A metrological traceability device for ultrasonic testing systems of hollow axles of rolling stock

Abstract

The application provides a kind of metrological traceability device for hollow axle ultrasonic detection system of rolling stock, and belongs to the technical field of rolling stock ultrasonic detection.The metrological traceability device includes: ultrasonic unit detection device, used for calibrating performance parameters of ultrasonic unit in hollow axle ultrasonic detection system; ultrasonic probe detection device, used for calibrating performance parameters of ultrasonic probe in hollow axle ultrasonic detection system; calibration test block, having a guide hole and at least one reflection structure; the calibration test block cooperates with the ultrasonic probe detection device to complete the calibration of performance parameters of the ultrasonic probe.The application significantly reduces calibration cost and improves equipment utilization, avoids assembly error introduced by disassembly, and stabilizes long-term precision and detection reliability of the detection system, realizes direct migration of laboratory-level metrological capability to field conditions, and ensures that the detection result has reliable metrological traceability and consistency.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic testing technology for locomotives and rolling stock, and in particular to a dedicated metrological traceability device for ultrasonic testing systems of hollow axles for locomotives and rolling stock. Background Technology

[0002] The wheelsets of high-speed trains and some locomotives generally use hollow axles. Because hollow axles are subjected to alternating stress during service, cracks may develop, necessitating periodic ultrasonic testing. Currently, all locomotive and rolling stock maintenance units use ultrasonic testing systems for hollow axles. The ultrasonic testing system for hollow axles consists of the overall equipment, the coupling and transmission system, the probe, the control system, and the ultrasonic unit. The ultrasonic unit is installed within the control system, and the ultrasonic probe is installed within the probe. During operation, the ultrasonic probe extends into the central hole of the hollow axle, contacting the inner wall of the hole and using it as the detection surface to perform flaw detection on the interior of the hollow axle.

[0003] Existing ultrasonic testing systems for hollow axles mainly consist of an ultrasonic unit (including ultrasonic transmitting and receiving modules) and an ultrasonic probe. The ultrasonic unit is responsible for data acquisition, signal processing, waveform and data display; the ultrasonic probe emits ultrasonic waves into the hollow axle and receives the reflected ultrasonic signals. Internally, it is composed of piezoelectric crystals that convert the ultrasonic vibration signals into electrical signals that can be received by the ultrasonic unit. Therefore, the performance of both directly determines the reliability of the test results.

[0004] Currently, the measurement of performance parameters of conventional ultrasonic units and probes primarily relies on laboratory conditions. However, due to the large size and complex structure of hollow axle ultrasonic testing systems, it is impossible to transport them to a qualified laboratory for calibration of the ultrasonic units and probes. Disassembling the ultrasonic units and probes from the ultrasonic testing system and then sending them to the laboratory for calibration presents problems such as a large workload (disassembly and reassembly of the ultrasonic units and probes) and a long calibration cycle. Therefore, calibration of such systems is difficult to conduct effectively in field conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a dedicated metrological traceability device for ultrasonic testing systems of hollow axles in locomotives and rolling stock, which can calibrate the ultrasonic testing system of hollow axles under on-site working conditions.

[0006] To achieve the above-mentioned objectives, this invention proposes a dedicated metrological traceability device for an ultrasonic testing system for hollow axles of locomotives and rolling stock, comprising:

[0007] An ultrasonic unit testing device is used to calibrate the performance parameters of the ultrasonic unit in a hollow axle ultrasonic testing system.

[0008] An ultrasonic probe testing device is used to calibrate the performance parameters of the ultrasonic probe in a hollow axle ultrasonic testing system.

[0009] The calibration block has a guide hole and at least one reflective structure; the calibration block works in conjunction with the ultrasonic probe testing device to calibrate the performance parameters of the ultrasonic probe.

[0010] This invention also proposes a testing method for an ultrasonic probe in an ultrasonic testing system for hollow axles of locomotives and rolling stock. The method includes providing a calibration block having at least one preset reflective structure, moving the calibration block relative to the ultrasonic probe under test along a preset path, and providing a pulse signal to the ultrasonic probe to excite it to emit ultrasonic waves. The ultrasonic waves are reflected by the reflective structure to form an echo signal. The echo signal is then acquired, and at least one performance parameter of the ultrasonic probe is calculated based on the echo signal.

[0011] The present invention also proposes a testing device for an ultrasonic probe in an ultrasonic testing system for hollow axles of locomotives and rolling stock, wherein the testing device for the ultrasonic probe includes at least:

[0012] The calibration block has at least one preset reflective structure, which is capable of generating an echo signal under the action of ultrasonic waves;

[0013] A pulse generator, connected to the ultrasonic probe, is used to provide a pulse signal to the ultrasonic probe to excite the ultrasonic probe to emit ultrasonic waves;

[0014] An oscilloscope, connected to the ultrasonic probe, is used to acquire the echo signal and display the waveform. This invention also proposes a testing method for the ultrasonic unit of a hollow axle ultrasonic testing system for locomotives and rolling stock. The ultrasonic unit to be tested is connected to a test circuit, which includes multiple switchable signal paths. Multiple test states are constructed by switching the signal paths of the test circuit. In each test state, a preset excitation signal is provided to the ultrasonic unit, and the response signal of the ultrasonic unit is acquired. Based on the response signal, at least one of the following parameters of the ultrasonic unit is calculated: pulse repetition frequency, crosstalk suppression, equivalent input noise, dynamic range, attenuator accuracy, time baseline, and amplitude linearity.

[0015] The present invention also proposes a testing device for the ultrasonic unit of an ultrasonic testing system for hollow axles of locomotives and rolling stock, wherein the testing device for the ultrasonic unit includes at least:

[0016] The signal generation unit is used to generate excitation signals;

[0017] Signal conditioning unit, used to adjust signal amplitude;

[0018] The signal acquisition unit is used to acquire waveform signals and measure voltage or time parameters.

[0019] The signal generation unit, signal conditioning unit, and waveform acquisition unit are selectively connected to the ultrasound unit to be tested via a circuit switching unit to perform the detection of at least one performance parameter of the ultrasound unit.

[0020] Compared with the prior art, the present invention has the following features and advantages:

[0021] This invention proposes a dedicated metrological traceability device for ultrasonic testing systems of hollow axles in locomotives and rolling stock. For the first time, it achieves full-parameter metrological calibration of the hollow axle ultrasonic testing system without disassembly or shutdown, under on-site conditions. The ultrasonic unit testing device can stably and automatically calibrate seven parameters: pulse repetition frequency, crosstalk suppression, equivalent input noise, dynamic range, attenuator accuracy, time-base linearity, and amplitude linearity. The calibration accuracy meets the requirements of JJG 746-2024, and the results can be directly verified using standard formulas and oscilloscope data. The ultrasonic probe testing device, in conjunction with a dedicated calibration test block, is the first to adapt to a probe structure with an integrated probe rod, achieving calibration of five parameters: RF pulse width, spectral bandwidth, echo sensitivity, beam angle, and crosstalk. The on-site precise calibration of probe parameters utilizes a test block with mirrored hole positions and multi-specification through-hole design, allowing the probe to be directly inserted for measurement without disassembly or replacement of the detection surface. The beam angle and incident point results can be directly reproduced and verified using the fixed dimensions of the test block, significantly reducing calibration costs and improving equipment utilization. It avoids assembly errors introduced by disassembly and assembly, and stably ensures the long-term accuracy and reliability of the detection system. The overall solution is not a simple combination of conventional instruments, but a specialized and systematic adaptation design for the structural characteristics of probe-integrated probes and hollow axle detection systems. It realizes the direct transfer of laboratory-level metrological capabilities to on-site working conditions, forming an on-site metrological calibration system that was previously impossible in the industry and cannot be replaced by conventional technical means, ensuring that the test results have reliable metrological traceability and consistency. Attached Figure Description

[0022] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0023] Figure 1 This is a schematic diagram of the detection method of the ultrasonic probe of the present invention;

[0024] Figure 2 This is a schematic diagram of the detection method of the ultrasonic unit of the present invention;

[0025] Figure 3 This is the electrical schematic diagram of the ultrasonic unit testing device of the present invention;

[0026] Figure 4 This is the electrical schematic diagram of the ultrasonic probe testing device of the present invention;

[0027] Figure 5 This is a schematic diagram of a typical time-domain echo signal of the ultrasonic probe of the present invention;

[0028] Figure 6 This is a schematic diagram of a typical frequency domain echo signal of the ultrasonic probe of the present invention;

[0029] Figure 7 This is a schematic diagram of the incident point measurement of the shear wave angle probe of the present invention;

[0030] Figure 8 This is a schematic diagram of the beam angle measurement of the shear wave angle probe of the present invention;

[0031] Figure 9 This is a schematic diagram of crosstalk measurement using a dual-crystal probe according to the present invention;

[0032] Figure 10 This is a two-dimensional outline drawing of the dedicated calibration test block for this invention.

