JPH03137560A - Ultrasonic flaw detector - Google Patents

Abstract

PURPOSE:To rapidly and properly discriminate or evaluate a flaw even when the angle of refraction of a probe or the thickness of a material to be inspected changes by respectively setting the angle of refraction of the probe and the thickness of the material to be inspected and generating the discrimination signal corresponding to a skip distance. CONSTITUTION:When the angle theta of refraction of the ultrasonic wave incident from a probe 3 is set to the first setting device 8, a conversion signal tan thetais outputted from a function generator 11. The output from the function generator 11 and the output from the second setting device 9 to which the thickness (t) of a material to be inspected are supplied to a multiplier 12 and the skip distance signal corresponding to a skip distance is obtained through a skip output circuit 13. A skip signal circuit 14 generates signals at a skip point and an intermediate point in synchronous relation to the timing signal from a synchronous control part 1. A descrimination signal circuit 15 receives the signals to generate a plurality of discrimination signals within a flaw detection range to display the same on a display device 7. As a result, the discrimination signals showing a flaw detection echo and a skip distance are simultaneously displayed on the display device 7.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to an ultrasonic detection device that injects ultrasonic waves obliquely into a test material and displays flaw detection echoes from a welded part, particularly in oblique angle flaw detection. This invention relates to simultaneous display of a flaw detection echo and an identification signal indicating a skip distance.

[Prior Art] FIG. 6 is an explanatory diagram showing an example of conventional welded part flaw detection.
3 is a probe that transmits/receives ultrasonic waves; 30 is a test material;
31 is a welded part, 32 is a defect, 33 is a skip point, t is the thickness of the test material 30, A is an incident point of the ultrasonic wave, and θ is a refraction angle.

The conventional ultrasonic flaw detection device is configured as described above, and is capable of detecting the position, size, and shape of various defects 32 such as cracks, poor fusion, slag entrainment, and blowholes in the welded part 31 of the welded test material 30. In this method, oblique flaw detection is performed by making ultrasonic waves obliquely incident on the test material 30 and changing the incident point A and the refraction angle θ.

Ultrasonic waves are incident from the probe 3 placed at the incident point A of the test material 30 at a refraction angle θ, and the central axis of the ultrasound waves and the position of the defect 32 are set so that the size of the echo is maximized. Aligned.

When the incident point A and the welding part 31 are located close to each other, the direct method of flaw detection using the reflected echo from the defect 32 of ultrasonic waves directly propagated from the incident point A, or when the welding part 31 is at the incident point A.
A single reflection method of flaw detection is performed using a defect echo after passing through a skip point 33 where an ultrasonic wave obliquely enters the test material 30 and is reflected from the back surface or the flaw detection surface.

At this time, the skip distance of the ultrasonic waves incident on the specimen 30, the beam path to the defect 32, etc. are determined as follows.

1 skip distance, 5=2t-tanθ, 1 skip beam path length W1q=2t/cosθ, probe/defect distance y
Beam path length Wγ = y/S inθ when .

[Problems to be Solved by the Invention] In the conventional ultrasonic flaw detection apparatus as described above, when detecting a defect 32 by oblique flaw detection of a weld 31 in a test material 30, in addition to various defect echoes from the weld 31, Flaw detection echoes consisting of interfering echoes such as reflected echoes from the bead are generated and displayed, so in order to identify a given defective echo and evaluate its size and shape, it is necessary to change the incident point A or the refraction angle θ or direct method, single reflection method, etc. are used.

At this time, identification is performed based on the mark indicating the skip distance and the display position of the defective echo.

However, the skip distance, the probe/defect distance, the beam path, etc. all depend on the refraction angle θ of the probe 3 and the thickness t of the material 30 to be inspected.

Therefore, it takes time to calculate the skip distance each time the refraction angle θ of the probe 3 or the thickness t of the test material 30 differs and to mark the skip distance at a predetermined position on the display.

In addition, the skip distance symbol given to the cursor board placed on the front of the display hides a part of the defective echo, and creates parallax between them, which impedes the identification and evaluation of a given defective echo and prevents correct identification and evaluation. There was a problem.

