KR20210079777A - Apparatus for metal crack detection using electromagnetic wave and cutoff cavity probe - Google Patents

Abstract

The present invention relates to a conductor crack detection device and a crack detection method using electromagnetic waves and a blocking cavity probe.
According to the present invention, there is provided an apparatus for detecting a crack in a conductor using an electromagnetic wave and a blocking cavity probe, comprising an opening for contacting a conductor plate and measuring whether the conductor plate is cracked, a blocking cavity probe coupled to the blocking cavity probe and electromagnetic wave An electromagnetic wave signal generator for generating an electromagnetic wave signal generator, a variable reactance for adjusting the electromagnetic field distribution in the blocking cavity probe, a variable resistor for adjusting the sensitivity of the blocking cavity probe by changing a resistance value of the blocking cavity probe, a current flowing in the blocking cavity probe A meter for measuring , a control unit that measures the amount of current when a conductive plate without cracks is contacted while varying the variable reactance, and obtains a reference current value using the change amount of the measured current, and the reference current is used and a crack determination unit for judging whether the conductor plate corresponding to the measurement target is cracked.

Description

Conductor crack detection device using electromagnetic wave and blocking cavity probe {APPARATUS FOR METAL CRACK DETECTION USING ELECTROMAGNETIC WAVE AND CUTOFF CAVITY PROBE}

The present invention relates to a conductor crack detection device using an electromagnetic wave and a blocking cavity probe, and to a conductor crack detection device using an electromagnetic wave and a blocking cavity probe that measures a reference current value and detects a crack in a conductor using the measured reference current value it's about

Non-Destructive Inspection (NDI: Non Destructive Inspection, NDT: Non Destructive Testing) is a technology that detects objects without destroying surface or internal scratches or defects of mechanical parts or structures. The inspection of the degree of corrosion inside the pipe is also included in the non-destructive inspection. There are several types of defects, and they are broadly classified into 7 types as follows. In other words, it is classified into Dent (dent, dent, dent), Nick (V-shaped groove), Notch (notch), Scratch (scratches, marks, scratches), Crack (cracks), Void (bubbles, etc.) can do.

The main purposes of non-destructive testing are (1) to ensure reliability, (2) to reduce costs, and (3) to promote improvement in manufacturing technology. Reliability is expressed as a number called reliability, and reliability is expressed as a satisfactory (possible) probability of a desired performance within a certain period of time. When 100% is taken as the upper limit, reliability is expressed as "actual uptime/expected uptime". Cost reduction referred to here is cost reduction for the purpose of avoiding economic losses due to unusable equipment or equipment due to unexpected failure and various losses due to accidents caused by this.

Non-destructive testing methods used to measure microcracks in metals are VT (Visual Testing), RT (Radiographic Testing), UT (Ultrasonic Testing), ET (Eddy Current Testing, Eddy Current Testing) test), MT (Magnetic Particle Testing), AT (Acoustic Emission), SM (Stress Measurement), PT (Penetrant Testing), IRT (Infrared Ray Testing, Thermography Test) and Near Infrared Spectroscopy.

However, this method is a method of detecting a surface defect of a conductor by injecting radiation and ultrasonic waves into the defect target, flowing a current to a metal surface, or applying magnetism, and thus measurement may not be possible depending on the environment.

In addition, since the general crack detection method using electromagnetic waves depends on the frequency used for the detectable crack width, a very high frequency must be used to detect hairline cracks, and the size of the waveguide probe is also very small, so handling is difficult and blocking The existing method using a cavity probe also has a disadvantage in that the sensitivity for measuring cracks is not sensitive because the reference current value is fixed to a minimum value or a maximum value and used.

Therefore, in order to improve the measurement sensitivity, a technique for detecting cracks in the conductor plate with better sensitivity by acquiring a region in which the change slope of the reference current value is rapidly changed is required.

The technology that is the background of the present invention is disclosed in Republic of Korea Patent Registration No. 10-1916411 (2019.01.30. Announcement).

The technical problem to be achieved by the present invention relates to a conductor crack detection device using an electromagnetic wave and a blocking cavity probe, and an electromagnetic wave and blocking cavity probe for measuring a reference current value and detecting a crack in a conductor using the measured reference current value To provide a conductor crack detection device.

