A dual-crystal ultrasonic probe and automatic sensitivity detection method of its flaw detection system

Abstract

The present invention discloses a method for automatically detecting the sensitivity of a dual-crystal ultrasonic probe and its flaw detection system. The method does not require the use of a standard test block. The dual-crystal ultrasonic probe's emitter and echo electrode independently transmit and receive interface waves. The emitter or echo electrode's wafer generates ultrasonic waves, which are then transmitted by the end face of the dual-crystal ultrasonic probe to form interface waves, which are then received by the wafer generating the ultrasonic waves. Alternatively, the emitter and echo electrode of the dual-crystal ultrasonic probe are connected in parallel to form a transmitting echo electrode. The transmitting echo electrode's wafer generates ultrasonic waves, which are then transmitted by the end face of the dual-crystal ultrasonic probe to form interface waves, which are then received by the wafer of the transmitting echo electrode. The present invention can automatically detect the sensitivity of a dual-crystal ultrasonic probe and its flaw detection system quickly and without the need for a standard test block.

Description

Technical Field

[0001] The present invention belongs to the field of ultrasonic nondestructive flaw detection, and in particular relates to a dual-crystal ultrasonic probe (also called ultrasonic transducer) and an automatic sensitivity detection method of a flaw detection system thereof. Background Art

[0002] The sensitivity of the existing traditional dual crystal ultrasonic probe needs to be measured using a standard test block (such as Figure 2 This method is suitable for testing the sensitivity of a small number of dual-element ultrasonic probes used indoors. It has established standards and methods. A dual-element ultrasonic probe operates in a transmit-receive mode. The right-hand transmitting element transmits ultrasonic waves, which travel through a wedge and into a standard test block. When the ultrasonic wave reaches the location of an artificial standard defect, it is reflected and transmitted to the left-hand receiving element, thereby detecting the defect in the artificial standard test block. The ability to detect artificial standard defects represents the sensitivity of the dual-element ultrasonic probe and flaw detection system.

[0003] However, when working outdoors and requiring a large number of probes, these traditional measurement methods are difficult to implement. This is especially true with the development of China's railways, where flaw detection testing has become routinely used in online inspections. This represents a breakthrough in the application of ultrasonic testing. In online inspection systems, which require hundreds or even more ultrasonic probes, traditional methods for testing the sensitivity of ultrasonic and flaw detection systems are time-consuming and require limited window time for online testing.

[0004] Therefore, in this case, a fast, no-online, automatic detection method for the sensitivity of dual-crystal ultrasonic probes and their flaw detection systems is needed to solve the current daily use problems of through-type flaw detection systems. Summary of the Invention

[0005] The object of the present invention is to provide a method for automatically detecting the sensitivity of a dual-crystal ultrasonic probe and its flaw detection system, which can automatically detect the sensitivity of a dual-crystal ultrasonic probe and its flaw detection system quickly in a short time without the need for a standard test block.

[0006] The present invention solves the technical problem, and the technical solution adopted is:

[0007] A dual-crystal ultrasonic probe and an automatic sensitivity detection method for its flaw detection system, the method not requiring the use of a standard test block. The dual-crystal ultrasonic probe's emitter and echo electrode independently transmit and receive interface waves: the emitter or echo electrode's crystal generates ultrasonic waves, which are then emitted by the end face of the dual-crystal ultrasonic probe to form interface waves, which are then received by the crystal that generates the ultrasonic waves.

[0008] Alternatively, the emitter and echo pole of the dual-crystal ultrasonic probe are connected in parallel to form a transmitting echo pole; the chip of the transmitting echo pole generates ultrasonic waves, and the end face of the dual-crystal ultrasonic probe emits and forms interface waves, which are received by the chip of the transmitting echo pole.

