JPS6395353A - Measuring range setter for ultrasonic flaw detector - Google Patents

Abstract

PURPOSE:To enable the setting of a measuring range easily and accurately, by a method wherein a data of a reflected wave received is stored into a waveform memory and address to be selected according to the measuring range are determined by computation to display data of the addresses. CONSTITUTION:When a trigger signal is outputted to a transmitting section 5 from a timing circuit 25, the transmitting section 5 outputs a pulse to an ultrasonic probe 2 and an ultrasonic wave is beamed into an object 1 to be inspected from a probe 2. The reflected wave of the ultrasonic wave is converted into an electrical signal with the probe 2 and received with a receiving section 6 to be stored into a waveform memory 23 through an A/D converter 22. This storing is accomplished by addressing with an address counters 24 for the memory 23 sequentially. Then, CPU26 reads sound velocity inputted into an input section 30 and a measuring range set with a setting section 29 according to the sequence in which they are stored in an ROM28. Then, computation is executed to determine how an address is selected within a measuring range in the memory 23 and a liquid crystal display section 31 is driven with a display section controller 32 to display data stored in the memory 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a measurement range setting device for an ultrasonic flaw detector that determines a measurement range in an object to be inspected.

[Conventional technology]

Ultrasonic flaw detectors are well known as devices that inspect the presence or absence of flaws inside an object without destroying the object. This ultrasonic flaw detector will be explained using figures.

FIG. 5 is a block diagram of a conventional ultrasonic flaw detector, in which 1 indicates the object to be inspected, 1f indicates a defect existing in the object to be inspected 1, and 2 indicates the ultrasonic wave inside the object to be inspected l. This is an ultrasonic probe that outputs an electrical signal proportional to the ultrasonic waves that are emitted and reflected. 3 is an ultrasonic flaw detector, which outputs ultrasonic generation pulses to the ultrasonic probe 2, and
A signal from the ultrasound probe 2 is received and the waveform of this signal is displayed.

The ultrasonic flaw detector 3 is composed of the following elements.

That is, 4 is a synchronous circuit that generates a signal voltage that gives temporal regulation to the operation of the ultrasonic flaw detector 3, and 5 is a synchronous circuit that outputs pulses for generating ultrasonic waves to the ultrasonic probe 2 based on the signal from the synchronous circuit 4. This is the transmitter. A receiving section 6 receives signals from the ultrasound probe 2, and is composed of an attenuation circuit 6a made up of a combination of voltage dividers made up of resistors, and an amplification circuit 6b. 7 is a detection circuit that rectifies the signal from the amplifier circuit 6b, and 8 is a vertical axis amplifier circuit.

Reference numeral 9 represents a sweep circuit that generates a triangular wave based on the synchronization signal from the synchronization diagram 84, and reference numeral 10 represents an amplifier circuit that amplifies the triangular wave signal of the sweep circuit 9. 2 is a display section that displays the signal waveform from the ultrasound probe 2, the horizontal axis is the time axis determined by the triangular wave output from the amplifier circuit 10, and the vertical axis is the vertical axis output from the amplifier circuit 8. A cathode ray tube is used as the 0 display section 11 that indicates the magnitude of the signal, and a scale is displayed on its surface. Reference numeral 12 denotes a measurement range setting section for setting the range to be inspected (measurement range) from the surface of the object 1 to be inspected. Reference numeral 13 denotes a delay time setting section that adds a delay time to the sweep start signal and moves the position of the waveform displayed on the display section 11 in parallel.

FIG. 6 is a circuit diagram of the sweep circuit shown in FIG. 5.

In the figure, 9a is an amplifier, 9r is a variable resistor, and 9C is a variable capacitor. The measurement range setting section 12 usually includes a coarse adjustment knob and a fine adjustment knob, and by rotating these knobs, the resistance value of the variable resistor 9r and the capacitance of the variable capacitor 9C are adjusted.

