JPH0763739A - Automatic ultrasonic flaw detecting method - Google Patents

Abstract

PURPOSE:To improve the flaw detecting efficiency and data accumulating efficiency of a flaw detecting method by making a probe to sufficiently make necessary automatic scanning and echo detection along the external shape of an object to be inspected irrespective of the external shape. CONSTITUTION:In an automatic ultrasonic flow detecting method in which flaw detection is performed based on the positional information of an ultrasonic flaw detecting probe 4 and intensity information of ultrasonic echoes by automatically scanning the whole body of an object 3 to be inspected with the probe 4 by automatically moving the probe in a grid at a fixed pitch over the entire body of the object 3 by means of a scanning device, the scanning extent of the probe 4 moved by of the scanning device is set to include the entire external shape of the object 3 and only the echo detecting values detected at the position of the object 3 on the scanning lines based on IF loss signals obtained form the probe 4 are fetched as flaw detecting information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a welding defect in an object,
The present invention relates to an automatic ultrasonic flaw detection method which is applied when, for example, automatically inspecting a cavity defect, a crack defect, etc. by a water immersion flaw detection method, in particular, by improving the probe scanning method and the obtained flaw detection information acquisition method, the flaw detection efficiency can be improved. The present invention relates to an improved automatic ultrasonic flaw detection method.

[0002]

2. Description of the Related Art A three-axis scanning method of X-axis, Y-axis and Z-axis is known as a conventional typical scanning method of a probe applied in automatic ultrasonic flaw detection. When an automatic inspection of an object such as a semiconductor device component is performed by this method, first, the probe is manually scanned on the object in the Z-axis direction to set the focal length of the probe.

Next, the probe is manually moved in the X-axis and Y-axis directions to the origin of the subject, that is, the center of the subject.
After that, the flaw detection stroke values of the scanning device in the X-axis and Y-axis directions are input to the control device of the scanning device having a microprocessor by means of keyboard input or the like in accordance with the size of the subject, and then an automatic scanning command is issued. The automatic scanning of the probe is executed by inputting.

In this case, since the scanning range of the scanning device in the X-axis direction and the Y-axis direction is to detect flaws on the entire surface of the object to be inspected, stroke values in the X-axis and Y-axis directions in a range larger than the size of the object are detected. Is usually input to automatically scan.

FIG. 4 shows an example of setting the scanning range which covers the entire subject in this way. That is, the scanning area b having the X-axis direction stroke value X1 and the Y-direction stroke value Y1 larger than the subject a is set, and the rectangular scanning is performed at the scanning pitch P1 from the scanning start point A.

On the other hand, conventionally, another automatic scanning method for detecting flaws on an object having an arbitrary shape is also known. That is, after manually focusing the object in the Z-axis direction, the probe is manually moved to a predetermined automatic scanning start position, and the subsequent automatic scanning detects that the probe is on the object and performs flaw detection. Is a method of implementing. This method uses the presence or absence of the IF loss signal of the ultrasonic flaw detector as a criterion for determination. When the IF loss signal is present, the scanning in the X-axis direction is continued, and when the IF loss signal disappears, In this method, the scanning device is moved in the Y-axis direction by one pitch, and the scanning device is operated in the direction opposite to the X-axis to perform flaw detection.

FIG. 5 shows an example of scanning based on this method. That is, in the case where the object a is, for example, a gourd shape having a recess a1 as shown in the drawing, probe scanning is performed from the scanning start point A to the scanning end point B according to the presence or absence of the IF loss signal, and as shown by the scanning line S, The probe faithfully moves along the shape of the subject a corresponding to the recess a1. In this method, by repeating the above-described X-axis and Y-axis direction scanning operations, it is possible to perform flaw detection along the outer shape of the subject even in the subject having an arbitrary shape.

[0008]

However, there are various problems in the above-described conventional automatic ultrasonic flaw detection method for performing automatic scanning by the conventional method. X-axis and Y shown in FIG.
In the scanning method by inputting the stroke value in the axial direction, flaw detection is performed in a range larger than the size of the subject, so flaw detection is also performed in a range of useless parts. In this case, there is a drawback that the flaw detection efficiency is deteriorated.

Further, when the flaw detection of the subject having an arbitrary shape shown in FIG. 5 is carried out along the shape, the presence or absence of the IF loss signal of the ultrasonic flaw detector when the probe is present on the subject is tested. The scanning in the X-axis direction is interrupted at the recess a1, and the undetected area (hatched area in the figure) c is generated on the opposite side of the recess a1 which is the turning point of the scanning. In some cases it was enough.

