JPS593254A - Ultrasonic flaw detecting apparatus - Google Patents

Abstract

PURPOSE:To carry out the positional evaluation of a reflector accurately and easily, by storing the thickness of an object to be inspected, the position where said thickness is present and tolerant distance length (available beam distance length) of reflected echo in buffer memory. CONSTITUTION:Buffer memory 15 is constituted so as to store the output and the ultrasonic refractive angle theta of a digitization circuit 14 and a position detector 13, the transmission speed V of ultrasonic beams and lift gate information Sz corresponding to the thickness of an object to be inspected. On the other hand, a processor 16 is constituted so as to selectively take in the data stored in the buffer memory 15 to carry out the automatic estimation of the position of a reflector and the automatic setting of a gate range. By this mechanism, the positional calculation of the reflector and the evaluation of the size thereof can be carried out accurately and easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic flaw detection device, and more particularly to an ultrasonic flaw detection device that can appropriately set the gate range of the A-scope display.

Ultrasonic flaw detection using the pulse method has advantages such as ease of handling, and is widely used for detecting defects, etc. existing in steel materials.

Below, a method for detecting defects present in steel materials will be explained.

In FIG. 1, a reflector (for example, a defect) 20, 21 is present in an object to be inspected (steel material) 12.

A probe 11 is placed on the surface of the steel material 12. This probe 11 moves in the X direction, which is the width direction, while fixing the surface of the steel material in the X direction, which is the length direction, and emits ultrasonic waves at each flaw detection position, and receives the reflected waves. do. Similarly,
Flaw detection in the X direction is performed while changing the X direction position one after another. The wave transmitting/receiving circuit 10 performs wave transmitting/receiving control of the probe 11 .

FIG. 2 shows how the probe 11 moves, ie, scans.

The probe 11 has scanning lines Ll, L2゜...L
,,L12.1. . . . Transmits an ultrasonic pulse beam toward the object to be inspected 12 at transmitting and receiving positions determined at predetermined intervals above, and reflects the reflectors 20 and 21 present on the object to be inspected 12.
can receive reflected pulse beams from

In this example, it is assumed that the inspected object 12 has a stepped wall thickness, and as shown in FIGS. 1 and 2, the width direction is the y direction, the length direction is the X direction, and the thickness direction is the two directions. shall be determined.

As shown in Figure 1, the ultrasonic pulse beam
1 toward the object to be inspected 12 at a refraction angle θ. In order to detect the reflectors 20 and 21 present in the object to be inspected 12, the probe 11 moves along the scanning line L in FIG. Ultrasonic beams are transmitted and received at the wave position. At this time, at the sending and receiving liquid level 1fU1, the gate range on the A scope is g! from the refraction angle θ and the wall thickness hl. On the other hand, the reflected pulse received by the probe 11 becomes as shown in Fig. The reflected pulses received by the probe 11 are as shown in FIG.

3 and 4, T is the transmission pulse and tll
~t14. t21~123 is the reflected wave response time, R11~
R14, R21 to R, 23 are received wave signals, PI3. P.I.
3 indicates the peak value (wave height) of the received wave signal. Furthermore, the received wave signals R11, R, and 12 in FIG. 3 indicate noise in the dead zone region near the probe.

In this example, the waveform of FIG. 3 is displayed on the A scope, and from this display information regarding the offending object 20, such as its position and size, can be obtained as follows.

That is, the display screen of the A scope is observed while repeatedly moving the probe 11, and the change in the peak value P of the reflected pulse R at that time is observed. At this time, when the wave height value P reaches the maximum (R13 in FIG. 3), the probe 11 moves to the first position.
As shown in the figure, the central beam is located at the wave transmitting/receiving position that irradiates the reflector 20, so the position Y++ at this time
The coordinates where the reflector 20 is present are determined from the propagation time t1a, and the size of the object to be inspected 20 is determined from the wave height value P13.

As described above, according to the conventional method, the positions and sizes of the reflectors 20 and 21 present on the object 12 to be inspected can be known.

However, conventionally, the gate range of the A scope has been set in consideration of the thickness and refraction angle of each object to be inspected. This takes into consideration the reception of reflected pulses from the bottom surface or boundary surface of the object to be inspected, and special care must be taken when the refraction angle is 0°. Therefore, there is a problem in that the gate range of the A scope must be set every time the thickness changes even though the same scanning line is used, and flaw detection takes a long time.

