WO1995020762A1 - Circuit excitateur de sonde ultrasonore - Google Patents

Circuit excitateur de sonde ultrasonore Download PDF

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Publication number
WO1995020762A1
WO1995020762A1 PCT/JP1995/000124 JP9500124W WO9520762A1 WO 1995020762 A1 WO1995020762 A1 WO 1995020762A1 JP 9500124 W JP9500124 W JP 9500124W WO 9520762 A1 WO9520762 A1 WO 9520762A1
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WO
WIPO (PCT)
Prior art keywords
probe
circuit
impedance
waveform
speed
Prior art date
Application number
PCT/JP1995/000124
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English (en)
Japanese (ja)
Inventor
Yoshio Udagawa
Original Assignee
Yoshio Udagawa
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP6028882A external-priority patent/JPH07218482A/ja
Priority claimed from JP6196111A external-priority patent/JPH0843065A/ja
Application filed by Yoshio Udagawa filed Critical Yoshio Udagawa
Publication of WO1995020762A1 publication Critical patent/WO1995020762A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details

Definitions

  • the present invention relates to an ultrasonic probe excitation circuit. More specifically, the present invention relates to a probe excitation circuit capable of significantly improving the accuracy of measurement or inspection in meat measurement or flaw detection using an ultrasonic probe. Background art
  • ultrasonic waves have been used to detect defects and the like inside the test material by non-crushing inspection, and an ultrasonic probe equipped with a transducer has been used.
  • the probe is connected to the flaw detection device via a conductive part such as a cable.
  • the transducer of the probe When performing an inspection, the transducer of the probe is vibrated by sending a spike voltage to the probe through the conducting part from the flaw detection device, and an ultrasonic wave is emitted toward the inside of the test material.
  • the probe receives the reflected wave from the inside of the test material, and the vibration of the vibrator changes the voltage, and again generates a voltage waveform in the conducting part.
  • the detection the presence or absence of a defect is determined.
  • the cable impedance If the impedance is large compared to the impedance of the transducer, an electric signal will be reflected in the transmission path (coaxial cable) between the probe and the amplifier when a transmission wave is generated, resulting in waveform distortion.
  • the voltage waveform generated by the reflected wave from the test material which is the object of the detection, often fell into the waveform due to the unnecessary reflection, resulting in a decrease in the accuracy of defect detection.
  • the first invention of the present application has been made based on the above background.
  • Ultrasonic probes used for measuring equipment and the like were generally provided in an excitation circuit as shown in FIG.
  • a indicates a charging circuit
  • b indicates a fast discharging circuit
  • c indicates a capacitor
  • d indicates a matching circuit
  • e indicates a cable
  • ⁇ indicates a probe.
  • a charging circuit a charges from a power supply (not shown), and instantaneously connects a load stored in a capacitor c to a transducer ⁇ , which is a vibrator.
  • An impulse excitation voltage was applied to f.
  • the high-speed discharge circuit b is a well-known means, such as a switch, capable of cutting off an image path.
  • the probe f receiving the impulse excitation voltage (spike hail pressure) emits ultrasonic waves to the test material.
  • the time until the transmitted ultrasonic wave is reflected from the target object is measured; the position of the defect is measured in the case of the detection test, and the target is measured in the case of the thickness measurement. He knew the thickness of things.
  • the impedance matching circuit d is arranged in parallel with the high-speed discharge surface b, and the impedance of the circuit on the probe ⁇ side is changed at and after the transmission.
  • the probe f does not match with the cable e, etc., and signal reflection occurs at both ends of the cable e. The reflection is picked up in the waveform from the probe ⁇ itself, and the S / N ratio is reduced. Had been lowered. This is because the reflected voltage of the above-mentioned reflected tatami mats disturbs the transmission voltage transmitted to the probe f side, which also disturbs the waveform of the ultrasonic wave emitted from the probe f.
  • the voltage R across the matching circuit d indicates the pick-up of the reflected wave.
  • the transmission waveform P has a large width W in the time axis direction of the transmission wave.
  • the inventions of the present application are intended to solve the above-mentioned problems by improving resolution with respect to elapsed time in flaw detection and wall thickness measurement.
  • the present invention provides the following ultrasonic probe excitation circuit. That is, the ultrasonic probe excitation surface according to the first invention of the present application has the probe 1 and the conductive portion 2 and has the following configuration.
  • the probe 1 is provided to a detector such as a flaw detection device via a conductive member 2.
  • the probe 1 receives a pulse voltage from the detector side of the conductive portion 2 to transmit ultrasonic waves to the test material. As well as receiving pulses It transmits the voltage to conduction city 2.
  • the transmission unit 2 is for transmitting the above-described pulse voltage of the probe 1 to the probe 1 and transmitting a voltage waveform generated by the reflected wave received by the probe 1 to the detector side, and further includes a variable impedance circuit. It is equipped with 3.