The present invention has been made in view of the above circumstances, and regardless of the shape of the subject, automatic scanning of the probe and echo detection can be performed in a range along the outer shape of the subject. It is therefore an object of the present invention to provide an automatic ultrasonic flaw detection method capable of improving flaw detection efficiency and data storage efficiency.

[0011]

In order to achieve the above-mentioned object, the present invention automatically and rectangularly scans an ultrasonic flaw detection probe with a scanning device at a constant pitch over the entire object, and the position of the probe. In an automatic ultrasonic flaw detection method in which flaw detection is performed based on information and intensity information of ultrasonic echoes, the scanning range of the probe by the operating device is set as a shape including the entire outer shape of the subject, while being obtained from the probe It is characterized in that only the echo detection value detected at the subject existing position on the scanning line based on the IF loss signal is taken in as flaw detection information.

In the preferred embodiment of the present invention, for example, when the inspection is performed on an object having a typical shape such as a circle or a triangle, the control / image processing computer uses a keyboard to set the radius of a circle, the three sides of a triangle, and the like. This is to input data, automatically calculate the external coordinate value of the subject, and input it to the memory.

In another desirable mode, the external coordinate data of the subject having an arbitrary shape may be input by pen input of a CAD tablet having a coordinate calculating function, which is connected to a control / image processing computer.

Still another desirable mode is to input the external coordinate data of a subject of an arbitrary shape by using an image processing device and a CCD camera connected to a control / image processing computer,
The image data of the subject by the CCD camera is converted into coordinate data by an image processing device and input.

[0015]

In the above method, for example, the scanning device is operated by the external coordinate data of the subject having an arbitrary shape which is previously input to the control / image processing computer memory. And
The probe is scanned on the subject in a shape that matches the outer shape of the subject and flaw detection is performed, and the control / image processing computer command is issued for each X-axis and Y-axis pitch data that is input to the control / image processing computer in advance. Then, the ultrasonic echo signal collected by the ultrasonic flaw detector from the probe is transmitted as analog data to the control / image processing computer. After completion of all automatic scanning, the control / image processing computer performs image processing calculation of flaw detection data and displays the result on the CRT. In this case, I
The echo data is not recorded in the portion where the subject does not exist due to the F loss signal.

According to the present invention, for any shape of the subject, automatic scanning of the probe within the range along the outer shape of the subject can be necessary and sufficient, and the echo detection can be performed in the shape of the subject. By omitting the part other than the range, the flaw detection efficiency and the data storage efficiency can be improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, the system configuration of an apparatus for carrying out the method of the present invention will be described with reference to FIG. In this embodiment, the subject installation table 2 is installed in the water tank 1, and the subject 3 is placed on it. The probe 4 has, for example, a vertical probe and is arranged in a water immersion state.
It is connected to the. The probe 4 is moved by the scanning means 6 to X.
Scanning is performed in three directions of the axis, the Y axis, and the Z axis.

The scanning means comprises, for example, a driver unit as a scanning device for driving the probe and a controller unit for sending a scanning signal to the driver unit. Further, the ultrasonic flaw detector 5 and the scanning means 6
A control / image processing computer 7 is connected via a signal line, and a keyboard 8 is connected to the control / image processing computer 7 as data input means.

Next, the operation of this embodiment will be described with reference to the flow chart shown in FIG. First, the external shape coordinate data of the subject having an arbitrary shape is input to the memory of the control / image processing computer 7 (step S1).

Next, the X-axis and Y-axis flaw detection pitches, the scanning origin coordinate values, and the X-axis and Y-axis scanning speed set values are input from the keyboard 8 (steps S2, S3, S4). Then, each scanning range of the X-axis and Y-axis scanning devices is calculated by the computer arithmetic unit based on the outer shape coordinate data of the subject 3 (step S5), and the scanning command is transferred to the scanning device controller (step S6).

Thereafter, the scanning device controller receives a scanning command, a scanning command is output to the driver unit, and the scanning means 6 performs probe scanning within a predetermined range. At this time, with the pitch value in the X-axis direction set in step S2, every time the X-axis scanning device moves by a pitch distance, the control / image processing computer 7 synchronously collects a flaw detection echo signal to the ultrasonic flaw detector 5. The instruction is sent.

Then, the flaw detection echo signal collected by the probe 4 and transmitted to the ultrasonic flaw detector 5 is transmitted to the control / image processing computer 7 as an analog signal, and the subject 3
After the automatic inspection is completed, the image processing of the flaw detection data stored in the memory unit of the control / image processing computer 7 is performed by the software program, and the processing for displaying on the CRT screen is performed.

