JP2896385B2 - Ultrasonic inspection method and apparatus - Google Patents

Description

The present invention relates to an ultrasonic inspection method and apparatus, and more specifically, to quantitatively display the presence or absence of peeling at a bonding interface and the presence or absence of voids in an object. It relates to a possible method and its device.

<Conventional technology> Ultrasonic waves are reflected at boundaries having different acoustic impedances (density x sound velocity), and the magnitude of the reflected signal is affected by the acoustic impedance of the substance constituting the interface. The phase of reflection is different between a case where ultrasonic waves are incident on a substance having a large acoustic impedance and a substance having a small acoustic impedance and a case where ultrasonic waves are incident on a substance having a large acoustic impedance. For example, when light is incident from a solid onto a substance having low impedance such as water or air, the phase of reflection is inverted.

Utilizing this phenomenon, there is known a method of inspecting the presence or absence of peeling of a joint portion of a material or an article and the presence or absence of a void by ultrasonic waves.

In this method, an object is immersed in a liquid tank (mainly a water tank), ultrasonic waves are emitted from the probe also placed in the liquid tank toward the object, and the object is reflected from, for example, a joint. The liquid is received and converted into an RF signal (RF signal: a signal amplified by a receiver detected by the probe), and the RF signal is displayed on a display device to check for a defect.

As a method of displaying an RF signal on a display device, an oscilloscope displays an A-scope display in which time is taken on the horizontal axis and the amplitude of the RF signal waveform is taken on the vertical axis, and the probe is vertically and horizontally positioned with respect to the subject. Scan and set the horizontal (X direction) distance of the probe movement on the horizontal axis of the monitor TV (television) and the vertical direction (Y direction) on the vertical axis, and calculate the positive peak of the RF signal waveform. There is a C scope display for displaying the maximum value or the maximum value of the absolute value of the negative peak in gradation.

If the subject has defects such as peeling of joints or voids,
The reflection of the ultrasonic wave at such an interface is almost 100%, and the level is higher than the reflection from a defect-free site. Also, when ultrasonic waves are incident on a substance having a high acoustic impedance (the product of the density of the substance and the speed of sound) from a substance having a large acoustic impedance, the phase of the reflected wave is inverted. When there is, the phase of the reflected wave from the portion having no defect is inverted with respect to the phase of the reflected wave. If the former phase is made negative, the latter phase becomes positive.

In the above-described conventional method using the A-scope display, the inspector empirically determines the two properties of the ultrasonic waves as evaluation samples. In the method using the C scope display, the inspector looks at the shading of the result of gradation display by utilizing the former property of ultrasonic waves, and also makes an empirical judgment.

The above two properties of ultrasonic waves do not always clearly appear for any peeling or voiding, for example, when the waveform level is slightly increased even if peeling off, or when phase inversion is not clearly recognized There is also.
Therefore, in such a case, the conventional inspection method based on the empirical judgment of the inspector cannot clearly determine the magnitude of the waveform level and the presence or absence of the phase inversion, and it is quite difficult to judge it. It takes a long time, and it is difficult to determine whether the waveform level indicates adhesion or peeling, even if the waveform level is the same from any of the joints of the objects.

In consideration of such points, an invention as disclosed in Japanese Patent Application Laid-Open No. Sho 62-174653 has been made. This is a probe that emits ultrasonic waves toward the subject, a pulser that transmits a pulse signal for generating ultrasonic waves to the probe, and a reflected wave of the ultrasonic waves from the subject. A receiver that receives and generates an RF signal according to the received signal, and a display unit that displays data of the RF signal, and an ultrasonic wave configured to determine the presence or absence of a defect of the subject from the display content of the display unit In the inspection apparatus, (a) a peak detector which is connected to the receiver and detects a maximum value of a positive peak and a maximum value of an absolute value of a negative peak of an RF signal ahead; and (b) is connected to the peak detector. Performing a calculation for comparing the magnitude relationship between the maximum value of the positive peak and the maximum value of the absolute value of the negative peak, transmitting a signal indicating the calculated value to the display means, and displaying the calculated value. Control means for The ultrasonic inspection device is used to determine whether or not the phase of the RF signal is inverted based on the calculated value displayed on the display means, thereby detecting the presence or absence of a defect in the peak sample. The presence or absence of a defect, in particular, the presence or absence of peeling at an adhesive portion or the presence or absence of a void in an object can always be detected accurately and quickly.