  • the variable impedance circuit 3 sets the impedance of the conductive section 2 to approximately the same as the impedance of the probe 1 when transmitting ultrasonic waves, and the impedance of the conductive section 2 when receiving reflected waves. It can be larger than the impedance of child 1.
  • the ultrasonic probe excitation circuit includes a low-speed charging circuit 101 capable of gradually charging electric charges, and a rapid discharge of electric charges when an appropriate charging pressure is reached.
  • High-speed discharge circuit 102 a series impedance 103, a conducting part 104, and a probe 105 that vibrates by receiving a spike pressure and emits ultrasonic waves.
  • the surface 101 is connected to the high-speed discharge circuit 102 via a series impedance 103.
  • the series impedance 103 restricts the above-mentioned discharge of a predetermined value or more.
  • the conductive portion 10 is a member such as a cable, and connects the low-speed charging circuit 101 and the series impedance 103 to the probe 105.
  • the ultrasonic probe excitation circuit according to the third investigation of the present invention has a low-speed charging surface 101 capable of gradually charging electric charges, and a rapid discharge of a load when an appropriate charging pressure is reached. It has a high-speed emission circuit 102 that performs the operation, a series impedance 103, a conduction section 104, and a probe 105 that vibrates by receiving a spike voltage and emits ultrasonic waves.
  • the low-speed charging circuit 101 is connected to the high-speed discharging circuit 102.
  • the series impedance 103 restricts the above-mentioned discharge above a predetermined level.
  • One end is connected between the low-speed charging circuit 101 and the high-speed discharging circuit 102, and the other end is connected. It is connected to one end of the head 104.
  • the conductive portion 104 is a conductive member such as a cable, and connects one end of the series impedance 103 to the probe 105.
  • the ultrasonic probe excitation circuit according to the first invention of the present application which employs the above-described means, is characterized in that the variable impedance circuit 3 of the transmission center 2 controls the impedance of the conduction section 2 when transmitting ultrasonic waves. Since the size is almost the same as that of the impedance in (1), it is possible to suppress the occurrence of reflection in the doujinro (2).
  • the impedance of the conducting part 2 is set to be larger than the impedance of the probe 1, so that the sound pressure and the signal voltage become almost proportional, and Pressure regeneration is now possible.
  • capacitance is given by arranging capacitors in parallel to the probe, and an amplifier with the highest possible input impedance is used. It is necessary to widen the received signal.
  • an equivalent circuit of a piezoelectric element used as a transducer of a probe can be generally represented as shown in FIG.
  • the waveform obtained when the probe is of a narrow band type and the transmission is in a wide band, that is, using a probe with a small wave number is as follows: Since both transmission and reception are almost the same as those using a broadband probe, it is appropriate to consider that the receiving characteristics of the ultrasonic transducer do not show much the resonance characteristics of the transducer, and are close to Equation I above. is there. With the probe alone (in a state where it is not connected to other devices), the above idea is satisfied. On the other hand, when it is connected to a flaw detector, it is considered that it is indicated by an equivalent path as shown in Fig. 24.
  • Equation IV C / kXV + l / (kR) X i Vd t... (IV)
  • the value R of impedance 933 is extremely large.
  • the sound pressure is proportional to the signal voltage. Therefore, when the reflected wave from the test material is received, the impedance of the conducting part 2 is made larger than the impedance of the probe 1 and approaches infinity, so that the sound pressure and the signal voltage are almost proportional. The sound pressure can be reproduced.
  • the ultrasonic probe excitation image path according to the present invention does not cause waveform distortion due to reflection in the transmission section during transmission, and enables reproduction of sound pressure.
  • the ultrasonic probe excitation circuit according to the second invention of the present application employing the above means includes a low-speed charging circuit 101 and a high-speed discharging circuit 102, and a series impedance 10 between them. The voltage is gradually discharged by the high-speed discharge circuit.
  • the series impedance 103 keeps the impedance as seen from the conducting part 104 constant during the period from excitation to reception of the reflected wave, facilitating circuit matching and reflecting useless signals. It is possible to avoid. Furthermore, since the excitation waveform is step-shaped, the transmission waveform becomes narrower.
  • one end of the series impedance 103 is connected to the low-speed charging path 101 and the high-speed discharge path 1. Since the other end of the serial impedance 103 is connected to one end of the conducting portion 104, the conventional impedance array is arranged in parallel as in the first invention. Unlike, I Nbidansu viewed from the conduction portion 1 0 4 side becomes constant, easy alignment of the circuit, is ⁇ bRIEF drawings is possible to avoid reflection of unnecessary signals description
  • FIG. 1 is an explanatory diagram showing one embodiment of a circuit according to the first invention of the present application.
