JPS61165660A - Ultrasonic flaw detection apparatus - Google Patents

Abstract

PURPOSE:To increase the internal flaw detection speed of a material, by simultaneously detecting the reflected wave from the interior of a material to be inspected by a plurality of ultrasonic vibrators at predetermined positions. CONSTITUTION:An ultrasonic probe 1 is integrally constituted of ultrasonic vibrators 21-2n arranged at equal intervals and the signals from the vibrators 21-2n are converged to ultrasonic waves through radiation wave transmitters 31-3n to be sent into a material to be inspected. The control signal from a signal controller 10 is applied to the receiving signal change-over switch 5 and trigger signal change-over switch 9 provided to the input/output terminal apparatus of a transmitting/receiving system to control the selective operation of the signal by each switch and controls that the reflected wave signal from a signal processor 7 is sent to a recording display device 11. A plurality of receiving vibrators 2 are especially selected from transmitting vibrators 21-2i and the reflected wave from the internal flaw of the material to be inspected is simultaneously detected at positions satisfying such a condition that propaga tion distance difference DELTAl is DELTAl<lambda/4 to the wavelength lambda of said reflected wave without providing a delay time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an ultrasonic flaw detection device that performs ultrasonic flaw detection of material defects at high speed.

[Technical background of the invention and its problems]

Conventionally, an ultrasonic beam is generated by pulse-exciting multiple ultrasonic transducers with an appropriate time delay.
There is a flaw detection device that can arbitrarily control the radiation direction of the generated ultrasonic beam. This device uses the same ultrasonic transducer used for transmitting waves to receive reflected waves from within a material due to the emission of ultrasonic beams.
After this, the reflected waves received by each transducer are added together for signal processing. Therefore, for the addition after the reflected waves are delayed, an analog addition method using a delay element or the like is usually used. However, in order to delay the ultrasonic waves reflected from within the material for an arbitrary period of time, it is necessary to combine a large number of delay elements, which inevitably complicates the circuit configuration. It is practically difficult to delay ultrasonic waves by an arbitrary amount of time.

(Objective of the Invention) In view of the above-mentioned circumstances, the present invention aims to speed up the inspection of white defects in materials and improve the defect detection accuracy by controlling only the timing of ultrasonic wave transmission without having a delay time in receiving reflected waves. The purpose is to provide an ultrasonic flaw detection device that can perform

[Summary of the invention]

The feature of the present invention is that it has a plurality of ultrasonic transducers arranged to form an ultrasonic probe, and any plurality of these transducers are pulse-excited with a delay time to generate ultrasonic waves. In an ultrasonic flaw detection device that is equipped with an ultrasonic generator that emits ultrasonic waves in a preset direction within the tested material, the reflected waves from inside the tested material are adjusted to the wavelength λ of the reflected waves. On the other hand, simultaneous detection is possible using multiple ultrasonic transducers positioned so that the propagation distance difference Δ1 satisfies the condition that Δp × λ/4, and reflected waves are received by controlling only the ultrasonic transmission timing. This technology speeds up the inspection of material white defects without any delay time, and improves defect detection accuracy.

(Example of the invention) Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows an example of a configuration according to an embodiment of the present invention. In the figure, an ultrasound probe 1 is integrally constituted by a plurality of ultrasound transducers 2(1) to 2(n) arranged at equal intervals. Each of these ultrasonic transducers 2(1) to 2(n)
are radiation wave transmitters 3(1) to 3 for generating ultrasonic waves.
(n), and converts the signal from this transmitter 3 into an ultrasonic wave and sends it into the material to be tested. In order to provide a trigger signal of a predetermined period to the transmitter 3, a trigger signal generator 8 is provided via a signal changeover switch 9. This trigger signal generator 8 has an arbitrary delay time set by a control signal from a signal controller 10, and a trigger signal generated according to the delay time is generated by a trigger signal changeover switch 9.
are given sequentially. This changeover switch 9 arbitrarily selects a signal with a delay time according to the control signal of the signal controller 10 applied at the same time and applies it to the corresponding arbitrary plurality of transmitters 3, transmitters 3(1) to 3( n), the transmitter 3 to be used at a time can be selected. In this way, an ultrasonic transmission system to the ultrasonic probe 1 is configured. In addition, each of the ultrasonic transducers 2(1) to 2(
n) are connected to limiters 4(1) to 4(n), respectively.

The high voltage of the signal received by the vibrator 2 is cut off via a limiter 4 and then applied to a received signal changeover switch 5 . This selector switch 5 is simultaneously given a control signal from a signal controller 10, and by arbitrarily selecting the output of the limiter 4, it is possible to select a predetermined ultrasonic transducer 2 when receiving a corresponding ultrasonic wave. It is. The arbitrary number of limiter outputs selected by the changeover switch 5 are added to one signal, and then given to the reflected wave receiver 6, where the signal is amplified. The signal amplified by this receiver 6 is given to a signal processor 7 to extract an electrical signal corresponding to the ultrasonic propagation distance, etc., and then given to a recording display 11 to measure the dimensions of material white defects, etc. The record will be displayed. In this way, an ultrasonic reception system from the ultrasonic probe 1 is configured.

