JPH0614029B2 - Defect measuring device for ultrasonic flaw detector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a defect location measuring device for an ultrasonic flaw detector which measures a defect location in an object to be inspected.

[Conventional technology]

The ultrasonic flaw detector is well known as a device for inspecting the presence or absence of a scratch inside an object without damaging the object. This ultrasonic flaw detector will be described with reference to the drawings.

FIG. 8 is a block diagram of a conventional ultrasonic flaw detector. In the figure, 1 indicates an object to be inspected and 1f indicates a defect existing in the object to be inspected 1. Reference numeral 2 denotes an ultrasonic probe that radiates ultrasonic waves into the inspection object 1 and outputs an electric signal proportional to the reflected ultrasonic waves. An ultrasonic flaw detector 3 outputs an ultrasonic wave generation pulse to the ultrasonic probe 2, receives a signal from the ultrasonic probe 2, and displays the waveform of this signal.

The ultrasonic flaw detector 3 is composed of the following elements. That is,
Reference numeral 4 is a synchronizing circuit for generating a signal voltage for timely controlling the operation of the ultrasonic flaw detector 3, and 5 is a transmitter for outputting a pulse for generating ultrasonic waves to the ultrasonic probe 2 in response to a signal from the synchronizing circuit 4. Is. Reference numeral 6'denotes a receiving unit for receiving a signal from the ultrasonic probe 2, and is composed of an attenuation circuit 6a composed of a combination of voltage dividers composed of resistors, and an amplification circuit 6b '. Reference numeral 7 is a detector circuit for rectifying the signal from the amplifier circuit 6b ', and 8 is a vertical axis amplifier circuit.

Reference numeral 9 is a sweep circuit for generating a triangular wave by the synchronizing signal from the synchronizing circuit 4, and 10 is an amplifier circuit for amplifying the triangular wave signal of the sweep circuit 9. Reference numeral 11 is a display unit for displaying a signal waveform from the ultrasonic probe 2, the horizontal axis is a time axis determined by the triangular wave output from the amplifier circuit 10, and the vertical axis is output from the vertical axis amplifier circuit 8. It is regarded as the size of the signal. Display 11
A cathode ray tube is used as a display, and a scale is displayed on its surface. A measurement range setting unit 12 sets a range (measurement range) to be inspected from the surface of the inspected object 1. Reference numeral 13 denotes a delay time setting unit that adds a delay time to the sweep start signal and moves the position of the waveform displayed on the display unit 11 in parallel.

FIG. 9 is a circuit diagram of the sweep circuit shown in FIG. In the figure,
Reference numeral 9a is an amplifier, 9r is a variable resistor, and 9c is a variable capacitor. The measurement range setting unit 12 usually comprises a knob for coarse adjustment and a knob for fine adjustment, and adjusts the resistance value of the variable resistor 9r and the capacitance of the variable capacitor 9c by rotating these knobs.

Next, an outline of the operation of the conventional ultrasonic flaw detector will be described. When a pulse is output from the transmitter 5 by the signal voltage from the synchronizing circuit 4, the ultrasonic probe 2 is excited by this pulse and radiates ultrasonic waves to the inspected object 1. Part of the emitted ultrasonic waves immediately returns to the ultrasonic probe 2 from the surface of the inspected object 1, and the other propagates in the inspected object 1.
It reaches the bottom of the object to be inspected 1, is reflected here, and returns to the ultrasonic probe 2. On the other hand, if the defect 1f exists in the inspected object 1, the ultrasonic waves are reflected also at the defect 1f and return to the ultrasonic probe 2. The ultrasonic waves returned to the ultrasonic probe 2 excite the ultrasonic probe 2 in proportion to its size, and the ultrasonic probe 2 outputs an electric signal corresponding thereto.