Here, (A) the calculation for comparing the magnitude relationship between the maximum value of the positive peak and the maximum value of the absolute value of the negative peak is a calculation that takes the difference between the former and the latter (B) The calculation for comparing the magnitude relationship between the maximum value of the positive peak and the maximum value of the absolute value of the negative peak is a calculation that takes the ratio of the former to the latter.

More specifically, the waveform of the RF signal in the material having the bonding portion indicates a close contact state in FIG. 5 and a peeled state in FIG. As can be seen from these graphs, if the material is in close contact, a maximum voltage peak (P ₁ ) appears on the positive side, and if the material has separated, the maximum voltage peak (N ₂ ) on the negative side. Appears. Therefore, according to the above method (A), depending on whether the value of the positive-side voltage peak value (P) -the negative-side voltage peak value (N) becomes positive or negative, whether the detection site is in close contact or peeling off. Is determined. That is, P ₁ −N ₁ > 0 in the close contact state, and P ₁ −N ₁ <0 in the detached state. In this way, the data divided into two, positive and negative, and color-coded into two colors are displayed on a C scope, so that the state of each part of the material can be easily identified.

On the other hand, in the method (B), the determination is made based on whether the value of P / N is larger or smaller than 1. That is, if the material detection site is in close contact, If the detection site is in the peeled state, It becomes. Therefore, in the method (B), the data identified by the magnitude of 1 is displayed in the C scope,
The state of each part of the material is determined.

Both of the above methods empirically introduce a threshold that seems appropriate to ensure the discrimination, but basically, based on the threshold based on an artificial agreement, The binarized (distributed) data identifying the contact / peeling is displayed on a C scope.

<Problems to be Solved by the Invention> However, with the recent progress in data analysis using a broadband probe, intermediate data that cannot be obtained by plane display of the binary data, that is, C-scope display, may have important significance. I understand.

More specifically, in addition to the waveform shown in FIG. 5 showing a completely adhered state and the waveform shown in FIG. 6 showing a completely peeled state, there are intermediate waveforms in a state where these waveforms are combined. That is, a waveform that does not clearly show the adhesive state or the peeled state may appear. This occurs at a site where adhesion and peeling are mixed.
It was confirmed that such an ambiguous portion exists in the adjacent portion from the bonding portion to the peeling portion as a stage before complete peeling occurs. Such a portion has an important meaning as a pre-stage of the progress of peeling. In addition, it can be seen from such data that there is a correlation between the height of the peak and the progress of peeling. However, due to the conventional recognition of the data, the above inspection methods cannot analyze such information, and the data cannot be analyzed.
The detected value is processed from the quantified data as either adhesion or peeling.

Therefore, the above-mentioned ambiguous area, so-called gray zone, was cleared as either black or white, and accurate evaluation of the material could not be performed in this regard. this is,
It abandons continuous analysis from complete close contact to the peeled state, which is a factor that has significantly reduced the determination accuracy.

 An object of the present invention is to solve the above problems.

<Means for Solving the Problems> Therefore, the present invention solves the above problems by providing the following means.

According to a first aspect of the present invention, a reflected wave of an ultrasonic wave emitted from an ultrasonic probe toward the inside of a test material is received and is used as an RF signal, and the maximum value of the positive peak of the RF signal and the RF The absolute value of the negative peak of the signal is detected, and the sum of the maximum value of the positive peak and the absolute value of the negative peak is calculated.
The ratio of either the maximum value of the positive peak or the absolute value of the negative peak is calculated, and the relationship between the two types of data using the sum value and the ratio value as independent parameters is displayed in a C scope. This provides an ultrasonic inspection method for inspecting the presence or absence of peeling of the above-mentioned joint.

