JPS597260A - Method and device for ultrasonic flaw detection - Google Patents

Abstract

PURPOSE:To estimate the angle of inclination of a flaw by using an array type probe for electronic scanning as a probe for wave transmission and reception, making parallel beams incident deflectively to the flaw direction after detecting the position of the flaw, and receiving the reflected wave by sectorial scanning. CONSTITUTION:The respective ultrasonic oscillators of an array type probe 1 for wave transmission and reception juxtaposed with plural pieces of ultrasonic oscillators are electrically coupled to an ultrasonic transmitter group 2 for excitation and an ultrasonic receiver group 3 which amplifies the received outputs of the reflected waves respectively. The group 2 and the group 3 are coupled to a controller 4 for delay time which determines the beam direction of the ultrasonic waves by selecting the ultrasonic oscillator groups for receiving ultrasonic waves changing momentarily and controlling the timings for wave transmission and the timings for wave reception. Parallel beams UBt are made incident to a flaw part TG having certain inclination and the waves reflected thereof are received by sectorial scanning Ss. When the sectorial scanning is accomplished so as to be perpendicular to the wave reception plane from the part TG, the reception level of the reflected waves is maximized; therefore, the inclination of the flaw part is estimated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an ultrasonic flaw detection method and apparatus for detecting defects in metals and non-metal materials using ultrasonic waves.

[Technical background of the invention]

If there is an internal defect in a structure, will the defect be excessively large? 1
? When a T-weight acts on the structure, the defective part will grow and cause serious accidents such as damage to the structure. Therefore, it is necessary to detect internal defects in advance. In internal defect detection, measuring the shape and size of defects is an important item.

Conventionally, for internal defect detection in structures, an ultrasonic beam is incident on the defective part, and in order to receive the reflected echo at the defective part, the transmitting angle probe is manually scanned while the receiving angle probe is manually scanned. The method used is to manually scan the angle probe, detect the reflected echo from the defect with high sensitivity, and estimate the tilt angle of the defect from the relative position of both probes, which takes a considerable amount of time. He was healed.

Furthermore, in the conventional method, it is not possible to arbitrarily select the incident angle of the ultrasonic beam of the angle probe used, so depending on the shape of the object, it is difficult to select the appropriate incident angle and probe depending on the inclination angle of the defect. Since the location could not be selected, the estimation accuracy was not sufficient.

[Object of the Invention] The present invention has been made in view of the above circumstances, and it is possible to perform flaw detection by fixing the probe at an arbitrary position, and also allows the inclination angle of the internal defect to be fixed regardless of the shape of the object to be inspected. It is an object of the present invention to provide an ultrasonic flaw detection method and apparatus that can estimate with high accuracy and perform flaw detection in a short time.

[Summary of the invention]

That is, in order to achieve the above object, the present invention uses an array type 1 probe for electronic scanning as a transmitting/receiving probe in ultrasonic flaw detection, and arbitrarily moves the probe on the surface of the object. After detecting a defect by moving or in a fixed position by fan-shaped electronic scanning, a parallel ultrasonic beam is deflected from the probe toward the defect and is incident, and the reflected wave from the defect is received by scanning in a fan-shaped manner. By detecting the point where the sensitivity is maximum,
Try to estimate the tilt angle of the defect.

That is, the present invention uses an array type probe as a transmitting/receiving probe, controls the excitation of this array type probe, and injects a parallel ultrasonic beam into an internal defect using an electronic scanning method. The reflected wave reflected from the internal defect is strongly reflected to the opposite side of the normal to the defect's slope at a reflection angle equal to the incident angle, but some reflected wave components are reflected from the defect surface. We focus on points that are scattered in various directions, and focus on reflected waves that pass through the same path as the incident wave. That is, a parallel beam is transmitted to the internal defect, reception is performed by fan-shaped scanning, and the reception direction of the partially reflected wave is fan-shaped scanned using an electronic scanning method to obtain the summed waveform of each ultrasonic transducer. The inclination angle of the internal defect is estimated under the highest sensitivity.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

The present invention uses an electronic scanning (electronic stationary) type ultrasonic device to perform flaw detection. Here, the electronic tanshi method uses an ultrasonic probe with multiple ultrasonic transducers arranged in parallel, and in the linear electronic sugin mode, the ultrasonic transducer 111 is used as one unit with multiple elements. This unit of ultrasonic transducer is excited to generate ultrasonic oscillation.