In addition, in the case of a nozzle as shown in FIG. 5, for example, when the sending/receiving liquid level is ti U s, the beam path length to the bottom surface is t3, and when the sending/receiving position is U4, the beam path length is t3. 14.1. As the beam path length varies over the entire surface, setting the gate range of the A scope becomes extremely difficult. Furthermore, if noise due to the characteristics of the probe is received, a plurality of pulses will be drawn on the A scope, making it difficult to detect the maximum peak value of the reflected pulse. For this reason, in the past, the probe was moved repeatedly to get an idea of which reflector was causing the damage, which made it difficult to obtain accurate information about the reflectors present in the object to be inspected, and as a result, it took a long time. It took.

As explained above, conventional ultrasonic flaw detection equipment has the disadvantage that it is not possible to accurately and easily obtain information about the reflector when the thickness of the object to be inspected is not uniform or when noise etc. occur. Ta.

An object of the present invention is to provide an ultrasonic flaw detection device that can accurately and easily obtain information regarding a reflector existing in an object to be inspected whose thickness is not uniform and even when noise or the like occurs. It's about doing.

The gist of the present invention is to determine the thickness of the object to be inspected, the position where the thickness exists, and the allowable reflected echo path length (effective beam path length).
is stored in the buffer memory as soft gate information, and the soft gate information in the buffer memory is read from the wave transmitting and receiving position during actual flaw detection to automatically evaluate the reflector position and automatically adjust the A scope gate range. The point is that you have to configure the settings.

Hereinafter, this development will be explained in detail with reference to the drawings.

FIG. 6 is a diagram showing an embodiment of the ultrasonic flaw detection apparatus of the present invention. The probes 11 on the object to be inspected 12 are moved while mutually specifying the Xs and Y directions by a scanning drive system (not shown). The wave transmitting/receiving circuit 10 controls ultrasonic generation in the probe 11.
(T) and reception of the received signal received by the probe 11 ()
1). In general, T is an ultrasonic pulse beam and R is a reflected pulse beam. Wave transmitting/receiving circuit 10
detects the reflected pulsed beam. Digitization circuit 1
4 converts the detection output into a digital signal.

The buffer memory 15 stores the outputs of the digitizing circuit 14 and the position detector 13 and the ultrasonic refraction angle θ.

The propagation velocity (2) of the ultrasonic beam and soft gate information Sf corresponding to the thickness of the subject body are stored. Among the data stored in the buffer, soft gate information S is stored prior to actual flaw detection. The refraction angle θ and the propagation velocity ■ are
It may be stored prior to the actual flaw detection, or it may be detected during the actual flaw detection and stored online.

Processor 16 selectively captures data stored in buffer memory 15 for automatic evaluation of reflector position and automatic setting of gate range. The display device 17 takes in the calculation results of the processor and displays A-1 on its screen.

The storage of the position information XsY, etc. in the buffer memory 15, the contents of the soft gate information, and the processing of these two by the processor 16 will be described in detail below.

FIG. 7 shows the storage state of the soft gate information S1. In Fig. 7 (a), S Gl , S G2 , ・−・−
..., SGN indicates a soft gate information area, each consisting of a group of soft gate information corresponding to the X and y positions of the subject. The contents of the soft gate information area SGI, 8G2 are shown in FIG. 7(b). Softgate information area SGI is
The area having the soft gate information Srl at the beginning and further having the soft gate information S, l is designated as X, l, X, l.

It is set as Y@Il'j*l. X, l(X <
(x
, y) is the area with Sat. Furthermore, 8.1 is the response time from ultrasonic transmission to reflected wave reception, that is, the beam path length 1@1+t.

It is also determined by Beam path length t is 1−+ < 1 <
1.1, and when X and y satisfy the above positional relationship, the corresponding soft gate information S□ can be specified. Further, hl indicates the thickness according to the soft gate information Sgl. Beam path 1. l* 1. , is also a value for setting the reference beam path range.

The above applies similarly to the soft gate information area SG2 shown in FIG. 7(b) at positions X, 2. X, 2.

ye2. The soft gate information St2 is specified by Y@2, beam path length t, and 2HL2. The same applies to other SGs.