In the present embodiment, the probe 4
Only the echo detection value detected at the position where the subject 3 is present on the scanning line based on the IF loss signal obtained from the above is taken in as flaw detection information.

In addition, in the above series of processing, the subject 3
Focusing work of the echo signal by driving the Z-axis scanning device of the probe 4 is performed by either an automatic focusing process or a manual focusing process.
It is executed at any stage before the transfer of the scanning command to the traveling device controller (step S6) in the flowchart.

FIG. 3 shows a case where flaw detection processing is performed on a circular member as an example of automatic inspection of a subject 3 having an arbitrary shape. In this case, first, the circular subject 9 is installed so that the coordinate point (0, 0) of the scanning device coincides with the center of the subject. Next, the scanning device is used to start scanning point 1 of the probe.
Perform processing to automatically move to 1.

After that, scanning is performed from the scanning start point 11 in the X-axis direction and the Y-axis direction along the contour of the scanning range 10 along the illustrated path. At this time, the scanning range 10 is set to be slightly larger than the outer shape of the circular subject 9. This makes it possible to perform automatic inspection over the entire range of the circular object at the time of flaw detection.

Further, even if the shape of the subject is an arbitrary shape other than a circle, in the process of inputting the outer coordinate data of the subject (step S1) of the above-mentioned flowchart, the outer coordinate data of the arbitrary shape is calculated and stored in the memory of the computer. By inputting to the area, the automatic inspection becomes possible like the circular object.

For example, when the present embodiment is applied to the gourd-shaped object to be inspected shown in FIG. 5, the entire scanning is performed beyond the recess, and at that time, the data of the recess is not recorded. Therefore, only the flaw detection data of the necessary part can be obtained,
Thereby, the flaw detection efficiency and the data storage efficiency can be improved.

The present invention is not limited to the above embodiment. For example, in the subject outer shape coordinate data input (step S1) in the above-described flowchart, the subject outer shape coordinate data is directly input to the computer memory.
In the case of a member such as a circular member, a triangular member, or a trapezoidal member that can automatically calculate typical external coordinate data, the radius of the circle,
By inputting the three-sided dimensions of the triangle and the like from the computer keyboard, the external coordinate data can be automatically calculated by the calculation program.

CA having a coordinate processing function in the computer
A method may be adopted in which the D tablet is directly connected, the contour of the subject having an arbitrary shape is drawn on the CAD tablet by the digitizer pen of the CAD tablet, and the contour coordinate data is transmitted to the computer and input into the computer memory.

Further, the CCD camera is connected to the image processing apparatus, the image processing apparatus and the computer are connected by a communication cable, the subject of an arbitrary shape is imaged by the CCD camera, and the image pickup is performed by the image processing of the image processing apparatus. It is also possible to calculate the outer shape coordinate data by using, to send the calculated outer shape coordinate data to the computer, and to input it to the computer memory.

[0032]

As described above, according to the present invention, it is necessary and sufficient to automatically scan the probe in the range along the outer shape of the object for any shape of the object, and to detect the echo. With regard to (2), the flaw detection efficiency and the data accumulation efficiency can be improved by omitting the portion other than the shape range of the subject.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of the system configuration of an ultrasonic flaw detector for implementing the method of the present invention.

FIG. 2 is a flowchart illustrating a processing procedure of a scanning method according to an embodiment of the present invention.

FIG. 3 is a diagram showing a specific scanning example according to the present invention.

FIG. 4 is a diagram showing a conventional method.

FIG. 5 is a diagram showing another conventional method.

[Explanation of symbols]

 1 water tank 2 subject installation table 3 subject 4 probe 5 ultrasonic flaw detector 6 scanning device scanning means 7 control / image processing computer 8 keyboard 9 circular subject 10 scanning range 11 scanning start point 12 scanning end point

Claims (1)

[Claims] 1. An automatic ultrasonic flaw detection probe is automatically square-scanned by a scanning device at a constant pitch over the entire object, and flaw detection is automatically performed based on position information of the probe and ultrasonic echo intensity information. In the ultrasonic flaw detection method, while setting the scanning range of the probe by the operating device to a shape including the entire outer shape of the object, the object detection position on the scanning line based on the IF loss signal obtained from the probe is detected. The automatic ultrasonic flaw detection method is characterized in that only the detected echo value is taken as flaw detection information.