This signal is input to the attenuation rotation 6a, adjusted to a size suitable for processing, and input to the detection circuit 7 via the amplification circuit 6b '. The detection circuit 7 rectifies the input signal in order to direct the display on the display unit 11 to make a one-sided swing instruction. At this time, the noise component mixed in the signal is also removed. The output signal of the detection circuit 7 is input to the display unit 11 via the vertical axis amplification circuit 8 and its magnitude is shown on the vertical axis of the display unit 11. On the other hand, the sweep circuit 9 generates a triangular wave voltage by the synchronizing signal of the synchronizing circuit 4, and this voltage is applied to the deflection electrode of the display unit 11 (cathode ray tube) via the amplifier circuit 10 to sweep the electron beam. By this sweep and the input signal from the vertical axis amplifier circuit 8,
The display unit 11 displays the waveforms of the two reflected reflected waves of the ultrasonic probe.

FIG. 10 is a waveform diagram of the displayed reflected wave. In the figure, the horizontal axis represents time and the vertical axis represents the magnitude of the reflected wave. T is a reflected wave from the surface of the inspected object 1, F ₁ is a reflected wave from the defect ₁ f, and B ₁ is a reflected wave from the bottom surface of the inspected object 1. A part of the reflected wave reflected from the bottom surface is re-reflected on the surface and returns to the inside of the inspected object 1 again. As a result, the reflected wave F ₂ from the defect 1f and the reflected wave B ₂ from the bottom surface appear again, but the magnitudes of the reflected waves F ₂ and B ₂ are naturally smaller than the magnitudes of the reflected waves F ₁ and B ₁ . In this way, the reflected wave from the defect 1f and the reflected wave from the bottom surface repeatedly appear while being attenuated. Since the sound velocity of the ultrasonic wave in the object 1 to be inspected is constant, the horizontal axis (time axis) represents the distance from the surface in the object 1 to be inspected.
The position of f is known.

By the way, generally, when inspecting the inspection object 1, it is not always necessary to inspect the entire surface from the top surface to the bottom surface.
In many cases, it is sufficient to inspect a specific area determined by the processing, welding, or the like performed on the inspected object 1. Such an area (specific area) will be described with reference to the drawings. 11th
The figure is a side view of the inspected object 1. In the figure, 2 is an ultrasonic probe, f ₁₀ , f ₁₁ , f ₁₂ , and f ₁₃ are defects in the inspected object 1, A ₁ and A ₂ are positions of the ultrasonic probe 2, and D is a chain line. Indicates a specific area limited by. Further, l _B is the object to be inspected 1
From the surface to the bottom surface, l _S is the distance from the surface to the upper limit of the specific area D, and l _E is the surface to the specific area D
Is the distance to the lower limit of. The specific area D is an area existing between the distance l _S and the distance l _E.

In the case of the inspected object 1 shown in FIG. 11 above, the defects f ₁₀ and f ₁₃ existing in the specific region D are particularly problematic. The defect f ₁₀ causes the ultrasonic probe 2 to be located at the position A _1. The defect f ₁₃ is detected when it is located at the position A ₂ . Then, by displaying the waveforms of the defects on the display unit 11, their positions and sizes can be known. On the other hand, the defects f ₁₁ and f ₁₂ are present outside the specific region D and are not so problematic as compared with the defects f ₁₀ and f ₁₃ . However, it is often necessary to know how many defects exist at which position, and it is particularly desirable to know whether a defect exists at a position close to the specific region D. Therefore, it is generally necessary to display a waveform corresponding to the thickness 1 _B of the inspected object 1 on the entire display surface of the display unit 11. Hereinafter, the waveform displayed on the display unit 11 will be described.

