JPH0325365A - Ultrasonic flaw detector - Google Patents

Abstract

PURPOSE:To easily display an image with high accuracy irrelevantly to the position and size of a defect part by making an ultrasonic wave incident in a sectorial shape on a body to be inspected at one point of a vibrator group as an incidence point while varying the angle of the incidence continuously. CONSTITUTION:Some of the vibrator group 12 of an array probe 11 makes the ultrasonic wave incident on the body 2 to be inspected in the sectorial shape at one point of the vibrator group 12 as the incidence point while the angle of incidence is varied continuously, and a reflected wave from a defect part is received to detect the part 3 in the form of an electric signal. Consequent ly, the ultrasonic wave is made incident on the body 2 to be inspected in the sectorial shape by using some of the vibrator group 12 of the probe 11 while varied in angle to detect the defect part 3 through sector scanning. At this time, a signal controller 15 switches vibrators 12 in order, position information on the incidence point of the vibrators 12 is inputted to an image processor 16 to generate defect image data on the part, which is sent to an image display part 17.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides an ultrasonic flaw detection device that uses ultrasonic waves to detect and display defective parts that occur in objects such as metals. Regarding.

(Prior art) Conventionally, defective parts such as holes generated in objects such as metal are detected using ultrasonic waves, and a defective image of the defective part is displayed on an image display such as a display from the detected reflected ultrasonic data. The aperture synthesis method was generally adopted as the ultrasonic flaw detection equipment shown in
(Japan Nondestructive Testing Association, published in 1989, see 129 Sada et al.).

Here, the aperture synthesis method generally uses an ultrasonic probe with wide directivity, and calculates the reflected wave intensity of the ultrasonic waves irradiated from the ultrasonic probe to the defective area and reflected. The distance from the sound wave emission point to the defective part is determined at one probe position, and the same data as above is collected by changing the probe position slightly, and finally the data is combined and image processed. By doing this, the defective part is displayed as an image.

FIG. 7 shows the principle of a general ultrasonic flaw detection device that employs this aperture image processing.

That is, the ultrasonic flaw detection device is equipped with an ultrasonic probe 1 that emits ultrasonic waves, but this probe 1 has a wider directivity than a normal ultrasonic probe. Commonly used.

This ultrasonic probe 1 is located at one reference point a on the surface of the object 2 to be inspected. The ultrasonic probe 1 irradiates the inside of the object 2 with ultrasonic waves through the ultrasonic flaw detector 4, and the reflected ultrasonic waves reflected from the defective part 3 are detected by the ultrasonic flaw detector 4.
By detecting the distance iiiWo from the reference point a
I know that there is a defective part 30 at .

This result is then input to the signal processing device 6 as reflected ultrasonic data from the ultrasonic flaw detector 4, while the position data of the probe 1 is detected by the position detector 5 and input manually to the signal processing device 6. Ru. This signal processing device fR6 processes both of the above data to create defect image data, and sends this data to the image display 7.

That is, in this image display 7, as a processing result of the signal processing device 6, a reflected ultrasonic wave is detected at a position at a distance Wo from the position ffiao of the probe 1 (that is, there is a defective portion 3).
, the corresponding radius W is centered at the corresponding position aO. The hardness is depicted.

Similarly, the ultrasound probe 1 is sequentially mechanically moved to points a1...an which are distances Rg1...go away from the reference point ao, and processing is performed sequentially, and the processing results at this time are imaged. It is displayed on the display 7.

As a result, the data is weighted more heavily in the area where the semicircles overlap, and as a result of the brightness modulation, it is displayed brightly, and as a result, the shape of the defective area 3 is changed to the image display 7.
It was designed so that +lj could be expressed as a defective image 3'.

In the above description, the defective part 3 is reproduced as the defective image 3' on the image display 7 by combining data on the image display 7 based on data at each position of the ultrasound probe 1. The above describes the case where the data is combined by the signal processing device @6 before displaying, and only the display of this weighted defect position information is performed on the defect image 3.
It is also common practice to reproduce the image on the image display 7 as .

