JPH02162255A - Ultrasonic inspection apparatus - Google Patents

Abstract

PURPOSE:To obtain the accurate data relating to the flaw of an object to be inspected on the basis of the difference between the echo of the difference between the echo signals obtained from respective ultrasonic probes by emitting ultrasonic signals from two ultrasonic probes having the same characteristics. CONSTITUTION:An ultrasonic transmitter 9 transmitting an ultrasonic pulse, the first and second ultrasonic probes UP1, UP2 and a receiver 50 are provided. The probe UP1 emits an ultrasonic signal to an object 6 to be inspected and the probe UP2 emits the dummy ultrasonic signal synchronous to the ultrasonic signal emitted to the object 6 to be inspected toward a dummy emitting object such as the air. The probe UP1 outputs the echo signal from the object 6 to be inspected and the probe UP2 outputs a dummy echo signal. Therefore, when the difference between the echo signal of the probe UP1 and the dummy echo signal of the probe UP2 is taken by the receiver 50, an unnecessary echo signal is cancelled each other out and the each signal from a flaw can be extracted.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an ultrasonic inspection device used in an ultrasonic flaw detection device, an ultrasonic microscope, or the like.

B. Prior Art FIG. 4 is a sectional view showing the general structure of an ultrasonic probe used in an ultrasonic flaw detection device.

The ultrasonic probe 1 is composed of a transducer 3 and a lens 4 housed in a case 2 of a predetermined shape. The device is configured to generate ultrasonic vibrations and emit an ultrasonic vibration beam to the subject through a lens 4 having a predetermined focal length.

FIG. 5 is a diagram showing a schematic configuration of a flaw detection device for detecting defects 7 inside the object 6. As shown in FIG.

When attempting to detect a defect 7 existing inside the object 6, the ultrasonic probe 1 shown in FIG. The ultrasonic vibrating beam is placed so that the focus of the ultrasonic vibration beam is on the depth position of the subject 6 where the specimen 6 is expected to be located. In this state, an ultrasonic pulse is applied from the transmitter 9 to the transducer 3 of the ultrasonic probe 1. Although the ultrasonic pulse may be either a single wave or a continuous wave, the following description will be made assuming that a continuous wave is used.

When an ultrasonic pulse is applied to the transducer 3, ultrasonic vibration is generated in the transducer 3, and this ultrasonic vibration becomes an ultrasonic vibration beam (
(ultrasonic signal) and is emitted toward the subject 6. The ultrasonic vibration beam is applied to the subject 6 as shown in FIG. 6(a).
It is reflected at the exit of the lens 4 leading to the defect 7, and is returned to the vibrator 3 as an ultrasonic echo signal. In FIG. 6(a), the ultrasonic echo signals reflected at the exit of the lens 4, the surface of the subject 6, and the defect 7 are shown as PQ, Ps, and Pf, respectively. The receiver 10 extracts only the echo signal Pf reflected by the defect 7 and determines the shape of the defect 7 and the like.

C0 Problem to be Solved by the Invention When determining the shape etc. of the defect 7 in this way, the ultrasonic echo signal PQ reflected at the exit of the lens 4 has a certain period of time depending on the sound speed and the thickness of the lens 4. and lens 4
In addition, the ultrasonic echo signal Ps from the surface of the object 6 that is delayed by an amount equivalent to the thickness of the medium 8 returns to the lens 4 and is multiplexed within the lens 4 in the same way as the ultrasonic echo signal PQ. Repeat the reflection.

Here, the ultrasonic pulse applied to the transducer 3 is expressed as Pp, and based on the application timing of Pp, the ultrasonic echo signals PQ, Ps, Pf and the echo signal PQ multiple reflected within the lens 4 ~PΩ, Figure 6 (
b) to (d). Therefore, Fig. 6(c)
The echo signal Pf from the defect 7 shown in FIG. be done.

However, the phase of the echo signal Pf from the defect 7 varies greatly depending on the depth to the defect 7 and the thickness of the medium 8, and which of the multiple reflection components in the lens is superimposed depends on the test conditions. different. For this reason, there is a problem that the phase and level of the echo signal Pf' vary greatly depending on the test conditions, etc., and information such as the shape of the defect 7 cannot be accurately detected depending on the echo signal Pf'.

A technical problem of the present invention is to accurately extract information that depends only on the defective portion by canceling multiple reflection components within the lens.

