KR101403216B1 - Apparatus and method of detecting surface defect of wire rod using ultrasonic wave - Google Patents

Abstract

An apparatus and a method for detecting surface defects of a circular wire using ultrasonic waves are provided. The surface defect detecting apparatus includes an ultrasonic sensor for receiving ultrasonic waves into a circular wire rod submerged in a certain medium and receiving reflected waves reflected by the circular wire material and reflecting the incident ultrasonic waves; And a control unit for detecting the position of the surface defect. The reflected wave is reflected by the first reflected wave which is reflected by the circular wire after the ultrasonic wave incident on the normal line perpendicular to the circumferential direction of the circular wire, The position of the surface defects of the circular wire can be detected by a simple method by including the ultrasonic wave incident on the wire material along the outer circumferential surface of the circular wire material and the second reflected wave reflected and reflected by the surface defect of the circular wire material.

Description

TECHNICAL FIELD [0001] The present invention relates to an apparatus and a method for detecting surface defects of a circular wire using ultrasonic waves,

The present invention is for detecting surface defects of a circular wire using ultrasonic waves.

In general, a visual inspection method, a leakage magnetic flux inspection method, a magnetic particle inspection method, and the like are used as methods for detecting defects of an inspection object.

The visual inspection method is a method of detecting defects of an inspection object from a photographed image using a CCD camera. However, in the case of a steel wire product, when there is a scale of a surface generated during cooling after the heat treatment, surface defects are obscured from the outside, and it is difficult to detect defects. Therefore, there is a problem that an additional process for removing the scale (scale) is required.

In the leaky magnetic flux detecting method, when the surface of the object to be inspected is normal, the magnetic flux of the surface is continuously formed in parallel with the surface. However, when a defect is generated on the surface, a leakage magnetic flux is generated in a direction perpendicular to the surface direction. By using a sensor, the surface defect is detected. Such leaky magnetic flux testing has excellent performance against defects (particularly, cracks) occurring on the surface or surface layer of the ferromagnetic metal. Particularly, the leaky magnetic flux detecting method is excellent in the ability to detect fine cracks even when the surface roughness is large. However, the cracking occurred in the same direction as the direction of the magnetic flux formed on the surface of the ferromagnetic body has weak detection capability, There is a problem that the leakage magnetic flux must be measured with respect to the entire surface of the object to be inspected by using the magnetic sensor in a state where the magnetic field is detected.

Magnetic particle testing is similar to the leaky magnetic flux method in that it forms a leakage magnetic flux at the defect site, but differs in that it injects a magnetic particle coated with a fluorescent substance to the object to accurately detect the leakage flux information. have. However, in the case of the magnetic particle test method, due to the limitation of the temperature characteristic of the fluorescent material, it is used when the temperature of the test object is generally 70 degrees or less, and further work such as magnetic particle injection and magnetic field formation of the test object is required There is a problem that it is difficult to grasp the existence of defects because the defects are adhered not only to the defects but also to the irregularities due to the roughness of the surface, and it is difficult to quantitatively determine the size of the defects.

The present invention provides an apparatus and method for detecting surface defects of a circular wire rod for detecting surface defects of a linear wire or a curved wire using ultrasonic waves.

According to the first aspect of the present invention, there is provided an ultrasonic diagnostic apparatus comprising: an ultrasonic sensor for receiving an ultrasonic wave into a circular wire rod submerged in a constant medium and receiving the reflected wave reflected by the circular wire rod after the incident ultrasonic wave is reflected; And a control unit for detecting a position of a surface defect of the circular wire based on a difference in reception time of the received reflected wave, wherein the reflected wave is transmitted to the circular wire through an ultrasonic wave incident on a normal line perpendicular to the circumferential direction of the circular wire, A first reflected wave that is reflected after being reflected by the first reflection wave; And a surface defect detection unit for detecting a surface defect of the circular wire including the second reflected wave reflected by the surface defect of the circular wire after the ultrasonic wave incident on the circular wire with an angle with the normal line moves along the outer circumferential surface of the circular wire, Device.

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According to the embodiment of the present invention, the control unit can calculate the position of the surface defect based on the time difference between the radius of the circular wire and the reception time of the first reflected wave and the reception time of the second reflected wave.

According to the embodiment of the present invention, the surface defect detection apparatus may further include a driving unit that moves the ultrasonic sensor along the axial direction of the circular wire.