12 (a) and 12 (b) are waveform diagrams displayed on the display unit 11. The waveforms when the ultrasonic probe 2 is positioned at the positions A ₁ and A ₂ are shown. Waveforms T and B are reflected waves from the front surface and the bottom surface of the inspected object 1, respectively, and F _{10 to} F ₁₃ are reflected waves from the defects f _{10 to} f _13, respectively. In this way, when the entire region corresponding to the thickness 1 _B of the inspection object 1 is displayed, the specific region D to be observed with particular attention is the display unit 11.
It is necessary to know which part is on the display surface of. Therefore, the ratio l _B ′ / l _B between the dimension l _B ′ between the reflected waves T and B on the display surface and the distance l _B is set to the distance l.
_The markers M ₁ and M ₂ are located at the positions of the dimensions l _S ′ and l _E ′ from the reflected wave T on the display surface obtained by multiplying _S and l _E.
Is drawn with a writing instrument or the like. Thereby, it becomes clear that the portion between the markers M ₁ and M ₂ corresponds to the specific region D, and the measurement becomes easy.

[Problems to be Solved by the Invention]

In the above conventional device, in order to display the reflected wave T and the reflected wave B on both ends of the display surface of the display unit 11, the coarse adjustment knob and the fine adjustment knob of the measurement range setting unit 12 are adjusted to expand or contract the waveform. In addition, the operation of operating the knob of the delay time setting unit 13 to perform the parallel movement of the waveform must be repeated, which requires considerable skill and is troublesome. Also, the marker M
_1, to know the entry point of the M ₂ requires the above calculation, it is cumbersome itself to fill location to fill in known.

Further, even if the waveform display and the markers M ₁ and M ₂ shown in FIGS. 12 (a) and 12 (b) are obtained by the above operation, the following problems occur.

That is, the resistance value of the resistor 9r of the sweep circuit 9, the capacitor 9c
And the amplification factor of the amplifier circuit 10 change depending on the temperature. Therefore, when the ambient temperature changes, the reflected wave is displaced in the horizontal axis direction.

On the other hand, the positions of the marked markers M ₁ and M ₂ remain unchanged. As a result, for example, when a waveform shift occurs to the left on the display surface, the reflected wave F ₁₀ of the defect f ₁₀ deviates from between the markers M ₁ and M ₂ , and, for example, the shift occurs to the right on the display surface. , The reflected wave F ₁₃ of the defect f ₁₃ is the marker M
₁ and M _{2 are} deviated from each other, and in any case, it is erroneously diagnosed that no defect exists in the specific region D. On the contrary to these cases, when there is a defect outside the specific region D but in the vicinity thereof, the reflected wave of the defect is the marker M ₁ . It is mis-diagnosed that there is a defect in the specific area D due to slippage between M ₂ . That is, there is an erroneous determination that a defective product is a good product and a good product is a defective product.

Furthermore, the position and size of the defect cannot be known without measuring a predetermined size on the display surface, and such measurement is troublesome. Not only that, but the measurement is not always performed accurately, and therefore the measurement accuracy of the position and size of the obtained defect may be reduced.

An object of the present invention is to solve the above-mentioned problems of the prior art, to perform waveform display accurately regardless of temperature change, and to easily and accurately perform the indication of a specific area without the trouble of writing a marker. Further, the present invention relates to a defect measuring device for an ultrasonic flaw detector, which is capable of easily and accurately knowing the position and size of the largest defect in a specific area.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a transmitter that outputs a predetermined pulse to an ultrasonic probe, a receiver that receives a signal from the ultrasonic probe, and a receiver that receives the signal. In the ultrasonic flaw detector having a display section for displaying the waveform of the signal based on the signal, a waveform memory is provided, and the input signal received by the receiving section is stored in the waveform memory at a predetermined sampling cycle. In addition to the waveform memory, a display memory for storing data to be displayed on the display unit is provided separately from the waveform memory, and the address of the waveform memory is selected according to the measurement range to be displayed on the display unit. Corresponding to an address, the data stored in the selected waveform memory address is transferred to the corresponding display memory address, and the cursor input section indicates a specific area within the measurement range. When two cursor position is indicated, corresponding to the position of each of the cursor in the display memory based on the position of the indicated two cursors are 2
One address is calculated, a cursor is displayed at the position corresponding to these two addresses, and at least one of the maximum peak value of the data at each address between the two addresses and the address storing the maximum peak value are stored. Is characterized in that