  • FIG. 2 is an explanatory diagram showing waveforms obtained by a circuit and the like according to the first invention of the present application.
  • FIG. 3 is a sharp view showing a waveform obtained by the circuit and the like according to the first invention of the present application.
  • FIG. 4 is an explanatory diagram showing waveforms obtained by the circuit and the like according to the first invention of the present application.
  • FIG. 5 is a more detailed explanatory diagram of the waveform shown in FIG.
  • FIG. 6 is an explanatory diagram showing a state of generation of a reflected wave during flaw detection.
  • FIG. 7 is an explanatory diagram showing a comparison between a waveform obtained by the circuit according to the first invention of the present cocoon and a conventional waveform.
  • FIG. 8 is an explanatory view showing another embodiment of the circuit according to the first invention of the present invention.
  • FIG. 9 shows the change of the signal waveform and the state of the impedance at each of the positions X 1, X 2, X 3, X 4, X 5 and X 6 of the circuit shown in FIG.
  • FIG. 10 is an explanatory diagram showing a waveform at the position of the variable impedance 30 of the circuit of the embodiment of FIG.
  • FIG. 11 is an explanatory diagram showing another embodiment of the circuit according to the second invention of the present II.
  • FIG. 12 is an explanatory view showing another embodiment of the image path according to the first invention of the present application.
  • FIG. 13 shows the impulses of the bike pulser (spike pressure) at the position SY1, the control voltage at the position SY2, and the overall Y3 of FIG.
  • FIG. 14 is an explanatory view showing an embodiment of the second invention of the present application.
  • FIG. 15 is an explanatory view showing an embodiment of the third invention of the present invention.
  • the 1st 611 is an explanatory diagram showing one embodiment of a circuit according to the second or third invention of the present application.
  • FIG. 17 is an explanatory diagram showing one embodiment of the circuit according to the second or third invention of the present application.
  • FIG. 18 is an explanatory diagram showing one embodiment of the circuit according to the second or third invention of the present application.
  • FIG. 19 is an explanatory diagram of an ultrasonic waveform obtained by implementing the second or third invention of the present application.
  • FIG. 20 is an explanatory view showing the second or third other embodiment.
  • FIG. 21 is an explanatory diagram showing one embodiment of the circuit according to the second or third invention of the present application.
  • FIG. 22 is an explanatory diagram of a waveform of an ultrasonic wave obtained by a conventional ultrasonic probe.
  • FIG. 23 is an explanatory diagram showing a conventional circuit.
  • FIG. 24 is an explanatory diagram showing a conventional circuit.
  • FIG. 25 is an explanatory diagram of a waveform of an ultrasonic wave obtained by a conventional ultrasonic probe.
  • FIG. 26 is an explanatory diagram showing an example of a conventional ultrasonic probe excitation surface.
  • the ultrasonic probe excitation image field has a probe 1 and a conduction section 2 and has the following configuration.
  • the probe 1 emits ultrasonic waves to the test material by receiving a pulsed pressure, and transmits a reception pulse voltage to the conduction unit 2 by receiving a reflected wave from the test material.
  • the conductive part 2 is for transmitting the spike voltage from the probe 1 and for transmitting the voltage waveform generated by the reflected wave received by the probe 1 to the flaw detector, and the variable impedance circuit 3 It is provided with.
  • the variable impedance circuit 3 sets the impedance of the transmission section 2 to the same as the impedance of the probe 1 when transmitting ultrasonic waves, and the impedance of the transmission section 2 when receiving a reflected wave. It is possible to make it larger than the one-by-one dance. The specific configurations of these components will be described in detail below.
  • the probe 1 is connected to a detector such as a flaw detector or a wall thickness measuring device via a conductive line 2 formed by a cable or other conductive wire. Detectors other than those that are not shown).
  • the pulse voltage generated by the flaw detection device S side of the transmission center 2, that is, the excitation pulse generation circuit 41 is sent to the probe 1 via the conduction section 2.
  • the transducer 1 vibrates under the pulse voltage.
  • the probe 1 emits an ultrasonic wave to the test material by the above vibration of the transducer.
  • the conduction city 2 is provided with a variable impedance circuit 3.
  • Reference numeral 31 in FIG. 1 indicates a grounding portion.
  • the variable impedance surface 3 includes the variable impedance 30 and places the variable impedance 30 under the control of the control circuit 40.
  • a control circuit 40 is connected to the excitation pulse generation circuit 41.
  • the excitation pulse generation circuit 41 is also placed under control.
  • the impedance value of the variable impedance '30 is set to be approximately the same as the impedance value of the probe 1. (This is because unnecessary reflection in the conducting part is suppressed by performing impedance matching).
  • control circuit 40 generates the excitation pulse (in the state of the variable impedance 30 described above), generates a spike compress on the @ 1 path 41, and vibrates the vibrator of the probe 1 at the same time as the variable impedance. Adjust 30 to automatically increase the impedance value.