According to a second aspect of the present invention, a reflected wave of an ultrasonic wave emitted from an ultrasonic probe toward the inside of a test material is received and an RF signal is generated. In the ultrasonic inspection method for inspecting the presence or absence of peeling of the part, the maximum value of the positive peak of the RF signal and the absolute value of the negative peak of the RF signal are detected, and the maximum value of the positive peak and the negative peak are detected. Is calculated, and the ratio of the sum value to either the maximum value of the positive peak or the absolute value of the negative peak is calculated, and one axis indicates the value of the sum and The color of the coordinate position specified by the value of the sum and the value of the ratio using plane coordinates in which each other axis shows the value of the ratio and each region has a different color, hue, or brightness in continuous tone. Or plot the hue or brightness on the corresponding C scope plane To provide an ultrasonic inspection method, wherein those forming the C scope display Te.

According to a third aspect of the present invention, there is provided a probe that emits an ultrasonic wave toward the inside of a test material, a pulser that transmits a pulse signal for generating an ultrasonic wave to the probe, A receiver that receives the reflected wave of the ultrasonic wave and generates an RF signal corresponding thereto, and a display unit that displays data of the RF signal, and displays a defect inside the test material with the display unit. In the ultrasonic inspection apparatus to perform the above RF
A positive detection circuit for detecting the maximum value of the positive peak of the signal,
A negative-side detection circuit that detects a negative peak absolute value of the RF signal, and an addition unit that adds the maximum value of the positive peak and the absolute value of the negative peak of the RF signal detected by each of the detection circuits, Dividing means for calculating a ratio between the sum and the maximum value of the positive peak or the absolute value of the negative peak, and the display means displays the ratio value and the sum value respectively. There is provided an ultrasonic inspection apparatus characterized in that the relationship between two types of data as independent parameters is plotted on a C scope plane and displayed on a C scope.

According to a fourth aspect of the present invention, there is provided a probe that emits an ultrasonic wave toward the inside of a test material, a pulser that transmits a pulse signal for generating an ultrasonic wave to the probe, A receiver that receives the reflected wave of the ultrasonic wave and generates an RF signal corresponding thereto, and a display unit that displays data of the RF signal, and displays a defect inside the test material with the display unit. In the ultrasonic inspection apparatus, the probe has a wide band, a positive detection circuit for detecting a maximum value of a positive peak of the RF signal, and an absolute value of a negative peak of the RF signal. A detection circuit for detecting the negative peak, an addition means for adding the maximum value of the positive peak and the absolute value of the negative peak of the RF signal detected by each of the detection circuits, and the added value, the positive peak Ratio of either the maximum value of the peak value or the absolute value of the negative peak Division means for calculating, and one axis has plane coordinates indicating the value of the sum and another axis crossing the axis has the value of the ratio, and each area of the coordinates has a different color, hue, or brightness in continuous tone. The display means plots data on a C-scope plane using the color, hue, or lightness of the coordinate position of the color chart determined by the sum value and the ratio value, and displays the C-scope. An ultrasonic inspection apparatus is provided.

<Operation> The present invention having the above means exerts the following effects.

In the first invention, the amplitude of the waveform is calculated by adding the maximum value of the detected peak of the RF signal and the absolute value of the negative peak of the RF signal, and furthermore, the positive peak or the negative peak with respect to the added value is calculated. It is possible to calculate the direction of the polarity by calculating the peak value (divided value) of the peak value of. Then, by displaying the relationship between the two types of data using the value of the sum and the value of the ratio as independent parameters, as a C scope, it is possible to continuously analyze the joint interface of the test material. .

In the second invention, the C-scope display can be performed with continuous tone colors or the like.

In the third invention, the sum of the maximum positive peak value and the absolute value of the negative peak of the RF signal sent from each detection circuit is added by the adding means, and the positive peak value or the positive peak value with respect to the sum value is added. The ratio to any of the negative peak values is calculated by the dividing means. Then, the relationship between the two types of data having the sum value (addition value) and the ratio value (division value) as independent parameters is displayed on the C scope by the display means,
The C scope display enables continuous analysis at the joint interface of the test material, and quantitative evaluation of the test material can be easily performed.

In the fourth invention, the above C scope display is
It is possible to make a continuous tone color.

<Example> A preferred example of the present invention will be described below with reference to the drawings.