[Action]

The reflected wave of the ultrasonic wave from the inspected object returns to the ultrasonic probe, and the ultrasonic probe outputs a signal corresponding to the reflected wave. The receiving unit receives this signal, and the output signal from the receiving unit is sequentially stored in the memory at a predetermined sampling period. In this state, the address of the waveform memory in the measurement range to be displayed is selected by a predetermined means to be associated with the address of the display memory, and the data is input to the corresponding address of the display memory. Also, with the cursor input section,
When the positions of the two cursors that specify a specific area are specified, the addresses of the display memory corresponding to the respective positions are calculated, and the addresses between the two obtained addresses are stored. At least one of the maximum peak value and its address can be obtained, and the size of the defect can be known from the peak value, and the position of the defect can be known from the address.

〔Example〕

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

FIG. 1 is a block diagram of an ultrasonic flaw detector according to an embodiment of the present invention. In the figure, those parts that are the same as those corresponding parts in FIG. 8 are designated by the same reference numerals, and a description thereof will be omitted. In the ultrasonic flaw detector, there are a case where the reflected wave is detected and displayed and a case where the reflected wave is not detected and displayed, but the present invention can be applied in any case. Therefore, in the following, an embodiment will be described in which the receiver 6 is constituted by combining the amplifier 6b 'of FIG. 8 and the detection circuit 7 as the amplification circuit 6b and detection is performed. 21
Shows the ultrasonic flaw detector of the present embodiment. This ultrasonic flaw detector 2
1 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 value converted by the A / D converter 22, and 24 is each address of the waveform memory 23. It is an address counter that is specified in order. Reference numeral 25 denotes a timing circuit, which gives a start signal to the transmitter 5, the A / D converter 22, and the address counter 24, respectively. A crystal oscillator is used for oscillation of the timing circuit 25.

Reference numeral 26 is a CPU (central processing unit) for performing required arithmetic operations and control, 27 is a RAM (random access memory) for temporarily storing parameters and data for arithmetic operations, 28
Is a ROM (read only memory) that stores the processing procedure of the CPU 26. Reference numeral 29 is a measurement range setting unit for inputting a desired measurement range, and 30 is a sonic velocity input unit for inputting a velocity (sonic velocity) at which an ultrasonic wave propagates in the inspected object 1. 31
Is a liquid crystal display unit, and 32 is a display unit controller which controls the display of the liquid crystal display unit 31 based on the data obtained as a result of the calculation and control of the CPU 26. A display memory 32m is provided in the display controller 32, and the display memory 32m stores data to be displayed on the liquid crystal display unit 31. Reference numeral 33 is a cursor designating portion for displaying the upper limit value (distance) l _S and the lower limit value (distance) l _{E of the} specific area D shown in FIG.

Next, the operation of the present embodiment is shown in FIG.
A block diagram of the waveform memory 23 shown in FIG.
This will be described with reference to the flowchart shown in the figure. In the following description, the object 1 to be inspected is as shown in FIG. 11, and the case where the ultrasonic probe 2 is at the position A ₁ or the position A ₂ will be described. First, a desired measurement range is set in the measurement range setting unit 29. When displaying as shown in FIGS. 12 (a) and 12 (b), the value of the measurement range is the distance l _B , which is set. Further, the sound velocity v _S determined by the material of the object 1 to be inspected is also input to the sound velocity input section. In this state, when a trigger signal is output from the timing circuit 25 to the transmission unit 5, the transmission unit 5 outputs a pulse to the ultrasonic probe 2, and the ultrasonic probe 2 transmits a pulse to the inside of the inspected object 1. Sound waves are emitted. The reflected wave of this ultrasonic wave is converted into an electric signal by the ultrasonic probe 2, and this signal is received by the receiving unit 6. The receiving unit 6 outputs the received reflected wave signal as a value suitable for the subsequent processing. This output reflected wave signal is
It is converted into a digital value in the A / D converter 22 at every predetermined sampling period, and the converted value is sequentially stored in the waveform memory 23. This storage is performed by the address counter 24 sequentially designating the addresses of the waveform memory 23. The sampling of the reflected wave signal and the addressing of the waveform memory 23 are performed by a start signal output from the timing circuit 25. Sampling of such a reflected wave signal and the waveform memory 23 of its digital value
The storage in the container will be described with reference to FIGS. 2 and 3.