The present invention includes a signal controller 10, and the control signal output from the signal controller 10 is transmitted to the reception signal changeover switch 5 and the trigger provided at the input/output end positions of the ultrasonic reception and transmission system as described above. It is applied to the signal changeover switch 9 to control the signal selection operation of each switch, and is further applied to the signal processor 7, and the reflected wave signal processed by the signal processor 7 is sent to the recording display 11. It is characterized by controlling the transmission of signals at the same time.

Based on the ultrasonic flaw detection device configured as described above, Fig. 2 shows the ultrasonic wave generation in the transmitting system, and Fig. 3 shows the signal processing of reflected waves in the receiving system in relation to the transducer. be. Therefore, one embodiment of the present invention will be described with reference to FIGS. 1 to 3.

The signal controller 10 selects the ultrasonic transducers 2(1) to 2(n) by giving the control signal 22 to the signal changeover switch 9 to select the radiation wave transmitters 3(1) to 3(i). Among them, an arbitrary number of transducers 2(1) to 2(1) for wave transmission are selected. Also, at this time, the signal controller 10 adjusts the delay time ΔT to Δ
A control signal 23 having Ti-1 is applied to the trigger signal generator 8.

As a result, the trigger signal generator 8 has a delay time of 6 to 1 to Δ"
A trigger signal group 15 (FIG. 2(a)) having a time interval of frequency 1 to 10 KH2 corresponding to i-1 is generated. These signals 15 are transmitted to the trigger signal changeover switch 9 and the transmitter 3 (
Via 1) to 3(i), transducers 2(1) to 2(
After being repeatedly sent to I), as shown in FIG. 2(b), the ultrasonic beams from the transducers 2(1) to 2(i) can be focused on the internal defect 16 of the material to be detected 14. 13 is emitted. After the ultrasonic beam 13 is emitted in this manner, the ultrasonic wave reflected from the internal defect 16 can generally be received by the same transducers 2(1) to 2(i) as used for transmitting waves. However, when the oscillators 2(1) to 2(i) are used as receiving oscillators to receive reflected waves, as shown in FIG.
As shown in a), a reflected wave 17 (
1) to 17(i>) are received with a delay time from each other. Therefore, in the present invention, in particular, a plurality of receivers from the wave transmitting transducers 2(1) to 2(i) are A wave oscillator 2 is selected to simultaneously receive reflected waves without delay time.

In the ultrasonic receiving system according to the present invention, the transducer 2 for receiving reflected waves is located at the center of the transducers 2(1) to 2(i) for transmitting waves, and the reflected waves are received between the transducers. The delay time, that is, the propagation distance difference ρ is Δ1 with respect to the ultrasonic wavelength λ.
A plurality of oscillators 2 having a small phase shift such as λ/4 or less are selected. In particular, the signal controller 10 provides a control signal 24 corresponding to the ultrasonic flaw detection angle θ to the reception signal changeover switch 5 based on the preset inter-oscillator distance d and the wavelength λ. Wave oscillator 2(k)~
2(m) is automatically selected. Therefore, the oscillators 2(k)~ obtained via the limiters 4(k)~4(m)
The received reflected waves 17(k) to 17(m) of 2(m) are simultaneously added without any delay time, and the reflected waves 19 after addition can be quickly formed.

The reflected waves 19 thus simultaneously added are amplified by the reflected wave receiver 6 and then sent to the signal processor 7. At this time, the signal controller 10 processes the signal 25 corresponding to the angle of the emitted ultrasonic beam 13 and the signal 26 corresponding to the position of the selected receiving transducer 2(k) to 2(m). Give to container 7. Thereby, the signal processor 7 selects the gate 20 and the threshold level 21 in a range corresponding to the ultrasonic propagation time required for round trip to the flaw detection area, and performs calculation of one added reflected wave. As a result, the added reflected wave 19
A signal indicating the height and position of the reflected echo when it exceeds the threshold level 21 is sent to the recording display 11. The recording display 11 displays the position, shape, and other dimensions of the internal defect 16 on a cathode ray tube or the like based on the signal from the processor 7, and also records it on a recording paper or the like.

In the above-mentioned embodiment, ultrasonic flaw detection related to the combination of wave transmitting transducers 2(1) to 2(i) and wave receiving transducers 2(k) to 2(m) was explained. Ultrasonic flaw detection can be performed similarly for other wave transmitting/receiving transducers 2 by switching the selection and combination. A program related to the selection of the wave transmitting/receiving transducer 2 is set in the signal controller 10 in advance. Then, each time the inspection inspection by the - set of vibrators 2 is completed, the signal processor 7 sends a completion signal 27 to the signal controller 10. As a result, the signal controller 10, for example, when the flaw detection inspection according to the above-mentioned embodiment is completed, next transmits the transducers 2(2) to 2(i+1), receives the transducers 2(k+1) to 2( If the transducers are selected and combined one by one by moving the vibration side 2 for transmitting and receiving waves one by one as in m + 1), it is possible to perform ultrasonic flaw detection by sequentially switching the combinations. can.