(Problem 8 to be Solved by the Invention) However, the conventional ultrasonic flaw detection apparatus using the aperture synthesis method described above has the following problems. That is, ■ An ultrasonic probe with wide directivity is required, but as a general characteristic of this type of probe, it is generally quite difficult to manufacture one that has uniform intensity characteristics in all directions. There is a difference in strength depending on the position of the defective part.

In addition, with data only when the ultrasonic probe is in position 1, it is not possible to detect in which direction the defective part exists, and due to the problem of the intensity difference mentioned above, the directional intensity It is difficult to correct for variations at each probe position.

- Since the position of the probe is moved mechanically, not only is the positional accuracy generally quite poor, but the moving speed is slow, and furthermore, it is difficult to make the moving pitch finer.

For this reason, in conventional general ultrasonic detection devices,
When displaying an image of the position and shape of a defective part, the current situation is that it is generally quite difficult to display and evaluate the defective part quickly and accurately with commercial accuracy, regardless of the size and position of the defective part. Met.

In view of the above, an object of the present invention is to provide an apparatus that can quickly and accurately display a single image regardless of the position or size of a defective portion.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, an ultrasonic flaw detection device according to the present invention includes an array probe in which a plurality of microscopic transducers are linearly arranged, and a single part of the array probe. Using a group of transducers, ultrasonic waves are applied in a fan shape into the body to be inspected with one point in the group of transducers as the incident point while continuously changing the angle of incidence, and the waves reflected from the defective part are received and detected as electrical signals. Timing control is performed to electronically switch the electronic scanning ultrasound flaw detector and the transducer group of the array probe, move them sequentially, and collect ultrasound data at the incident point at each moving position. a signal controller, an image processor that estimates the defect position from the reflected ultrasonic data at each of the incident points and forms defect image data according to the shape of the defective part, and an image display that displays the defect image data. It is equipped with a container.

(Function) According to the present invention configured as described above, sector scanning is performed by a group of transducers centered around a certain transducer of the array probe, and defect reflection signals at that time are collected. Then, the center of sector scanning is sequentially moved to adjacent transducers via a signal controller, and sector canning by a group of transducers is performed sequentially, and the defect reflection signal due to each sector canning is detected. Collect each. Then, the sector scanning data at each of these incident points is processed by an image processor together with the position information of the incident point, and each data is combined based on the defect reflection signal to form defect image data. can be displayed on the image display.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

Inside the array probe 11, there are a plurality of micro oscillators 12. which are shaped like short 111 cm and extend parallel to the surface of the object 2 to be inspected.
12... are arranged in a straight line, and an electronic scanning ultrasonic flaw detector 13 is connected to this array probe 11.

A packing material 14 is filled behind each of the vibrators 12, 12, . . . to eliminate interference between the vibrators 1212 and improve damping characteristics.

The electronic scanning ultrasonic flaw detection device 13 uses a part of the transducer groups 12.12... of the array probe 11 to detect the object to be inspected by using one point of the transducer group 12.12... as an incident point. Ultrasonic waves are incident in a fan shape into the defective portion 2 while continuously changing the input angle, and the reflected wave from the defective portion 3 is received to detect the defective portion 3 as an electrical signal.

As a result, a certain group of transducers 1 of the array probe 11
2.12... is used to irradiate the inspection object 2 with string sound waves while sequentially changing the angle in a fan-like manner to perform sector scanning in which defective portions 3 are detected.

This sector scanning operation by the electronic scanning ultrasonic flaw detector 13 is a well-known clamping technique.
. . . to control the intensity of the ultrasonic beam to be constant regardless of the angle of incidence.

The electronic scanning ultrasonic flaw detector 13 is connected to a signal controller 15, and the electronic scanning ultrasonic flaw detector 13 and signal controller 15 are each connected to an image processor 16.

This signal controller 15 electrically switches the transducer groups 12, 12, etc. of the array probe 11, moves them sequentially, and collects ultrasonic data at the incident point at each moving position. As a result, the signal controller 15 sequentially switches the group of transducers 12, 12, etc. that perform sector scanning, and also controls the timing of the ultrasonic beam. Positional information on the incident point of the irradiating vibrator 12 is input to the image processor 16.

This image processor 16 extracts the anti-1/I signal from the defective portion 3 from the ultrasonic signal data obtained from the scanning ultrasonic flaw detector 13 and the above position information, and performs a combination process on this reflected signal. The defect image data is shaped using the image data.