According to an embodiment of the present invention for achieving this technical problem, in a conductor crack detection device using electromagnetic waves and a blocking cavity probe, the blocking cavity probe includes an opening for contacting the conductor plate and measuring whether the conductor plate is cracked. , an electromagnetic wave signal generator coupled to the blocking cavity probe and generating an electromagnetic wave, a variable reactance for adjusting an electromagnetic field distribution in the blocking cavity probe, a variable for adjusting the sensitivity of the blocking cavity probe by changing a resistance value of the blocking cavity probe A resistor, a meter for measuring the current flowing in the blocking cavity probe, and measuring the amount of current indicated to the meter when a conductor plate without cracks is contacted while varying the variable reactance, and using the change amount of the measured current to measure the reference current A control unit for acquiring a value, and a crack determination unit for determining whether the conductor plate corresponding to the measurement target is cracked by using the reference current.

The blocking cavity probe may be implemented in any one of a rectangular shape, a square shape, a circular shape, and an oval shape.

The control unit may adjust the value of the variable reactance to obtain a first reactance value at a point at which the current becomes a minimum value and a second reactance value at a point at which the current becomes a maximum value, respectively.

The controller may measure a slope with respect to the change amount of the current between a point at which the current becomes a minimum value and a point at which the current becomes a maximum value, and set a current value at a point where the slope is greatest as the reference current value.

If the third reactance value corresponding to the current value at the point where the slope is greatest is less than a fourth reactance value that is an intermediate value between the first reactance value and the second reactance value, the slope of the change amount of the current is the second extracts a fifth reactance value at a point large by , and if the fifth reactance value is greater than the third reactance value, a current value corresponding to the fifth reactance is set as a reference current value, and the fifth reactance value is the second reactance value If it is less than or equal to the 3 reactance value, the current value corresponding to the third reactance may be set as the reference current value.

The crack determination unit may determine that there is no crack in the conductor plate when the measured current is equal to the reference current, and determine that there is a crack in the conductor plate when the measured current is greater than or less than the reference current have.

As described above, according to the present invention, since the crack of the conductor plate is measured by setting the current value at the point where the slope of the change amount of current is large as the optimal reference value, the method of detecting cracks in the conductor plate using the existing minimum or maximum value. It is possible to detect cracks in the conductor plate with higher sensitivity and accuracy.

1 is a block diagram showing the configuration of a conductor crack detection apparatus according to an embodiment of the present invention.
2 is a view for explaining a conductor crack detection apparatus according to an embodiment of the present invention.
3 is a top view showing a top surface of a blocking cavity probe according to an embodiment of the present invention.
4 is a rear view showing the rear surface of the blocking cavity probe according to an embodiment of the present invention.
5 is a view showing a state in which the conductor crack detection apparatus according to an embodiment of the present invention measures a conductor plate without cracks.
6A to 6C are diagrams for explaining a set reference current value according to an embodiment of the present invention.
7 is a view showing a state in which the conductor crack detection apparatus according to an embodiment of the present invention measures a conductor plate corresponding to a measurement target.
8 is a view showing a current value measured by moving a conductor crack detection device on a conductor plate corresponding to a measurement target according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

Then, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them.

1 is a block diagram showing the configuration of a conductor crack detection apparatus according to an embodiment of the present invention, and FIG. 2 is a view for explaining a conductor crack detection apparatus according to an embodiment of the present invention.

As shown in FIG. 1 , the conductor crack detection apparatus 100 according to an embodiment of the present invention includes a blocking cavity probe 110 , an electromagnetic wave signal generator 120 , a variable reactance 130 , a variable resistor 140 , and a meter 150 . ), a control unit 160 and a crack determination unit 170 .

That is, as shown in FIG. 2 , the conductor crack detection apparatus 100 includes an electromagnetic wave signal generator 120 , a variable reactance 130 , a variable resistor 140 , a meter 150 , and a control unit 160 to the blocking cavity probe 110 . ) and the crack determination unit 170 are connected.