First, the present invention focuses on the point that mechanical damping changes in the process of transitioning from the bonded state to the separated state at the bonding boundary, and by using a broadband pulse using a broadband probe, Since the echo is affected by the damping change, the correlation between the mechanical interlayer coupling strength and the damping change of the echo is incorporated into the data processing to visualize the pseudo intensity distribution.

 FIG. 1 shows an embodiment of the present invention.

(1) is a high-frequency flaw detector having an ultrasonic probe,
(2) is a scanning mechanism for moving the probe relative to the test material. The scanning mechanism (2) is controlled by a mechanism controller (3).

The high-frequency flaw detector (1) sends data obtained from the probe to the calculation unit (4). The operation unit (4) controls the controller (3) to control the mechanism unit to scan the probe to an appropriate part of the material. The automatic control (scanning) of the probe is performed by the system of the arithmetic unit (4) → the mechanical unit controller (3) → the scanning unit (2) → the high frequency flaw detector (1).

The data obtained by the operation unit (4) is stored in the hard disk (5) as needed. If unnecessary, the hard disk (5) may be provided without providing.

The operation unit (4) is connected to the display (6),
The C scope display can be performed in real time. This video can be hard copied by a video printer (7).

Even if an oscilloscope (8) is connected to the high-frequency flaw detector (1) to obtain an A-scope display, it is effective for ensuring the evaluation.

When a narrow-band probe is used as a probe, it can be estimated that a certain kind of acoustic filter acts due to a unique and discontinuous damping characteristic at an incomplete joint. The echo is significantly attenuated by the filtering effect of the boundary. For this reason, it is extremely difficult to detect an incomplete connection boundary. When an ultrasonic pulse generated by a broadband probe is incident on an incompletely coupled portion, a large echo is obtained while exhibiting a narrow band characteristic due to a damping characteristic of the incompletely coupled portion. Therefore, if processing is performed using a broadband probe in the present application, this portion can be recognized, and the reliability of the peeling inspection can be improved and the inspection time can be shortened.

Here, broadband means that the RF waveform is around 1.5 lambda,
It should be at least 2.5 lambda or less and the -6db frequency band should be 50% or more of the center frequency.

The high-frequency flaw detector (1) includes the above-described probe that emits ultrasonic waves toward the test material via water, and the probe is scanned by the scanning mechanism groove (2) as described above. Are sequentially scanned.

The high-frequency flaw detector (1) includes a pulsar for transmitting a pulse signal for generating ultrasonic waves to the probe, and a receiver for receiving a reflected wave of the ultrasonic waves from the test material and generating an RF signal corresponding thereto. And

Further, in the middle of the system from the high-frequency flaw detector (1) or the high-frequency flaw detector (1) to a display (6) which is one of display means (the other display means is the above-described video printer (7)). 2 has a configuration shown in FIG.

More specifically, an amplifier (9) for amplifying a received signal obtained by the high-frequency flaw detector (1) and an RF input from the receiver
Extracting only the reflected wave from the inspection part of the signal
A gate circuit (10) is provided to open and pass the RF signal for a predetermined time after a predetermined delay time. A gate circuit (10) for detecting only a positive waveform of the RF signal passing through the gate circuit (10);
It is short-circuited to a negative detection circuit (12) that detects only the negative waveform of the RF signal that has passed through the gate circuit (10). The positive and negative waveform signals obtained here are sent to respective A / D conversion circuits (AD conversion circuits) (13) and (14), where they are digitally processed and the maximum value (P) (P) ( N)
Detected by the A / D conversion circuits (13) and (14). The maximum values (P) and (N) of the positive and negative peaks obtained here are sent to the matrix circuit (15). This matrix circuit (1
Necessary operations are performed in 5) or separately by setting a CPU (CPU: central processing unit) (4) '.

 That is, it indicates the echo intensity (amplitude).

 The value of A = P + N and the damping coefficient (polarity) are shown.

(Hereinafter, the description will be continued with the case where the numerator is P for the damping coefficient.)

Further, the above values are plotted as (A, D) in a graph showing the echo intensity (A) on the vertical axis and the damping coefficient (D) on the horizontal axis in the matrix circuit (15).