  • the impedance value of the conduction 2 is larger than that of the probe 1, contrary to the initial value.
  • the reflected wave from the test material received by the probe 1 is transmitted by the conduction section 3.
  • Reference numeral 42 in FIG. 1 indicates an amplifier. Amplifier 42 is used in this embodiment. Therefore, it is appropriate to use a high-income Cainbee dance amplifier.
  • the amplifier 42 amplifies the voltage waveform of the reflected wave from the test material and sends it to the detector.
  • Reference numerals 5a and 5b denote parallel capacitance supply units. It has capacitors 50a, 50b, switches 51a, 51b, and grounds 52a, 52b, respectively. When transmitting, the switches 51a and 51b are OFF, and when receiving the reflected wave, short-circuit and discharge to the grounding 52a.52b side.
  • This parallel capacitance supply section is used when the inter-electrode capacitance of the probe (931 in Fig. 12) is small and the second term of Equation IV cannot be ignored even if the variable impedance is maximized. That is, when the second term is sufficiently smaller than the first term of the equation shown in Equation IV (usually about 10% or less of the first term, but depending on the purpose of use, It is sufficient if the ratio of the term is larger than this.) This is to increase the term 1 of the equation.
  • the present invention includes a probe 1 and a conductive member 2, and the probe 1 is provided on a detector such as a flaw detection device via a conductive portion 2.
  • the ultrasonic detector emits an ultrasonic wave to the specimen by receiving the spike voltage from the detector, and transmits the received pulse voltage to the conduction center by receiving the reflected wave from the specimen.
  • Numeral 2 is for transmitting the spike voltage to the probe 1 and for transmitting the hail pressure waveform generated by the ultrasonic reflected wave received by the probe 1 to the detector side.
  • the variable impedance circuit 3 is provided with a beadance image 3 and a parallel capacitance supplying section 5a, 5b.
  • the impedance of the conducting section 2 is set to the impedance of the probe.
  • the parallel capacitance supply units 5a and 5b can further increase the impedance of the conduction unit 2 as compared with the impedance of the probe.
  • Ultrasonic probe excitation characterized by being It can be implemented as a drawing path.
  • the parallel capacitance supply sections 5a and 5b are not provided. Can be implemented. Further, the arrangement of the parallel capacitance supply units 5a and 5b may be immediately adjacent to the probe or as shown in FIG.
  • FIG. 2 shows a general waveform of one wave obtained with a step-type pulsar.
  • A shows the waveform obtained by the probe having the circuit according to the present invention
  • B shows the waveform obtained by the conventional method (the right side of FIG. 2 respectively). Shown).
  • B is a waveform with a fixed impedance of the cable and about 200 ⁇ at the resonance frequency obtained by impedance matching with the cable at 50 ⁇ . , 10 MHz, 85 PF) ⁇
  • the vertical axis represents voltage
  • the horizontal axis represents time
  • the probe is a direct contact type with a frequency of 1 MHz and a diameter of 56 mm.
  • a 1 shows the result of the frequency decimation of the waveform A
  • B 1 shows the result of the frequency decimation of the waveform B.
  • the horizontal axis indicates frequency
  • the vertical axis indicates amplitude.
  • Fig. 3 shows the same waveform A2 obtained using the ultrasonic probe (56 mm in diameter) shown in Fig. 2 above, and another water immersion probe (diameter 2 0 mm ) Is placed in water, and the reflected echo A 3 on the iron plate surface when a large iron plate reflector at about 3 O mm is perpendicular to the beam is shown.
  • the time axis of the A3 waveform is set to 10 times the time axis of the A2 waveform.
  • the waveforms indicated by the dotted lines A 20 and A 30 in the figure show the cases where the transducers of the above-mentioned waveforms A 2 and A 3 were completely damped, respectively. This is an imaginary curve that seems to have no ringing and looks like dotted lines A 20 and A 30.
  • the circuit of the new method related to this cocoon investigation has the advantage that the time axis resolution is high first. As shown in Fig. 4, in the case of wall thickness measurement, the time when the package echo usually overlaps the surface echo is usually observed. And the minimum measured wall thickness.
  • the upper waveform B 11 shows a conventional waveform
  • the lower waveform A 11 shows a waveform obtained using the surface according to the present invention.
  • the measurement using the circuit according to the present invention can be performed up to the reference line w0.
  • the waveform B11 it is difficult to separate the waveforms B111 and B111 when the waveform B112 approaches the reference line W in the conventional method. It was impossible to measure. This is because the width of the positive and negative waveforms was too large in the direction of the amplitude (vertical direction in FIG. 4) in the waveform of one wave, and this waveform was in the way.