According to an embodiment of the present invention, the constant medium may include water.

According to the embodiment of the present invention, the circular wire material may include a linear shape or a curved shape.

According to the embodiment of the present invention, the predetermined angle may be an angle of incidence such that the refraction angle of the ultrasonic wave incident on the circular wire becomes 90 degrees.

According to the embodiment of the present invention, the second reflected wave may include a reflected wave that is reflected in the clockwise direction along the outer peripheral surface of the circular wire after being reflected by the surface defect, and a reflected wave that is returned in the counterclockwise direction.

According to a second aspect of the present invention, there is provided a method of detecting an ultrasonic wave, the method comprising: a first step of causing an ultrasonic sensor to receive an ultrasonic wave into a circular wire rod submerged in a constant medium, the reflected ultrasonic wave being reflected by the circular wire; And a second step of detecting a position of a surface defect of the circular wire on the basis of a reception time difference of the received reflected wave in the control unit, wherein the reflected wave is transmitted to the circular wire through ultrasonic waves incident on a normal line perpendicular to the circumferential direction of the circular wire A first reflected wave that is reflected after being reflected by the circular wire; And a surface defect detection unit for detecting a surface defect of the circular wire including the second reflected wave reflected by the surface defect of the circular wire after the ultrasonic wave incident on the circular wire with an angle with the normal line moves along the outer circumferential surface of the circular wire, Method is provided.

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According to the embodiment of the present invention, the second step includes a step of calculating the position of the surface defect based on the time difference between the radius of the circular wire and the reception time of the first reflected wave and the reception time of the second reflected wave .

According to the embodiment of the present invention, the surface defect detecting method may further comprise moving the ultrasonic sensor along the axial direction of the circular wire in the driving unit.

According to an embodiment of the present invention, the constant medium may include water.

According to the embodiment of the present invention, the circular wire material may include a linear shape or a curved shape.

According to the embodiment of the present invention, the predetermined angle may be an angle of incidence such that the refraction angle of the ultrasonic wave incident on the circular wire becomes 90 degrees.

According to the embodiment of the present invention, the second reflected wave may include a reflected wave that is reflected in the clockwise direction along the outer peripheral surface of the circular wire after being reflected by the surface defect, and a reflected wave that is returned in the counterclockwise direction.

According to one embodiment of the present invention, ultrasonic waves are incident on a circular wire rod that is locked to a certain medium, and the position of the surface defects of the circular wire rod is detected based on the reception time difference of the reflected wave reflected by the circular wire rod .

FIG. 1A is an overall configuration diagram of a surface defect detecting apparatus for a circular wire using ultrasonic waves according to an embodiment of the present invention,
FIG. 1B is a view of the surface defect detecting device of FIG. 1A viewed in the axial direction (Z direction) of the circular wire.
2 is a view for explaining ultrasonic waves incident on a circular wire according to an embodiment of the present invention.
Figs. 3A to 3E are views for explaining reflected waves received by time according to an embodiment of the present invention. Fig.
4 is a view for explaining a process of detecting the position of a surface defect from the received first reflected wave and second reflected wave according to an embodiment of the present invention.
5 is a flowchart for explaining a surface defect detection method of a circular wire using ultrasonic waves according to an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. The shape and the size of the elements in the drawings may be exaggerated for clarity and the same elements are denoted by the same reference numerals in the drawings.

FIG. 1A is an overall configuration diagram of a surface defect detecting apparatus for a circular wire using an ultrasonic wave according to an embodiment of the present invention. FIG. 1B is a view showing the surface defect detecting apparatus of FIG. 1A viewed in the axial direction (Z direction) to be. FIG. 2 is a view for explaining ultrasonic waves and reflected waves incident on a circular wire according to an embodiment of the present invention. FIGS. 3A to 3E are diagrams for explaining reflected waves received in time according to an embodiment of the present invention FIG. 4 is a view for explaining a process of detecting the position of surface defects from the received first reflected wave and second reflected wave according to an embodiment of the present invention.

1A and 1B, an apparatus for detecting a surface defect of a circular wire using an ultrasonic wave according to an embodiment of the present invention includes an ultrasonic wave W1 applied to a circular wire rod S immersed in a fixed medium 101, An ultrasonic sensor 120 for receiving the reflected ultrasonic wave W1 reflected by the circular wire rod S and returning the reflected wave W2 to the circular wire rod S based on the reception time difference of the received reflected wave W2, And a controller 140 for detecting the position of a surface defect DF of the surface defect DF.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a surface defect detecting apparatus for a circular wire using ultrasonic waves according to an embodiment of the present invention will be described in detail with reference to FIGS. 1A to 4. FIG.