Next, an outline of the operation of the conventional ultrasonic flaw detector described above will be explained. When a pulse is output from the transmitter 5 in response to a signal voltage from the synchronization circuit 4, the ultrasonic probe 2 is excited by the pulse and emits ultrasonic waves toward the object 1 to be inspected. Some of the emitted ultrasonic waves immediately return to the ultrasonic probe 2 from the surface of the object to be inspected 1, and the rest propagates within the object to be inspected 1, reaches the bottom of the object to be inspected 1, and is reflected there. and return to the ultrasonic probe 2. On the other hand, if a defect 1r exists in the object to be inspected 1, the ultrasonic waves are also reflected from the defect If and return to the ultrasonic probe 2. These ultrasonic waves returned to the ultrasonic probe 2 excite the ultrasonic probe 2 in proportion to their magnitude, and the ultrasonic probe 2 outputs an electric signal corresponding to this.

This signal is input to an attenuation circuit 6a, adjusted to a size suitable for processing, and input to a detection circuit 7 via an amplifier circuit 6b. The detection circuit 7 rectifies the input signal so that the display unit 11 displays a one-sided swing instruction. At this time, noise components mixed in the signal are also removed. The output signal of the detection circuit 7 is input to the display section 11 via the vertical axis amplifier circuit 8, and its magnitude is displayed on the vertical axis of the display section 11. On the other hand, the sweep circuit 9 generates a triangular wave voltage according to the synchronization signal of the synchronization circuit 4,
This voltage passes through the amplifier circuit 10 to the display section 11 (cathode ray tube).
is applied to the deflection electrode to sweep the electron beam. Due to this sweep and the input signal from the vertical axis amplifier circuit 8, the waveform of the reflected wave returned to the ultrasound probe 2 is displayed on the display section 11.

FIG. 7 is a waveform diagram of the displayed reflected waves. In the figure, the horizontal axis shows time and the vertical axis shows the magnitude of reflected waves.

T is the reflected wave from the surface of the object to be inspected 1, F is the defect 1f
B+ is a reflected wave from the bottom surface of the object 1 to be inspected. S indicates a scale drawn on the display section 11. A part of the reflected wave reflected from the bottom surface is re-reflected from the surface and returns to the inside of the object to be inspected l. As a result, defect 1f
The reflected wave F2 from the bottom surface and the reflected wave B2 from the bottom surface appear again, but the reflected waves Ft, B! Of course, the size of the reflected wave F9,
Smaller than the size of BI. In this way, the reflected wave from the defect 1f and the reflected wave from the bottom surface appear repeatedly while being attenuated. Note that since the sound speed of the ultrasonic wave within the object to be inspected 1 is constant, the horizontal axis (time axis) represents the distance from the surface of the object to be inspected 1, and from this waveform diagram, the position of the defect 1f can be determined. Prove.

By the way, in general, when inspecting the object 1 to be inspected, it is not necessarily necessary to inspect the entire object from the surface to the bottom.
In many cases, it is sufficient to inspect a certain depth range from the surface. In this case, the waveform display is within its range (measurement range).
It is desirable to display only the following information, which allows for more accurate analysis.

Here, a method for setting such a measurement range will be explained. Now, suppose the distance from the surface to the bottom is 200mm
Consider the case where the measurement range is set to 100 mm (within 100 mm from the surface) of the object to be inspected. In this case, a specimen with a thickness of 100 mm made of the same material as the object to be inspected 1 is prepared. Next, when ultrasonic waves are emitted to the specimen, reflected waves T, B+, Bz, . . . are displayed on the display section 11.
...appears. Therefore, by operating the coarse adjustment knob and fine adjustment knob of the measurement range setting section 12 to expand or contract the horizontal axis, the reflected wave B is displayed on the scale SL at the left end of the display section 11.
1 is also the reflected wave B on the SR scale on the right end.

Adjust so that it appears. In this case, only the reflected waves B+ and Bz are displayed on the display section 11, and the distance between the scales SL and Se at both left and right ends corresponds to a positional distance of 100w+m. Next, the knob of the delay time setting section 13 is rotated to move the waveform in parallel to the right, and the reflected wave T is aligned with the scale SL at the left end. When ultrasonic waves are emitted to the object to be inspected 1 in this state, the surface (scale S
A measurement range of 100 mm (scale S+t) from L) will be displayed.