The A-D graph is image-processed by the image processing circuit (16) and displayed by the above-mentioned display means.

This matrix circuit (15) and image processing circuit (16)
Each data plotted can be quantitatively confirmed by the position on the graph obtained through the above, but if the hue of the image is displayed as being different depending on the plotted position, the data can be further easily understood. .

This is a matrix circuit (15) and an image processing circuit (1
A device corresponding to color graphics is prepared in 6), and the display (6) and the video printer (7) are configured for color.

In the configuration shown in FIG. 2, each device from the amplifier (9) and the gate circuit (10) to each of the A / D conversion circuits (13) and (14) is the high-frequency flaw detector (1) shown in FIG. The matrix circuit (15) and the image processing circuit (1
6) (and the CPU (4) ') may be provided in the calculation unit (4) of FIG. The CPU in the configuration of FIG.
(4) 'is synonymous with the operation unit (4) in FIG. 1, and the configuration (each device) in FIG. 2 is interposed as a separate system from the high-frequency flaw detector (1) to the display (6). It may be a thing.

As an example of the aforementioned color display, it is easy to confirm if different hues are displayed at each position (a), (b), (c), and (d) as shown in the graph of FIG.

In the matrix circuit (15), the positive side echo intensity (P) is set on the vertical axis, and the negative side echo intensity is set on the horizontal axis.
This is effective as a graph to be plotted. In this case, for example, as shown in FIG. 4, it is easy to confirm if the positions (a) '(b)' (c) '(d)' of each graph are displayed with different hues.

In the matrix display of FIG. 3, position (a) indicates a peeled state, and position (c) indicates a bonded state. The position (b) indicates that peeling is beginning. Position (d)
Indicates that there is no echo.

For example, if position (a) is displayed in red, position (b) is displayed in yellow, position (c) is displayed in blue, and position (d) is displayed in white,
Low echo height due to white, non-inverted echo with high damping due to blue, or glued, echo inverted with high damping, or peeling with red, echo with low damping due to yellow, starting to peel Can be confirmed.

Further, the above-mentioned damping coefficient (D) has a good linearity with respect to the inversion of the phase, regardless of the size of the waveform. (A) shows the reflection ability regardless of the damping characteristics.

In the case of color display, the hue, color, or brightness may change continuously, or an appropriate number of gradation display may be used. In this case, 5 to 8 gradations are appropriate. Needless to say, the present invention can be implemented with a higher or lower gradation.

It is also effective to use a matrix circuit (15) capable of performing the above-described color-coded plotting on the inspection site plane correspondence graph (X, Y).

The present invention relates to various composite materials (FRP, FRM, CRC, CR
M, laminated metal, various molded electronic parts, etc.), which are problems as structural defects, such as peeling, cracks, voids (adhesives, materials), etc. Flaw detection) is applied, and it is possible to express a pseudo intensity distribution in a completely coupled portion by performing arithmetic processing not only on the phase inversion region but also on the damping change in the in-phase region. By this processing, a good result can be obtained in understanding the distribution of the matrix and the reinforcing material such as the filler and the fiber in the composite material, and the internal distribution state (difference of the contained substance) of the planar composite structural material (electronic components such as semiconductors and capacitors).

<Effects> By implementing the present invention, it is possible to accurately display a low-quantity image display near the boundary with respect to a defect or the like of a material, and it is easy to confirm the image display.

In particular, it is possible to display in a continuous tone color or the like, and the inspection result can be handled as a map. Therefore, it is possible to accurately and quantitatively determine a defect of a material to the vicinity of the boundary without requiring skill.

 An apparatus capable of achieving the above effects can be provided.