FIG. 2 is a waveform diagram of the reflected wave signal. In the figure, the horizontal axis represents time, and the vertical axis represents the magnitude (voltage) of the reflected wave signal. T and F ₁₀ show the same reflected waves as shown in FIG. 12 (a). Note that, in FIG. 2, only the horizontal axis is drawn in an extremely enlarged manner. Next, FIG. 3 is an explanatory diagram of the contents of the waveform memory 23. Each block shown in a line in the column means a data accommodating portion in the waveform memory 23, and D ₍₀₎ , D ₍₁₎ , ... D _(n-1) , D ₍ described in each accommodating portion. _n) , D _{(n + 1)}
... is the data of the reflected wave signal converted into a digital value by the A / D converter 22. These data are represented by D _(i) as a general form. Further, the symbols A _{M (0)} , A _{M (1)} , ... A _{M (n-1)} , A _{M (n)} , A _{M (n + 1)} written on the left side of each accommodation portion.
... indicates the address of the corresponding storage unit. These addresses are represented by A _{M (i)} as a general form.

Now, at the time t ₀ shown in FIG. 2, the timing circuit 2
When a start signal is output from A to D / A converter 22 and address counter 24, A / D converter 22 A / D converts the voltage of reflected wave T at that time to obtain data D ₍₀₎ . . Further, the address counter 24 designates the address A _{M (0)} of the waveform memory 23. As a result, the data D ₍₀₎ is stored in the address A _{M (0)} of the waveform memory 23. Next, at a time t ₁ after the time τ _{S has} elapsed, the timing circuit 25
Again from the A / D converter 22 and the address counter 24
When a start signal is output to, the reflected wave T at that time also
Is the voltage of the conversion by the A / D converter 22 and the data D ₍₁₎ is obtained, since the address counter 24 designates the next address A _{M (1),} the address A _{M (1)} of the waveform memory 23 The data D ₍₁₎ is stored. In this case, the time τ _S becomes the sampling time (for example, 50 ns). Thereafter, similarly, the data of the reflected waves T, F ₁₀ , and B and their repeated reflected waves are stored in the waveform memory 23.

Next, the CPU 26 follows the procedure stored in the ROM 28 and first inputs the sound velocity v _S input to the sound velocity input unit 30.
And the measurement range 1 _B set in the measurement range setting unit 29 is sequentially read (procedures P ₁ and P ₂ shown in FIG. 4). Then, to display the measurement range l _B across the transverse direction of the liquid crystal display unit 31, i.e., displays the reflected wave B of the reflected wave T to the display surface left of the LCD display unit 31, corresponding to the distance l _B at the right end In order to do so, how to retrieve the data stored in the waveform memory 23 is calculated (procedure P ₃ ). Hereinafter, this calculation will be described.

As described above, the waveform memory 23 stores the data of repeated reflected waves equal to or less than the reflected wave T. However, what is required in this is the data within the measurement range, and the data within these measurement ranges may be displayed between the left and right ends of the display surface of the liquid crystal display unit 31. Generally, when displaying on the liquid crystal display unit 31, display data is stored in a display memory 32m provided in the display unit controller 32. The address of the display memory 32m is prepared for the number of liquid crystal dots arranged in the horizontal direction (for example, 200). Using this address as a general form, A _{L (j)} (j =
0, 1, 2, ... 199). This display memory 3
The address of 2 m is usually smaller than the number of data in the measurement range stored in the waveform memory 23 (that is, the number of addresses in the measurement range) if the measurement range has a certain value. Therefore, in order to display the data within the measurement range between the left and right ends of the display surface, the above calculation is executed to determine how to select the address within the measurement range in the waveform memory 23. It will be.