[0009] Furthermore, the steps of the method are as follows:

[0010] (1) The emitter, echo electrode or transmitting echo electrode of the dual-crystal ultrasonic probe emits ultrasonic waves. Due to the existence of the end surface of the emitter, echo electrode or transmitting echo electrode itself, the wave height amplitude and gain value of each interface wave are recorded at this time;

[0011] (2) when the wave height amplitude of the interface wave of the emitter, echo electrode, or transmitting echo electrode is respectively the same as the wave height reference amplitude of the dual-crystal ultrasonic probe and the front-end of the flaw detection system thereof, determining the difference between the gain value of the emitter, echo electrode, or transmitting echo electrode and the gain reference value of the front-end of the dual-crystal ultrasonic probe and the flaw detection system thereof at this time;

[0012] (3) During the sensitivity self-test, the gain value of the emitter, the gain value of the echo electrode, or the gain value of the emission echo electrode is first reduced by the respective differences in (2) until the wave height amplitude of the emitter, the echo electrode, or the emission echo electrode reaches the wave height reference amplitude, then the sensitivity of the dual crystal ultrasonic probe and its flaw detection system is considered qualified;

[0013] (4) After the self-test is completed, the probe gain value is restored to the gain of the dual-crystal ultrasonic probe and the flaw detection system before the self-test.

[0014] Furthermore, the step (2):

[0015] On the basis of the wave height amplitude of the emitter of (1), the gain value thereof is continuously reduced until the wave height amplitude of the emitter reaches the wave height reference amplitude, and the gain value at this time is recorded as S4; S4 is compared with the gain reference value to obtain the difference △S1 of the emitter;

[0016] Or, based on the echo pole wave height amplitude of (1), the gain value is continuously reduced so that the echo pole wave height amplitude reaches the wave height reference amplitude, and the gain value at this time is recorded as S5; S5 is compared with the probe gain reference value to obtain the difference △S2 of the echo pole;

[0017] Alternatively, the gain value of the transmitting echo pole is continuously reduced based on the wave height amplitude of the transmitting echo pole in (1) so that the wave height amplitude of the transmitting echo pole reaches the wave height reference amplitude, and the gain value at this time is recorded as S6; S6 is compared with the probe gain reference value to obtain the difference △S3 of the echo pole.

[0018] Furthermore, in step (3): first, the gain value of the emitter, the gain value of the echo pole or the gain value of the emission echo pole are respectively reduced by the respective differences in (2), and the operation of (1) is repeated until the wave height amplitude of the emitter, the echo pole or the emission echo pole reaches the wave height reference amplitude respectively, then the sensitivity of the dual crystal probe and its flaw detection system is considered to be qualified.

[0019] Furthermore, the multiple dual-crystal ultrasonic probes of the flaw detection system independently complete the steps of the automatic detection method.

[0020] Furthermore, before the automatic sensitivity detection method starts, the sensitivity of the dual-crystal ultrasonic probe and its flaw detection system is detected using artificial standard defects of a standard test block, and the wave height amplitude and probe gain value at this time are recorded as the wave height reference amplitude and the probe gain reference value.

[0021] A method for automatically detecting the sensitivity of a dual-crystal ultrasonic probe and its flaw detection system utilizes the probe's own interface waves during operation. This method uses a portion of the probe itself (typically its own organic glass) as a test block, eliminating the need for traditional standard test blocks. Specifically, one crystal of the dual-crystal ultrasonic probe generates ultrasonic waves, which are reflected by the probe's organic glass end surface to form interface waves, which are then received by the crystal.

[0022] The sensitivity self-test of the twin-crystal ultrasonic probe and its flaw detection system is carried out through the interface wave generated by the end face of the organic glass. The twin-crystal ultrasonic probe works in a transmit-receive mode. During normal operation, the interface wave cannot be received due to the characteristics of the twin-crystal ultrasonic probe. When entering the self-test mode, the circuit design makes the transmitting chip and receiving chip of the twin-crystal ultrasonic probe independently transmit and receive ultrasonic signals. Figure 1 、 Figure 3 、 Figure 4 、 Figure 5 shown.

[0023] Compared with the existing technology, the beneficial effects of the present invention are as follows:

[0024] (1) By utilizing the interface wave self-testing ultrasonic probe and the sensitivity of the flaw detection system, rapid and efficient probe self-testing can be performed, saving time, especially in the field where the probe is used frequently, such as the trackside dynamic flaw detection equipment used in the rail transit field.