[0033] Figure 11 This is a three-dimensional outline drawing of the dedicated calibration test block for this invention.

[0034] Figure 12 This is a matching diagram of the special calibration test block and probe of the present invention.

[0035] Explanation of reference numerals in the attached figures

[0036] 10. Calibration block; 11. First reflection structure; 12. Second reflection structure; 13. Guide channel; 14. Third reflection structure; 20. Pulse generator; 30. Oscilloscope; 40. Switching circuit; 200. Ultrasonic probe; 210. Probe rod; 300. Detection device for ultrasonic unit; 310. Signal generation unit; 321. Fixed attenuator; 322. Standard attenuator; 330. Signal acquisition unit; 340. Switching unit; 400. Ultrasonic unit. Detailed Implementation

[0037] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, and these should all be considered to fall within the scope of the invention.

[0038] This invention proposes a dedicated metrological traceability device for an ultrasonic testing system for hollow axles of locomotives and rolling stock, comprising:

[0039] An ultrasonic unit testing device is used to calibrate the performance parameters of the ultrasonic unit in a hollow axle ultrasonic testing system.

[0040] An ultrasonic probe testing device is used to calibrate the performance parameters of the ultrasonic probe in a hollow axle ultrasonic testing system.

[0041] The calibration block has a guide hole and at least one reflective structure; the calibration block works in conjunction with the ultrasonic probe testing device to calibrate the performance parameters of the ultrasonic probe.

[0042] The present invention proposes a dedicated metrological traceability device for ultrasonic testing systems of hollow axles in locomotives and rolling stock. By integrating an ultrasonic unit testing device, an ultrasonic probe testing device, and a calibration test block with guide holes and a reflection structure, it can directly calibrate seven parameters of the ultrasonic unit, such as pulse repetition frequency, crosstalk suppression, and dynamic range, as well as five parameters of the ultrasonic probe, such as radio frequency pulse waveform and beam angle, on-site without disassembling the ultrasonic unit and probe from the hollow axle ultrasonic testing system. Furthermore, the guide holes of the calibration test block adapt to the probe rod structure and the reflection structure provide a standard echo, enabling the ultrasonic probe integrated within the probe rod to complete performance parameter measurements without disassembly.

[0043] The proposed invention provides a dedicated metrological traceability device for ultrasonic testing systems of hollow axles in locomotives and rolling stock. The ultrasonic unit testing device, the ultrasonic probe testing device, and the calibration test block with guide holes and reflective structures work together to achieve on-site, non-disassembly calibration of the hollow axle ultrasonic testing system. This allows for the calibration of core component performance parameters without the need for external testing, and the calibration process complies with metrological verification regulations. Parameter results can be directly verified through waveform acquisition and standard calculations, ensuring stable and reliable calibration accuracy. Furthermore, the calibration operation is reduced from several days to tens of minutes, and measurement results can be directly reproduced and verified using an oscilloscope module and host computer software. This significantly reduces overall calibration costs while maintaining calibration accuracy, ensuring the continuous reliability of the testing system.

[0044] like Figure 1As shown, the present invention also proposes a testing method for an ultrasonic probe in an ultrasonic testing system for hollow shafts of locomotives and rolling stock. The method includes providing a calibration block 10, which has at least one preset reflective structure. The calibration block 10 moves relative to the ultrasonic probe 200 under test along a preset path and provides a pulse signal to the ultrasonic probe 200 to excite the ultrasonic probe 200 to emit ultrasonic waves. The ultrasonic waves are reflected by the reflective structure to form an echo signal. The echo signal is acquired, and at least one performance parameter of the ultrasonic probe 200 is calculated based on the echo signal.

[0045] The ultrasonic probe testing method of the ultrasonic testing system for hollow axles of locomotives proposed in this invention provides a calibration test block 10 with a preset reflective structure. As the calibration test block 10 moves relative to the ultrasonic probe 200 under test along a preset path, it sends a pulse signal to the ultrasonic probe 20 to excite ultrasonic waves. The echo signal generated by the reflective structure is used to directly calculate the probe's incident point position, beam angle, pulse width, spectral bandwidth, and relative pulse echo sensitivity. This allows for on-site measurement of multiple parameters without removing the ultrasonic probe 200 from the probe rod 30. Moving along the preset path allows the ultrasonic probe 200 to sequentially align with different reflective structures, achieving incident point positioning and geometric calculation of the beam angle, without the need for any general-purpose test blocks or disassembly. After the echo signal is acquired by an oscilloscope, the pulse width can be read from the time-domain waveform, and the pulse spectrum and bandwidth can be obtained through discrete Fourier transform. All measurement processes can be reproduced on-site, and the data can be verified.

[0046] The ultrasonic probe detection method of the ultrasonic testing system for hollow shafts of locomotives proposed in this invention simplifies the complex measurement that originally required repeated positioning using multiple instruments in the laboratory into on-site moving scanning of a single calibration test block 10, which significantly reduces the difficulty of operation and time cost, while ensuring the consistency of the performance parameters of the ultrasonic probe 200 with its actual working state, and has outstanding non-obviousness.

[0047] This invention also proposes a testing device for an ultrasonic probe in an ultrasonic testing system for hollow axles of locomotives and rolling stock, wherein, as... Figure 4 As shown, the ultrasonic probe detection device 100 includes at least:

[0048] The calibration block 10 has at least one preset reflection structure, which can generate an echo signal under the action of ultrasound.

[0049] The pulse generator 20 is connected to the ultrasonic probe 200 and is used to provide a pulse signal to the ultrasonic probe 200 to excite the ultrasonic probe 200 to emit ultrasonic waves.

[0050] The oscilloscope 30 is connected to the ultrasonic probe 200 and is used to acquire echo signals and display waveforms.

[0051] The ultrasonic probe testing device 100 of the ultrasonic testing system for hollow axles of locomotives and rolling stock proposed in this invention integrates a calibration block 10, a pulse generator 20, and an oscilloscope 30. Utilizing the preset reflection structure of the calibration block 10, it can stably generate measurable echo signals under pulse signal excitation, and the waveform is visually displayed on the oscilloscope 30, providing a direct and repeatable physical basis for accurately calculating the performance parameters (such as the beam angle) of the ultrasonic probe 200. This ultrasonic probe testing device 100 supports on-site calibration without disassembling the ultrasonic probe, significantly simplifying the calibration process, shortening measurement time, and ensuring the consistency and verifiability of echo signal acquisition. This ultrasonic probe testing device 100 integrates a complex testing system that originally required multiple independent instruments in a laboratory into a single portable device, breaking through the technical convention in the field of requiring probe disassembly and the use of a general-purpose test block, and possesses outstanding non-obviousness.

[0052] In one optional embodiment of the present invention, such as Figure 10 and Figure 11 As shown, the calibration block 10 has a first reflection structure 11 and a second reflection structure 12. The first reflection structure 11 is an arc-shaped surface reflection structure, and the second reflection structure 12 is a circular aperture reflection structure.

[0053] In an optional embodiment of the present invention, the diameter of the circular hole of the second reflective structure 12 is set according to the probe specifications of the hollow axle ultrasonic testing system, and there are four hole diameters: φ30mm, φ40mm, φ60mm and φ65mm.

[0054] In an optional embodiment of the present invention, the radius of the arc of the first reflective structure 11 is 100 mm.

[0055] In an optional embodiment of the present invention, the preset path is: move the ultrasound probe 200 to find the highest reflected echo of the reflective structure, and remain stationary at the location where the highest reflected echo is found to obtain the echo signal.