Here, τ _S : sampling time 1 _B : measurement range v _S : sound velocity of ultrasonic waves in the object 1 to be inspected t: time until the reflected wave returns ΔA: address in the waveform memory 23 corresponding to the measurement range 1 _B D _{t is} the number of liquid crystal dots arranged in the horizontal direction of the liquid crystal display unit 31 (or the number of addresses of the display memory 32 m), the time t required for returning the reflected wave at the distance of the measurement range 1 _B from the surface is t = 2 l _B / v _S (1) Number of addresses ΔD stored in the waveform memory within this time
Is Of the addresses of this address number ΔA, the number of liquid crystal dots D
To select an address according to _t (the number of addresses in the display memory 32m), it is sufficient to select the address at a ratio of ΔA / D _t . That is, each address A _{M (0)} , A _{M (1)} , ... A _{M (n-1) of} the waveform memory 23 shown in FIG.
_{A M (n), A M} (n + 1), assuming that selects the address of the i-th each for displaying the measurement range l _B of ......... number i is represented by the following equation.

However, j is a positive integer {0 to (D _t -1)}. In procedure P ₃ , the calculation of this equation (3) is executed.

Since the number i obtained in step P ₃ is the address of the waveform memory, it must be an integer. Therefore, this number i is converted into an integer by an appropriate means (procedure P ₄ ). next,
The data at the address A _{M (i) in} the waveform memory 23 is transferred to the address A _{L (j)} in the display memory 32 m (procedure P ₅ ). Next, the liquid crystal display unit 31 is driven by the display unit controller 32 (procedure P ₆ ), and the data stored in the display memory is sequentially displayed. Thus, the liquid crystal display unit 31 will appear all the waveform of the reflected wave in the measurement between left and right end scale ranging l _B.

Next, the above procedure will be described by applying a specific example.
Now, the sampling time τ _S , the measurement range 1 _B , the sound velocity v _S ,
It is assumed that the number of liquid crystal dots D _t is the following value.

_{τ S = 50ns (20MHZ) l} B = 200mm v s = 5.9Km / s ( to be inspected material and steel) _D t = 200 points First, numerical 5.9 the speed of sound input unit 30 is, also, the measurement range setting unit 29 Numerical value 200 is input to and this value is read (procedures P ₁ and P ₂ ). Next, in procedure P ₃ , the number ΔA of addresses in the waveform memory 23 corresponding to the measurement range of 200 mm is obtained from the equation (2).

That is, the addresses A _{M (0) to} A _M of the waveform memory 23
_This means that the waveform data in the range of 200 mm from the surface is stored in _{M (1355)} . Since the data of these addresses are stored in all the addresses A _{L (0) to} A _{L (199)} of the display memory 32 m, the addresses A _{M (0) to} A _{M of the} waveform memory 23 are stored.
Which address is selected from _{M (1355)} is obtained by the equation (3).

Here, the number 6.81 is sequentially multiplied by the integers 0 to 199 to determine the address to be selected. At the time of this multiplication, the number i is converted into an integer (procedure P ₄ ). In this example, integer conversion is performed by rounding.

Each address of the waveform memory selected in this way,
Corresponding to each address of the display memory 32m in the order _{A L (0) ~A L (} 199), stores the data of the former address to the latter address (Step P _5). This is summarized in the table below.

That is, the data stored in the waveform memory address in the above table is stored in the display memory address described on the left side thereof. Finally, display is performed on the liquid crystal display unit 31 based on the stored data (procedure P ₆ ).

By the operation described above, the waveform within the measurement range is displayed on the display surface of the liquid crystal display unit 31. As described above, it is necessary to add a mark for clarifying the specific area D2 to this display waveform. The present embodiment uses two cursors displayed in the waveform as this mark. The operation of cursor display will be described below with reference to the display waveform diagram shown in FIG. 5 and the flow chart shown in FIG.