  • a tight wave called a half wave is obtained, so that flaw detection or wall thickness measurement can be performed with extremely high accuracy.
  • the waveform of Fig. 4 is shown in Fig. 5 as a more detailed graph based on the data.
  • This probe is a direct contact probe with a delay material.
  • the material to be inspected is a lmm aluminum plate.
  • One scale on the vertical axis indicates 1 Omv
  • the scale on the horizontal axis indicates 100 ns (nano-second) (one scale is about 0.1 cm in FIG. 4).
  • S of this waveform C1 indicates a surface echo.
  • E 1 indicates the first back echo and E 2 indicates the second back echo.
  • E 1 indicates the first back echo and E 2 indicates the second back echo.
  • Another advantage of using the above-described circuit according to the present invention is that the bandwidth is wide.
  • A101 of the waveform 1 shows a waveform of one defect obtained by the circuit according to the present invention, that is, a waveform obtained by the sound pressure reproduction type circuit.
  • the area indicated by the spot indicates the size of the defect.
  • the B101 force shows the conventional waveform, and the h force shows the echo height of the conventional waveform.
  • Waveform 2 in FIG. 7 is a waveform similarly obtained for another defect. This
  • B102 indicates the conventional waveform
  • A102 indicates the waveform obtained by the sound pressure reproduction type circuit of the present invention.
  • A103 shown in waveform 3 in Fig. 7 is a waveform that is finally detected, that is, a waveform obtained by combining waveform 1 and waveform 2 in Fig. 7, and is different from the conventionally obtained combined waveform B103.
  • switches F l which enable high-speed switches such as two FETs or transistors, are provided.
  • F2 has been dispatched.
  • the control circuit 40 is connected to these switches Fl and F2. More specifically, a differentiating circuit 6 constituted by a capacitor 61 and a grounded impedance 62 is interposed between the control circuit 40 and the switch F1. Further, the other end of the switch F 1 is connected to the high-voltage charging circuit 7. As shown in FIG. 8, the high-voltage charging circuit 7 is connected to the switch F 1 and is connected to the variable impedance 30. The switch F 1 and the variable impedance 30 are connected to the probe 1 at the other end as a main component of the variable impedance circuit 3, and are connected between the variable impedance 30 and the probe 1. One end of the switch F2 is connected.
  • reference numeral 63 denotes a ground portion of the impedance 62
  • reference numeral 64 denotes a ground portion of the switch F1
  • reference numeral 65 denotes a ground portion of the switch F2
  • reference numeral 66 denotes a ground portion of the probe 1. I have. Further, the amplifier 42 is connected to the middle of the switch F2 on the ground side, and an impedance 45 is interposed between the ground unit 65 and the switch F2.
  • FIG. 9 shows the change of the signal waveform and the state of the impedance at the husband * of the positions X 1, X 2, X 3, X 4, X 5, and X 6 of the circuit shown in FIG.
  • X3 indicates the value of the impedance at the switch F1. As indicated by X3 in FIG. 9, the “high” position of the waveform indicates a high impedance, and the “low” position indicates a low impedance. A high portion of the waveform of X indicates that the switch F2 is ON.
  • the waveform obtained at the variable impedance 30 position in FIG. 8 is shown in FIG. This is a waveform obtained by changing the impedance value at the position of the variable impedance 30.
  • the probe indance (1/2 ⁇ fc) here is 100 ⁇ ⁇
  • one vertical scale indicates 100 mv
  • one horizontal scale indicates 50 ns (nano-second). (Approximately 1 cm in Fig. 0).
  • R 1 is when the variable impedance 30 is 25 ⁇
  • R 2 is when the variable impedance 30 is 50 Q
  • R 3 is when the variable impedance 30 is 75 ⁇ .
  • R 4 is 100 ⁇ for variable impedance
  • R 5 is 150 ⁇ for variable impedance
  • R 6 is 200 ⁇ for variable impedance 30 ⁇ .
  • R7 is when the variable impedance 30 is set to 300 ⁇
  • R8 is when the variable impedance 30 is set to 400 ⁇
  • R9 is when the variable impedance 30 is set to 500 ⁇ . Time waveforms are shown respectively.
  • the ratio in the vertical direction (downward) to the horizontal direction is large, and a tight and sharp waveform is obtained.
  • Sweep rate pitch F 1 is completely the state ON, the the resistance is about 5 Omega e Therefore, it is sufficient to add 5 ⁇ to each of the above resistance values, but this value is an error range and can be ignored.
  • Fig. 11 emphasizes the improvement of characteristics in addition to the conventional spike pulsar method.
  • the diode D 2 is disposed between the capacitor C 1 and the diode D 1, and the diode D 2 is arranged between the capacitor C 1 and the diode D 1.
  • a damping resistor R 2 (variable impedance 30) constituting the variable impedance circuit 3 is arranged in parallel with the probe 1. I have.