00 Means for Solving the Problems The present invention will be described with reference to the reference numerals in the drawings showing embodiments. The present invention includes an ultrasonic transmitter 9 that transmits ultrasonic pulses, and a subject 6 that receives the ultrasonic pulses. A first ultrasonic probe UP that emits an ultrasonic signal to and emits an echo signal from the subject 6.
The present invention is applied to an ultrasonic inspection apparatus including a receiver 50 that extracts an echo signal from a defect 7 of a subject 6 included in the echo signal.

The above technical problem is solved by the first ultrasonic probe UPI.
is an ultrasonic probe with the same characteristics as the first ultrasonic probe UPI that receives the ultrasonic pulse from the transmitter 9 and is synchronized with the ultrasonic signal emitted by the first ultrasonic probe UPI as a dummy injection target. A second ultrasonic probe UP2 is provided which outputs a pseudo echo signal from a dummy injection target. Further, the receiver 5o extracts an echo signal from the defect by calculating the difference between the echo signal output by the first ultrasonic probe UPI and the pseudo echo signal output by the second ultrasonic probe UP2. Configure it to do so.

E0 action The first ultrasonic probe UPI emits an ultrasonic signal toward the subject 6. The second ultrasonic probe UP2 emits a dummy ultrasonic signal synchronized with the ultrasonic signal to the subject toward a dummy emission target such as into the air. The first ultrasonic probe UPI outputs an echo signal from the subject 6, and the second
The ultrasonic probe UP2 outputs a pseudo echo signal. This pseudo echo signal includes only echo signals that are included in the echo signals output from the first ultrasonic probe UPI and are originally unnecessary for the examination. Therefore, if the receiver 50 calculates the difference between the echo signal of the first ultrasound probe tJF'l and the pseudo echo signal of the second dummy ultrasound probe UP2, the unnecessary echo signal is canceled. The echo signal from defect 7 can be extracted.

Note that in the above-mentioned sections and Section E which describe the present invention in detail, figures of embodiments are used to make the present invention easier to understand, but the present invention is not limited to the embodiments.

F. Embodiment FIG. 1 is a sectional view showing an embodiment in which the present invention is applied to an ultrasonic flaw detection device.

The ultrasonic probe 11 is constructed by housing a diaphragm 13 and a lens 14 at one end of a case 20 having a predetermined shape, and housing a diaphragm 16 and a lens 17 having the same shape and characteristics at the other end. There is. The diaphragm 13 and the lens 14 constitute the first ultrasonic probe UPI, the diaphragm 16 and the lens 17 constitute the second ultrasonic probe UP2, and the diaphragm 16 and the lens 17 constitute the second ultrasonic probe UP2. The UPI is installed to emit an ultrasonic vibration beam (hereinafter referred to as an ultrasonic signal) toward the subject 6 via the medium 8, and the second ultrasonic probe UP2 is a dummy emission target. It is installed to emit ultrasonic signals into the air.

Here, the diaphragm 13 of each ultrasonic probe UPI, UP2.
At 16, there is a circulator 12 that sends signals only in the direction indicated by the arrow.
A transmitter 10 is connected to the circulator 12.15 via a transmission cable 5B. Also,
The circulators 12.15 are each connected to a receiver 50 via an output terminal a, b. The receiver 50 includes a code converter 18 that inverts the polarity of the echo signal from the output terminal A and adjusts the level due to the difference in acoustic impedance between the air and the medium 8, and a signal from the output of the code converter 18 and the output terminal a. and an adder 19 that adds the echo signals of the echo signals. An output terminal C is connected to the adder 19, and a defect is determined based on a signal output from the adder 19.

The operation of the above configuration will be explained below with reference to the waveform diagram of FIG.

First, ultrasonic pulses are transmitted from the transmission cable 5B to the circulatory system 1.
2.15 to the diaphragms 13.16, ultrasonic vibrations are generated simultaneously in each diaphragm 13.16. Among these, the ultrasonic vibrations generated by the diaphragm 13 are emitted to the subject 6 via the lens 14 as an ultrasonic signal. As a result, the ultrasonic echo signals PQ, Ps, and Pf reflected at the exit of the lens 14, the surface of the subject 6, and the defect 7 are returned to the circulatory system 12 via the lens 14 and the diaphragm 13, and are output from the output terminal a. be done. On the other hand, the ultrasonic vibrations generated by the diaphragm 16 are emitted into the air via the lens 17 as an ultrasonic signal. Then, the pseudo echo signal PQ reflected at the exit of the lens 17 is transmitted to the lens 17 and the diaphragm 1.
6 to the circulatory system 15, and output from the output terminal.