[Problem that the invention seeks to solve]

To set the measurement range in the conventional device, as described above, prepare a sample having a thickness equal to the measurement range and made of the same material as the object to be inspected 1, and use the two knobs on the measurement range setting section 12 and the delay It is extremely troublesome because it is necessary to operate the knobs of the time setting section 13, and considerable skill is required to match the reflected waves B+ and Bg with the scales sL and S during these operations. Furthermore, specimens having the required material and thickness do not always exist; in fact, they often do not exist, and in this case, it is almost impossible to set the measurement range.

However, for a material with a certain sound velocity, the values of the resistor 9r and capacitor 9C of the sweep circuit 9 are calculated in advance for each measurement range, and the measurement range is displayed on one knob (for example, a rough adjustment knob) of the measurement range setting section 12. It is also possible to display the speed of sound by calculation in advance on the other knob (for example, the fine adjustment knob) corresponding to the display above, and set the measurement range using both knobs, but the variable capacitor 9
Since C is used, each of the above displays itself is a non-linear display, and it is extremely difficult to set the knobs accurately.
Therefore, it is almost impossible to accurately set the measurement range. If the measurement range cannot be set accurately, it will not be possible to accurately read the position of the defect.

In this way, with the conventional bag π mentioned above, accurate setting of the measurement range is extremely troublesome even when a test piece is present, and almost impossible when a test piece is not present. there were. In addition to this, even if the measurement range could be set accurately, there would be the following problems. That is,
The resistance value of the resistor 9r of the sweep circuit 9, the capacity of the capacitor 9C, and the amplification factor of the amplifier circuit 10 change depending on the temperature.

Therefore, when the ambient temperature changes, errors occur even in the accurately set measurement range. This means that the reflected waves are shifted in the horizontal axis direction, making it impossible to accurately determine the position of the defect.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art described above and to relate to a measurement range setting device for an ultrasonic flaw detector that can easily and accurately set a measurement range.

[Means for solving problems]

In order to achieve the above object, the present invention includes a transmitter that outputs predetermined pulses to an ultrasound probe, a receiver that receives signals from the ultrasound probe, and a receiver that receives signals from the ultrasound probe. In an ultrasonic flaw detector equipped with a display section that displays the waveform of the signal based on the received signal, a memory is provided and input signals received by the receiving section are sequentially stored in the memory in the order of their addresses at a predetermined sampling period. On the other hand, a measurement range setting section for setting the measurement range necessary for analyzing the waveform of the input signal and a sound velocity input section for inputting the speed of sound propagating inside the liquid-damaged object are provided, and the value set in the measurement range setting section is provided. A calculation means calculates the address of the memory to be selected based on the sound speed input to the sound speed input section and the sampling period, and data is extracted from the address selected by this calculation and displayed on the display section. It is characterized by

[For production]

The reflected ultrasonic wave from the object to be inspected returns to the ultrasonic probe, and the ultrasonic probe outputs a signal corresponding to this reflected wave. The receiving section receives this signal, and the output signals from the receiving section are sequentially stored in the memory at a predetermined sampling period. When setting a measurement range, an arbitrary measurement range is set in the measurement range setting section, and the speed of sound in the object to be inspected is input into the sound speed input section. The calculation means calculates an address in which data to be extracted from among the data stored in the memory is stored, based on the set measurement range and the input sound speed. According to the result of this calculation, data at the corresponding address is sequentially extracted, and this data is displayed on the display section by the display control means.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a block diagram of an ultrasonic flaw detector according to an embodiment of the present invention. In the figure, parts that are the same as those shown in FIG. 5 are given the same reference numerals, and explanations thereof will be omitted. Reference numeral 21 indicates an ultrasonic flaw detector of this embodiment. This ultrasonic flaw detector 21 is composed of the following elements. That is, 22 is an A/D converter that converts the output signal of the receiver 6 into a digital value, 23 is a waveform memory that stores the values converted by the A/D converter 22, and 24 is a memory that stores each address of the waveform memory 23. This is an address counter that is specified in order. Reference numeral 25 denotes a timing circuit, which provides activation signals to the transmitter 5, A/D converter 22, and address counter 24, respectively. A crystal oscillator is used for oscillation of this timing circuit 25.