FIG. 8 shows the position detector 13. The storage state of online information captured via the digitization circuit 14 is shown. FIG. 8(a) shows a group of information formed for each scanning position. In the figure, the scanning position (x++ yt) (9) and a part of the scanning position Tt, (xl+ y2) are shown. This is an indication.

The probe 11 uses a multi-channel system, and has 3
shall have a channel. The 3 channels are a channel that performs flaw detection directly below the scanning position (θ-00), a channel that performs flaw detection at an angle of 45° to the right of the scanning position (θ = 45°), and a channel that performs flaw detection at an angle of 60° to the right of the scanning position. This is a channel (θ=60°) for positional flaw detection. However, in FIG. 8, instead of θ==0°, θ-45°, θ=60°, θ=θl, θ=θ2. It is generalized as θ−θ3.

Furthermore, echo heights P+, Px, and Pg of received waves to be captured are set for each channel, and only echoes exceeding these echo heights are captured and stored. Information area A
Tl 1 , A T12 , and ATIs are areas for storing an echo A having a value larger than the echo height and the beam path length T at that time.

FIG. 8 6:I) shows the detailed structure of the information area ATII.

4 sets of echo and beam path (A11l Tit L
(AI21T12 L (A+a+ TIril (
AI41 Tl4) is stored in the import case (10). Therefore, the echo height Pl described above is a set value for capturing four high-level echoes. By setting this peak height, it is possible to remove echoes at a level below the peak height.

FIG. 8(c) is an example of information ATI2, and shows four sets of echoes and the beam path at that time.

In addition to the above various data, the propagation velocity V of the ultrasonic waves is stored as data. The propagation velocity V may be different for each channel; for example, for direct flaw detection, a longitudinal wave velocity VL is given, and for flaw detection in an inclined direction, a transverse wave velocity Va is given. Furthermore, when there are parts of the object to be inspected that are made of different materials, the propagation velocity V is set accordingly.

FIG. 9 shows a flowchart of processing centered on the processor 16.

The probe 11 scans each scanning line Lr + L2 + · from the starting point (XOryo) to the ending point (Xm+y-) in FIG.
. . . The movement is controlled along Ll+Ll+1+ . As a result, data as shown in FIG. 8 is formed on the buffer memo (11) 15.

The processor 16 reads information corresponding to the sending/receiving liquid level 1t (x, y) from the reflected pulse (echo) stored in the memory 15 (flow 1oO). Furthermore, the table SG of the soft gate information groups SGI, SG2°, . . . shown in FIG. 7 is searched. SGI→SG2→SG3→・・・
. . . and finds the SGI corresponding to the probe position (Flow 101). This search for the applicable SGI is
For probe prediction tiffix, y, Xa + < X < Xe + ・Old...
...(1)'j a l < y < Y @ 1
・Old and old...If (2) holds true, it becomes a case.

Next, the beam path (propagation time) range F1+L1 is read out from the corresponding SGI of the probe fix, y, and compared with the echo time T of the reflected pulse at the X and y positions.

t # I < T < t * 1...
Group...If (3), the beam path is within the applicable range, and the SGI soft gate information Sg+ at that time
(12) (Flow 102). The pulse information is then stored in the memory 15 as a target for evaluating the position and size of the reflector (Flow 103). In flow 104, the pulse train Imo 1
It is checked whether soft gate judgment has been performed for all pulses of , and has been completed. 'Laba, Flow 105
Then, it is checked whether the soft gate has been performed for the entire pulse train of line Ll. When it is confirmed in 70-106 that the soft gate determination for all lines has been completed, the process ends.

101*l It:K, This is a process of calculating the reflector position (x, y, z) from the reflected pulse information obtained in the process of FIG. First, in flow 107, the selected reflected pulse information is read. What is this reflected pulse information?
The information is as shown in FIG.

In flow 108, the reflector position (X, Y, Z) is calculated from the corresponding reflected pulse information.

Calculation of the reflective body position fit, (X, Y, Z) is, for example, as follows.

X = X ・・・・・・・・・
(4) (13) Y=tsinθ1y ・・・・・・・・・(5)
Z=tcO! Iθ...Old...(6)
Here, X and y are the probe positions, θ is the refraction angle, and t is the beam path length. However, Z is the corresponding soft gate information Sg+
If the thickness of the object to be inspected is a dog, then Z = 28g + (h I ) Z ・
・River - (Given by force.

