 6.

[0035] An ultrasonic testing instrument 14 is electrically connected to a probe 15, which is positioned above the workpiece 7 and is used to scan and test the workpiece 7.

[0036] A spatial coordinate shifting mechanism is installed on the detection water tank 10. The output end of the spatial coordinate shifting mechanism is equipped with a probe 15. The spatial coordinate shifting mechanism is used to adjust the spatial coordinate position of the probe 15.

[0037] By placing the workpiece 7 into the nylon sleeve 6 in the testing tank 10, making it parallel to the axis of the rotating shaft 5 and immersing it in the liquid, the rotation of the paired rotating shafts 5 causes the nylon sleeves 6 on the two shafts 5 to rotate in the same direction, thus causing the metal rod workpiece 7 to rotate at a uniform speed in one direction. At this time, the spatial coordinate shifting mechanism drives the probe 15 to move spatially above the workpiece 7 and along the extension direction of the workpiece 7 to scan and detect the surface of the workpiece 7. The probe 15 receives the ultrasonic echo signal and converts it into a voltage signal, which is then output to the ultrasonic testing instrument 14. The ultrasonic testing instrument 14 processes the received voltage signal and extracts the signal characteristics, which are then presented on the display of the ultrasonic testing instrument 14 in the form of waveform graphics. The presence of defects in the workpiece 7 can be determined based on the waveform graphics, which will not be elaborated here.

[0038] It should be noted that in existing technologies, probes used for inspecting bars with large curvature and thin walls are all focusing probes. This means that the probe used has a specific focusing range suitable for the thickness of the object being inspected. When using this type of probe for manual contact inspection, the uniformity of the coupling agent application causes the coupling agent thickness to constantly change; furthermore, coupling agent accumulates around the probe as it moves during inspection. Both of these combined factors can lead to the instrument's oscilloscope displaying waveforms of false defect signals. When this occurs, it is necessary to repeatedly reapply and wipe the coupling agent around the probe, and reconfirm whether the false defects are caused by the coupling agent, resulting in low detection sensitivity and the risk of missed detections.

[0039] Therefore, the automatic ultrasonic testing system for small-diameter metal rods provided in this application, through the use of liquid immersion ultrasonic testing, ensures consistency during testing because the liquid medium can stabilize acoustic coupling. The probe does not directly contact the workpiece being inspected, thus avoiding instability caused by changes in the coupling agent. Furthermore, the automated ultrasonic testing provided in this application effectively solves the problem of the influence of subjective human factors on the test results introduced by the manual operation of the focusing probe in existing technologies, which involves adjusting the movement speed and coverage scanning. This achieves improved detection sensitivity and convenient control of the movement speed.

[0040] It should be further noted that the ultrasonic testing instrument 14 selected in this embodiment is a type A pulse-echo ultrasonic flaw detector with a frequency range of 1 to 10 MHz. The ultrasonic testing instrument 14 should have: 1) a continuously adjustable attenuator of more than 80 dB. When ultrasonic waves propagate in different materials (such as steel and aluminum) or workpieces of different thicknesses, the energy attenuation varies greatly. A wide attenuation range can flexibly adjust the intensity of the received signal to ensure that whether it is a strong reflection signal near the surface (requiring large attenuation to avoid overload) or a weak defect signal in the deep part (requiring small attenuation for amplification and identification), it can be clearly presented on the display screen to avoid signal distortion due to excessive strength or loss due to excessive weakness; 2) each step is no more than 2 dB. Small step adjustment can achieve fine control of signal strength. For example, when the difference between the defect signal and the background noise is small, a step of 2dB or even smaller can accurately match the signal attenuation requirements, avoiding signal adjustment "overshoot" due to excessively large step sizes, ensuring the measurement accuracy of the defect echo height, and providing accurate data for defect size estimation (such as equivalent calculation); 3) Its accuracy is that the error between any two adjacent 12dB is within ±1dB, and the maximum cumulative error is not greater than 1dB. The accuracy of the attenuator directly determines the reliability of the signal amplitude measurement. If the attenuation error is too large, it will lead to the deviation in the calculation of the defect echo height, and thus misjudge the defect size (such as misjudging a small defect as a large defect, or missing a small defect). Strict accuracy control can ensure the consistency of signal attenuation under different detection scenarios, and ensure the repeatability and comparability of detection results (such as when the same workpiece is detected at different times and with different equipment, the data can be effectively compared); 4) The horizontal linearity error should not be greater than 1%, and the vertical linearity error should not be greater than 5%, to ensure the accuracy of the defect position.