[0056] In one optional embodiment of the present invention, such as Figures 10 to 12 As shown, the calibration block 10 has a guide channel 13 into which the probe 210 of the ultrasonic testing system for hollow axles of locomotives and rolling stock extends. The guide channel 13 guides the ultrasonic probe 200 on the probe 210 to move along a preset path. With this structure, it is not necessary to remove the ultrasonic probe 200 integrated on the probe 210. The probe 210 can be directly inserted into the calibration block 10 through the guide channel 13. The guide channel 13 guides the probe 210 to move axially, ensuring that the probe maintains a stable posture and path during movement, thus completing the incident point positioning and beam angle measurement.

[0057] In one optional example, the guide channel 13 has multiple aperture specifications (φ30mm, φ40mm, φ60mm, φ65mm) to accommodate probes of different models of hollow axle ultrasonic testing systems. During measurement, the probe 210 moves along the guide channel 13 so that the ultrasonic probe 200 is aligned with the R100 arc surface and the φ50mm transverse hole in sequence, which is accurate in positioning and easy to operate.

[0058] In an optional example, the two ends of the guide channel 13 are end A and end B, respectively, with the first reflective structure 11 positioned closer to end B and the second reflective structure positioned closer to end A.

[0059] In an optional example, the first reflection structure 11 adopts an R100 arc surface and is located at one end of the calibration block 10. It is used to measure the incident point position of the ultrasonic probe 200. The ultrasonic probe 200 enters from end A of the guide channel and moves back and forth to find the highest reflected echo of the R100 arc surface. At this time, the incident point position of the ultrasonic probe 200 is located at the center of the R100 arc surface. The second reflection structure 12 adopts a φ50mm circular hole and is located inside the calibration block 10. It is used to measure the beam angle of the ultrasonic probe 200. The ultrasonic probe 200 enters from end B of the guide channel and moves back and forth to find the highest reflected echo of the φ50mm circular hole. At this time, the ultrasonic probe beam enters along the diameter direction of the φ50mm circular hole.

[0060] By setting an R100 arc surface as the first reflection structure 11 and a φ50mm circular hole as the second reflection structure 12 on the calibration test block 10, the two functions of incident point positioning and beam angle measurement are respectively provided. The geometric characteristics of the center of the R100 arc surface enable the probe incident point to be accurately located through the highest echo position, and the diameter direction characteristics of the φ50mm circular hole enable the probe beam direction to be determined through the highest echo position. The two reflection structures are fixedly arranged on the test block and their relative positional relationship is known. By simply moving the probe rod through the guide channel 13 to align the first reflection structure 11 and the second reflection structure 12 in sequence, the two key geometric parameters of incident point position and beam direction can be obtained.

[0061] In an optional embodiment of the present invention, according to relevant standards, for the measurement of the ultrasonic probe beam angle, when the beam angle of the angle probe is between 34° and 66°, the ultrasonic probe should be placed... Figure 11 The location shown is measured using the highest reflected echo from a φ50mm circular aperture. The beam angle of the angle probe in a hollow axle ultrasonic testing system is generally around 45°, therefore it should be measured according to... Figure 11 Place the probe at the indicated location.

[0062] In an optional embodiment of the present invention, the performance parameters of the ultrasonic probe include at least the pulse width, such as... Figure 5As shown, the pulse width of the echo signal is measured in the time domain waveform and used as the pulse width of the ultrasonic probe.

[0063] In an optional embodiment of the present invention, the pulse width of the echo signal is measured in the time domain waveform and used as the pulse width of the ultrasonic probe 200. Specifically, when the ultrasonic probe 200 is a single-crystal probe, KA1 and KA2 in the switching circuit 40 are turned on; when the ultrasonic probe 200 is a dual-crystal probe, KA1 and KA3 in the switching circuit 40 are turned on, so that the ultrasonic probe 200, the pulse generator 20, and the oscilloscope 30 constitute a test circuit. The pulse generator 20 generates a high-voltage negative pulse to excite the ultrasonic probe 200. The ultrasonic probe 200 generates an echo signal of ultrasound on the calibration test block 10. After the echo signal is converted into a voltage signal, it is connected to the oscilloscope 30. The waveform of the echo pulse can be displayed by the measurement software. The amplitude of the echo signal is adjusted to 80%-100% of the full width of the vertical scale of the fluorescent screen. The peak-to-peak amplitude of the echo is h, and the pulse width is L. The measurement software measures the echo width in the time domain waveform display mode, thus obtaining the pulse width of the ultrasonic probe. The ultrasonic probe is excited by a pulse generator 20 to generate an ultrasonic echo. The pulse width of the echo signal is directly measured in the time domain waveform. This allows for on-site acquisition of the time domain characteristics of the radio frequency pulse waveform without disassembling the probe. Adjusting the echo signal amplitude to 80%-100% of full amplitude ensures the stability and repeatability of the waveform amplitude during pulse width measurement. The measurement software automatically reads the echo width in the time domain waveform display mode, making the pulse width parameter quantifiable and reproducible. By measuring the pulse width of the echo signal in the time domain waveform, the time characteristics of the emitted pulse of the ultrasonic probe 200 are directly quantified and detected, allowing for accurate determination of the pulse duration parameter of the ultrasonic probe, providing a basis for evaluating the resolution of the ultrasonic probe.

[0064] In an optional embodiment of the present invention, the performance parameters of the ultrasonic probe 200 include at least the pulse spectrum and bandwidth, such as... Figure 6 As shown, the echo signal is transformed in the frequency domain to obtain the pulse echo spectrum; based on the upper and lower frequency corresponding to the amplitude drop of a preset decibel in the spectrum, the pulse spectrum and bandwidth are calculated.

[0065] In an optional example of this implementation, the ultrasonic probe is a single-crystal probe, and KA1 and KA2 in the switching circuit 40 are turned on.

[0066] In another optional example of this implementation, the ultrasound probe is a dual-crystal probe, and KA1 and KA3 in the switching circuit 40 are turned on.

[0067] In one optional example of this implementation, the pulse echo spectrum is obtained by performing a discrete Fourier transform on the echo signal.

[0068] In an optional example of this implementation, the preset decibel level is -6 dB; the pulse spectrum and bandwidth are calculated using the following formula:

[0069] f0=(f u +f l ) / 2 (8)

[0070] ∆f rel =[(fu–fl) / f o ×100% (9)

[0071] Where f0 is the pulse spectrum, f u and f l These are the upper and lower frequency limits corresponding to -6dB, Δf rel For bandwidth.

[0072] The pulse spectrum is calculated using the arithmetic mean formula, and the bandwidth is calculated using the relative bandwidth formula, thus standardizing the quantitative calculation of pulse spectrum and bandwidth. Among them, -6dB is a common standard for ultrasonic probe spectrum measurement. Using this decibel value ensures the comparability of measurement results. Both pulse spectrum and bandwidth can be directly read from the spectrum diagram and substituted into the formula for calculation. The calculation process is simple and clear, and the results can be reproduced and verified.

[0073] In an optional embodiment of the present invention, the performance parameters of the ultrasonic probe 200 further include relative pulse-echo sensitivity, which is calculated by measuring the voltage of the pulse signal and the voltage of the echo signal, and by using the following formula:

[0074] S r =20lg(V out / V in (10)

[0075] In the formula, Sr is the relative pulse echo sensitivity, and V out V is the voltage of the echo signal. in The voltage of the pulse signal.

[0076] In an optional example of this implementation, the ultrasonic probe 200 is a single-crystal probe, KA1 and KA2 in the switching circuit 40 are turned on, and the ultrasonic probe 200, pulse generator 20 and oscilloscope 30 constitute a test circuit.

[0077] In another optional example of this implementation, the ultrasonic probe 200 is a dual-crystal probe, KA1 and KA3 in the switching circuit 40 are turned on, and the ultrasonic probe 200, pulse generator 20 and oscilloscope 30 constitute a test circuit.

[0078] In this embodiment, the initial stage of the test process is the same as that of the pulse width test. Based on the pulse width test, the voltage V of the transmitted pulse signal at this time is read out. in and the voltage V of the echo signal out The pulse echo sensitivity is calculated according to formula (10). The above test method can quantitatively evaluate the energy conversion efficiency of the ultrasonic probe on site without disassembling the probe, convert the voltage ratio between transmission and reception into decibel values, so that the sensitivity parameter has a clear physical meaning and quantifiability, and the measurement results can be directly reproduced and verified by the voltage reading function of oscilloscope 30.