For example, by sequentially shifting the pitch by one oscillator [7] and excitation, the oscillation position of the ultrasonic beam is shifted in an orderly manner.

The ultrasonic transducers that are excited so that the one-wave sound beam converges as a beam are shifted in excitation timing between those located toward the center of the beam and those located to the sides. The emitted ultrasonic waves are focused using the phase difference between the ultrasonic waves generated by each vibrator. (This is called electronic focus).

In addition, in the sector electronic scan (fan-shaped scan) mode, for one unit of ultrasonic vibration %iJ + child group to be excited, the radiation direction of the ultrasonic beam is J for every one pulse of the ultrasonic beam.
The excitation timing of each vibrator is changed according to the direction so as to change in a fan-like manner.

Such a multiplex scanning type ultrasound device captures ultrasound echoes using an excited ultrasound transducer, converts them into electrical signals, and obtains ultrasound images.

An embodiment of the present invention is shown in FIG. FIG. 1 is a block diagram showing the configuration of an electronic scanning type ultrasonic flaw detection device according to the present invention. Each ultrasonic transducer of this transmitting/receiving phase array type 1 probe 1 has an ultrasonic transmitter group 2 for excitation of ultrasonic waves and an ultrasonic wave generator for amplifying the received output of reflected waves of ultrasonic waves. It is electrically coupled to receiver group 3. Here, the ultrasonic transmitters constituting the ultrasonic transmitter group 2 and the ultrasonic receivers constituting the ultrasonic receiver group 3 correspond to the number of sonic wave transducers in the wave transmitting/receiving array probe. Only the corresponding number is available.

The ultrasonic transmitter group 2 and the ultrasonic receiver group 3 select the ultrasonic transducer group for transmitting and receiving ultrasonic waves that changes from time to time, and the ultrasonic transmission time timing and ultrasonic reception time timing to each ultrasonic transducer. It is coupled to a delay time controller 4 which controls the ultrasonic beam direction and determines the beam direction of the ultrasonic wave. In particular, during reception, depending on the signal from the delay time controller 4,
The received signal ultrasonic waveform from each ultrasonic transducer is delayed, and the signals detected by each ultrasonic transducer from the same direction and the same depth position can be added to enable reception by fan-shaped scanning. In addition, the delay adder 5, which is capable of storing the added waveform, makes it possible to obtain the added ultrasonic waveform.

Furthermore, among the waveforms obtained by fan-shaped scanning, the summation waveform exhibiting the maximum sensitivity is detected and extracted, and after being detected and amplified by the detection amplifier 6, the summation waveform is displayed on an image display device, for example, a cathode ray tube 7, and A gate is attached to a predetermined ultrasonic beam path range by the detection amplifier 6, thereby making it possible to use the same method as in the conventional method.

Moreover, 8 is a signal processor, and this signal processor 8 calculates the inclination angle of the defect from the sound velocity and delay time of the ultrasonic wave, and makes it possible to display the results on the display 9.

Note that the person is the subject and the TG is the defective part.

