JPS6151563A - Ultrasonic flaw detecting device - Google Patents

Abstract

PURPOSE:To improve the S/N of a received signal and also to improve defect resolution irrelevant to the kind, size and the kind of defect, of a material to be inspected, etc., by providing a reception system with a filter group of plural filters having different frequency characteristics. CONSTITUTION:The filter group 4 forms a multichannel analog filter composed of many filters which have filter characteristics in the same shape, but differ in center frequency. Then, a signal received by a receiver 3 is amplified, channel by channel, by the filter group; and the beam route and amplitude value are measured by a beam route counting circuit 5 and an amplitude value measuring circuit 6 and then data on the same data route is stored in the input data memory 8A of a microcomputer 8 for arithmetic. The position of an ultrasonic probe 1 which is detected by a probe position detector 7 is stored in the memory 8A. Then, an arithmetic part 8D performs arithmetic processing and the flaw detection result is displayed 10. Consequently, a filter optimum for a defective echo is applied, so the S/N is increased and a fine defect is detected.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to an ultrasonic detector 1 for measuring the presence or absence of defects and the dimensions of defects existing on the surface or inside of a metal material or the like as an object to be inspected.
The present invention relates to an ultrasonic flaw detection device, and particularly to an ultrasonic flaw detection device that improves the S/N ratio of a received signal and improves defect resolution.

[Technical background of the invention and its problems 1 In ultrasonic deep scratches, one way to reliably detect defects is to improve the ratio of the defect signal to noise, that is, the S/N ratio. In particular, in order to detect minute defects such as stress corrosion abrasion that occurs in austenitic stainless steel, there are The defect detection limit is often determined by the S/N ratio.

Therefore, in the conventional ultrasonic exploration H stomach, flaw detection method.

Attempts are being made to meet the above-mentioned requirements for improving the sZN ratio by improving data processing methods and the like. However, the type of material being tested,
A uniform measure for improving the S/N ratio regardless of the size or type of defect has not yet been disclosed.

[Objective of the Invention] The present invention has been made based on the above circumstances, and its purpose is to detect the type of material of the object to be inspected, the size of the defect (irrespective of its severity, etc.) An object of the present invention is to provide an ultrasonic flaw detection device that can improve the S/N ratio and defect resolution of the No.

[Summary of the Invention] In order to achieve the above object, the ultrasonic flaw detection device according to the present invention has different frequency characteristics. ! A filter group consisting of y number of filters is installed in the ultrasonic receiving system, and the signal group that has passed through the filter group is filtered so that only desired signal components are obtained from the received signal obtained from the ultrasonic transducer. It is characterized by improved S/N ratio and defect resolution of the received signal through arithmetic processing.

[Embodiment of the Invention] An ultrasonic probe+1 device according to the present invention will be described below according to an embodiment shown in FIG.

In FIG. 1, reference numeral 1 denotes an ultrasonic probe such as an angle probe having an ultrasonic transducer 1A inside, and a wave body P.
placed above. 2 is a pulser that applies a high voltage pulse for excitation to the ultrasonic probe 1. This balsa 2 excites the ultrasonic probe 1 and transmits an ultrasonic beam UB to the human body P. Reference numeral 3 denotes a receiver, which receives, via the ultrasound probe 1, an ultrasound echo IJE formed by the ultrasound beam UB reflected by the defect CL in the subject P.

Reference numeral 4 denotes a filter group (multi-channel analog filter) consisting of a large number of filters having the same filter characteristic shape but different center frequencies. This filter group 4 takes in the received signal from the receiver 3, and outputs a signal from which components other than predetermined frequency components have been removed.

5 is a beam path measuring circuit, 6 is an amplitude value measuring circuit,
These A/D convert the output signal from filter group 4,
The beam path and maximum amplitude value are measured based on the digital signal. Reference numeral 7 denotes a probe position detector that detects the position of the ultrasound probe 1 on the subject P. Reference numeral 8 denotes a calculation microcomputer, which stores the outputs from the beam path measurement circuit 5 and the amplitude value measurement circuit 6 as one data group, as well as input data for storing the output from the probe position detector 7 at that time. DAC curve memory 8B in which data indicating the DAC (distance amplitude characteristic) curve is stored in advance, object shape memory 8C in which data indicating the shape of the object P is stored in advance
1 based on the data of A, 8B, and 8C! It is composed of an arithmetic unit 8D that executes the data processing described above.

9 is D5 which converts the output from the calculation unit 8D into an analog signal.
'A converter. Reference numeral 10 denotes a display device that displays an image based on the output of the D/A converter 9 using a display method such as a Δ scope, B scope, or C scope. 11 is a control microcomputer that controls each of the circuits described above.

゛In the above, the amplitude value data groups at the same beam path stored in the input data memory 8A are each stored in the calculation unit 8D.
11 is performed to detect the maximum value of the absolute value of the amplitude, and this maximum one value is adopted as the amplitude value of each beam path, and the beam path difference is calculated based on the DAC curve stored in the DAC curve memory 8B. A signal exceeding a predetermined reference value after canceling out the effects is converted into an analog signal by the D/A converter 9 and displayed on the display device 10 as a defect.

Further, the data of the object shape stored in the object shape memory 8C of the calculation microcomputer 8 is stored in the calculation section 8.
Shape calculation processing is performed by D, and the processing result is
Like the aforementioned defect data, it is converted into an analog signal by the D/A converter 9, and is displayed on the display device@10 together with the aforementioned defect data.