[0079] In an optional embodiment of the present invention, the performance parameters of the ultrasonic probe 200 also include the beam angle. Based on the incident point position of the ultrasonic probe 200, the geometric position of the second reflection structure 12, and the preset geometric relationship on the calibration block 10, a geometric model is established to calculate the beam angle of the ultrasonic probe.

[0080] First, such as Figure 7 As shown, the location of the incident point (the leading edge of the ultrasonic probe) of the ultrasonic probe 200 is determined as follows: The ultrasonic probe 200 enters from end A of the guide channel 13. The ultrasonic probe 200 is moved back and forth to find the highest reflected echo of the R100 arc surface. At this time, the incident point of the ultrasonic probe 200 is located at the center of the R100 arc surface. Using a depth gauge, the distance from the leading edge of the ultrasonic probe 200 to the edge of the calibration block 10 is measured at end B of the guide channel 13 and recorded as L1. The location of the incident point L0 of the ultrasonic probe 200 (the distance from the incident point to the leading edge of the probe rod) is calculated according to formula (11):

[0081] L0 = 120 - L1 (11)

[0082] L0—Distance from the incident point to the front end of the probe; L1—Distance from the front end of the probe to the edge of the test block.

[0083] Then, the ultrasonic probe 200 enters from end B of the guide channel 13. Moving the ultrasonic probe 200 back and forth, it locates the highest reflected echo from the φ50mm circular hole on the calibration block 10. According to the principle of ultrasonic flaw detection, at this point, the probe's sound beam travels along the diameter of the φ50mm circular hole and enters the hole. A depth gauge is used to measure from end A; the distance from the tip of the probe to the edge of the block at this point is recorded as L2.

[0084] On calibration block 10, such as Figure 8 As shown, a right triangle is established using points X, O, and Y. The probe's beam angle is numerically equal to the angle ∠YOX.

[0085] tan∠YOX=(L2-20-35+L0) / 73;

[0086] The probe beam angle can be calculated using formula (12):

[0087] ∠YOX =arctan(L2-20-35+L0) / 73(12)

[0088] In this embodiment, the incident point of the ultrasonic probe 200 is located by the highest reflected echo of the first reflective structure 11 (R100 arc surface), and the direction of the ultrasonic beam of the ultrasonic probe 200 is determined by the highest reflected echo of the second reflective structure 12 (φ50mm horizontal hole). A right-angled triangle geometric model is established using the incident point position, the geometric position of the second reflective structure, and the preset geometric relationship on the test block. The measurement of the beam angle is transformed into the angle calculation of the right-angled triangle. The quantitative measurement of the beam angle can be completed on site without disassembling the probe. Only the distance parameter needs to be measured by a depth gauge during the measurement process. The calculation process is simple and clear, and the measurement results can be reproduced and verified.

[0089] In an optional embodiment of the present invention, the ultrasonic probe 200 is a dual-crystal straight probe. The performance parameters of the ultrasonic probe 200 also include crosstalk. The dual-crystal straight probe is placed on the calibration test block 10, and the highest reflected echo of the third reflection structure 14 at a preset distance from the detection surface is found. The gain is adjusted so that the amplitude of the echo reaches a first preset amplitude, and the gain value G1 is recorded. The gain is increased so that the amplitude of the probe interface wave reaches a first preset amplitude, and the gain value G2 is recorded. The crosstalk value is calculated as the difference between G2 and G1.

[0090] In an optional example of this embodiment, the third reflective structure 14 is located between the first reflective structure 11 and the second reflective structure 12, and the third reflective structure 14 is a groove.

[0091] Specifically, KA3 and KA4 in switching circuit 40 are connected, and the ultrasonic probe 200, pulse generator 20, and oscilloscope 30 constitute the test circuit. For example... Figure 9 As shown, the ultrasonic probe 200 is placed on the calibration block 10, and the highest reflected echo of the third reflection structure 14 at a distance of 53 mm from the detection surface is found.

[0092] Specifically, adjust the echo amplitude in the oscilloscope 30 to 80% of the full vertical scale of the fluorescent screen, and record the gain value at this time as G1; then increase the gain so that the amplitude of the probe interface wave (coupled surface wave) also reaches 80% of the full vertical scale of the fluorescent screen, and record the gain value at this time as G2. The difference between G2 and G1 is the crosstalk value of the ultrasonic probe 200.

[0093] In an optional embodiment of the present invention, the ultrasonic probe detection device 100 further includes a calculation module, which is connected to the pulse generator 20 and the oscilloscope 30 and calculates the performance parameters of the ultrasonic probe 200 based on the pulse signal and the echo signal.

[0094] In practice, the calculation module is implemented using host computer measurement software. The pulse generator 20 generates a high-voltage negative pulse to excite the ultrasonic probe 200. The echo signal generated by the ultrasonic probe 200 is converted into a voltage signal and then connected to the oscilloscope 30. The oscilloscope 30 uses a high-speed AD acquisition card and is connected to the host computer. The calculation module uses the measurement software to read and calculate voltage and waveform parameters. During pulse width testing, the calculation module measures the echo width as the pulse width in time-domain waveform display mode. During pulse spectrum and bandwidth testing, the calculation module performs discrete Fourier transform processing on the echo signal to obtain the pulse echo spectrum and calculates the pulse spectrum and bandwidth. During relative pulse echo sensitivity testing, the calculation module reads the voltage V of the transmitted pulse signal. in and the voltage V of the echo signal out The calculation module calculates the relative pulse echo sensitivity. During beam angle testing, it calculates the beam angle using geometric formulas based on the measured values ​​of the incident point and the transverse aperture. During crosstalk testing, it reads the gain values ​​G1 and G2 and calculates the difference as the crosstalk value. Connected to the pulse generator 20 and oscilloscope 30, the calculation module automatically reads the voltage, waveform, and gain parameters of the pulse and echo signals. It then performs all calculations of pulse width, pulse spectrum and bandwidth, relative pulse echo sensitivity, beam angle, and crosstalk according to preset formulas, eliminating the need for manual readings or calculations. The module's measurement software can simultaneously measure the echo width in time-domain waveform display mode, perform discrete Fourier transform on the echo signal to obtain the spectrum, read the voltage parameters and substitute them into the logarithmic formula to calculate sensitivity, calculate the beam angle based on the geometric distance parameters, and calculate the crosstalk value based on the gain difference. This automates and standardizes the calculation process for the five performance parameters, and the calculation results are reproducible and verifiable.

[0095] like Figure 2 As shown, this invention also proposes a testing method for the ultrasonic unit of a hollow axle ultrasonic testing system for locomotives and rolling stock. The ultrasonic unit to be tested is connected to a test circuit, which includes multiple switchable signal paths. Multiple test states are constructed by switching the signal paths of the test circuit. In each test state, a preset excitation signal is provided to the ultrasonic unit, and the response signal of the ultrasonic unit is acquired. Based on the response signal, at least one of the following parameters of the ultrasonic unit is calculated: pulse repetition frequency, crosstalk suppression, equivalent input noise, dynamic range, attenuator accuracy, time baseline, and amplitude linearity.

[0096] The ultrasonic unit detection method of the ultrasonic testing system for hollow shafts of locomotives proposed in this invention connects the ultrasonic unit to a test circuit containing multiple switchable signal paths, applies a preset excitation signal under different test states and obtains the response signal, thereby realizing the quantitative calculation of key performance parameters such as pulse repetition frequency, crosstalk suppression, equivalent input noise, dynamic range, attenuator accuracy, time baseline and amplitude linearity.

[0097] The ultrasonic unit detection method of the ultrasonic testing system for hollow shafts of locomotives proposed in this invention can comprehensively and accurately evaluate multiple core indicators of the ultrasonic unit. The test results can be directly verified through the response signal, and have good repeatability and verifiability.

[0098] The ultrasonic unit testing method of the hollow shaft ultrasonic testing system for locomotives and rolling stock proposed in this invention uses the same test circuit to complete the measurement of multiple parameters through path switching, which simplifies the configuration of test equipment, reduces calibration complexity and maintenance costs, and improves the consistency of the testing process and the reliability of the system.