This invention was made to solve this problem, and even if the refraction angle θ of the probe 3 or the thickness t of the test material 3O changes, the skip distance can be easily reduced by 1%, and the flaw detection echo can be echoed simultaneously. It is an object of the present invention to provide an ultrasonic flaw detection device that can quickly and appropriately identify and evaluate predetermined defective echoes without suffering similar obstacles.

[Means for Solving the Problems] An ultrasonic flaw detection device according to the present invention includes a first setter that sets the refraction angle of the ultrasonic waves incident on the test material, and a first setter that sets the thickness of the test material. 2 setting devices, and a skip distance circuit that receives signals from the first setting device and the second setting device and generates a signal corresponding to the skip distance at which the ultrasonic waves transmitted in the test material are reflected on the back surface or the flaw detection surface. , an identification signal circuit that receives a signal from the skip distance circuit and generates a plurality of identification signals over a flaw detection range;
It is equipped with a display that simultaneously displays flaw detection echoes and identification signals.

[Function] In the present invention, a first setter that determines the refraction angle of the probe used for oblique angle flaw detection of welded parts, and a second setter that sets the thickness of the test material that is in d contact. According to the above settings, an identification signal is generated from the identification signal circuit for each skip distance over the flaw detection range via the skip distance circuit. The flaw detection echo, marker, bright spot, identification signal displayed in color, etc. are displayed simultaneously on the display, so the mutual relationship can be easily understood.

However, during flaw detection of welds, in addition to echoes of various defects such as cracks, poor fusion, slab entrainment, and blowholes, interference echoes such as reflected echoes from the weld are generated and displayed.

In order to identify a given defect echo from among the flaw detection echoes and evaluate its position, size, and shape, it is necessary to change the ultrasonic incident point A on the test material, or to identify the defect using the direct irradiation method or single-reflection method. Flaw detection is performed by irradiating ultrasonic waves from multiple directions.
This is done in consideration of the relative position and refraction angle between the echo displayed at this time and the identification signal. Since both are displayed on the same display screen so that they can be distinguished from each other, defects can be identified and evaluated quickly and appropriately.

[Embodiment] An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 3 is the same as the conventional device described above, 1 is a synchronization control section that generates a timing signal, 2 is a transmitting circuit, 4 is a receiving circuit, 5 is a scanning circuit, 6 is a video amplifier, 7 is a display, 8 is a first setting device for setting the refraction angle θ of the probe 3, 9
1Ω is a second setting device that sets the thickness t of the material to be inspected 30; 1Ω is a skip distance circuit that receives signals from the first setting device 8 and second setting device 9 and generates a signal for each skip distance; 11 is a skip distance circuit that generates a signal for each skip distance; A function generator that outputs a predetermined conversion signal based on the refraction angle θ, 1
2 is a multiplier; 13 is a skip output circuit that outputs a signal according to the skip distance; 14- is a skip signal circuit that generates a signal that divides the flaw detection range according to the skip distance;
Reference numeral 5 indicates an identification signal circuit that receives the output from the skip signal circuit -1A- and generates an identification signal.

In the ultrasonic flaw detection apparatus configured as described above, the timing signal from the synchronization control section 1 energizes the probe 3 via the transmission circuit 2, and the generated ultrasonic waves are directed diagonally toward the specimen 30. The ultrasonic waves are reflected at the skip points 33 on the back surface and the flaw detection surface and propagate therein. Welded part 3 by angle inspection
Detection echoes such as defect echoes and interference echoes from 1.
The signal is received by the probe 3, passes through the receiving circuit 4 and the video amplifier 6, and is displayed on the display 7 by the scanning circuit 5 synchronized with the timing signal.

When the refraction angle θ of the ultrasonic wave incident from the probe 3 is set in the first setting device 8, the conversion signal tanθ is output from the function generator 11.
is output. On the other hand, the Ryokawa force from the second setter 9, in which the thickness t of the test material 30 is set, is supplied to the multiplier 12 and passed through the skip output circuit 13 to produce t-t according to the skip distance.
A 1/2 skip distance signal of anθ is obtained.