[0025] (2) It provides a simple and effective means to judge the sensitivity of the dual crystal probe or the sensitivity of the flaw detection system of large ultrasonic flaw detection equipment.

[0026] (3) The present invention is a supplement and improvement to the sensitivity detection of the traditional ultrasonic flaw detection system, and meets the current development needs of railway wheel non-destructive flaw detection entering the field of daily use. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the principle of the present invention.

[0028] Figure 2 This is a schematic diagram of using a standard test block to test the sensitivity of a dual crystal probe.

[0029] Figure 3 It is a schematic diagram of the emitter self-detection of the present invention.

[0030] Figure 4 It is a schematic diagram of the echo pole self-detection of the present invention.

[0031] Figure 5 It is a schematic diagram of the self-detection of the transmitting and echoing electrodes formed by connecting the transmitting and echoing electrodes in parallel.

[0032] Figure 6 It is a flow chart of the method of the present invention.

[0033] Among them, 1, 2, 3, and 4 are all switch contact points (relays and other on-off components can be used), 5 is a controller, 6 is an emitter, 7 is an ultrasonic control unit (used to generate ultrasonic excitation high voltage and display echoes, and can also be replaced by an ultrasonic detector), 8 is a transmitting line, 9 is an echo line, 10 is a transmitting line interface, 11 is an echo line interface, 12 is an echo electrode, 13 is a standard test block, and 14 is a dual-crystal ultrasonic probe. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0035] The principle of the automatic sensitivity detection method of the dual-crystal ultrasonic probe and its flaw detection system of this embodiment is as follows: a part of the dual-crystal ultrasonic probe 14 itself (the wedge located on its end surface, generally made of organic glass) is regarded as a test block, and the interface wave of the dual-crystal ultrasonic probe 14 is used. The emitter 6 of the dual-crystal ultrasonic probe 14 (mainly the emitter crystal, wedge, cable and related circuits) emits ultrasonic waves (at this time, the echo electrode 12 is disconnected), and the ultrasonic waves form interface waves (such as Figure 3 As shown), the emitter 6 stops emitting ultrasonic waves and receives interface waves. Similarly, the echo electrode 12 (mainly receiving the wafer, wedge, cable and related circuits) emits ultrasonic waves (the emitter 6 is disconnected at this time), and the ultrasonic waves form interface waves on the organic glass of the echo electrode 12. At this time, the echo electrode 12 stops emitting ultrasonic waves and receives the interface waves of the echo electrode 12 (as shown). Figure 4 As shown), that is, the echo electrode 12 and the emitter 6 each transmit and receive the interface wave independently of each other, and the amplitude of the interface wave is used to perform sensitivity self-test of the ultrasonic dual crystal probe and its flaw detection system.

[0036] Example 1:

[0037] The working process of the automatic sensitivity detection method of the dual crystal ultrasonic probe and its flaw detection system of this embodiment is as follows: Figure 6 As shown:

[0038] Step 1: Using the artificial standard defects of the standard test block (such as Flat-bottom hole, the specific defect depends on the flaw detection standard), test the sensitivity of the dual-crystal ultrasonic probe and its flaw detection system, record the sensitivity amplitude (wave height amplitude) at this time as H1 (set as the reference value), and record the probe gain value S1 at this time (set as the reference value).

[0039] Step 2: Use the emitter 6 of the dual crystal ultrasonic probe 14 to emit ultrasonic waves (at this time, the echo line of the echo electrode 12 is disconnected). Due to the presence of the organic glass of the emitter 6 itself, an interface wave (such as Figure 3 As shown), the emitter 6 receives the interface wave through a special circuit. At this time, the wave height amplitude is H2 and the probe gain is S2.

[0040] Step 3: Use the echo electrode 12 of the double crystal ultrasonic probe 14 to transmit ultrasonic waves (the emission line of the emitter 6 is disconnected at this time). Due to the presence of the organic glass of the echo electrode 12 itself, an interface wave (such as Figure 4 As shown), the echo pole 12 receives the interface wave through a special circuit. At this time, the wave height amplitude is H3 and the probe gain is S3.

[0041] Step 4: Based on the wave height amplitude H2 in step 2, continuously reduce the probe gain until it reaches the wave height amplitude H1 in step 1. Record the probe gain value at this time as S4.