This image processor 16 is connected to an image display 17, and the defect image data is inputted to this image display 17, and the defect ii of the defect portion 3! jk3' is this]! ! It is displayed at a position corresponding to the surface of the object to be inspected 2 on the ll image display 17, so that a cross-sectional view of the object to be inspected 2 can be viewed.

Sector scanning using the scanning ultrasonic flaw detector 13 will be explained with reference to FIG. 6.

That is, as shown in the figure, each transducer 12, 12, etc. arranged in the array probe 11 is given an appropriate delay characteristic by the electronic scanning ultrasonic flaw detector 13, and By sequentially exciting the vibrator 12 located in the section, the ultrasonic wave can be made incident at an arbitrary angle θ hn direction from the incident point a.

By changing the way the delay time is given, the angle of incidence of the ultrasonic wave from the incident point a is changed to θ1. θ2
...θ． Ultrasonic waves at multiple incident angles are sequentially changed, that is, ultrasonic line (1). (2) It is possible to perform almost continuous inspection using (m).

This method of injecting ultrasonic waves in a fan shape centered on one incident point a is called sector scanning, and in this sector scanning, each ultrasonic line (1) is , (2)...
(The intensity of the illusion can be easily made uniform.

In addition, when this electronic scanning type ultrasonic flaw detector 13 is used, as shown in the same figure, the electronic scanning type ultrasonic flaw detector 13 is
By connecting the scope display 18 and the image display 17' to the scope display 18, the defect reflection signal obtained as a result of sector scanning (i.e.,
In the case of the same figure, the ultrasonic lines (n-1) and (n) (reflected signals are generated from the defective part 3) are displayed on the image display 17' by the B-scope display 19 with brightness adjustment. It is common practice to recreate the image as a defective image.

In the embodiment shown in FIG. 1 above, an array probe capable of switching the transducer groups 12, 12, etc. is used for the electronic scanning ultrasonic flaw detector capable of sector scanning shown in FIG. 6. The switch 11 is equipped with a signal controller 15 that outputs this switching signal, and its operating state will be explained with reference to FIG.

That is, the transducers 1212 that constitute the array probe 11...
. . , a group of transducers 12.12 located within the interval g1 are first selected, and these transducers 12.
12..., a radiation line (1) centered at the incident point at. (2)...Execute the sector scanning up to (1) and collect defect reflection signal data at that time. In this case, the defect signal from the defective portion 3 will be detected by the radiation lines (n) to (n+2).

After this first sector scanning data collection is completed, the signal controller 13 moves the transducer group 12.12.
... is selected and the same data collection as above is performed. Thereafter, the transducer groups 12, 12... are sequentially moved by one bit of transducers, and finally the transducer group 1 is located within the interval gg.
2.12... performs sector scanning from the incident point aρ, and collects defect reflection signal data at that time.

In this case, the defective signal from the defective portion 3 becomes the radiation line 01 line (k) to (k+2).

Switching of the timings of block switching, sector scanning, and data collection of these series of transducer groups is performed by a signal controller 15 shown in FIG.

Further, in the image processor 16, the signal opposite signal data obtained as described above is applied to the ultrasonic wave incident point a of each transducer group 1212... . . . Composite processing is performed in comparison with the position of aa, and the result is displayed on the image display 17 as defect image data.

Based on the data obtained from Figure 2 above,
The case where defective image data processed by the image processor 16 is displayed on the image display 17' will be described with reference to FIGS. 3 and 4.

That is, at the incident point a1, the ultrasonic lines (]1) to (n
+2), the reflection number 1g from the defective part 3 becomes W
．． (n), Wt. (n+1) and WX, (I1+
2), the image display 17 displays the width of the ultrasound beam centered on the ultrasound line at a location corresponding to the incident point a1 of each ultrasound line, the angle of incidence, and the signal generation position. The brightness is modulated and displayed by a length corresponding to . In addition, in the case of the incident point an, the ultrasonic line (k) to (k+2)
The defect reflection signal detected by the W. ! ．． (k), W. (k+1) and W, . (k
+2).

g In this case, the results of ultrasound lines (k) and (k+1) are displayed at the same location as the results detected by ultrasound lines (n+1) and (n+2) and are displayed as cross points, so The brightness will be modulated to be brighter. However, in reality, the point of incidence is a o "" a
1, sector scanning data from a large number of elbow entry points is collected and the results are displayed on the image display 17, so that the data points are generated along the contour of the defective part 3. As a result, a defect contour with deep brightness modulation is displayed as the reproduced defect image 3'.