26 is a CPU (central processing memory) that performs necessary calculations and controls; 28 is a ROM (ROM) that stores the processing procedures of the CPU 26;
read-only memory). 29 is a measurement range setting section for inputting a desired measurement range, and 30 is a sound velocity input section for inputting the speed at which ultrasonic waves propagate within the object 1 to be inspected (sound velocity). 31 is a liquid crystal display section, and 32 is a display section controller that controls the display of the liquid crystal display section 31 based on data obtained as a result of calculation and control by the CPU 26.

Next, the operation of this embodiment is shown in FIG. 2, which is a waveform diagram of reflected waves.
A block diagram of the waveform memory 23 shown in FIG.
This will be explained with reference to the flowchart shown in the figure. First, a desired measurement range 1* (this value is shown in the object to be inspected 1 shown in FIG. 1) is set in the measurement range setting section 29. Further, the sound speed V, which is determined by the material of the object 1 to be inspected, is also input to the sound speed input section. In this state, when a trigger signal is output from the timing circuit 25 to the transmitter 5,
The transmitter 5 outputs a pulse to the ultrasonic probe 2, and the ultrasonic probe 2 emits ultrasonic waves into the object 1 to be inspected. This reflected ultrasound wave is converted into an electrical signal by the ultrasound probe 2, and this signal is received by the receiver 6. The receiving section 6 is
The received reflected wave signal is output as a value suitable for subsequent processing. This output reflected wave signal is converted into a digital value in the A/D converter 22 at every predetermined sampling period, and the converted values are sequentially stored in the waveform memory 23. This storage is performed by the address counter 24 sequentially specifying the addresses of the waveform memory 23.

Sampling of the reflected wave signal and address designation of the waveform memory 23 are executed by a start signal output from the timing circuit 25. Sampling of such reflected wave signals,
The storage of the digital value in the waveform memory 23 will be explained with reference to FIGS. 2 and 3.

FIG. 2 is a waveform diagram of the reflected wave signal. In the figure, the horizontal axis is time, and the vertical axis is the magnitude of the reflected wave signal (W1 pressure).T, F indicate the same reflected waves as shown in FIG. In addition, in FIG. 2, only the horizontal axis is extremely enlarged. FIG. 3 is a block diagram of the waveform memory 23. Each block numbered in a column is a waveform memory 2.
D means the data storage section in 3, and is written in each storage section. )+D+11+ ・・・ ・・・ ・・
・D++%-11+ D (+a)r D
(n+. . . . is the A/D converter 22
This is the data of the reflected wave signal converted into a digital value. These data are expressed as D(1, in general form. Also,
The symbols AM(.) and AM(+
1+・・・・・・AM(It-IllAM+lI
), AM(11+111 . . . indicate the addresses of the corresponding storage units, and these addresses are expressed as A11(1) in general form.

Now, at time t0 shown in FIG.
5 outputs a start signal to the A/D converter 22 and address counter 24, the A/D converter 22 A/D converts the voltage of the reflected wave T at that time and outputs data D. ). Further, the address counter 24 specifies the address A, 4 (.) of the waveform memory 23. As a result, data D (
. , is stored at address AM+111 of the waveform memory 23. Next, at time t1 after time τ3 has elapsed, when the timing circuit 25 again outputs the activation signal to the A/D converter 22 and address counter 24, the voltage of the reflected wave T at that time is also output to the A/D converter. 22, data D C1+ is obtained, and the address counter 24
is the next address A□8. Since waveform memory 2 is specified,
Data D(1) is stored at address A,(1) of No.3. In this case, the time τ is the sampling time (for example, 50
ns). Hereinafter, in the same way, reflected waves T, F+, B
+, Ft, Bz . . . data will be stored in the waveform memory 23.