Ultrasonic echo signals obtained from these output terminals a and b are input to the receiver 50 shown in FIG. The polarity of the pseudo echo signal from the output terminal is reversed by the code converter 18, and the acoustic impedance is corrected.
It is input to an adder 19. As a result, the adder 19 receives the data shown in FIG. 3(a).

An echo signal as shown in (b) is input. here,
pp and -Pp are ultrasonic pulses applied to the diaphragm 13.16, PQ, ~PQ are echo signals multiple reflected within the lens 14, -pa1 to -PQ3 are echo signals multiple reflected within the lens 17, Ps is an echo signal reflected from the surface of the object 6, Pf' is an echo signal from the defect 7 including the intra-lens multiple reflection component PQ, and Pp, -pp, P
Qi and -PQ, and -PQ, ,PQ, and -PQ.

are at the same phase and level, and their polarities are opposite. This means that the first ultrasonic probe UPI consisting of a diaphragm 13 and a lens 14 and the second ultrasonic probe UP2 consisting of a diaphragm 16 and a lens 17 have the same ultrasonic characteristics. This is because ultrasonic pulses are applied at the same timing and ultrasonic signals are output in synchronization.

Therefore, when such echo signals are added in the adder 19, as shown in FIG. Defects on the surface and inside 7
Only the echo signals Ps and Pf reflected from the adder 19 remain and are output from the output terminal C of the adder 19. That is, the echo signal Pf from the defect 7 is extracted in a form that does not include any intra-lens multiple reflection components. This can be extracted without being affected by multiple reflections within the lens even if the distance between the lens 14 and the subject 6 or the thickness of the medium 8 changes. This results in
It becomes possible to obtain accurate information about the defect 7.

Note that in the above description, the first and second ultrasonic probes UPI
, UP2 are integrally formed in the same case, but they may be made separately as long as they have the same ultrasonic characteristics. Although the injection target was injected into the air, the ultrasonic signal was injected into the air through the same medium 8, or the ultrasonic signal was ejected into the air through the same medium 8 to a dummy object with the same specifications as the object 6 without defects. A dummy ultrasonic signal may also be emitted. That is, the present invention is not limited to the embodiments as long as it is a dummy injection target that can obtain multiple reflection components output from an ultrasonic probe directed toward a subject. Furthermore, although the ultrasonic flaw detection device has been described, the present invention can also be applied to other ultrasonic inspection devices such as an ultrasonic microscope.

G1 As explained in detail in the invention, in the present invention, one of two ultrasonic probes with the same characteristics emits an ultrasonic signal toward the subject, and the other emits a dummy signal into the air or the like. Ultrasonic signals are emitted toward the target, and unnecessary echo signals such as multiple reflection components within the lens are canceled out based on the difference between the echo signals obtained from each ultrasonic probe, and echo signals from defects are extracted. Therefore, it is possible to accurately obtain information regarding defects in the object.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of an ultrasonic inspection apparatus according to the present invention, FIG. 2 is a block diagram of a circuit for extracting echo signal components from defects, and FIG. 3 is an operation of the embodiment of FIG. 1. FIG. 4 is a cross-sectional view showing the general configuration of an ultrasonic probe, and FIG. 5 is a diagram showing the configuration of a flaw detection device using the ultrasonic probe shown in FIG. The figure shown in FIG. 6 is a waveform diagram of an echo signal for explaining the operation of the apparatus shown in FIG. 6: Subject 8: Medium 10: Receiver 12.15: Circulatory system 13.16: Diaphragm 14.17: Lens 18: Code converter 19: Adder 20: Case 50: Receiver 7: Defect 9: Transmission Machine 11: Ultrasonic probe Figure 1 Figure 2

Claims (1)

[Scope of Claims] An ultrasonic transmitter that transmits ultrasonic pulses, and a first ultrasonic transmitter that receives the ultrasonic pulses, emits an ultrasonic signal to a subject, and outputs an echo signal from the subject. In an ultrasonic inspection apparatus comprising a sonic probe and a receiver that extracts an echo signal from a defect in the object included in the echo signal, an ultrasonic probe having the same characteristics as the first ultrasonic probe The sonic probe receives the ultrasonic pulse and emits an ultrasonic signal synchronized with the ultrasonic signal emitted by the first ultrasonic probe toward a dummy emission target, and It has a second ultrasonic probe that outputs a pseudo echo signal from the injection target, and the receiver receives the echo signal output from the first ultrasonic probe and the second ultrasonic probe. An ultrasonic inspection apparatus characterized in that an echo signal from a defect is extracted by calculating a difference between pseudo echo signals output by a child.