In the above embodiment, it is possible to collect ultrasonic data at various incident angles at one incident position. However, this method had the disadvantage that it was not possible to identify where the defective part was, and there were differences in the intensity of the reflected signal depending on the position of the defective part. The defect can be eliminated and the defect position can be specified, and the intensity of the reflected signal can be corrected based on the position of the defective part. Furthermore, by performing sector scanning using aperture control, ultrasonic waves of a constant intensity can be made to be incident in each incident direction.

Furthermore, in the case of the conventional aperture alignment method, it was necessary to scan the probe mechanically, but in the case of the full length method, the movement of the incident point is entirely controlled electronically. The data collection speed becomes extremely high, the positional accuracy of the incident point is good, and the movement pitch can also be made finer.

Furthermore, as the ultrasonic data, since the flaw detection data for each incident direction at each incident point position is distorted as described above, when a defect image is formed, an image with better viscosity can be obtained.

In the case of the above embodiment, a case has been described in which the reproduction of a defective part is performed using data ε at one incident position and then combined on the image display section. It is also possible to perform weighting based on the position and intensity of the defect reflection data, and display only the position and size information of the defective part on the imaging display section.

Furthermore, in the above embodiment, an example is shown in which data processing is performed by converting each transducer group 12, 12... in a single array probe 11 into blocks, but as shown in FIG. , a plurality of (two in the figure) array probes 11.11 are arranged in series and connected via a support 19, and each array probe 11, 11 is sequentially sector-scanned, and its fat The data for ε may be processed and displayed in the same manner as for ε.

〔Effect of the invention〕

Since the present invention has the above-described structure, the ultrasound data at the JIJ point position of each person is not a single beam using a probe with wide directivity as in the aperture matching method, but is obtained using sector scanning. This results in multiple pieces of ultrasound data, so by performing intensity corrections such as aperture control, it is possible to obtain uniform intensity for each human incidence angle, and it is also possible to obtain sector scanning data at each incident point. Since the position of the defective portion can be estimated from even one sector scanning data, it becomes easy to correct directional intensity changes.

Furthermore, by electronically switching the incident point, the position accuracy of the ultrasonic line for incident point sector scanning is improved.
The moving speed is also high, and the moving pitch can be made extremely small.

Therefore, it is possible to quickly and accurately display an image regardless of the position or size of the defective portion.

[Brief explanation of drawings]

1 to 4 show an example of the present invention, in which FIG. 1 is a schematic configuration diagram, FIG. 2 is a diagram showing radiation lines in a state where the transducer group is switched, and FIG. Fig. 4 is a principle diagram for explaining the synthesis state of the corresponding defect images, Fig. 5 is a schematic configuration diagram showing the main parts of Ike's embodiment, and Fig. 6 is an electronic scanning ultrasonic flaw detection device. FIG. 7 is a diagram illustrating the principle of defect image reconstruction using the conventional aperture merging method. 2... Object to be inspected, 3... Defect portion, 11... Array probe, 12... Vibrator, 13... Electronic scanning ultrasonic flaw detector, 15... Signal controller , 16... Image processor, 17... Image display device.

Claims (1)

[Claims] An array probe in which a plurality of minute transducers are linearly arranged, and a group of transducers in a part of the array probe into the body to be inspected with one point of the group of transducers as an incident point. An electronic scanning ultrasonic flaw detector that injects ultrasonic waves in a fan shape while continuously changing the incident angle and detects reflected waves from defective parts as electrical signals; a signal controller that performs timing control to collect ultrasonic data at the incident point at each moving position by switching and sequentially moving; and a signal controller that estimates the defect position from the reflected ultrasonic data at each of the incident points. An ultrasonic flaw detection apparatus comprising: an image processor that forms defect image data according to the shape of a defective part; and an image display that displays the defect image data.