  • the damping resistor R2 is usually constituted by FET or a combination of FET and a resistor.
  • Reference numeral 42 denotes an amplifier
  • variable impedance circuit 3 has almost the same impedance value as that of the probe during transmission, and has a high damping resistance R 2 (variable impedance) controlled by the control circuit 40 when receiving ultrasonic waves (reflected waves). Impedance value. '
  • the damping resistor R2 becomes a large impedance, and the amplifier 42 amplifies the waveform proportional to the sound pressure.
  • the probe cable that constitutes the conductive part 2 is about 5 m long and has a characteristic impedance of about 50 ⁇ .
  • R 2 is set to 100 ⁇ .
  • the waveform in that case is B.
  • the waveform is A when R2 is set to about 50 ⁇ during transmission and the equation is equal to or greater than I0 ⁇ ⁇ ⁇ during reception.
  • Each frequency spectrum is shown in the lower left of the figure. From FIG. 22, it can be seen that a waveform having a smaller wave number and a wider band than the conventional method can be obtained.
  • FIG. 12 illustrates an embodiment of a method for easily adding a flaw detector or a thickness measuring instrument that already exists.
  • 80 indicates a pulse transmission path of the existing device
  • 81 indicates a receiving circuit of the existing device.
  • a switch F1 which is controlled by a control circuit 40, is provided in a conduction section 2 connecting the probe 1 and these circuits 80, 81, and this switch F2 constitutes a variable impedance circuit 3. It is connected to the conduction ⁇ 2 through the variable impedance 30.
  • the switch F1 employs an FET or a transistor capable of high-speed switching, such as a transistor.
  • FIG. 13 shows the spike pulser (spike voltage) at the position Y1, the control overpressure at the position Y2, and the impedance of the whole Y3.
  • the impedance of the whole Y3 is almost the same as that of the variable impedance 30 on the left, and gradually rises after the spike voltage is generated, and the impedance on the right is high. Leads to.
  • examples of the second and third inventions of the present application will be described.
  • the circuit according to the present invention has a low-speed charging surface 101 capable of gradually charging the electric charge, and rapidly discharges the electric charge when an appropriate charging pressure is reached. It has a high-speed packing surface path 102, a series impedance 103, a conductive section 104, and a probe 105 which vibrates and emits ultrasonic waves by receiving a spike voltage.
  • the low-speed charging circuit 101 is connected to the high-speed discharging circuit 102 via a series impedance 103.
  • the series impedance 103 limits the hail above a predetermined level.
  • the conductive portion 104 is a conductive member such as a cable, and connects the probe 105 with the portion between the low-speed charging surface 101 and the series impedance 103.
  • FIG. 15 shows a configuration for obtaining the same operation and effect as the above. It has a low-speed charging circuit 101 that can gradually charge the load, a high-speed discharging circuit 102 that discharges the electric charge rapidly when an appropriate charging pressure is reached, and a series impedance 103 It has a conduction tube 104 and a probe 105 which vibrates by receiving a bike voltage and emits ultrasonic waves.
  • the low-speed charging surface 101 is connected to the high-speed discharging circuit 102.
  • the series impedance 103 limits the above-mentioned discharge above a predetermined level.
  • One end of the series impedance 103 is connected between the low-speed charging circuit 101 and the high-speed discharging circuit 102, and the other end is conductive. It is connected to one end of the city 104.
  • the conductive member 104 is a power supply member such as a cable, and connects one end of the series impedance 103 to the probe 105.
  • “slow” in the low-speed charging circuit 101 means that the probe is gradually charged with the compress so as not to excite the probe 105. Meaning, if it is such a power circuit, what kind is adopted -
  • “high speed” of the high-speed discharge circuit 102 means that the probe 105 has a power supply capability that can excite the probe 105.
  • the present invention can be implemented even if a suitable one is adopted.
  • the circuit shown in Fig. 16 requires a low power supply voltage, and is suitable for a battery-powered device.
  • the low-speed charging circuit 101 is a transformer connected to the power supply 110 (+ V c c). Further, it is connected to a low-speed charging circuit 101 through a high-speed discharging surface 102 formed by a transistor and a variable series impedance 103. 1 3 1 indicates impedance for negative voltage limit.
  • Reference numeral 1332 denotes a diode for rectifying a current flowing only in the charging direction
  • reference numerals 133 and 134 denote a diode for maintenance
  • reference numeral 135 denotes a FET.
  • Reference numerals 1 2 1 and 1 2 2 denote impedance provided in the high-speed discharge circuit 102, impedance 1 2 1 is for controlling the input current 1, and impedance 1 2 2 is a transistor This is for rapid discharge between the base and emitter of the high-speed discharge circuit 102.
  • a switch 107 capable of high-speed switching such as a transistor.