When the flaw detection inspection is completed for all the transducers 2(1) to 2(n) in this way, the transducers 2(1) to 2(i
) may be repeatedly inspected. Furthermore, if a program for changing the ultrasonic radiation angle is set in the signal controller 10 in advance, after the flaw detection inspection by switching the transducer 2 is completed, the radiation angle can be changed to perform a flaw detection inspection. Therefore, by the above-described flaw detection inspection, internal defects in the material to be flawed can be detected more clearly and in detail.

In addition, although the above-mentioned embodiment describes the case where the ultrasonic beam is focused and radiated, the present invention can also be applied to the case where the ultrasonic beam is emitted as a parallel beam for flaw detection inspection. can. That is, if the defective surface is substantially orthogonal to the emitted parallel ultrasonic beam, the waves reflected by the defective surface will also become parallel beams and will be received with Δρ=0.

Furthermore, if the program capacity of the signal control TLL device is increased using a computer or the like, internal defects in the material, the shape of the back surface of the material, etc. can be detected by various flaw detection methods. For example, when a reflected echo from an internal defect in a material is detected, the focus of the ultrasonic wave is matched to the detection position of the reflected echo, and the material is inspected from each direction to determine the shape, size, etc. of the internal defect. Detection accuracy can be further improved.

Furthermore, in the above-described embodiments of the present invention, the one-probe method was explained in which the transducer for transmitting and receiving is shared, but the transducer is divided into transducers for transmitting and receiving, and a dedicated vibrator is used for each. The present invention can also be applied to a device employing the so-called two-probe method in which subgroups are arranged.

〔Effect of the invention〕

As described above, the present invention uses a plurality of ultrasonic transducers arranged at equal intervals, and controls the ultrasonic transducers by considering only the timing of ultrasonic wave generation from the transducer. The ultrasonic waves received by the receiving transducers that are automatically selected according to each scale parameter are added simultaneously without any delay time, and the combination of transmitting and receiving transducers is also possible. Since these are sequentially switched electrically, there is no need for complex signal processing, and various types of ultrasonic flaw detection, such as moving the focus position of the ultrasonic beam and changing the ultrasonic radiation angle by switching the Sa element, can be easily performed. In addition, it is possible to improve defect detection accuracy.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a configuration example according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating an embodiment of a transmission system according to the present invention, in which (a) shows a signal group of a trigger signal generator; (b)
3 is a diagram showing the radiation state of the ultrasonic beam, FIG. 3 is a diagram illustrating an embodiment of the receiving system according to the present invention, and FIG.
The received signal between the transducers shown in FIG. 2B, (1) is a diagram illustrating an example of selection of a receiving transducer, and FIG. 3C is a diagram illustrating signal processing of reflected waves. 1... Ultrasonic probe, 2... Ultrasonic transducer, 13.
... Ultrasonic beam, 14... Material to be tested, 15... Trigger signal group, 16... Material white defect, 17... Vibrator received signal, 18... Phase shift, 19... -Additional reflected wave signal, 20...Gate, 21...Threshold level, 22-27...Control signal, △p...Ultrasonic propagation distance difference, θ...Flaw detection angle, d... Distance between ultrasonic transducers. Applicant's agent Sato - Yusei Ien (J) Haya 3 Figure 1 (C)

Claims (1)

[Claims] 1. A plurality of ultrasonic transducers are arranged to form an ultrasonic probe, and any plurality of these transducers are pulse-excited with a delay time to generate ultrasonic waves. In an ultrasonic flaw detection device that is equipped with an ultrasonic generator that generates sound waves and radiates the ultrasonic waves in a preset direction within the tested material, the reflected waves from inside the tested material are It is characterized in that simultaneous detection is possible by a plurality of the ultrasonic transducers located at positions where they can receive the wave so that the propagation distance difference Δl with respect to the wavelength λ of the wave satisfies the condition Δl<λ/4. Ultrasonic flaw detection equipment. 2. In the apparatus according to claim 1, the ultrasonic transducer for receiving reflected waves is automatically operated according to parameters such as the ultrasonic flaw detection angle, the distance between the arranged ultrasonic transducers, and the wavelength of the ultrasonic wave. An ultrasonic flaw detection device characterized in that it can be selected according to the following criteria. 3. In the device according to claim 1, the ultrasonic transducers used as a set for transmitting waves and for receiving waves can be continuously operated by electrically sequentially switching the combinations. An ultrasonic flaw detection device characterized by being capable of ultrasonic flaw detection.