Next, according to the procedure stored in the ROM 28, the CPU 26 first inputs the sound velocity V input into the sound velocity input section 30,
and the measurement ranges l and I set in the measurement range setting section 29.
are sequentially read (steps P+ and Pz shown in FIG. 4). Next, in order to display the measurement ranges l and I on the entire horizontal direction of the liquid crystal display section 31, in other words, the scale 1 at the left end of the liquid crystal display section 31 is
(In order to display the reflected wave T and the position corresponding to the distance l and I on the scale at the right end, it is calculated how to extract the data stored in the waveform memory 23 (Step P, ), this calculation will be explained below.

The waveform memory 23 stores data of repeated reflected waves equal to or smaller than the reflected wave T, as described above.

However, what is needed is data within the measurement range, and the data within the measurement range is displayed on the liquid crystal display section 31.
It is sufficient to display it between the scales at the left and right ends of . Generally, when displaying on the liquid crystal display section 31, data for display is stored in a display memory (not shown) provided in the display section controller 32. The addresses of this display memory are prepared for the number of horizontally arranged liquid crystal dots (for example, 200). Using this address in general form, AL(J)(j-0+L 2...
......199). If the measurement range is a certain value, the address of this display memory is the waveform memory 2.
Normally, the number is smaller than the number of data within the measurement range stored in No. 3 (that is, the number of addresses within the measurement range).

Therefore, in order to display the data within the measurement range between the left and right end scales, the above calculation is performed to determine how to select the address within the measurement range in the waveform memory 2.3. That will happen.

Here, τS : Sampling time l : Measurement range ■, : Sound speed of the sound wave inside the object 1 to be tested t : Time until the reflected wave returns Δ : Address of the address in the waveform memory 23 corresponding to the measurement range lR If the number Dt is the number of liquid crystal dots arranged in the horizontal direction of the liquid crystal display section 31 (or the number of addresses in the display memory), the time t required for the reflected wave from the distance of the measurement range 18 to return from the surface is t = 2 tt * /VS --・
・Old - (1) Number of addresses stored in the waveform memory within this time τ3 τ3'VS Select an address from among the addresses of this number ΔA according to the number of liquid crystal dots (number of addresses in display memory) In this case, addresses can be selected based on the ratio of ΔA/DL. That is, the waveform memory 23 shown in FIG.
Each address A□. ,.

AM+I11 "1""'AMIn-111AM(n)
+ AM (measuring range I of nails...)
Assuming that every i-th address is selected to display I+, the number i is the following formula % Formula % However, j is a positive integer (from O to (Dt-1)).

In the 0 procedure P, the calculation of equation (3) is executed.

The number i obtained in step P is the address number of the waveform memory, so naturally it must be an integer. Therefore, this number i is converted into an integer by an appropriate means (step P4), and the data at each address AH(1) obtained in this way is stored at each predetermined address AL in the display memory (not shown).
(Transferred to jl (procedure Ps)) Next, the display unit controller 32 drives the liquid crystal display unit 31, and (
Step P6), the data stored in the display memory is sequentially displayed. As a result, all the waveforms of the reflected waves within the measurement ranges 1 and 1 appear between the scales at both the left and right ends of the liquid crystal display section 3.

Next, the above procedure will be explained by applying a specific example 9. Now, sampling time τ5, measurement range I! Eh, speed of sound v8,
Assume that the number of liquid crystal dots is as follows.

τs -500ns (20MHz)l*-200m
m Vs=5.9Km/5 DL-200 points First, the numerical value 5.9 is input into the sound velocity input section 30, and the numerical value 200 is input into the measurement range setting section 29, and this value is read (step P+, Pg). Next, step P! In this step, the number ΔA of addresses in the waveform memory 23 corresponding to the measurement range of 200 mm is determined using equation (2).