  • . 1 7 1 1 7 2 shows the impedance provided sweep rate pitch 1 0 7 beta
  • the low-speed charging circuit 101 it is also possible to use an element capable of high-speed switching, such as FET, in addition to a transistor (the transistor shown is a transistor).
  • FET field-effect transistor
  • the low-speed charging circuit 101 which has obtained the appropriate voltage and has been charged, is turned on by the switch 107, so that a small current flows through the conduction center 104, and is transferred to the probe 105. Stores electric charge.
  • high-speed discharge circuit 102 When switch 107 is turned off, high-speed discharge circuit 102 is also turned on at the same time. The signal is turned on, and a step-like waveform is sent to the probe 105 through the conduction section 104. That is, the electric charge stored in the probe 105 is discharged by the rapid current P2.
  • FIG. 17 An example in which a relatively small circuit configuration is possible is shown in Figure 17. This means that a high voltage of about 100 to 100 V is obtained from the power supply 110, and a relatively large resistance of about 100 to 500 ⁇ is provided in the circuit. is there.
  • the low-speed charging circuit 101 is implemented by using a transistor or an element capable of high-speed switching (FET in the illustrated example) such as FET.
  • FET field-speed switching
  • 1 1 and 2 indicate an amplifier. The minute current p 1 is sent to the probe 105 side, and the returning load P 2 is discharged by the high-speed discharge circuit 102.
  • the high-speed discharging circuit 102 and the low-speed charging circuit 101 can be realized with a relatively simple configuration as described above, they can be formed in a relatively small size.
  • FIG. 17 the one shown in FIG. 17 is effective when the transducer 105 has a plurality of transducers (channels) because it saves space.
  • Fig. 18 shows another example of the circuit configuration. This means that the change in the charging curve of the probe 105 due to the load is small.
  • a ramp waveform generating circuit 201 is provided together with a rectangular wave generating circuit 200 so that a desired waveform can be obtained as much as possible.
  • the figure shows a low-speed charging circuit with 101 power
  • 102 shows a high-speed discharging circuit.
  • the high-speed discharging circuit 102 uses FETs.
  • the present invention is not limited to a certain type of FET, but may be implemented in place of a high-speed switch such as a transistor if it is capable of high-speed switching, and a switch capable of high-speed switching such as a transistor.
  • the switch 107 has a transistor 1 7 3 for protecting the transistor of this switch 107. Is provided.
  • the reference numeral 140 denotes a transformer or other resistor whose base side is connected to the square wave generation circuit 200, the emitter side is connected to the conduction section 104, and the collector side is connected to the amplifier 112. 2 shows a switch formed by the elements.
  • the switch 140 is provided with an impedance 123 in order to stabilize the switch at 0 when the switch is on.
  • FIG. 19 shows an example of a waveform obtained by implementing the present invention.
  • the vertical axis y indicates the transmission pressure
  • the horizontal axis X indicates the time axis.
  • the scale of vertical t * y is different from that of Fig. 25).
  • the voltage R received by the probe 105 has a small wave number because the reflected wave is suppressed from being picked up.
  • the transmission waveform P has a width in the time axis direction of the transmission wave. W has become smaller.
  • the transmission waveform P in FIG. 26 has two downwardly convex portions, that is, two valleys G.
  • the valley G is There is one.
  • the width W in the time axis direction of the present invention is suppressed to an extremely small value.
  • each embodiment enables high-precision flaw detection or wall thickness measurement, and when accuracy requirements are not strict, the probe has a conventional parallel inductance. Sometimes you want something cheaper. At this time, it is uneconomical to use a wide-area probe that meets the accuracy requirements described above.
  • the transducer 105 itself generally uses a vibrator, if the vibrator is used alone, a useful vibration for emitting ultrasonic waves is obtained. It has the problem that vibration occurs in the radial direction (surrounding) of the vibrator at the same time as the movement occurs in the thickness direction. This (the latter) vibration is lower than the flaw detection frequency because the width of the vibrator in the radial direction is larger than its thickness, and therefore, the attenuation in the probe and the wiping test material is small. However, it appeared as noise on flaw detection.
  • the inductance 106 arranged in parallel with the probe 105 has low impedance at low frequency, so that the voltage becomes 0 during the slow charging and ⁇ and the rapid discharge When the current is applied, the current is drained instead of being discharged. At this time, since the inductance 106 tries to maintain the current flowing from the function, a negative voltage (generally called kickback) is applied to the probe 105. Will give. After all, in this case, the probe 105 (oscillator) vibrates due to this negative voltage.
  • kickback a negative voltage
  • the probe 105 reverse-polarizes when a positive voltage is applied, and the probe 105 does not function. To avoid this, switch the voltage to negative. It is appropriate to provide a well-known configuration to the circuit described above.