The skip signal circuit - engineering A- synchronizes with the above timing signal and charges and discharges the integrating circuit between the skip distance signal level and the zero level, thereby increasing the skip distance S by 0.5.
Signals are generated at skip points 33 corresponding to S, 13, 1.5S, and so on, as well as intermediate points therebetween. A plurality of identification signals within the flaw detection range generated by the identification signal circuit 15 upon receiving the above signal are displayed on the display 7.

As a result, the flaw detection echo and the identification signal indicating the skip distance are displayed simultaneously on the display 7, so that the incident point A can be changed,
From the relative position with the flaw detection echo displayed by the direct radiation method or single reflection method, it is possible to distinguish between defect echoes and interference echoes within the flaw detection echo, as well as select a predetermined defect echo, and
The position of the defect 32 in 0, its size, shape, etc. can be accurately grasped.

FIG. 2 is a block diagram of the main part of FIG. 1, where 20 is a first function circuit that outputs trigonometric function signals, 21 is a second function circuit that outputs other trigonometric function signals, 22 is a reference power supply, and 23 is a 24 is a divider, 24 is an output circuit, 25 is a gate circuit, 26 is an integration circuit, 27 is a matching circuit, and 28 is a selection circuit.

When the refraction angle θ of the probe 3 is set in the first setting device 8 using a switch or the like, a sine wave signal 3 is output from the first function circuit 20.
inθ is output, and the second function circuit 21 is connected to the reference power supply 2.
2 and outputs 5in (90''-θ). Both are added to the divider 23 to output sinθ/CO5θ,
Tanθ is obtained from the output circuit 24.

The thickness t signal of the test material 30 set in the second setting device 9 using a switch or the like and the output of the function generator 11 pass through the multiplier 12, and then the skip output circuit 13 outputs the signal t-tanθ.
A signal Vo corresponding to 1/2 skip distance is obtained.

In the skip signal circuit -IA-, a gate circuit 25 synchronized with the timing signal from the synchronization control section 1 generates a gate signal corresponding to the flaw detection range. For example, a selection circuit 28 constituted by a flip-flop is set by a gate signal, and an integration circuit 26 is connected to a power source E and charged. When the charging potential exceeds the skip distance equivalent signal Vo, the matching circuit 27 outputs an output, and at the same time as the identification signal circuit 15 constituted by a ring counter advances, the selection circuit 28 output is inverted, and the integrating circuit 26 is switched to the power supply -F. It is switched and discharge starts. When the discharge potential reaches zero level, the coincidence circuit 27
is output again, the identification signal circuit 15 advances again, and at the same time, the output of the selection circuit 28 is inverted again, and the integration circuit 26 is connected to the power supply E again to perform charging.

These operations are repeated over the duration of the gate signal, that is, over the flaw detection range, and the identification circuit 15 sequentially outputs identification signals corresponding to the skip distance.

FIG. 3 shows an example of operating waveforms, where ■ is the gate signal, ■ is the output of the integrating circuit 26, ■ is the skip signal, ■, ■, ■,
■ indicates each terminal Q1, Q2, Q3, Q4 of the identification signal circuit 15
It shows identification signals sequentially output from .

As described above, in synchronization with the synchronization control unit 1, each time an ultrasonic wave is emitted, an identification signal corresponding to the skip distance of ultrasonic propagation within the test material 30 is sequentially generated and supplied to the display 7 to indicate the skip distance. The bright spot on the markaya baseline is displayed simultaneously with the flaw detection echo.

Identification can be made easier by displaying the marker in the opposite direction to the signal. In addition, when the identification signal is used as R, G, and B color signals depending on the skip distance, a composite video signal is formed together with the flaw detection echo and supplied to a color display, and the flaw detection range is divided by color and the defect echo is displayed. Its location can be easily identified by its color.