[0099] The ultrasonic unit testing method of the ultrasonic testing system for hollow shafts of locomotives proposed in this invention integrates the seven-parameter measurement process, which originally required multiple independent instruments to be set up separately in the laboratory, into a programmable controllable path switching sequence within a single device. This enables rapid on-site calibration of all parameters, significantly improving testing efficiency and result consistency. Furthermore, the ultrasonic unit does not need to be disassembled from the system during the entire process, allowing for multi-dimensional performance evaluation to be integrated into a single controllable testing process.

[0100] The present invention also proposes a testing device 300 for the ultrasonic unit of an ultrasonic testing system for hollow axles of locomotives and rolling stock, wherein the ultrasonic unit testing device 300 includes at least:

[0101] Signal generating unit 310 is used to generate excitation signals;

[0102] Signal conditioning unit, used to adjust signal amplitude;

[0103] The signal acquisition unit 330 is used to acquire waveform signals and measure voltage or time parameters.

[0104] The signal generating unit 310, the signal conditioning unit, and the signal acquisition unit 330 are selectively connected to the ultrasonic unit to be tested via the circuit switching unit 340 to perform the detection of at least one performance parameter of the ultrasonic unit.

[0105] The ultrasonic testing device 300 of the ultrasonic unit of the ultrasonic testing system for hollow axles of locomotives and rolling stock proposed in this invention, such as... Figure 3As shown, it integrates a signal generation unit 310, a signal conditioning unit, and a signal acquisition unit 330, and achieves selective connection with the ultrasonic unit 400 through a circuit switching unit 340. It can combine different functional units as needed to accurately and repeatably measure multiple performance parameters of the ultrasonic unit 400 (such as dynamic range, attenuator accuracy, time baseline linearity, etc.). The test results can be directly verified through voltage or time parameters.

[0106] The ultrasonic testing device 300 of the ultrasonic testing system for hollow axles of locomotives proposed in this invention adopts a modular structure and circuit switching mechanism, avoiding the redundant configuration of multiple independent testing devices, reducing hardware costs and maintenance complexity, while improving the consistency of the testing process and system stability. This ultrasonic unit testing device 300 integrates multi-functional testing capabilities into a unified architecture, consolidating it into a programmable controllable circuit switching and signal conditioning path within a single device. This enables one-click full-parameter testing on-site, significantly improving testing efficiency and data consistency, while avoiding installation errors introduced by disassembly.

[0107] In an optional embodiment of the present invention, the signal generation unit 310 may be an arbitrary waveform signal generator, used to generate a continuous sine wave signal or a sudden sound signal when equivalent input noise and dynamic range calibration are performed.

[0108] In an optional embodiment of the present invention, the signal conditioning unit includes at least a fixed attenuator 321 and a standard attenuator 322. The fixed attenuator 321 is used to attenuate the output signal of the ultrasonic unit 400 before it is input to the oscilloscope, reducing the signal amplitude to within the safe input voltage range of the oscilloscope. The standard attenuator 322 is used to adjust the gain and attenuation of the signal before it is input to the ultrasonic unit 400 during calibration of performance parameters such as equivalent input noise, attenuator error, amplitude linearity error, and timing line linearity error.

[0109] In an optional embodiment of the present invention, the signal acquisition unit 330 is an oscilloscope used for displaying and processing waveform signals when pulse repetition frequency, crosstalk suppression, and equivalent input noise are considered; at the same time, it realizes the measurement of parameters and voltage values ​​in the time and frequency domains of the waveform.

[0110] In an optional embodiment of the present invention, the performance parameters of the ultrasonic unit 400 include at least pulse repetition frequency, crosstalk suppression, dynamic range, equivalent input noise, attenuator error, amplitude linearity, and time-base linearity.

[0111] Specifically, the ultrasonic unit's testing device 300 calibrates the ultrasonic unit 400's pulse repetition frequency, crosstalk suppression, dynamic range, equivalent input noise, attenuator error, amplitude linearity, and timing line linearity. By calibrating these parameters using the ultrasonic unit's testing device 300, a comprehensive quantitative test of the ultrasonic unit 400's transmitted pulse timing characteristics, transmit / receive isolation, noise level, dynamic response range, attenuation control accuracy, time reference accuracy, and amplitude display linearity is achieved. This verifies the ultrasonic unit 400's data acquisition, signal processing, and waveform display performance, ensuring the reliable operation of the ultrasonic unit when detecting internal defects in hollow axles under field conditions.

[0112] In an optional embodiment of the present invention, the test circuit has a pulse repetition frequency test state. In the pulse repetition frequency test state, the output signal of the ultrasonic unit 400 is acquired, the time interval between at least two adjacent pulses in the output signal is measured, and the reciprocal of the time interval is used as the pulse repetition frequency.

[0113] In practical implementation, KA1 and KA5 in circuit switching unit 340 are turned on. The ultrasonic unit 400, fixed attenuator 321, and signal acquisition unit 330 (oscilloscope) constitute the test circuit. The ultrasonic unit 400 is set to a one-transmit-one-receive mode, and the output signal is connected to the signal acquisition unit 330 (oscilloscope) through the fixed attenuator 321. The sampling rate and sampling length of the signal acquisition unit 330 (oscilloscope) are adjusted so that it can display at least two pulse signals. The pulse repetition frequency is obtained by calculating the reciprocal of the time interval between the two pulses. The measurement process can be completed on-site without disassembling the ultrasonic unit. The adjustment of the sampling rate and sampling length ensures that the signal acquisition unit 330 (oscilloscope) can completely capture adjacent pulse waveforms. The time interval measurement and reciprocal calculation are both completed automatically by the measurement software, and the results can be directly verified from the waveform of the signal acquisition unit 330 (oscilloscope).

[0114] In an optional embodiment of the present invention, a crosstalk suppression detection state is provided. In the crosstalk suppression detection state, the transmitting end voltage and receiving end voltage of the ultrasonic unit 400 are acquired, and crosstalk suppression is calculated based on the ratio of the transmitting end voltage to the receiving end voltage.

[0115] In practical implementation, KA3, KA4, KA9, and KA10 in the circuit switching unit 340 are turned on. The input and output terminals of the ultrasonic unit 400, two 50Ω non-inductive resistors, and the signal acquisition unit 330 (oscilloscope) constitute the test circuit. The ultrasonic unit 400 is placed in a transmit-receive mode. The voltage signals at the input and output terminals of the ultrasonic unit 400 are divided by the two 50Ω resistors and connected to the two channels of the signal acquisition unit 330 (oscilloscope). The voltage value is obtained through the voltage measurement function of the signal acquisition unit 330 (oscilloscope), and crosstalk suppression is calculated according to the formula:

[0116] De = 20lg(V) 50 / V e )

[0117] Where De is crosstalk suppression, and V 50 Ve represents the transmitting voltage of the ultrasonic unit, and Ve represents the receiving voltage of the ultrasonic unit. The voltage signals at the input and output terminals of the ultrasonic unit are divided by two 50Ω non-inductive resistors and then connected to two channels of an oscilloscope. The transmitting and receiving voltages are simultaneously acquired. Crosstalk suppression is calculated by taking the logarithm of the ratio of the transmitting to receiving voltages. The measurement can be performed on-site without disassembling the ultrasonic unit. Crosstalk suppression quantitatively characterizes the energy leakage from the transmitter output to the receiver input in decibels. The calculation results can be directly verified from the oscilloscope voltage readings.

[0118] In an optional embodiment of the present invention, an equivalent input noise test state is provided. In the equivalent input noise test state, the gain of the ultrasonic unit 400 is adjusted to the maximum and the input signal is disconnected, and the electrical noise level is recorded. After reducing the gain, a continuous wave excitation signal is connected to the ultrasonic unit 400. The level or attenuation of the continuous wave excitation signal is adjusted until the level of the continuous wave excitation signal is equal to the electrical noise level. The voltage value and attenuation of the continuous wave excitation signal at this time are measured, and the equivalent input noise is calculated based on the voltage value, attenuation, and reduced gain value.