Here, the variable reactance 130 may use a coaxial line with a variable length.

In addition, the blocking cavity probe 110 includes an opening for contacting the conductor plate.

3 is a top view showing a top surface of the blocking cavity probe according to an embodiment of the present invention, and FIG. 4 is a rear view showing the rear surface of the blocking cavity probe according to an embodiment of the present invention.

That is, as shown in FIGS. 3 and 4 , the blocking cavity probe 110 has an electromagnetic wave signal generator 120 , a variable reactance 130 , a variable resistor 140 , a meter 150 , and a control unit 160 on the upper surface and the rear surface. And a part for connecting the crack determination unit 170 is installed.

Although the shape of the blocking cavity probe 110 is expressed as a rectangle in FIG. 3 , the shape of the blocking cavity probe 110 may be implemented in any one of a rectangular shape, a square shape, a circular shape, and an oval shape.

Next, the electromagnetic wave signal generator 120 is coupled to the blocking cavity probe 110 and generates an electromagnetic wave.

Then, the variable reactance 140 is coupled to the blocking cavity probe 110 and adjusts the electromagnetic field distribution in the blocking cavity probe 110 .

Next, the variable resistor 150 is coupled to the blocking cavity probe and adjusts the sensitivity of the blocking cavity probe by changing the resistance value.

In addition, the meter 150 is attached to the blocking cavity probe 110 to measure a current value flowing in the blocking cavity probe 110 .

In addition, as shown in FIG. 2 , the meter 150 measures any one of a current or a voltage flowing inside the blocking cavity probe 110 .

Next, the control unit 160 measures the amount of current flowing inside the blocking cavity probe when the conductive plate without cracks is touched while varying the variable reactance 140 , and the reference current value is obtained using the change amount of the measured current. acquire

Then, the crack determination unit 170 determines whether the conductor plate corresponding to the measurement target is cracked by using the reference current.

That is, the crack determination unit 170 determines that there is a crack in the conductor plate when a current exceeding the error range is measured _{in the reference current value (I 0 ).}

Here, the error range may be set by the sensitivity of the conductor crack detection apparatus 100, and may be adjusted by the user's selection.

5 is a diagram illustrating a state in which the conductor crack detection apparatus according to an embodiment of the present invention measures a reference current value in a state in which a conductor plate without cracks is in contact.

As shown in FIG. 5 , the user brings the conductor crack detection device 100 into contact with a conductor plate in which cracks do not exist.

In addition, the user adjusts the variable reactance 130 in a state in which the conductor crack detection device 100 is brought into contact with the conductor plate in which cracks do not exist.

Here, the user adjusts the variable reactance 130 in order to obtain a current flowing in the inside of the blocking cavity probe as a reference current in the conductor plate without cracks.

6A to 6C are diagrams for explaining a set reference current value according to an embodiment of the present invention.

That is, as shown in FIGS. 6A to 6C , the value of the measured current is changed according to the change of the reactance value.

Then, the controller 160 sets the reactance value at the point where the value of the current is the minimum as shown in FIG. 6A as the first reactance value, and sets the reactance value at the point where the value of the current becomes the maximum as the second reactance value. .

Then, the controller 160 measures the slope of the change amount of the current according to each reactance value between the first reactance value and the second reactance value.

Then, as shown in FIG. 6A , the controller 160 sets the current value at the point having the largest slope value as the reference current value, and sets the reactance value at the point having the largest slope value as the third reactance value.

Also, as shown in FIG. 6B , when the third reactance value is smaller than the fourth reactance value, the controller 160 extracts the fifth reactance value at the point where the slope of the change amount of the current is the second largest.

Here, the fourth reactance value is an intermediate value between the first reactance value and the second reactance value. That is, when the first reactance value is 40 (Ω) and the second reactance value is 50 (Ω), the fourth reactance value is 45 (Ω).

And, as shown in FIG. 6B , when the fifth reactance value is less than or equal to the third reactance value, the controller 160 sets the current value corresponding to the third reactance as the reference current value.

On the other hand, as shown in FIG. 6C , when the fifth reactance value is greater than the third reactance value, the controller 160 sets the current value corresponding to the fifth reactance as the reference current value.