  • FIG. 21 An example in which such a configuration is provided in the circuit shown in FIG. 17 is shown in FIG.
  • a capacitor 15 1 is interposed between the low-speed charging circuit 101 and the high-speed discharging circuit 102 and the probe 105, and a diode 15 2 Arranged and grounded.
  • the capacitor 15 1 and the diode 15 2 have a conducting part 104 and the force shown between the low-speed charging circuit 101 and the high-speed discharging circuit 102.
  • ⁇ A similar effect can be obtained by arranging these elements between the conductive part 104 and the probe 105 and practicing them.
  • the first invention of the present application By implementing the first invention of the present application, it is possible to reproduce sound pressure without causing waveform distortion due to reflection in the transmission area during transmission. For this reason, the resolution with respect to the elapsed time (time axis direction) has been significantly improved.
  • the disturbance of the transmitted waveform was suppressed, the wave number of the generated ultrasonic wave was reduced, and the time axis resolution was significantly improved. For this reason, the minimum measurable wall thickness in the wall thickness measurement has become smaller, and it has become possible to measure the wall thickness of extremely thin objects that could not be measured conventionally.
  • an inductance is arranged in parallel with the probe (vibrator), and the outer diameter of the probe 105 to suppress low-frequency vibrations below the flaw detection frequency With a certain force, in the circuit according to the present invention, it is possible to obtain a spike compress even with such a probe, and it has versatility.
  • the resolution with respect to the elapsed time (time direction) can be significantly improved.

Abstract

Le circuit excitateur de sonde ultrasonore de la présente invention se compose d'une sonde (1) et d'un conducteur (2), la sonde (1) étant connectée, par le conducteur (2), à un détecteur tel qu'un détecteur de défauts métallurgiques. Dès qu'elle reçoit du détecteur une pointe de tension, la sonde génère une onde ultrasonore en direction d'un objet soumis à examen. La sonde reçoit l'onde réfléchie depuis l'objet et envoie au conducteur (2) une tension impulsionnelle de réception. Un circuit à impédance variable (3) équipe le conducteur (2), qui envoie à la sonde (1) la pointe de tension et au détecteur le signal en tension correspondant à l'onde réfléchie. Ce circuit à impédance variable (3) permet au conducteur (2) d'avoir la même impédance que la sonde (1) lors de l'envoi de l'onde ultrasonore, et une impédance supérieure à celle de la sonde (1) lors de la réception de l'onde réfléchie. Cela permet, d'abord de reproduire une pression sonore sans que la réflexion dans le conducteur ne génère de distorsion de signal lors de l'envoi, et par suite, d'accroître le pouvoir séparateur dans le temps pour la détection des défauts métallurgiques ou pour la mesure d'épaisseur.
PCT/JP1995/000124 1994-01-31 1995-01-31 Circuit excitateur de sonde ultrasonore WO1995020762A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP6028882A JPH07218482A (ja) 1994-01-31 1994-01-31 超音波探触子励振回路
JP6/28882 1994-01-31
JP6/196111 1994-07-27
JP6196111A JPH0843065A (ja) 1994-07-27 1994-07-27 超音波探触子励振回路

Publications (1)

Publication Number Publication Date
WO1995020762A1 true WO1995020762A1 (fr) 1995-08-03

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Application Number Title Priority Date Filing Date
PCT/JP1995/000124 WO1995020762A1 (fr) 1994-01-31 1995-01-31 Circuit excitateur de sonde ultrasonore

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Country Link
WO (1) WO1995020762A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110118817A (zh) * 2019-05-31 2019-08-13 云谷（固安）科技有限公司 导线检测装置及其检测方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS437674Y1 (fr) * 1965-03-22 1968-04-05
JPS5057694A (fr) * 1973-09-21 1975-05-20
JPH01124443A (ja) * 1987-11-10 1989-05-17 Fuji Electric Co Ltd 医用超音波探触子の送受信整合回路
JPH01160535A (ja) * 1987-12-17 1989-06-23 Toshiba Corp 超音波診断装置
JPH0618655A (ja) * 1992-07-06 1994-01-28 Oki Shisutetsuku Tokai:Kk 発音器

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS437674Y1 (fr) * 1965-03-22 1968-04-05
JPS5057694A (fr) * 1973-09-21 1975-05-20
JPH01124443A (ja) * 1987-11-10 1989-05-17 Fuji Electric Co Ltd 医用超音波探触子の送受信整合回路
JPH01160535A (ja) * 1987-12-17 1989-06-23 Toshiba Corp 超音波診断装置
JPH0618655A (ja) * 1992-07-06 1994-01-28 Oki Shisutetsuku Tokai:Kk 発音器

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110118817A (zh) * 2019-05-31 2019-08-13 云谷（固安）科技有限公司 导线检测装置及其检测方法

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