[0042] Step 5: Based on the wave height amplitude H3 in step 3, continuously reduce the probe gain until it reaches the amplitude wave height H1 in step 1. Record the probe gain value at this time as S5.

[0043] Step 6: Compare the difference between S4 and S1 to obtain △S1, and compare the difference between S5 and S1 to obtain △S2.

[0044] Step 7: Before performing a sensitivity self-test on the dual-crystal ultrasonic probe and flaw detection system, automatically reduce the probe gain of the emitter 6 and the probe gain of the echo electrode 12 by the values ​​of △S1 and △S2 in step 5 above. When the wave height amplitudes of the emitter 6 and the echo electrode 12 reach H1, respectively, the dual-crystal probe and its flaw detection system are considered to have qualified sensitivity.

[0045] The self-test process is the same as steps 2 and 3 above, specifically as follows:

[0046] (a) The switch contacts 1 and 2 in the controller 5 are turned on (the switch contacts 3 and 4 are turned off), the emitter 6 finishes transmitting the ultrasonic wave, the switch contacts 1 and 4 are turned on (the switch contacts 2 and 3 are turned off), the transmitting line of the probe is used as the echo line, and the ultrasonic detection equipment receives the echo, so that the emitter 6 of the ultrasonic probe can be self-tested. Figure 3 shown.

[0047] (b) The switch contacts 2 and 3 in the controller 5 are turned on (the switch contacts 1 and 4 are turned off), the echo line completes the echo pole 12 emitting ultrasonic waves, the switch contacts 3 and 4 are connected (the switch contacts 1 and 2 are turned off), the echo line echoes, and the echo pole 12 self-test is completed, as shown in FIG. Figure 4 shown.

[0048] Step 8: After the self-test is completed, the system software automatically restores the probe gain to the probe gain of the dual-crystal ultrasonic probe and the flaw detection system before the self-test.

[0049] Example 2:

[0050] Use Figure 5 The transmitter and echo electrode shown are connected in parallel to form a transmitter echo electrode, and a method for automatically detecting the sensitivity of a dual-crystal ultrasonic probe and its flaw detection system is performed. The general process of this method is the same as that of Example 1.

[0051] Step 1: Using the artificial standard defects of the standard test block (such as Flat-bottom hole, the specific defect depends on the flaw detection standard), test the sensitivity of the dual-crystal ultrasonic probe and its flaw detection system, record the sensitivity amplitude (wave height amplitude) at this time as H1 (set as the reference value), and record the probe gain value S1 at this time (set as the reference value).

[0052] Step 2: Use the double crystal ultrasonic probe 14 to transmit ultrasonic waves, and due to the presence of the organic glass of the transmitting echo electrode itself, an interface wave (such as Figure 5 As shown), the transmitting echo pole receives the interface wave through a special circuit. At this time, the wave height amplitude is H6 and the probe gain is S6.

[0053] Step 3: Based on the wave height amplitude H6 in step 2, continuously reduce the probe gain until it reaches the wave height amplitude H1 in step 1. Record the probe gain value at this time as S6.

[0054] Step 4: Compare the difference between S6 and S1 to obtain △S3.

[0055] Step 5: Before performing a sensitivity self-test on the dual-crystal ultrasonic probe and flaw detection system, automatically reduce the probe gain of the transmitting echo pole by the value of △S3. When the wave height amplitude of the transmitting echo pole reaches H1, the dual-crystal probe and its flaw detection system are considered to have qualified sensitivity.

[0056] Step 6: After the self-test is completed, the system software automatically restores the probe gain to the probe gain of the dual-crystal ultrasonic probe and the flaw detection system before the self-test.