That is, address 80 of the waveform memory 23. ,~A□,1.
) stores waveform data in a range of 200 mm from the surface. In order to store the data of these addresses in all addresses AL(.) to ALH 啼q) of the display memory, the address A□ of the waveform memory 23 is set. ,~A,p
Which address to select from gn:+ss+ is determined using equation (3).

-6, 81 ,). In this example, integer conversion is performed by rounding off.

Each address of the waveform memory selected in this way is
Each address AL(@) to AL(+?n) of the display memory in order.
, and the data of the former address is stored in the latter address (procedure Ps). This can be summarized in a table as follows.

That is, the data stored in the waveform memory address in the table above is stored in the display memory address listed on the left side. Finally, a display is performed on the liquid crystal display section 31 based on these stored data (step P6).

In this way, in this embodiment, the reflected wave data is temporarily stored in the waveform memory, the address to be selected according to the measurement range is calculated, and the data of the '7 address is displayed. To determine the range, simply enter the measurement range and sound speed values in the measurement range setting section and sound speed input section, and it can be done extremely easily and accurately. You can choose one, and there is no need for two pieces. Since the measurement range can be accurately displayed over the entire area between the scales at both ends of the liquid crystal display section, the position of defects, etc. can be inspected with high accuracy.

Furthermore, in the configuration of this embodiment, a shift in the reflected wave occurs only when the sampling time is out of order, but since a crystal oscillator is used in the timing circuit that determines the sampling time, Accurate sampling time can be obtained, and even if the temperature fluctuates, the sampling time will not be affected, so there will be no deviation in reflected waves, and from this point of view, highly accurate and reliable inspection can be performed. be able to.

In addition, in the description of the above embodiment, the liquid crystal display section was explained as an example of the display section, but the display section is not limited to the liquid crystal display section.
Obviously, ordinary cathode ray tubes, plasma displays, etc. can be used.

〔Effect of the invention〕

As described above, in the present invention, the data of the received reflected waves is stored in the waveform memory, each address to be selected according to the measurement range is calculated, and the data of these addresses is displayed. The range can be set extremely easily and accurately, and the waveform does not shift due to changes in temperature after setting.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an ultrasonic flaw detector according to an embodiment of the present invention, FIG. 2 is a waveform diagram of a part of reflected waves, FIG. 3 is a block diagram of the waveform memory shown in FIG. 1, and FIG. is a flowchart explaining the operation of the ultrasonic flaw detector shown in FIG. 1, FIG. 5 is a block diagram of a conventional ultrasonic flaw detector, FIG. 6 is a circuit diagram of the sweep circuit shown in FIG. 5, and FIG. FIG. 3 is a waveform diagram of reflected waves. 1...Object to be inspected, 1f...
...Defect, 2... Ultrasonic probe, 5...
...... Transmission section, 6...... Receiving section,
21... Ultrasonic flaw detector, 22...
...A/D converter, 23... Waveform memory, 24... Address counter, 25
......timing circuit, 26...
...CPU, 27...RAM, 28.
......ROM, 29...Measurement range setting section, 30...Sound velocity input section, 31
......Liquid crystal display section Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Procedure amendment (voluntary) November 1988 770

Claims (1)

[Claims] a transmitter that outputs a predetermined pulse to the ultrasound probe; a receiver that receives the signal from the ultrasound probe; and a waveform of the signal based on the signal received by the receiver. In an ultrasonic flaw detector, the ultrasonic flaw detector includes a memory for sequentially storing input signals received by the receiving unit in addresses at a predetermined sampling period, and a measurement range necessary for analyzing the waveform of the input signal. a measurement range setting section to be set; a sound speed input section to input the speed of sound propagating within the object to be tested; and an address of the memory to be selected based on the set measurement range, the input sound speed and the sampling period. 1. A measuring range setting device for an ultrasonic flaw detector, characterized in that the measuring range setting device for an ultrasonic flaw detector is provided, comprising: a calculation means for calculating , and a display control means for displaying data of an address selected by the calculation means on the display section.