[0119] In specific implementation, KA1, KA2, KA5, KA7, and KA8 in the circuit switching unit 340 are turned on, and the ultrasonic unit 400 is placed in a one-transmit-one-receive mode. The input and output terminals of the ultrasonic unit 400, the arbitrary waveform signal generator, the fixed attenuator 321, the standard attenuator 322, and the oscilloscope constitute the test circuit. First, the ultrasonic unit gain is adjusted to the maximum, the input signal is disconnected, and the electrical noise level on the ultrasonic unit display screen is recorded. The gain is reduced by 40dB and the input signal is connected. The output terminal of the ultrasonic unit 400 is connected to the external trigger input terminal of the arbitrary waveform signal generator and the trigger input terminal of the oscilloscope through the fixed attenuator 3321. The arbitrary waveform signal generator is adjusted to generate a continuous sine wave signal, and this signal is connected to the input terminal of the oscilloscope module. At the same time, it is connected to the input terminal of the ultrasonic unit 400 through the standard attenuator 322. The standard attenuator and the input signal level are adjusted until the input signal level is equal to the aforementioned electrical noise level on the display screen. The peak-to-peak voltage value Vin of the input signal is measured at this time, and the attenuation S of the standard attenuator is recorded.

[0120] Calculate the equivalent input noise V using formula (2). ein :

[0121] V ein =V in / 10 (S+40 / 20) (2)

[0122] Calculate the noise per square root bandwidth using formula (3):

[0123] n in =V ein / (f u -f l ) 1 / 2 (3)

[0124] By adjusting the gain of the ultrasonic unit 400 to the maximum recording noise floor level, reducing the gain, and then connecting a continuous wave excitation signal, the excitation signal level or attenuation is adjusted so that the input signal level is exactly equal to the noise level. The input signal voltage and attenuation are measured at this time. Then, based on the voltage value, attenuation, and reduced gain value, the equivalent noise at the input end is calculated. Finally, the equivalent input noise and the noise per square root bandwidth are obtained. The measurement can be completed on-site without disassembling the ultrasonic unit. The equivalent input noise quantitatively characterizes the noise floor level of the ultrasonic unit receiver in the form of voltage value. The calculation results can be reproduced and verified by oscilloscope waveform and attenuator readings.

[0125] In an optional embodiment of the present invention, the test circuit has a dynamic range test state; in the dynamic range test state, a burst sound signal is used as an excitation signal and connected to the ultrasonic unit 400; the gain of the ultrasonic unit 400 is adjusted to the minimum value, and the amplitude of the excitation signal is adjusted until the ultrasonic unit display is saturated or reaches a first preset amplitude, and the voltage of the excitation signal at this time is measured as the maximum input voltage; the gain of the ultrasonic unit 400 is adjusted to the maximum value or the electrical noise level is at a second preset amplitude, and the amplitude of the excitation signal is adjusted so that the amplitude displayed by the ultrasonic unit 400 reaches a third preset amplitude, and the voltage of the excitation signal at this time is measured as the minimum input voltage; the dynamic range is calculated based on the maximum input voltage and the minimum input voltage or the equivalent input noise.

[0126] In practical implementation, KA1, KA2, KA5, KA7, and KA8 in the circuit switching unit 340 are connected to form a test circuit. The ultrasonic unit 400 is set to a one-transmit-one-receive mode. The input (output) terminal of the ultrasonic unit 400, the signal generation unit 310 (arbitrary waveform signal generator), the fixed attenuator 321, the standard attenuator 322, and the signal acquisition unit 330 (oscilloscope) constitute the test circuit.

[0127] The output of the ultrasonic unit 400 is connected to the external trigger input of an arbitrary waveform signal generator and the external trigger input of an oscilloscope via a fixed attenuator 321. The signal generation unit 310 is adjusted to generate a burst signal of 10 cycles, and this signal is connected to the input of the signal acquisition unit 330 (oscilloscope). Simultaneously, a standard attenuator 322 is connected to the input of the ultrasonic unit 400. The gain of the ultrasonic unit 400 is adjusted to its minimum value, and the amplitude of the signal generator output signal is increased until the ultrasonic unit 400 displays saturation, or the waveform amplitude reaches 100% of the full screen height. The voltage of the input signal at this time is measured as Vmax. The ultrasonic unit 400 is then set to its maximum gain (if the electrical noise level is greater than 5% of the full screen height, the gain is reduced until the electrical noise level amplitude is 5% of the full screen height). The amplitude of the output signal of the signal generation unit 310 is adjusted so that the signal amplitude displayed on the ultrasonic unit 400 screen reaches 10% of the full screen height. The voltage of the input signal at this time is measured as Vmax. min .

[0128] When V min Below equivalent input noise V ein Then, calculate the dynamic range according to formula (4):

[0129] (4)

[0130] When V min Not less than the equivalent input noise V ein At that time, the dynamic range is calculated according to formula (5):

[0131] (5)

[0132] The above measurement process can be completed on-site without disassembling the ultrasonic unit. The dynamic range is quantitatively characterized in decibels as the ratio of the maximum signal to the minimum signal that the ultrasonic unit can display, reflecting the amplitude response capability of the ultrasonic unit 400. The calculation results can be reproduced and verified by the waveform and gain settings of the signal acquisition unit 330.

[0133] In another optional embodiment of the present invention, the test circuit has an attenuator accuracy test state; in the attenuator accuracy test state, a periodic signal is used as an excitation signal and connected to the ultrasonic unit 400; the gain of the ultrasonic unit 400 is set to an intermediate value, and the attenuation of the ultrasonic unit 400 and the amplitude of the excitation signal are adjusted so that the displayed amplitude is a reference amplitude; the gain of the ultrasonic unit 400 is changed and the attenuation is adjusted synchronously to maintain a constant displayed amplitude, and the deviation between the gain of the ultrasonic unit 400 and the attenuation is recorded as the attenuator error.

[0134] Specifically, KA1, KA2, KA5, KA7, and KA8 in the circuit switching unit 340 are connected to form a test circuit. The ultrasonic unit 400 is set to a transmit-receive mode, and the output of the ultrasonic unit 400 is connected to the external trigger input of the signal generation unit 310 and the trigger input of the oscilloscope through the fixed attenuator 321. The input (output) of the ultrasonic unit 400, the signal generation unit 310, the fixed attenuator 321, the standard attenuator 322, and the signal acquisition unit 330 constitute the test circuit.

[0135] The signal generating unit 310 generates a sine wave signal with one cycle (e.g., a repetition frequency of 1 kHz, a signal frequency of 5 MHz, and a sine wave signal of 500 mV), and connects the signal to the input terminal of the signal acquisition unit 330; at the same time, it is connected to the input terminal of the ultrasonic unit 400 through a standard attenuator 322.

[0136] With the gain of the ultrasonic unit 400 adjusted to an intermediate value, and the standard attenuator 322 set to be 10 dB higher than the ultrasonic unit gain, the output signal amplitude of the signal generating unit 310 is adjusted to occupy 80% of the full screen height. The gain of the ultrasonic unit 400 is reduced in appropriate steps, and the standard attenuator 322 is adjusted to maintain the signal at a constant height. The deviation between the gain of the ultrasonic unit 400 and the standard attenuator 322 is recorded, which is the attenuator error of the ultrasonic unit 400.

[0137] The above measurement process can be completed on-site without disassembling the ultrasonic unit 400. The attenuator error is quantitatively characterized by the decibel deviation value, reflecting the degree of deviation between the actual attenuation of the attenuator and the nominal value. The measurement results can be reproduced and verified by displaying the amplitude on the signal acquisition unit 330 and the standard attenuator reading.

[0138] In another optional embodiment of the present invention, the test circuit has a time baseline linearity test state; in the time baseline linearity test state, multiple regular pulse test signals are used as excitation signals and connected to the ultrasonic unit 400; the repetition frequency and sound path range are adjusted so that multiple pulses separated from each other appear on the display screen of the ultrasonic unit 400; the attenuation amount and excitation signal amplitude are adjusted so that the pulse amplitude is a reference amplitude; the delay is adjusted so that the leading edge of the pulse at a specific position is aligned with the designated position of the horizontal scale, and the deviation between the theoretical position and the actual position of the leading edge of the remaining pulses is measured, and the time baseline linearity error is calculated with the maximum deviation.