In FIG. 5, 31 is the liquid crystal display unit shown in FIG. 1, T, F ₁₀ ,
B is the same reflected wave as shown in FIG. 12 (a).
C _S and C _E respectively indicate a front cursor and a rear cursor, which are displayed by vertical broken lines on the display surface. G ₁ is a defect f
The first display portion for displaying the size of ₁₀ in dB, G ₂ is the defect f ₁₀
2 is a second display unit that displays the distance from the surface of the device in mm. The front cursor C _S and the rear cursor C _E are displayed as follows.

First, the cursor instruction unit 33 is instructed about the upper limit value l _S and the lower limit value l _E of the specific area D. The CPU 26 determines these values.
Read l _S , l _E (procedure P ₁₁ shown in FIG. 6). Then the value l
The address of the display memory corresponding to _S , l _E is calculated (procedure P ₁₂ ). Here, the address corresponding to the value l _S , that is, the address of the front cursor is A _{L (CS)} , and the address corresponding to the value l _E , that is, the address of the rear cursor is A _{L (CE)} ,
The total number of addresses in the display memory 32m (20 in the example above)
Since 0) is D _t , each address is obtained as follows. That is, using _{AL (CS)} *, _{AL (CE)} *, Is calculated, and A _{L (CS)} *, A _{L (CE)} * is converted into an integer (procedure P ₁₃ ), whereby the address A _{L (CS)} of the front cursor C _S and the rear cursor C _{E in} the display memory 32 m are calculated. The address _{AL (CE)} is determined. These addresses have already waveform data is stored, the data is changed to data of a dashed line INDICATING cursor (steps P _14). Next, the display controller 32 is driven to display the data of the two addresses A _{L (CS)} and A _{L (CE)} on the display unit 3.
When it is displayed on the display surface of No. 1 (procedure P ₁₅ ), cursors C _S and C _E are displayed in the waveform as shown in FIG.

Next, in the waveform of the specific region D sandwiched between the front cursor C _S and the rear cursor C _E , the maximum peak value (only the reflected wave F _{10 in the} case of FIG. 5) and the position of the peak value The operation of obtaining the distance from the surface of the inspection object 1 and displaying them will be described with reference to the flowchart shown in FIG.

First, in the display memory 32m, the front cursor C _S
Address A _{L (CS)} and rear cursor C _E address A _{L (CE)}
Peak value data D _pk (D _p1 , D _p2 , ...) _{Is obtained} from the data stored in the addresses between and (step P ₂₁ shown in FIG. 7). How to obtain such peak value data is
If the data at each address is read in sequence and the data when the value changes from increasing to decreasing is taken out, this becomes the peak value data D _pk . In the case of the waveform shown in FIG. 5, there is only one peak value data. Next, the maximum peak value data D _pmax among the peak value data D _pk and the address A _{L (pmax)} storing the data are obtained (procedure P ₂₂ ). Next, the position corresponding to this address A _{L (pmax)} , that is, the distance l _{pmax (mm)} from the surface of the object to be inspected 1 and the actual peak value h _{pmax (dB)} are obtained (procedure P ₂₃ ).
These can be obtained from the following equations.

In (6), (pmax) is the number of the address AL _(pmax) ,
Further, in the equation (7), K ₀ is a positive constant. Finally, the procedure P ₂₃
The value l _pmax obtained in step 2 is displayed on the second display section G ₁ shown in FIG.
Further, the value h _pmax is displayed on the first display portion G ₂ (procedure P ₂₄ ).

The waveform display, the cursor display, and the display of the peak value and its position in this embodiment have been described above. As can be seen from the above, in the present embodiment, in the waveform display, 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 address is displayed. Therefore, the waveform display can be easily performed, and the once-displayed waveform can be accurately displayed without causing a shift due to ambient conditions such as a temperature change.

Further, in the cursor display, the front cursor and the rear cursor can be displayed on the display surface only by instructing the upper limit value and the lower limit value of the specific area to the cursor instruction section, which requires time and effort for writing a marker or the like. Without this, it is possible to easily and accurately instruct a specific area.