This makes it possible to provide a device that can achieve the above-described effects, thereby making it possible to easily and surely confirm a previous stage of peeling / defect.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a main part thereof. FIG. 3 and FIG. 4 are matrix display graphs obtained by implementing the present invention. FIG. 5 is a voltage-time graph of a reflected wave showing the bonding state of the test material, and FIG. 6 is a voltage-time graph of a reflected wave showing the peeling state of the test material. (1) High frequency flaw detector, (4) Operation unit, (6)
…display.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiaki Matsumura 728 Hishie, Higashiosaka-shi, Osaka Inside the Osaka Office of Krautkramer Felster Co., Ltd. (72) Inventor Hisato Araki 5 Nishinakajima, Yodogawa-ku, Osaka-shi, Osaka No. 9-6, (56) References JP-A-62-174653 (JP, A) JP-A-58-213248 (JP, A) JP-A 1-248053 (JP, A) (58) Int.Cl. ⁶ , DB name) G01N 29/00-29/28

Claims (4)

(57) [Claims] An RF signal is received by receiving a reflected wave of an ultrasonic wave emitted from an ultrasonic probe toward the inside of a test material, and a maximum value of a positive peak of the RF signal and a negative value of the RF signal are received. The absolute value of the peak is detected, and the sum of the maximum value of the positive peak and the absolute value of the negative peak is calculated. The sum value and the maximum value of the positive peak or the absolute value of the negative peak are calculated. Calculating the ratio to any one of the above, and displaying the relationship between the two types of data using the sum value and the ratio value as independent parameters by C scope, thereby inspecting the presence or absence of peeling of the joint. Sonic inspection method. 2. An RF signal is received by receiving a reflected wave of an ultrasonic wave emitted from the ultrasonic probe toward the inside of the test material, and the data of the RF signal is displayed on a C scope to separate the joint. In the ultrasonic inspection method for inspecting the presence or absence of, the maximum value of the positive peak of the RF signal and the absolute value of the negative peak of the RF signal are detected, and the maximum value of the positive peak and the absolute value of the negative peak are detected. Is calculated, and the ratio between the sum value and either the maximum value of the positive peak or the absolute value of the negative peak is calculated, and one axis indicates the value of the sum and intersects with this axis. Axis indicates the value of the ratio, and each area uses plane coordinates having different colors, hues, or lightness in continuous tone, and the color or hue of the coordinate position specified by the value of the sum and the value of the ratio. The brightness is plotted on the corresponding C scope plane and Ultrasonic inspection method, wherein those forming the-loop display. 3. A probe for emitting ultrasonic waves toward the inside of a test material, a pulser for transmitting a pulse signal for generating ultrasonic waves to the probe, and the ultrasonic wave from the test material. A receiver that receives a reflected wave of a sound wave and generates an RF signal according to the received signal, and a display unit that displays data of the RF signal, wherein the display unit displays a defect inside the test material. In one ultrasonic inspection apparatus, a positive detection circuit that detects the maximum value of the positive peak of the RF signal, a negative detection circuit that detects the negative peak absolute value of the RF signal, and detection by each of the detection circuits Adding means for adding the maximum value of the positive peak and the absolute value of the negative peak of the obtained RF signal; and this added value and one of the maximum value of the positive peak or the absolute value of the negative peak. Dividing means for calculating the ratio of An ultrasonic inspection apparatus characterized in that a relationship between two types of data having the ratio value and the sum value as independent parameters is plotted on a C scope plane and displayed on a C scope. 4. A probe for emitting ultrasonic waves toward the inside of a test material, a pulser for transmitting a pulse signal for generating ultrasonic waves to the probe, and the ultrasonic wave from the test material. A receiver that receives a reflected wave of a sound wave and generates an RF signal according to the received signal, and a display unit that displays data of the RF signal, wherein the display unit displays a defect inside the test material. In one ultrasonic inspection apparatus, the probe is of a wide band, and a positive detection circuit that detects a maximum value of a positive peak of the RF signal, and detects an absolute value of a negative peak of the RF signal. A negative-side detection circuit; addition means for adding the maximum value of the positive peak and the absolute value of the negative peak of the RF signal detected by each of the detection circuits; and the addition value and the maximum value of the positive peak Or calculate the ratio to either absolute value of the negative peak A division means and a color in which one axis has the above sum value and another axis crossing this axis has planar coordinates showing the above ratio value, and each area of the coordinates has a different color or hue or brightness in continuous tone. And a display means for plotting data on a C-scope plane by using a color, a hue, or a lightness of a coordinate position of the color chart determined by the sum value and the ratio value, and displaying the C-scope display. An ultrasonic inspection apparatus, characterized in that: