JPS62180267A - Ultrasonic flaw detecting device - Google Patents

Abstract

PURPOSE:To perform flaw detection with the best SN ratio by providing a frequency varying means, a wave number varying means, etc., checking a frequency suitable to a sample and performing transmission at the best frequency, and selecting a wave number. CONSTITUTION:A wave number varying circuit 8 outputs an operation time control signal CLTn for a frequency varying circuit 6 based on the output signal of a synchronizing circuit 1 corresponding to a set value set by a wave number setting means 9. The circuit 6 outputs a pulse CLTwmn corresponding to the set value of frequency setting 7 to a transmission part 2 within a time controlled with the output signal CLTn of the circuit 8. The transmission part 2 outputs a transmit signal corresponding to said signal to a probe 3. The probe 3 varies the transmission frequency and reception frequency on the basis of the transmit signal of the transmission part 2 and makes an ultrasonic wave incident on the sample. For the purpose, an echo which is displayed 5 is monitored for every set value set by the means 9 and 7 to know set values of the means 9 and 7 with the best SN ratio for the sample.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for non-destructively inspecting the inside of a material using ultrasonic waves.

[Conventional technology]

As a means of finding defects in solid objects such as metals, ultrasonic waves are injected into the material, and the reflected waves from the defects (hereinafter referred to as echoes) are captured and displayed on a display such as a CRT to determine the size of the defect and the material. There is an ultrasonic flaw detector as a device for measuring the position of defects inside.

Conventionally, an ultrasonic flaw detection device as shown in FIG. 4 has been proposed as this type of device. In the figure, (1)(-) is a synchronization section that outputs the synchronization signal necessary for each circuit, (2) is a transmission section that generates a transmission signal based on the output signal from the synchronization section fi+, and (3) is a transmission section. (2) A probe that generates ultrasonic waves based on the transmitted signal and makes the ultrasonic waves incident on the test material, and captures echoes from the test material and converts them into electrical signals.
4) is a receiving unit that amplifies the electrical signal from the probe (3);
(5) is a display that displays the output signal of the receiving section (4).

Conventional ultrasonic flaw detection equipment is configured as described above, so the probe (3) is
A transmission signal was applied from the transmitting section (2) to detect flaws.

[Problem that the invention seeks to solve]

Conventional ultrasonic flaw detection equipment only transmits at a fixed transmission frequency and wave number as mentioned above, so only one arbitrary point on the custom-made frequency of the probe is used. It was not possible to transmit the optimum transmission frequency and transmission wave number for the material to be tested, so it was necessary to replace the probe using only the nominal frequency displayed on the probe as information. A probe with a nominal frequency close to the frequency was selected. However, there is no way to select the number of transmitted waves, and the main body of the ultrasonic flaw detection device that generates an arbitrary number of waves is converted, but there are limits to the types of probes and devices, and in reality, the number of waves is austenitic. Reflected waves from particles that occur during inspection of materials or flaw detection of single-particle coarse materials (this is called a forest echo, but it is the echo that degrades the S/N on the display)
/ You're making N feel bad.

This invention was made to solve these problems, and it has nine frequency variable means and wave number variable means to find the optimum frequency for the material being tested, transmit at the optimum frequency, and select the wave number. The purpose of this invention is to obtain an ultrasonic flaw detection device that can detect flaws with optimal S/N.

[Means for solving problems]

The ultrasonic flaw detection apparatus according to the present invention is provided with a frequency variable circuit and frequency setting means for varying the transmission frequency, and a wave number variable circuit and wave number setting means for varying the number of transmitted waves.

[Effect]

In this invention, by varying the transmission frequency and the number of transmission waves and performing transmission optimally for the material to be inspected, it is possible to reduce the factors that cause forest echoes, etc., which worsen the S/N of flaw detection, and to facilitate flaw detection. can be done.

〔Example〕

Figure 1 shows an embodiment of the ultrasonic flaw detection device according to the present invention.
FIG. In Fig. 1, (11 to (51) are similar to those shown in Fig. 4. (6) varies the pulse width to the transmitter (2) in synchronization with the output signal of the synchronous circuit (1). A variable frequency circuit (7) is a frequency setting means for outputting a control signal to the variable frequency circuit (6), (8I is a variable wave number circuit that varies the wave number of the output signal of the variable frequency circuit (6), (9) is It is a wave number setting means that outputs a control signal to the wave number variable circuit (81).

Next, the operation of the above embodiment will be explained with reference to FIGS. 1 to 3. Based on the output signal of the synchronous circuit (1), the wave number variable circuit (8: is the setting set by the wave number setting means (9) (directly corresponding to the operating time control signal CL of the frequency variable circuit (6)
Tn (CLTn shown in FIG. 3) is output. The frequency variable circuit (6) is the output signal 0LTn of the wave number variable circuit (81).
The pulse (0L-T'i shown in FIG. 3) corresponding to the set value set by the frequency setting means (7) within the time controlled by
Vmn) is output to the transmitter (2). The transmitting section (2) outputs a transmitting signal corresponding to the output signal CLTWmn) of the frequency variable circuit (6) to the probe (31). In this embodiment, the above operation is performed as OLTWm(m =
1. λ3. ) of m°° in a certain time period (wave number controlled by the output signal CLTn of the variable wave number circuit (8) (n =
1.2.3. The time (nt shown in Fig. 2) until the ``'n parameter of ...) reaches its maximum is kept fixed, and the wave number ``n'' controlled by the output signal CLTn of the variable wave number circuit (8) is sequentially increased. Output signal C!LT of the variable frequency circuit (6)
Get Wmn. In addition, the output signal C of the variable wave number circuit +81
The wave number "n-t" controlled by LTn is set by the wave number setting means (9
), the wave number setting means (9) is set to n, = 1.
Set. At the same time, the frequency setting means (7) sets m=2 of the output signal CLTWIun of the frequency variable circuit (6), and connects the CLTw 21 shown in FIG. 3 to the frequency variable circuit (6).
outputs.