Further, since the position and size of the maximum peak value among the peak values of the reflected wave in the specific area are displayed, the state of the maximum defect in the specific area can be grasped easily and accurately.

In the description of the above embodiments, the liquid crystal display unit is illustrated as the display unit, but the display unit is not limited to the liquid crystal display unit.
Obviously, a cathode ray tube, a plasma display unit or the like can be used. In addition, not only the maximum defect in the specific area is displayed, but all defects or defects having a peak value equal to or higher than a predetermined peak value may be displayed. Further, the peak value and the position can be displayed at appropriate places, and they can be represented by a print or the like instead of the display. Further, either one of the peak value and the position may be obtained.

〔The invention's effect〕

As described above, in the present invention, the received reflected wave data is stored in the waveform memory, each address selected according to the measurement range is calculated, and the data of these addresses is displayed. Can be displayed accurately. Further, the front cursor and the rear cursor can be displayed on the display surface only by inputting the cursor position in the cursor input section, and thus the specific area can be easily and accurately designated. Further, since the means for obtaining the peak value in the specific area and the address of the peak value is provided, the defect existing in the specific area can be accurately grasped.

[Brief description of drawings]

FIG. 1 is a block diagram of an ultrasonic flaw detector according to an embodiment of the present invention, FIG. 2 is a partial waveform diagram of a reflected wave, and FIG. 3 is a content explanatory diagram of a waveform memory shown in FIG. FIG. 5 is a flow chart for explaining the waveform display operation of the ultrasonic flaw detector shown in FIG. 1, FIG. 5 is a front view of the liquid crystal display unit shown in FIG. 1, and FIG. 6 is a flow chart for explaining the cursor display operation. 7th
FIG. 8 is a flow chart for explaining the operation of peak value display, FIG. 8 is a block diagram of a conventional ultrasonic flaw detector, and FIG.
Circuit diagram of the sweep circuit shown in the figure, Fig. 10 is a waveform diagram of the reflected wave, Fig. 11 is a side view of the object to be inspected, and Figs. 12 (a) and 12 (b).
FIG. 9 is a front view of the display unit shown in FIG. 1 ... Object to be inspected, 1f ... Defect, 2 ... Ultrasonic probe, 5 ... Transmitting section, 6 ... Receiving section, 21 ... Ultrasonic flaw detector, 22 ... A / D converting section, 23 ... Waveform memory, 24
...... Address counter, 25 ...... Timing circuit, 26
... CPU, 27 ... RAM, 28 ... ROM, 29 ...
… Measurement range setting unit, 30 ... Sonic velocity input unit, 31 ... Liquid crystal display unit, 32 ... Display unit controller, 32m ... Display memory, 33 ... Cursor instruction unit.

Claims (1)

[Claims] 1. A transmitting unit that outputs a predetermined pulse to an ultrasonic probe, a receiving unit that receives a signal from the ultrasonic probe, and a receiving unit that is based on the signal received by the receiving unit. In an ultrasonic flaw detector having a display unit that displays the waveform of the signal, a waveform memory that sequentially stores the input signal received by the receiving unit at a predetermined sampling cycle,
A display memory for storing data to be displayed on the display unit,
Selecting means for selecting an address of the waveform memory according to a measurement range to be displayed on the display section, and data transferring means for transferring data of the address selected by the selecting means to a corresponding address of the display memory, A cursor input section for inputting the positions of two cursors pointing to a specific area in the measurement range, and two of the display memories corresponding to these two positions based on the two positions input to the cursor input section. A calculation means for calculating one address, a cursor display means for displaying a cursor at a position corresponding to the two addresses obtained by the calculation means, and an address between the two addresses calculated by the calculation means. Obtain at least one of the maximum peak value in each stored data and the address storing the maximum peak value Defect measuring apparatus of the ultrasonic flaw detector, characterized in that a and stage.