Next, an example of the operation of the present invention will be explained with reference to FIG. 2. In Fig. 2, the device of the present invention controls the operation timing of each of the group of ultrasonic transducers to be driven by the delay time controller 4 according to the mode of electronic scanning, and thereby By controlling each transmitter of the sonic wave transmitter group 2 and each receiver of the ultrasonic receiver group 3 and controlling the transmission/reception timing of each ultrasonic transducer, it is possible to electronically scan the ultrasound transmission direction arbitrarily. Therefore, after detecting the defective part TG by moving the probe 1 arbitrarily on the surface of the subject, it is possible to transmit the ultrasonic beam to the defective part TG at an arbitrary angle. In addition, when receiving waves, the received signals of each ultrasonic transducer are delayed by applying an appropriate delay time different from that during transmitting, so that the received signals obtained from the same direction and the same depth are obtained at the same timing. By adding these values, an effect similar to that obtained by directing the beam laminate in a direction different from the beam direction during wave transmission can be obtained, and the scanning modes for transmission and reception can be made different.

Therefore, in the wooden device, a parallel beam of ultrasonic waves UBt from each transducer of the probe 1 is made incident on the defective part TG with a certain inclination, and the reflected wave of the parallel beam from the defective part TG is reflected from the defective part TG. At the time of reception, the data is received by performing fan-shaped scanning SS. That is,
In the delay adder 5, the outputs of each receiver 4P output from each transducer are delayed in accordance with each transducer position, so that the signals from the same depth can be added, and are added together. By converting it into a waveform, the detection amplifier 6 detects and amplifies the optimal summed waveform, and displays it on the cathode ray tube 7.

1. On the cathode ray tube 7, the sensitivity of the summed waveform of the ultrasonic beam received from the defect is maximized by the front fan-shaped tanshi. The delay time when received is the same as the delay time when receiving by fan-shaped scanning perpendicular to the wave receiving surface from the defective part TG. After detecting the maximum level of the signal level, the delay time data and ultrasonic sound speed data at that time are given to the signal processor 8, the signal processor 8 calculates the first equation VC, and the defective part is detected from the calculated value. The tilt angle α of the TG is obtained and displayed on the display 9.

According to the present invention, the inclination angle α of the defect at this time is given by the following equation when considered based on FIG.

C・Δt α7Co5−' --Fist−・Akaguchi・(1) Here,
α is the inclination angle of the defect TG, a is the distance between arbitrary transducers that received the wave, C is the sound speed of the ultrasonic wave in the object A, and Δt is the maximum sensitivity of the added waveform obtained by the fan-shaped scan described above. This is the arrival time difference between the arbitrary oscillators of the reflected echo at time, that is, the delay time.

In addition, vE in Fig. 3 is the reflected echo from the defect TO,
U BF is the reflected wavefront of the reflected echo from the defect TO.

Based on the above), this device can estimate and display the inclination angle of the defective portion TG accurately and in a short time simply by bringing the probe into contact with the surface of the object to be inspected.

In addition, with the device of the present invention, the inclination angle of the defect BB T <) can be estimated by fixing the probe I at an arbitrary position and performing flaw detection, so it can sufficiently cope with changes in the shape of the surface of the object to be inspected. It has become useful.

By the way, in the above-described embodiment of the present invention, the inclination angle of the defective part TG is estimated using the probe 1 from an arbitrary position on the object A, but arrows B and O are shown in FIG. As shown in
Move the probe 1 in various directions on the surface of the object A, and use the same method as above to find the point where the sensitivity of the added waveform is maximum, and estimate the inclination angle of the defective part TG. It is also possible.

Furthermore, in the embodiment of the present invention, the parallel beam UBt is transmitted to the defective part TG, and the parallel beam reflected from the defective part TG is received by scanning in a fan shape on the receiving side. In order to estimate the inclination angle of Flaw detection can be carried out using the same method described above, by changing the parallel beam, focused beam, and fan scanning on the transmitting and receiving sides, such as estimating the inclination angle of the defective part TG from the wave angle, delay time, sound velocity, etc. For example, it becomes possible to estimate the tilt angle of the defective portion TG.

In addition, the ultrasonic transducer is divided into two parts, one for transmitting and one for receiving.
It is also possible to estimate the inclination angle of the defective portion TG using a method similar to that described above.