FIG. 11 shows two positions Ul by the probe 11.

The state of flaw detection at U2 is shown in Fig. 12, and the two positions Ul
, shows an example of display of A Quco-1 in U2. However, Ul, U2
Although the display examples are shown on the same time axis for convenience of drawing, this is only for convenience of display. What is clear from the figure is that the noise fLll,R,12 at the neighboring points was removed, that the gate information Sil 1812 was appropriately selected, and that A
The display on the scope is appropriate, and only echoes above a predetermined peak can be displayed and noise can be appropriately removed. Furthermore, as a result of these comprehensive results, it can be seen that the detection of defects etc. is accurate.

(14) According to the above embodiment, the gate circumference on the A scope can be specified by the position It of the probe and the propagation time of the reflected echo, and the pulse required for displaying the reflected pulse can also be determined by the probe position It and the propagation time of the reflected echo. only have the advantage of being visible.

Note that although the information table in FIG. 8 is based on the premise of -short calculation, this may be performed by the processor 16. FIG. 13 shows another embodiment from this point of view. Transmitter/receiver 101
The analog signal from the position detector 13 is sent to the AD converter 1 in a time-division manner.
8 takes in and converts A and D. The processor 19 takes in the output of the AD transformer 18, and also receives other inputs θ, V, S
, and create a pull as shown in FIGS. 7 and 8 in the buffer memory 20. After that, by searching this table and performing arithmetic processing, the corresponding 8g
Processes such as searching for + and evaluating reflected pulses are performed and displayed on a display device (not shown).

In this embodiment, processor 19 now stands alone in FIG.

Since the table shown in FIG. 8 can be edited and arithmetic processing can be performed based on this table, consistency in processing can be maintained.

(15) As explained above, according to the present invention, flaw detection can be performed with the same A scope gate setting even on objects to be inspected with uneven thickness, and the flaw detection time can be shortened. Furthermore, since the gate can be set according to changes in wall thickness, the position calculation and size evaluation of the reflector can be performed accurately and easily. Furthermore, since noise generated during flaw detection can be removed, more accurate flaw detection can be performed.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of conventional ultra-leech wave flaw detection, Figure 2 is a diagram showing its scanning procedure, Figures 3 and 4 are time charts of reflected waves, and Figure 5 is when a nozzle is the object to be inspected. 1st brother 4th, 6th
The figure is an embodiment of the present invention, Figures 7 (A), (B), and 8 (A), (B), and (C) are table diagrams in the memory.
Figures 9 and 10 are process flowcharts, Figure 11 is an explanatory diagram of flaw detection, Figure 12 is an example of A scope display, and Figure 13 is
The figure shows another embodiment. DESCRIPTION OF SYMBOLS 10... Transmitter/receiver, 11... Probe, 12... Subject, 13... Position detector, 14... Digitization circuit, 15... Buffer memory, 16... Processor , 17 (16) ... Display device [1゜ Agent Patent attorney Masami Akimoto (17) Kaya 1 Koman\ (χ牝j?l) 3 eyes 4 eyes 5 eyes $ 2 0 304-1 7th Moha (A2 (B) 8th (4) 1 bite)
(/＼)ATIIAT12 JP-A-59-3254 (7) 9 pieces of grass 10 pieces of grass 0g ■

Claims (1)

[Claims] 1. An ultrasonic probe that moves while scanning over an object to be inspected, and transmits ultrasonic pulses to the ultrasonic probe, and transmits ultrasonic waves into the object to be inspected. At the same time, there is a transceiver that receives the reflected waves detected by the probe, and for each scanning position of the probe, the actual reflected echoes received by the transceiver within the permissible path length range for reflected echoes at that position are selected. An ultrasonic flaw detection apparatus comprising: a processor for selecting a corresponding gate range; and a display means for displaying reflected echoes selected by the processor on an A-scope according to the selected gate range. 2. The ultrasonic flaw detection apparatus according to claim 1, wherein the selection of the reflected echoes is carried out under conditions not only within the allowable path length range of the reflected echoes but also at or above the reflected echo reference standard.