[0139] In practical implementation, KA1, KA2, KA5, KA7, and KA8 in the circuit switching unit 340 are connected to form a test circuit. The ultrasonic unit 400 is set to a one-transmit-one-receive mode, and the output terminal of the ultrasonic unit 400 is connected to the external trigger input terminal of the signal generating unit 310 and the trigger input terminal of the signal acquisition unit 330 through the fixed attenuator 321.

[0140] The signal generating unit 310 generates 11 regular sinusoidal pulse test signals, which are then connected to the input terminal of the signal acquisition unit 330; and connected to the input terminal of the flaw detector via a standard attenuator. The ultrasonic unit 400 is set to a delay of 0s, and the repetition frequency and sound path range of the signal generating unit 310 are adjusted so that 11 regular, separate pulse test signals appear on the display screen of the ultrasonic unit 400.

[0141] Set the gain of the ultrasonic unit 400 to 50% of the total gain value. Adjust the output signal amplitude of the standard attenuator 322 and the signal generation unit 310 until the test pulse displayed on the ultrasonic unit 400 is 80% of the full screen height. Adjust the pulse repetition frequency and delay time so that the leading edge of the third pulse is at 20% of the horizontal scale, and the leading edge of the ninth pulse is at 80% of the horizontal scale. Record the deviation of the leading edge of the remaining nine pulses from the theoretical position of the horizontal scale, and take the maximum deviation. Calculate the baseline linearity error according to formula (6):

[0142] (6)

[0143] The above measurement process can be completed on-site without disassembling the ultrasonic unit 400. The time baseline linearity error quantitatively characterizes the linearity of the ultrasonic unit 400 time baseline, reflecting the degree to which the proportional relationship between the pulse position on the screen and the actual time is maintained. The measurement results can be reproduced and verified by oscilloscope waveform and scale reading.

[0144] In an optional embodiment of the present invention, the test circuit has an amplitude linearity test state; in the amplitude linearity test state, a periodic signal is used as an excitation signal and connected to the ultrasonic unit 400; the initial gain of the ultrasonic unit 400 is recorded, the attenuation is set as a reference value, and the amplitude and gain of the excitation signal are adjusted so that the displayed amplitude is the reference amplitude; keeping the gain constant, the attenuation is set to multiple different values, and the amplitude of the displayed signal under each attenuation is measured; the amplitude linearity error is calculated based on the deviation between the measured displayed signal amplitude and the theoretical amplitude.

[0145] In practical implementation, KA1, KA2, KA5, KA7, and KA8 in circuit switching unit 340 are connected to form a test circuit. The ultrasonic unit is set to a one-transmit-one-receive mode, and the output terminal of ultrasonic unit 400 is connected to the external trigger input terminal of signal generation unit 310 and the trigger input terminal of oscilloscope through fixed attenuator 321; the input and output terminals of ultrasonic unit 400, signal generation unit 310, fixed attenuator 321, standard attenuator 322, and signal acquisition unit 330 constitute the test circuit.

[0146] The signal generation unit 310 generates a sine wave signal with one cycle (e.g., a repetition frequency of 1 kHz, a signal frequency of 5 MHz, and a sine wave signal of 500 mV), and connects the signal to the input terminal of the signal acquisition unit 330 (oscilloscope); and connects it to the input terminal of the ultrasonic unit 400 through a standard attenuator.

[0147] At the start of the test, record the initial gain setting; set the standard attenuator 322 to 2dB and adjust the input signal and gain of the ultrasonic unit 400 so that the signal reaches 80% of the full screen height; without changing the gain of the ultrasonic flaw detector, set the standard attenuator 322 to the value given in the first column of Table 1, and measure the signal amplitude on the ultrasonic unit screen under different attenuation values.

[0148] Table 1:

[0149] Standard attenuator setting / dB The theoretical value of the displayed signal amplitude (percentage of full screen height / %) Acceptable metrics (percentage of full-screen height / %) 1 90 88-92 2 80 Reference line 4 64 62-66 6 50 48-52 8 40 38-42 12 25 23-27 14 20 18-22 20 10 8-12 26 5 3-7

[0150] Calculate the amplitude linearity error using formula (7):

[0151] (7)

[0152] The above measurement process can be completed on-site without disassembling the ultrasonic unit 400. The amplitude linearity error quantitatively characterizes the linearity of the response of the ultrasonic unit 400 to the amplitude of the input signal, reflecting the degree to which the proportional relationship between the displayed amplitude and the amplitude of the input signal is maintained under different attenuation levels. The measurement results can be reproduced and verified by oscilloscope waveforms and attenuator readings.

[0153] In an optional embodiment of the present invention, both the signal generating unit 310 and the signal conditioning unit are programmable functional modules. The test parameters of the signal generating unit 310 and the signal conditioning unit are set by sending corresponding instructions via host computer software.

[0154] In an optional embodiment of the present invention, the signal acquisition unit 330 adopts a high-speed AD acquisition card, which is connected to the test host computer, and realizes the reading and calculation functions of voltage parameters and waveform parameters through measurement software.

[0155] The detailed explanations of the above embodiments are intended only to explain the present invention so as to facilitate a better understanding of the present invention. However, these descriptions should not be construed as limiting the present invention for any reason. In particular, the various features described in different embodiments can be arbitrarily combined with each other to form other embodiments. Unless there is an explicit description to the contrary, these features should be understood to be applicable to any embodiment, and not limited to the described embodiments.

Claims

1. A dedicated metrological traceability instrument for an ultrasonic testing system of hollow axles for locomotives and rolling stock, characterized in that, include: An ultrasonic unit testing device is used to calibrate the performance parameters of the ultrasonic unit in a hollow axle ultrasonic testing system. An ultrasonic probe testing device is used to calibrate the performance parameters of the ultrasonic probe in a hollow axle ultrasonic testing system. The calibration block has a guide hole and at least one reflective structure; the calibration block works in conjunction with the ultrasonic probe testing device to calibrate the performance parameters of the ultrasonic probe.

2. The dedicated metrological traceability device for the ultrasonic testing system of hollow axles of locomotives and rolling stock as described in claim 1, characterized in that, The performance parameters of the ultrasonic unit include at least pulse repetition frequency, crosstalk suppression, dynamic range, equivalent input noise, attenuator error, amplitude linearity, and time-base linearity.

3. The dedicated metrological traceability device for the ultrasonic testing system of hollow axles of locomotives and rolling stock as described in claim 1, characterized in that, The performance parameters of the ultrasonic probe include at least the radio frequency pulse waveform, pulse spectrum and bandwidth, relative pulse echo sensitivity, beam angle and crosstalk.

4. A testing method for an ultrasonic probe in an ultrasonic testing system for hollow axles of locomotives and rolling stock, characterized in that, A calibration block is provided, the calibration block having at least one preset reflective structure, the calibration block is moved along a preset path relative to the ultrasound probe under test, and a pulse signal is provided to the ultrasound probe to excite the ultrasound probe to emit ultrasound waves, the ultrasound waves are reflected by the reflective structure to form an echo signal; the echo signal is acquired and at least one performance parameter of the ultrasound probe is calculated based on the echo signal.

5. The detection method of the ultrasonic probe as described in claim 4, characterized in that, The preset path is as follows: move the ultrasound probe to find the highest reflected echo of the reflective structure, and remain stationary at the location where the highest reflected echo is found to obtain the echo signal.

6. The detection method of the ultrasonic probe as described in claim 4, characterized in that, The performance parameters of the ultrasonic probe include at least the pulse width, which is measured in the time domain waveform as the pulse width of the ultrasonic probe.

7. The detection method of the ultrasonic probe as described in claim 4, characterized in that, The performance parameters of the ultrasonic probe include at least the pulse spectrum and bandwidth. The echo signal is frequency domain transformed to obtain the pulse echo spectrum. The pulse spectrum and bandwidth are calculated based on the upper and lower frequency corresponding to the amplitude drop of a preset decibel in the spectrum.

8. The detection method of the ultrasonic probe as described in claim 4, characterized in that, The preset decibel level is -6dB; the pulse spectrum and the bandwidth are calculated according to the following formulas: f0 = (f u + f l ) / 2 Δf rel = [(f u - f l ) / f0] × 100% Where f0 is the pulse spectrum, f u and f l These are the upper and lower frequency limits corresponding to -6dB, Δf rel For bandwidth.