Figure 4 is an example of A scope display, Figure 4 (a) is an example of marker display, and Figure 4 (b) is an example of color display, where ■ is the transmission signal, [phase] is the defect echo, and ■ is the identification signal. (marker),
@ indicates an identification signal (color).

As mentioned above, the marker indicating the skip distance, the bright spot, the color identification signal, and the defect echo from the welding part 31 are displayed at the same time on the A scope display, and the relative relationship between the defect echo and the identification signal can be accurately grasped. The defect echoes can be identified and the position, size, and shape of the defect 32 can be easily estimated.

Figure 5 is an example of B scope display. In the figure, 7, ■,
■, [Phase], (1), @ are the same as the A scope display, and the probe 3 is slid over the test material 30 via the couplant while transmitting/receiving ultrasonic waves. Then, planar flaw detection is performed on an area of the test material 30 that is limited by the movement range of the probe 3 and the ultrasonic flaw detection range, and the defect 32 is displayed in eight scopes.

At this time, when the flaw detection echo and the identification signal are displayed simultaneously in the same manner as the A-scope display, the flaw detection range is divided by dividing lines or color display consisting of the locus of the marker bright spot of the identification signal. Therefore, the position of the defect 32 on the test material 30 can be easily identified in the above display.

Color display can be performed by supplying a composite video signal consisting of a video signal of the flaw detection echo and an identification signal used for color classification to, for example, an active matrix drive type color liquid crystal display.

The above display allows the defect 32 to be detected and evaluated quickly and appropriately.

[Effects of the Invention] As explained above, the present invention provides an identification signal that sets the refraction angle of the probe and the thickness of the material to be tested during oblique flaw detection of a welded part, and generates an identification signal according to the skip distance. With the simple structure of providing a circuit, the skip distance can be automatically obtained by setting the refraction angle and thickness.

Identification signals according to the skip distance such as marker, brightness, color, etc. and flaw detection echoes can be displayed at the same time, so you can quickly identify a given defect from various defect echoes and interference echoes, and evaluate its position, size, shape, etc. Moreover, it has the effect of being able to be performed properly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram of the main part of FIG. 1, and FIG. 3 is an example of operating waveforms.
FIG. 4 is an example of an A scope display, FIG. 5 is an example of a B scope display, and FIG. 6 is an explanatory diagram showing an example of a conventional welded part flaw detection. In the figure, 3 is a probe, 7 is a display, 8 is a first setting device, 9 is a second setting device, UΩ is a skip distance circuit, 11 is a function generator, 12 is a multiplier, and 13 is a skip output. circuit,
14 is a skip signal circuit, and 15 is an identification signal circuit. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (7)

[Claims] (1) In an ultrasonic flaw detection device that obliquely injects ultrasonic waves into the test material and displays flaw detection echoes from the welded part, there is a first setting device that sets the refraction angle of the ultrasonic waves that enter the test material; A second setting device sets the thickness of the material to be inspected, and a skip distance at which the ultrasonic waves propagating within the material receiving signals from the first setting device and the second setting device is reflected from the back surface or the flaw detection surface. a skip distance circuit that generates a corresponding signal; an identification signal circuit that receives the signal from the skip distance circuit and generates a plurality of identification signals over a flaw detection range; and a display that simultaneously displays the flaw detection echo and the identification signal. An ultrasonic flaw detection device characterized by being equipped with. (2) The ultrasonic flaw detection apparatus according to claim 1, wherein the identification signal is a marker displayed on the base line of the display according to the skip distance. (3) The ultrasonic flaw detection apparatus according to claim 1, wherein the identification signal is a bright spot displayed on the base line of the display according to the skip distance. (4) The ultrasonic flaw detection apparatus according to claim 1, wherein the identification signal is a color signal that displays the display area of the indicator in different colors according to the skip distance. (5) The ultrasonic flaw detection device according to claim 1, wherein the display displays an A-scope display. (6) The ultrasonic flaw detection device according to claim 1, wherein the display displays a B-scope display. (7) The ultrasonic flaw detection device according to claim 1, wherein the display is a color display.