〔Effect of the invention〕

As detailed above, according to the present invention, there is provided a probe for transmitting and receiving ultrasonic beams using the electronic scanning method in which a plurality of ultrasonic transducers are arranged in parallel, and the operation timing of each ultrasonic transducer of this probe is controlled. The ultrasonic beam is transmitted in a fixed direction by controlling the delay, and the reception is performed by fan-shaped electronic scanning by delaying and adding the reception outputs of each ultrasonic transducer 411
] control means, and the reception of the ultrasonic transducer at two predetermined points on the probe when the detection output from the internal defect of the object among the detection output of the received ultrasonic waves reaches the maximum level. The system includes a means for determining the electronic scanning direction at which the maximum level is obtained when receiving waves by fan-shaped electronic scanning based on time delay time difference data, and a display means for displaying the determined electronic scanning direction. When a parallel ultrasonic beam is incident on a defective part, the reflected wave from the defective part is strongly reflected to the opposite side of the normal line, which is equal to the incident angle with respect to the normal line of the slope of the defect.
Focusing on the fact that some reflected wave components are scattered in various directions on the defect surface, we performed a fan-shaped scan using the lightning and child scanning method, and determined the angle in the scanning direction that gives the maximum level of reflected waves from the defect. Utilizing the fact that the inclination of the part can be known, the control means transmits a parallel beam from a contact at an arbitrary position to a defect in the object to be inspected, and further receives the wave in a fan-shaped scan, The maximum detection sensitivity can be obtained according to the tilt angle of the defect, and the tilt angle at this time is calculated and displayed based on the delay time data, making it easy to determine the tilt angle of the defect within the object. Furthermore, according to the present invention, it is possible to sufficiently deal with complex shapes on the surface of the object to be inspected without moving the contact over a wide range, and compared to conventional flaw detection methods, it takes less time and It is possible to provide an ultrasonic flaw detection method and apparatus having the following characteristics that greatly improve accuracy.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the device of the present invention, and FIG.
The figure is a diagram for explaining the operation of the method of the present invention, and FIG. 3 is a diagram for explaining that the inclination angle of a defect can be calculated by the apparatus of the present invention. The fourth part and FIG. 5 are diagrams for explaining the present invention in detail. 1... Array type probe, 2... Ultrasonic transmitter group, 3
...Ultrasonic receiver group, 4...Delay time I controller, 5
...Delay adder, 6...Detection amplifier, 7...Cathode ray tube, 8...Signal processor, g...Display device. Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (4)

[Claims] (1) Using a probe for transmitting and receiving ultrasonic waves using the electronic scanning method, in which multiple ultrasonic transducers are arranged in parallel, an ultrasonic beam is directed in one direction toward the defective part within the subject. The method is characterized in that the wave is transmitted and received by fan-shaped electronic scanning, and the inclination angle of the defect is estimated in the scanning direction in which the received signal of the reflected wave from the defect in the object has a maximum level. Ultrasonic flaw detection method. (2) The ultrasonic flaw detection method according to claim 1, characterized in that the transmitted ultrasonic wave uses a parallel beam. (3) The ultrasonic flaw detection method according to claim 1, characterized in that the transmitted ultrasonic waves are focused at any specific position of the defective part. (4) A probe for transmitting and receiving ultrasonic beams using the electronic scanning method in which multiple ultrasonic transducers are arranged in parallel, and the operation timing of each ultrasonic transducer of this probe is delayed and controlled to transmit ultrasonic beams in a fixed direction. A control means for transmitting a sound wave beam and for receiving a sound wave by delaying and adding the received output sounds of each ultrasonic transducer by fan-shaped electronic scanning; Receiving waves by fan-shaped electronic scanning based on the delay time difference data of the ultrasonic transducer at two predetermined points on the probe when the detection output from the internal defect of the object reaches its maximum level. 1. An ultrasonic flaw detection apparatus comprising: means for determining an electronic scanning direction in which the maximum level is reached; and a display means for displaying the determined electronic scanning direction.