By repeating the above operations, the ultrasonic waves incident on the test material from the probe (3) vary the frequency and wave number and propagate through the test material. Propagated ultrasound: Probe again (3)
is converted into an electrical signal and sent to the display (5) via the receiver (4).
By monitoring the echo on the display (5), it is possible to determine the optimum conditions for the output signal CLTw of the frequency variable circuit (6) for the test material (set by the wave number setting means (9)). value "'n" and frequency setting means (7
) becomes clear, and the optimum conditions for the material to be tested can be selected.Next, the operation of the variable frequency circuit (6) is shown in Fig. 3. In FIG. 3(a), the variable wave number circuit (8) is a mono multivibrator (hereinafter referred to as M/M) αα, resistance Ral~Ran<, Ral<
Ra2<-<Ran), resistance Ra1~Ra
Selector AQ31 that switches n and capacitor Ca
It consists of mosquitoes. In addition, the frequency variable circuit (6) is connected to the resistor RB.
.

to RBn (RBI < RB2 <-< RBn
), resistor R]3+ -%-RBn selector B
l(A), resistance RC1 to RCn(, R(! + < R
C2<...<Rcn), resistance RC+ "" RC
Selector C09 to switch n, capacitor CB, C
It is composed of O and M/MB, C1111,12.

M/MAal is selected by the selector A (131) based on the control signal set by the wave number setting means (9).
An output signal CLTn having a time width of 1a shown in FIG. 3(b) is outputted by a predetermined resistance of ~Ran and a capacitor +jCa. RC selected by the selector C Kasumi based on the control signal set by the 1 frequency setting means (7) in synchronization with the M1MCUr&XM/MAIJrJo output signal CLTn.
An output signal CLTWm having a time width of tw shown in FIG.
Output n. M/MB (lυ is synchronized with one output signal CLTWmn of M/MCα2, and is selected by selector B (I41) based on the control signal set by the frequency setting means (7). y
The output signal CLDW having a time width of tw shown in FIG. 3(1) due to EB is input to the above M/MC! Output to one input terminal of αυ.

As mentioned above, variable wave number circuit (8), 9 variable frequency circuit (6
) is configured so that a signal whose transmission frequency and transmission wave number can be varied can be outputted to the transmitter (2).

The transmitter (2) receives the output signal C of the frequency variable circuit (6).
LTWmn (, CI shown in FIG. 2, TV 1.1.
CLTW 1.2° A transmission signal is generated based on CLTWmn. The probe (3) changes the transmission wave number n and the transmission frequency m based on the transmission signal from the transmitting section (2), and displays the echo displayed on the 1 indicator (51) in order to inject the ultrasonic wave into the specimen. The above wave number setting means (9) and frequency setting means (7)
By monitoring each set value set in , it is possible to know and set the set values of the wave number setting means (9) and frequency setting means (7) with the best S/N for the material being tested. .

〔Effect of the invention〕

As described above, according to the present invention, it is possible to set the optimum transmission frequency and transmission wave number for the material to be inspected without selecting the probe or the main body of the ultrasonic flaw detection apparatus. This allows the material to be tested to have the highest S.
In addition to being able to detect flaws with a good frequency and wave number of /N, it also has the characteristics of being able to detect phase interference in the vicinity of the probe (near-field sound field) and also being able to lower it by varying the frequency.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an ultrasonic flaw detection device according to the present invention.
FIG. 2 is an operation timing diagram of the present invention. FIG. 3 is an explanatory diagram of a variable wave number circuit to a variable frequency circuit according to the present invention, and FIG. 4 is a block diagram of a conventional ultrasonic flaw detector. In the figure, (tBgo synchronization section, (2) is the transmitting section, (3) is the probe, (4) is the receiving section, (51 is the display, (6) is the frequency variable circuit, (7) is the frequency setting (8) is a wave number variable circuit, (9) is a wave number setting means, αG-(12 is a mono multivibrator, and α3-QS is a selector. In the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] a synchronizing section that generates a predetermined repetition frequency; a transmitting section that generates a transmission signal based on the output signal from the synchronizing section; and a transmitting wave number of the transmitting section in synchronization with the output signal of the synchronizing section. a variable wave number circuit that varies a wave number; a wave number setting means that sets a wave number to the variable wave number circuit; a variable frequency circuit that varies the transmission frequency of the transmitter based on an output signal of the variable wave number circuit; a frequency setting means for setting a frequency, and a probe that converts a transmission signal generated from the transmitting section into an ultrasonic signal, causes the ultrasonic wave to be incident on the test material, and converts a reflected wave from the test material into an electrical signal. An ultrasonic flaw detection apparatus comprising: a receiving section that amplifies the electrical signal from the probe; and a display that displays the waveform of the receiving section.