[0057] The above description of the embodiments enables professional and technical personnel in this field to implement or use the present invention. Various modifications to the embodiments are obvious to professional and technical personnel in this field. The general principles defined in this article can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown in this article. Any technical solution obtained by equivalent replacement or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A dual-crystal ultrasonic probe and its automatic sensitivity detection method for flaw detection system, characterized in that: The automatic sensitivity detection method does not require the use of a standard test block, and the end face wedge of the dual-crystal ultrasonic probe itself is used as the test block; The emitter and echo electrode of the dual-crystal ultrasonic probe transmit and receive interface waves independently: the crystal of the emitter or echo electrode generates ultrasonic waves, and the end face of the dual-crystal ultrasonic probe transmits and forms interface waves, which are received by the crystal that generates the ultrasonic waves. Alternatively, the emitter and echo electrode of the dual-crystal ultrasonic probe are connected in parallel to form a transmitting echo electrode; the crystal of the transmitting echo electrode generates ultrasonic waves, and the end face of the dual-crystal ultrasonic probe emits ultrasonic waves to form interface waves, which are received by the crystal of the transmitting echo electrode; The steps of the method are as follows: (1) The emitter, echo electrode or transmitting echo electrode of the dual-crystal ultrasonic probe emits ultrasonic waves. Due to the existence of the end surface of the emitter, echo electrode or transmitting echo electrode itself, the wave height amplitude and gain value of each interface wave are recorded at this time; (2) when the wave height amplitude of the interface wave of the emitter, echo electrode or emission echo electrode is respectively the same as the wave height reference amplitude of the dual-crystal ultrasonic probe and the front of the flaw detection system thereof, determine the difference between the gain value of the emitter, echo electrode or emission echo electrode and the gain reference value of the front of the dual-crystal ultrasonic probe and the flaw detection system thereof; (3) During the sensitivity self-test, the gain value of the emitter, the gain value of the echo electrode or the gain value of the emission echo electrode is first reduced by the respective differences in (2) until the wave height amplitude of the emitter, the echo electrode or the emission echo electrode reaches the wave height reference amplitude respectively. Then, the sensitivity of the dual crystal ultrasonic probe and its flaw detection system is considered qualified; (4) After the self-test is completed, the probe gain value is restored to the gain of the dual-crystal ultrasonic probe and the flaw detection system before the self-test.

2. The method for automatically detecting the sensitivity of a dual-crystal ultrasonic probe and its flaw detection system according to claim 1, characterized in that: Step (2): On the basis of the wave height amplitude of the emitter of (1), the gain value thereof is continuously reduced until the wave height amplitude of the emitter reaches the wave height reference amplitude, and the gain value at this time is recorded as S4; S4 is compared with the gain reference value to obtain the difference △S1 of the emitter; Or, based on the echo pole wave height amplitude of (1), the gain value is continuously reduced so that the echo pole wave height amplitude reaches the wave height reference amplitude, and the gain value at this time is recorded as S5; S5 is compared with the probe gain reference value to obtain the difference value △S2 of the echo pole; Alternatively, the gain value is continuously reduced based on the wave height amplitude of the transmitting echo pole in (1) so that the wave height amplitude of the transmitting echo pole reaches the wave height reference amplitude, and the gain value at this time is recorded as S6; S6 is compared with the probe gain reference value to obtain the difference △S3 of the echo pole.

3. The method for automatically detecting the sensitivity of a dual-crystal ultrasonic probe and its flaw detection system according to claim 1 or 2, characterized in that: In the step (3): firstly, the gain value of the emitter, the gain value of the echo electrode or the gain value of the emission echo electrode is reduced by the respective differences in the step (2), and the operation of the step (1) is repeated until the wave height amplitude of the emitter, the echo electrode or the emission echo electrode reaches the wave height reference amplitude respectively, then the sensitivity of the dual crystal probe and its flaw detection system is considered to be qualified.

4. The method for automatically detecting the sensitivity of a dual-crystal ultrasonic probe and its flaw detection system according to claim 1, characterized in that: The multiple dual-crystal ultrasonic probes of the flaw detection system independently complete the steps of the automatic detection method.

5. The method for automatically detecting the sensitivity of a dual-crystal ultrasonic probe and its flaw detection system according to claim 1, characterized in that: Before the automatic sensitivity detection method starts, the sensitivity of the dual-crystal ultrasonic probe and its flaw detection system is detected using an artificial standard defect of a standard test block, and the wave height amplitude and probe gain value at this time are recorded as the wave height reference amplitude and the probe gain reference value.

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