9. The detection method of the ultrasonic probe as described in claim 6, characterized in that, The performance parameters of the ultrasonic probe include at least the relative pulse-echo sensitivity, the voltage of the pulse signal, and the voltage of the echo signal. Calculate the relative pulse echo sensitivity using the following formula. S r = 20lg(V out / V in ) In the formula, Sr is the relative pulse echo sensitivity, and V out V is the voltage of the echo signal. in The voltage of the pulse signal.

10. The detection method of the ultrasonic probe as described in claim 4, characterized in that, The performance parameters of the ultrasonic probe include at least the beam angle. The calibration block has a first reflection structure and a second reflection structure. The ultrasonic probe is moved along a preset path, and the highest reflected echo of the first reflection structure on the calibration block is measured to determine the probe incident point position. The ultrasonic probe is then moved along the preset path, and the highest reflected echo of the second reflection structure on the calibration block is measured. Based on the probe incident point position, the geometric position of the second reflection structure, and the preset geometric relationship on the calibration block, a geometric model is established, and the beam angle of the ultrasonic probe is calculated.

11. The detection method of the ultrasonic probe as described in claim 4, characterized in that, The ultrasonic probe is a dual-crystal straight probe. The performance parameters of the ultrasonic probe also include crosstalk. The dual-crystal straight probe is placed on the calibration test block, and the highest reflected echo of the third reflection structure at a preset distance from the detection surface is found. The gain is adjusted so that the amplitude of the echo reaches the first preset amplitude, and the gain value G1 is recorded. Increase the gain so that the amplitude of the probe interface wave reaches the first preset amplitude, and record the gain value G2; Calculate the crosstalk value as the difference between G2 and G1.

12. A testing device for an ultrasonic probe in an ultrasonic testing system for hollow axles of locomotives and rolling stock, characterized in that, The detection device of the ultrasonic probe includes at least: The calibration block has at least one preset reflective structure, which is capable of generating an echo signal under the action of ultrasonic waves; A pulse generator, connected to the ultrasonic probe, is used to provide a pulse signal to the ultrasonic probe to excite the ultrasonic probe to emit ultrasonic waves; An oscilloscope, connected to the ultrasound probe, is used to acquire the echo signal and display the waveform.

13. The detection device for the ultrasonic probe as described in claim 12, characterized in that, The detection device further includes a calculation module, which is connected to the pulse generator and the oscilloscope and calculates the performance parameters of the ultrasonic probe based on the pulse signal and the echo signal.

14. The detection device for the ultrasonic probe as described in claim 12, characterized in that, The calibration block has a guide channel into which the probe of the ultrasonic testing system for hollow axles of locomotives and rolling stock can be inserted. The guide channel is used to guide the ultrasonic probe on the probe to move along the preset path.

15. The detection device for the ultrasonic probe as described in claim 12, characterized in that, The calibration block has a first reflection structure and a second reflection structure. The first reflection structure is an arc-shaped surface reflection structure, and the second reflector is a circular aperture reflection structure.

16. A method for detecting the ultrasonic unit of an ultrasonic testing system for hollow axles of locomotives and rolling stock, characterized in that, The ultrasonic unit to be tested is connected to a test circuit, which includes multiple switchable signal paths. By switching the signal paths of the test circuit, multiple test states are formed respectively. In each test state, a preset excitation signal is provided to the ultrasonic unit, and the response signal of the ultrasonic unit is acquired. Based on the response signal, at least one of the following is calculated for the ultrasonic unit: pulse repetition frequency, crosstalk suppression, equivalent input noise, dynamic range, attenuator accuracy, time baseline and amplitude linearity.

17. The detection method for an ultrasonic unit as described in claim 16, characterized in that, The test circuit has a pulse repetition frequency test state. In the pulse repetition frequency test state, the output signal of the ultrasound unit is acquired, the time interval between at least two adjacent pulses in the output signal is measured, and the reciprocal of the time interval is used as the pulse repetition frequency.

18. The detection method for an ultrasonic unit as described in claim 16, characterized in that, The test circuit has a crosstalk suppression detection state. In the crosstalk suppression detection state, the transmitting end voltage and receiving end voltage of the ultrasonic unit are acquired, and crosstalk suppression is calculated based on the ratio of the transmitting end voltage to the receiving end voltage.

19. The detection method for an ultrasonic unit as described in claim 16, characterized in that, The test circuit has an equivalent input noise test state; in the equivalent input noise test state, the gain of the ultrasonic unit is adjusted to the maximum and the input signal is disconnected, and the electrical noise level is recorded; after reducing the gain, a continuous wave excitation signal is connected to the ultrasonic unit; Adjust the level or attenuation of the continuous wave excitation signal until the level of the continuous wave excitation signal is equal to the electrical noise level; measure the voltage value and attenuation of the continuous wave excitation signal at this time, and calculate the equivalent input noise based on the voltage value, the attenuation and the reduced gain value.

20. The detection method for an ultrasonic unit as described in claim 16, characterized in that, The test circuit has a dynamic range test state. In the dynamic range test state, a burst sound signal is used as the excitation signal and connected to the ultrasonic unit. The gain of the ultrasonic unit is adjusted to the minimum value, and the amplitude of the excitation signal is adjusted until the ultrasonic unit displays saturation or reaches a first preset amplitude. The voltage of the excitation signal at this time is measured as the maximum input voltage. The gain of the ultrasonic unit is adjusted to the maximum value or the electrical noise level is set to a second preset amplitude. The amplitude of the excitation signal is adjusted so that the ultrasonic unit displays an amplitude of a third preset amplitude. The voltage of the excitation signal at this time is measured as the minimum input voltage. The dynamic range is calculated based on the maximum input voltage and the minimum input voltage or the equivalent input noise.

21. The detection method for an ultrasonic unit as described in claim 16, characterized in that, The test circuit has an attenuator accuracy test state; in the attenuator accuracy test state, a periodic signal is used as the excitation signal and connected to the ultrasonic unit; the gain of the ultrasonic unit is set to an intermediate value, and the attenuation of the ultrasonic unit and the amplitude of the excitation signal are adjusted so that the displayed amplitude is the reference amplitude; the gain of the ultrasonic unit is changed and the attenuation is adjusted synchronously to maintain a constant displayed amplitude, and the deviation between the gain of the ultrasonic unit and the attenuation is recorded as the attenuator error.

22. The detection method for an ultrasonic unit as described in claim 16, characterized in that, The test circuit has a time-baseline test state; in the time-baseline test state, multiple regular pulse test signals are used as excitation signals and connected to the ultrasonic unit; Adjust the repetition frequency and sound path range to make multiple pulses appear on the display screen of the ultrasonic unit; adjust the attenuation and excitation signal amplitude to make the pulse amplitude a reference amplitude; Adjust the delay to align the leading edge of the pulse at a specific position with the designated position on the horizontal scale. Measure the deviation between the theoretical and actual positions of the remaining leading edges of the pulses, and calculate the baseline linearity error using the maximum deviation.

23. The detection method for an ultrasonic unit according to claim 16, characterized in that, The test circuit has an amplitude linearity test state; in the amplitude linearity test state, a periodic signal is used as the excitation signal and connected to the ultrasonic unit; the initial gain of the ultrasonic unit is recorded, the attenuation is set as a reference value, and the excitation signal amplitude and gain are adjusted so that the displayed amplitude is the reference amplitude; keeping the gain constant, the attenuation is set to multiple different values, and the displayed signal amplitude under each attenuation is measured; the amplitude linearity error is calculated based on the deviation between the measured displayed signal amplitude and the theoretical amplitude.

24. A testing device for the ultrasonic unit of an ultrasonic testing system for hollow axles of locomotives and rolling stock, characterized in that, The detection device of the ultrasonic unit includes at least: The signal generation unit is used to generate excitation signals; Signal conditioning unit, used to adjust signal amplitude; The signal acquisition unit is used to acquire waveform signals and measure voltage or time parameters. The signal generation unit, signal conditioning unit, and waveform acquisition unit are selectively connected to the ultrasound unit to be tested via a circuit switching unit to perform the detection of at least one performance parameter of the ultrasound unit.

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