That is, the controller 160 determines the third reactance value as the noise value and sets the fifth reactance value as the reference current value.

Also, as shown in FIG. 6A , when the controller 160 selects the vicinity of the second reactance value, the controller 160 may set the current value at a point where the slope of the current change amount is large as the reference current value.

7 is a view showing a state in which the conductor crack detection apparatus according to an embodiment of the present invention measures a conductor plate corresponding to a measurement target, and FIG. 8 is a view showing a conductor on a conductor plate corresponding to a measurement target according to an embodiment of the present invention. It is a diagram showing the value of the current measured by moving the crack detection device.

Then, as shown in FIG. 7 , the user brings the conductor crack detection device 100 into contact with the conductor plate corresponding to the measurement target.

Then, the user measures the current value while moving the conductor crack detection apparatus 100 in contact with the conductor plate corresponding to the measurement target.

Then, as shown in FIG. 8 , when the current value measured from the conductor plate corresponding to the measurement target is measured as the reference current value, the conductor crack detection apparatus 100 determines that there is no crack at the corresponding point.

In addition, as shown in FIG. 8 , when the current value measured from the conductor plate corresponding to the measurement target is greater than or smaller than the reference current value, the conductor crack detection apparatus 100 determines that there is a crack at the corresponding point.

As described above, according to the embodiment of the present invention, since the crack of the conductor plate is measured by setting the current value at the point where the slope of the change amount of current is large as the optimal reference value, the crack of the conductor plate is prevented using the existing minimum or maximum value. It is possible to detect cracks in the conductor plate with higher sensitivity and accuracy than the detection method.

Although the present invention has been described with reference to the embodiment shown in the drawings, which is merely exemplary, those of ordinary skill in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: conductor crack detection device, 110: blocking cavity probe,
120: electromagnetic signal generator, 130: variable reactance,
140: potentiometer, 150: meter,
160: control unit, 170: crack determination unit

Claims (6)

In the conductor crack detection device using electromagnetic wave and blocking cavity probe,
a blocking cavity probe comprising an opening for contacting the conductor plate and for measuring whether the conductor plate is cracked;
an electromagnetic wave signal generator coupled to the blocking cavity probe and generating an electromagnetic wave;
variable reactance to adjust the electromagnetic field distribution within the blocking cavity probe;
a variable resistor for adjusting the sensitivity of the blocking cavity probe by changing a resistance value of the blocking cavity probe;
a meter for measuring the current flowing in the blocking cavity probe;
A control unit that measures the amount of current when the conductor plate without cracks is brought into contact while varying the variable reactance, and obtains a reference current value using the change amount of the measured current; and
and a crack determination unit for determining whether a conductor plate corresponding to a measurement target is cracked by using the reference current. According to claim 1,
The blocking cavity probe is
A conductor crack detection device implemented in any one of rectangular, square, circular and oval shapes. 3. The method of claim 2,
The control unit is
A conductor crack detection device for obtaining a first reactance value at a point where the current becomes a minimum value and a second reactance value at a point where the current becomes a maximum value by adjusting the value of the variable reactance, respectively. 4. The method of claim 3,
The control unit is
Conductor crack detection apparatus for measuring the slope of the change amount of the current between the point at which the current becomes the minimum value and the point at which the current becomes the maximum value, and sets the current value at the point where the slope is the largest as the reference current value. 5. The method of claim 4,
The control unit is
If the third reactance value corresponding to the current value at the point where the slope is the largest is less than the fourth reactance value that is the middle value between the first reactance value and the second reactance value, the slope of the change amount of the current is the second largest point. extract the fifth reactance value of
If the fifth reactance value is greater than the third reactance value, a current value corresponding to the fifth reactance is set as a reference current value, and if the fifth reactance value is less than or equal to the third reactance value, it corresponds to the third reactance Conductor crack detection device that sets the current value to the reference current value. 5. The method of claim 4,
The crack determination unit,
If the measured current is equal to the reference current, it is determined that there is no crack in the conductor plate, and when the measured current is greater than or less than the reference current, it is determined that there is a crack in the conductor plate.

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