[0041] Specifically, the ultrasonic testing instrument 14 selected in this embodiment is model CTS-4020, and its performance indicators and requirements comply with the provisions of my country's industry standard for ultrasonic flaw detectors JB / T10061-1999.

[0042] In this regard, considering that the sound waves of probe 15 need to pass through the water layer, and that there is some loss of sound energy, a high-energy probe 15 is used to ensure the detection of defects. Secondly, considering that the rod has a large curvature, the contact area between probe 15 and the workpiece 7 during detection is small. In order to ensure detection sensitivity and the ability to detect small defects during automatic detection, a point-focusing probe is adopted. For example, the parameters of the selected point-focusing probe are: model 15M6SJ30DJ, crystal size Ф6mm, focusing depth 30mm, and waveform longitudinal (L).

[0043] For example, multiple nylon sleeves 6 are evenly distributed along the axial direction of the rotating shaft 5, and the distance between the nylon sleeves 6 at both ends of the rotating shaft 5 matches the maximum scanning stroke of the probe 15. For example, the first and last nylon sleeves 6 can be corresponding to the starting and ending positions of the probe 15, respectively, while the middle nylon sleeve 6 serves as the intermediate positioning point of the probe 15. Each nylon sleeve 6 corresponds to a unique number, so that the operator can confirm the exact location of the defect on the workpiece 7. For example, driven by the spatial coordinate shifting mechanism, the probe 15 moves slowly and uniformly from the starting position of the scanning trajectory to the ending position, with a moving speed not exceeding 150 mm / s. For example, the moving speed of the probe 15 does not exceed 100 mm / s. When the probe 15 shifts along the axial direction of the rotating shaft 5, the ultrasonic testing instrument 14 will also simultaneously acquire the displacement of the probe 15. Thus, after the detection ends, the operator can find the adjacent nylon sleeve 6 according to the defect coordinate position displayed by the ultrasonic testing instrument 14 to locate the position range of the defect on the workpiece 7, thereby achieving the function of locating and marking the defect.

[0044] For example, while the moving speed of the probe 15 (the moving speed along the axis of the rotating shaft 5) is controlled at 0.1 mm / s to 1 mm / s, the rotation speed of the workpiece 7 is controlled at 0.1 mm / s to 0.5 mm / s, so as to avoid the probe 15 and the workpiece 7 moving too fast and thus causing missed detection.

[0045] The nylon sleeve 6 is detachably installed between the nylon sleeve 6 and the rotating shaft 5, so that the nylon sleeve 6 can be replaced according to the shaft diameter of the workpiece 7 to achieve stable support for the workpiece 7 and expand the size range of the workpiece to be inspected.

[0046] For example, see [link to relevant documentation]. Figure 2 The supporting indexing drive component includes a synchronous transmission belt 51, a driving transmission wheel, a driven transmission wheel, and an indexing motor 52. The output end of the indexing motor 52 is connected to the driving transmission wheel, and the input end of the rotating shaft 5 is fixedly connected to the driven transmission wheel. The synchronous transmission belt 51 is sleeved on the driving transmission wheel and the driven transmission wheel to achieve synchronous rotation of the two rotating shafts 5.

[0047] For example, see [link to relevant documentation]. Figure 1 and Figure 2 The spatial coordinate shifting mechanism includes an X-axis adjustment module, a slide block 18, and a Z-axis adjustment module 12. The output end of the X-axis adjustment module is drivenly connected to the slide block 18. The X-axis adjustment module is used to adjust the slide block 18 to shift along the axial direction of the rotating shaft 5. The slide block 18 is provided with the Z-axis adjustment module 12. The output end of the Z-axis adjustment module 12 is drivenly connected to the probe 15. The Z-axis adjustment module 12 is used to adjust the distance between the probe 15 and the detection surface of the workpiece 7, that is, the Z-axis adjustment module 12 is used to adjust the position of the probe 15 in the vertical direction.

[0048] The output end of the Z-axis adjustment module 12 is also provided with a probe adjustment module 13, and the output end of the probe adjustment module 13 is provided with a probe 15. The probe adjustment module 13 is used to adjust the displacement of the probe 15 in the clearance direction, wherein the clearance direction is perpendicular to the vertical direction and the axial direction of the rotating shaft 5.

[0049] The probe adjustment module 13 includes a rotation frame 16 and a rotation drive. The rotation drive is located at the output end of the Z-axis adjustment module 12, and the output end of the rotation drive is connected to the rotation frame 16. The probe 15 is arranged on the side of the rotation frame 16 facing the detection water tank 10.

[0050] The X-axis adjustment module includes an X-axis adjustment motor 20, a slide rail 11, and a lead screw 17. The output end of the X-axis adjustment motor 20 is connected to the lead screw 17. Both ends of the lead screw 17 are rotatably mounted on the slide rail 11. The lead screw 17 is threadedly connected to a slide block 18, which is slidably connected to the slide rail 11. Driven by the X-axis adjustment motor 20, the lead screw 17 drives the slide block 18 to slide back and forth along the axis of the rotating shaft 5. The maximum scanning stroke range of the probe 15 is the distance that the slide block 18 moves along the axis through the Z-axis adjustment module 12 and the probe adjustment module 13.

[0051] It should be noted that, in order to prevent the slide block 18 from overtravel and causing mechanical collision when moving along the slide rail 11 between the starting position and the ending position, limit switches 19, i.e., a position detection sensor, can be set at both ends of the slide rail 11. When the slide block 18 moves to the position where the limit switch 19 is set, the limit switch 19 will be triggered to control the X-axis adjustment motor 20 to stop running.

[0052] For example, the indexing drive is an indexing motor. The indexing drive drives the indexing frame 16 to perform indexing in the horizontal plane. That is, the indexing drive drives the indexing frame 16 to move the probe 15 to a position directly above the workpiece 7. After the inspection is completed, the indexing drive can be used to drive the indexing frame 16 to move the probe 15 horizontally to one side of the workpiece 7. Thus, when the workpiece 7 is taken out of the nylon sleeve 6 by the robotic arm, it will not be interfered with by the probe 15, which facilitates material handling.

[0053] For example, see [link to relevant documentation]. Figure 1 and Figure 2The liquid immersion automatic ultrasonic testing system also includes an electrical control box 1, which is equipped with a touch screen 2. Operators can adjust the operating parameters of various system components via the touch screen 2 on the electrical control box 1. A control box door 101 is provided on one side of the electrical control box 1 to facilitate maintenance. A protective cover 4 is provided on the side of the electrical control box 1 adjacent to the testing water tank 10 to block water splashes when the workpiece 7 is immersed in the liquid, thus protecting the electrical control box 1.

[0054] A safety monitoring mechanism 3 is also installed on one side of the electrical control box 1. The safety monitoring mechanism 3 includes an emergency stop device and an instrument alarm device. The emergency stop device is used to switch the system from automatic adjustment mode to manual adjustment mode. During the inspection and flaw detection of the workpiece 7, unexpected situations may occur, such as power outages or equipment jamming. In such cases, simply pressing the emergency stop button on the emergency stop device will switch the system from automatic adjustment mode to manual adjustment mode, ensuring the safety of personnel and equipment. Moreover, because the detection system is stable, the immersion method can shield unnecessary non-defect waveforms and has a good signal-to-noise ratio. Therefore, an alarm function for defects exceeding the standard can be set during automatic detection. This way, the inspector does not need to constantly observe the display screen of the ultrasonic instrument; they can judge the detection status by the alarm sound emitted by the instrument alarm device, greatly improving the risk of missed detection due to human factors.

[0055] It should be noted that before the automatic ultrasonic immersion testing system for small-diameter metal rods is put into formal use, it needs to be debugged using test blocks. A test block is a standardized reference object with artificial defects (such as flat-bottomed holes) manufactured according to the specific dimensions of the workpiece 7 being tested, used to calibrate the performance of the testing equipment. Figure 3 As shown, this is a schematic diagram of a traditional test block, which has a stepped surface and cannot be used for horizontal placement on the nylon sleeve 6 of this application. Therefore, the optimized test block structure is as follows: Figure 4 As shown, it is a cylindrical component, which can be placed horizontally on the nylon sleeve 6 in the liquid to facilitate the adjustment of the probe 15 detection position.

[0056] Specifically, after the test block is placed on the nylon sleeve 6, the probe 15 is moved to a position directly above the workpiece 7 under the adjustment of the spatial coordinate shifting mechanism. The probe 15 is then moved downward until all artificial equivalent defects on the optimized test block can be detected. At this point, the downward movement of the probe 15 is stopped and its height position is fixed. The water layer for liquid immersion testing is also determined at this time. If the water layer initially injected cannot achieve a satisfactory effect by adjusting the probe 15, it indicates that the water layer height is insufficient. The water layer thickness should be increased until the adjustment is satisfactory.

[0057] It should be noted that the adjustment of the water layer should be based on the theoretical calculation formula (1):

[0058] H=F+L(c2 / c1-1) (1)

[0059] Where F is the actual focal length of the probe; H is the liquid layer height; L is the actual thickness of the workpiece 7 being focused on; c2 is the longitudinal wave velocity of the ultrasonic wave in the workpiece 7; and c1 is the longitudinal wave velocity of the ultrasonic wave in the workpiece 7.

[0060] Due to variations in the tested material and water itself, the theoretically calculated liquid level is corrected for each batch of workpieces tested. This allows the instrument's oscilloscope screen to reach the theoretically calculated water level, and the maximum reflected wave amplitude can be obtained by manually fine-tuning the Z-value of probe 15. Figure 4 The diameter of the optimized test block shown is Ф18mm. The maximum amplitude of the flat-bottomed hole at a depth of 9mm in the optimized test block, obtained by adjusting the water layer as described above, is the detection sensitivity. Under this sensitivity, the remaining depth of the optimized test block corresponding to the flat-bottomed hole is adjusted to produce the DAC curve.

[0061] The testing water tank 10 is fixedly mounted on the frame 8, and the lower end of the frame 8 is provided with adjustable casters 9. The adjustable casters 9 have moving and locking functions. When in the moving state, the adjustable casters 9 allow the entire testing system to be moved easily, and when in the locked state, the adjustable casters 9 ensure that the testing water tank 10 remains in a horizontal state during the testing process.

[0062] It should be further noted that before the automatic ultrasonic testing system for liquid immersion of small-diameter metal rods is put into formal use, the system's detection sensitivity needs to be determined and accepted. The following is an example of the process for determining and accepting the detection sensitivity in practical application of this utility model's technical solution.

[0063] The sensitivity should be determined by selecting the appropriate reference emitter based on the quality class and adjusting the reference sensitivity.

[0064] Specifically as follows:

[0065] Direct wave radial scanning, utilizing Figure 4 DAC (Distance-Amplitude Correction) curves were plotted for flat-bottomed holes at different distances in the optimized test block, and extended to the entire diameter range. The detection sensitivity should be at least 6 dB higher than the reference sensitivity.

[0066] Furthermore, during the calibration and verification process, since the testing is conducted using a semi-automatic ultrasonic immersion method, measures should be specified to prevent various types of drift. Drift refers to deviations in software and control sequence that can affect the effectiveness of control.

[0067] A comparison of the results of manual and automatic inspections shows that the actual inspection performance of the liquid immersion method is far superior to that of the manual contact method (the contact method, due to its short probe detection distance, the coupling effect between the probe and the workpiece, and the influence of factors such as the signal-to-noise ratio, cannot meet the inspection requirements during calibration). See details... Figure 5 and Figure 6 Comparison of acoustic signal displays. It can be seen that the immersion method for sensitivity calibration results in low grass-like echoes and a good signal-to-noise ratio, while the manual contact method results in high grass-like echoes and a poor signal-to-noise ratio.

[0068] To prevent drift of the calibrated timing curve during automatic inspection due to the rotation of the inspected workpiece, a TCG curve with the same function as the DAC curve is used for sensitivity setting, providing better observability. Simultaneously, two gates lock the initial wave pulse and the bottom wave pulse, preventing missed defects and inaccurate identification due to drift. See details... Figure 7 .

[0069] According to the standard requirements, the acceptance should be carried out in accordance with the requirements of Table 1. Since the comparative test block has been artificially defected according to the acceptance requirements and the entire testing system can detect it, it fully meets the acceptance requirements.

[0070] Table 1 Acceptance Requirements

[0071]

[0072] It should be noted that, in the use of this liquid immersion automatic ultrasonic testing system for small-diameter metal rods, the workpiece 7 to be tested is placed in the liquid in the testing water tank 10 and supported on the nylon sleeve 6. Driven by the indexing motor 52, the synchronous transmission belt 51 drives the paired rotating shafts 5 to rotate in the same direction through the driven transmission wheel, so that the workpiece 7 of the small-diameter metal rod is rotated at a uniform speed. At this time, the height position between the probe 15 and the workpiece 7 is adjusted by the drive adjustment of the Z-axis adjustment module 12, and the position is adjusted by the drive adjustment of the probe adjustment module 13, so that the indexing frame 16 moves the probe 15 along the clearance direction to be directly above the workpiece 7.

[0073] Then, the X-axis adjustment motor 20 is started, and the slide block 18 is driven by the lead screw 17, so that the slide block 18 slides along the slide rail 11, thereby realizing that the probe 15 moves at a constant speed along the axis of the workpiece 7. During the displacement process of the probe 15 from the starting position to the ending position, combined with the rotation of the workpiece 7 itself, the probe 15 realizes a full automatic scanning detection of the surface of the workpiece 7. The detection results are then displayed graphically by the ultrasonic detector 14 to intuitively show the defect situation and defect location of the workpiece 7.

[0074] After the inspection is completed, the probe adjustment module 13 drives the indexing frame 16 to horizontally rotate the probe 15 to one side of the workpiece 7. At this time, the probe 15 is no longer directly above the workpiece 7, which makes it easier for the staff to remove the workpiece 7 after the inspection is completed. During the removal process, there will be no interference from the probe 15. After a new workpiece 7 of the same batch is placed in, the probe adjustment module 13 can be driven in reverse to drive the indexing frame 16 to move the probe 15 back to the horizontal position directly above the workpiece 7, without having to restart the Z-axis adjustment module 12 to adjust the height of the probe 15, thus improving the inspection efficiency.

[0075] Furthermore, a safety monitoring mechanism 3 is installed on one side of the electrical control box 1. This mechanism includes an emergency stop device and an instrument alarm device. During the inspection and flaw detection of workpiece 7, unexpected situations may occur, such as power outages or equipment jamming. In such cases, simply pressing the emergency stop button on the emergency stop device switches the system from automatic to manual adjustment, ensuring the safety of personnel and equipment. Moreover, due to the stability of the detection system, the immersion method's ability to shield unnecessary non-defect waveforms, and its excellent signal-to-noise ratio, an alarm function for exceeding defect limits can be set during automatic detection. This eliminates the need for inspectors to constantly monitor the ultrasonic instrument's display screen; they can judge the inspection status simply by listening to the alarm sound emitted by the instrument alarm device, significantly reducing the risk of missed defects due to human error.

[0076] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A liquid-immersion automatic ultrasonic testing system for small-diameter metal bars, characterized by comprising: include: The test water tank (10) is used to hold the liquid that immerses the test workpiece (7); The support mechanism is set in the testing water tank (10). The support mechanism includes a support indexing drive, a rotating shaft (5) and a nylon sleeve (6). The output end of the support indexing drive is connected to the rotating shaft (5). The rotating shafts (5) are arranged in pairs and the rotating directions of the paired rotating shafts (5) are the same. The nylon sleeve (6) is fixedly set on the rotating shaft (5). The testing workpiece (7) is horizontally placed on the nylon sleeve (6). An ultrasonic testing instrument (14) is electrically connected to a probe (15), which is positioned above the workpiece (7) and is used to scan and test the workpiece (7). A spatial coordinate shifting mechanism is installed on the detection water tank (10). The output end of the spatial coordinate shifting mechanism is equipped with a probe (15). The spatial coordinate shifting mechanism is used to adjust the spatial coordinate position of the probe (15).

2. The liquid immersion automatic ultrasonic testing system for small diameter metal rod according to claim 1, wherein Multiple nylon sleeves (6) are evenly distributed along the axis of the rotating shaft (5), and the distance between the nylon sleeves (6) at both ends of the rotating shaft (5) matches the maximum scanning stroke of the probe (15).

3. The liquid immersion automatic ultrasonic testing system for small diameter metal rod according to claim 2, wherein The supporting indexing drive includes a synchronous transmission belt (51), a driving transmission wheel, a driven transmission wheel, and an indexing motor (52). The output end of the indexing motor (52) is connected to the driving transmission wheel, and the input end of the rotating shaft (5) is fixedly connected to the driven transmission wheel. The synchronous transmission belt (51) is sleeved on the driving transmission wheel and the driven transmission wheel.

4. The liquid immersion automatic ultrasonic testing system for small diameter metal rod according to claim 3, characterized in that, The spatial coordinate shifting mechanism includes an X-axis adjustment module, a slide (18), and a Z-axis adjustment module (12). The output end of the X-axis adjustment module is connected to the slide (18). The X-axis adjustment module is used to adjust the slide (18) to shift along the axial direction of the rotating shaft (5). The slide (18) is provided with a Z-axis adjustment module (12). The output end of the Z-axis adjustment module (12) is connected to a probe (15). The Z-axis adjustment module (12) is used to adjust the distance between the probe (15) and the detection surface of the workpiece (7).

5. The liquid immersion automatic ultrasonic testing system for small diameter metal rod according to claim 4, wherein The output end of the Z-axis adjustment module (12) is also provided with a probe adjustment module (13), and the output end of the probe adjustment module (13) is provided with a probe (15). The probe adjustment module (13) is used to adjust the displacement of the probe (15) in the clearance direction, wherein the clearance direction is perpendicular to the vertical direction and the axial direction of the rotating shaft (5).

6. The liquid immersion automatic ultrasonic testing system for small diameter metal rod according to claim 5, wherein The probe adjustment module (13) includes a rotation frame (16) and a rotation drive. The rotation drive is located at the output end of the Z-axis adjustment module (12), and the output end of the rotation drive is connected to the rotation frame (16). The probe (15) is located on the side of the rotation frame (16) facing the detection tank (10).

7. The system for automatic immersion ultrasonic testing of small diameter metal rod according to claim 6, wherein The X-axis adjustment module includes an X-axis adjustment motor (20), a slide rail (11), and a lead screw (17). The output end of the X-axis adjustment motor (20) is connected to the lead screw (17). Both ends of the lead screw (17) are rotatably mounted on the slide rail (11). The lead screw (17) is threadedly connected to a slide block (18), and the slide block (18) is slidably connected to the slide rail (11).

8. The liquid immersion automatic ultrasonic testing system for small diameter metal rod according to claim 7, wherein The liquid immersion automatic ultrasonic testing system also includes an electrical control box (1), on which a touch screen (2) is installed.

9. The system for automatic immersion ultrasonic testing of small diameter metal rod according to claim 8, wherein A safety monitoring mechanism (3) is also provided on one side of the electrical control box (1). The safety monitoring mechanism (3) includes an emergency stop device and an instrument alarm device. The emergency stop device is used to switch the system from automatic adjustment state to manual adjustment state.

10. The liquid immersion automatic ultrasonic testing system for small diameter metal rod according to claim 9, wherein The detection water tank (10) is fixedly mounted on the frame (8), and the lower end of the frame (8) is provided with adjusting casters (9).

Images