The operation of this embodiment with the above configuration will be explained with reference to FIGS. 2 to 7. The signal received by the receiver 6 is amplified by the filter group 4, which has a plurality of filters with the same filter characteristics but slightly different center frequencies, as shown in FIG. 2 for each channel.
After the beam path and amplitude values are measured by the beam path measuring circuit 5 and the beam path measuring circuit 6, the data of the same beam path is stored as one data group in the input data memory 8A of the calculation microcomputer 8. .

At the same time, the position of the ultrasound probe 1 is detected by the probe position detector 7 and stored in the input data memory 8A of the microcomputer 8.

In the input data memory 8A of this demonstration microcomputer 8, each of the above-mentioned data is recorded in the format shown in Table 1 below.
9 will be given.

Table 1 As shown in Table 1 above, the amplitude 1 for channels 1 to n at a certain probe position (Pl) and a certain beam path length (Ll)
iii (A 111.A 112.・A Iin)
, then change the beam path (L2) and change the amplitude values of channels 1 to n (A 121.A 122.-A 12
n), this is repeated once, and when it is completed m times, the amplitude values for channels 1 to n for each beam path length when the position of the probe is changed −C times as the primary are stored.

Next, the data stored in the input data memory 8A is the amplitude absolute value of the amplitude values obtained in channels 1 to n at one probe position and one beam path in the performance section 8D. An arithmetic process is performed to detect the maximum value of the data, and the data is changed into a format as shown in Table 2 below, and is stored again in the input data memory 8A.

Table 2 Next, these data stored in the input data memory 8A are stored in the DAC curve memory 8B of the performance microcomputer 8, including data at the same probe position.
Using the AC concavity 25 as shown in FIG. 3 stored in , the calculation unit 8D normalizes the amplitude with respect to the beam path on the DAC curve of the maximum absolute value of the amplitude shown in Table 2. 1. Change Table 2 as shown in Table 3 below.

M 3 Normalized amplitude value shown in Table 3 (A IL/B 1.A
12/B2 ・Alm, /Bm, A21. /Bl
, A2m/Bm, -..., A-1 m, /3m), those exceeding a certain reference value A are displayed on the display device 10 as defects. Also) ■■ Microcomputer 8
The data stored in the object shape memory 8C is also stored in the calculation unit 8.
Since it is processed in D and displayed on the display device 10 in the same poem,
The depth 10 result is displayed as a cross-sectional image (B scope image) as shown in FIG.

As described above, in this embodiment, R
; Since a Q filter can be applied, the SIN ratio can be improved, and therefore, it is possible to detect minute defects, and
Since the defect is displayed as a cross-sectional image, it is possible to grasp the position of the defect. +
2 becomes easier.

Next, another embodiment of the present invention will be described with reference to FIG. That is, instead of calculating the details of filters with different frequency characteristics by hardware as shown in Fig. 1, the FF
A microcomputer 8 uses software to calculate filters with different characteristics as shown in FIG.
The calculation section 8D of the calculation microcomputer 8 converts from the time domain to the frequency domain or from the frequency domain to the time domain.
It may also be configured to do this. With this configuration, filters with different stroke characteristics can be applied, and the filter characteristics can be easily changed.

In particular, if the frequency characteristics of the defect are known, a filter adapted to the frequency characteristics of the defect can be easily applied.
It becomes possible to further improve the S/N ratio, that is, to detect even smaller defects.

The present invention is not limited to the above embodiments, and can be implemented with various modifications without departing from the gist of the present invention.

[Effects of the Invention] As described above, according to the present invention, ultrasonic waves are transmitted and received to and from a subject using an ultrasonic transducer, and ultrasonic waves are applied to a defect existing inside the subject. In the probing device, a filter consisting of a plurality of filters each having different frequency characteristics is provided in the ultrasonic receiving system, so that only a desired signal component is received 1q out of the receiving number 18 received 1q from the ultrasonic transducer. Since the signal that passed through the above filter group was subjected to strict processing, the SZN of the received signal is
An ultrasonic maintenance device that can improve the ratio and defect resolution can be provided.

[Brief explanation of the drawing]

FIG. 1 shows (n
2 is a diagram showing the filter characteristics of the filter group in FIG. FIG. 5 is a block diagram showing the configuration of another embodiment of the present invention. 1... Ultrasonic probe, 1A... Ultrasonic transducer, 2.
...Balsa, 3...Receiver, 4...Filter group,
5... Beam path measurement circuit, 6... Amplitude value measurement circuit, 7... Probe position detector, 8... Microcomputer for calculation, 8A... Memory for input data, 8B.
... DAC curve memory, 8C... object shape memory, 8D... fault section, 8E... filter memory, 9
...D/A converter, 10...display device, 11...
Control microcomputer. Applicant's representative Patent attorney Takehiko Suzue

Claims (1)

[Claims] In an ultrasonic flaw detection device that transmits and receives ultrasonic waves to and from a test object using an ultrasonic transducer to ultrasonically detect defects existing inside the test object, a filter group consisting of a plurality of filters each having different frequency characteristics. is provided in the ultrasonic receiving system, and arithmetic processing is performed on the signal group that has passed through the filter group so that only desired signal components are obtained from the received signal obtained from the ultrasonic transducer, and the S/ of the received signal is An ultrasonic flaw detection device characterized by improved N ratio and defect resolution.