First, referring to FIGS. 1A and 1B, the pulse generating unit 110 generates a pulse signal under the control of the controller 140 and applies the generated pulse signal to the ultrasonic sensor 120. FIG.

The ultrasonic sensor 120 causes the ultrasonic wave W1 to be incident on the surface of the circular wire rod S which is locked to a certain medium according to the pulse signal applied by the pulse generator 110. When the incident ultrasonic wave W1 passes through the circular wire rod S S to receive the reflected wave W2 that is reflected back. The above-described ultrasonic sensor 120 may include a non-focusing type ultrasonic sensor. The received reflected wave W2 may be transmitted to the signal processing unit 130. [

Here, the circular wire rod S may be immersed in a fixed medium 101 (e.g., water) filled in the case 100 as shown in FIG. 1B, and a part thereof may be immersed in a medium The ultrasonic sensor 120 is positioned and the ultrasonic wave W1 can be incident on the lower direction. That is, according to the embodiment of the present invention, the ultrasonic wave W1 is incident on the surface of the circular wire material S while the circular wire material S is submerged in water. The reason for doing this is that the ultrasonic wave passes through the air This is because ultrasonic waves can be incident on the wire by using a constant medium. Further, according to the embodiment of the present invention, the circular wire rod S may include a linear shape or a curved shape.

Hereinafter, the ultrasonic wave incident on the circular wire will be described in detail with reference to FIG.

As shown in FIGS. 1A and 2, the ultrasonic waves W1 are generated perpendicularly to the surface of the ultrasonic sensor 120, and are incident on the surface of the circular wire rod S. 2, in the case of the ultrasonic waves 211 and 212 incident on the surface of the circular wire rod S with the normal line NL perpendicular to the circumferential direction of the circular wire rod S and the critical angle c, And is then moved along the outer circumferential surface of the circular wire rod S. As will be described later, the ultrasonic waves 211 and 212 incident at the critical angle? C are reflected by the surface defects DF (hereinafter referred to as 'second reflected wave') and are uniformly distributed along the outer peripheral surface of the circular wire rod S And then the control unit 140 can detect the position of the surface defect DF of the circular wire rod S based on the reflected wave. Here, the critical angle? C is a specific angle for generating surface waves, and the angle of refraction is 90 degrees.

On the other hand, in the case of the ultrasonic waves 201 and 203 incident at incidence angles exceeding the critical angle? C, they are reflected to the outside of the circular wire rod S by the outer peripheral surface of the circular wire rod S.

In the case of the ultrasonic waves 202 incident at an incident angle less than the critical angle? C, the light is refracted inside the circular wire rod S, and is then reflected multiply inside the circular wire rod S, It can disappear.

However, in the case of the ultrasonic waves 213 incident on the normal line NL perpendicular to the circumferential direction of the circular wire rod S among the ultrasonic waves 202 incident at an incident angle less than the critical angle c, (Hereinafter, referred to as 'first reflected wave').

1A, the driving unit 150 may move the ultrasonic sensor 120 in the axial direction (D, Z) of the circular wire rod S under the control of the controller 140, It is possible to inspect the entire length of the circular wire rod S in the axial direction (D, Z).

On the other hand, the signal processing unit 130 performs signal processing on the reflected wave W2 received from the ultrasonic sensor 120. [ As an example of the signal processing, the reflected wave W2 can be amplified or converted into a digital signal. The signal-processed reflected wave W2 may be transmitted to the control unit 140. [ In this case, the reflected wave W2 transmitted from the ultrasonic sensor 120 may be directly transmitted to the controller 140. [0033] FIG.

Finally, the control unit 140 can detect the position of the surface defect DF of the circular wire rod S based on the difference in the reception time of the received reflected wave W2. More specifically, the control unit 140 calculates the position of the surface defect DF based on the radius of the circular wire S, the time difference between the reception time of the first reflected wave 213 and the reception time of the second reflected wave 211, .

3A to 3E are diagrams for explaining reflected waves received by time according to an embodiment of the present invention.

Ultrasonic waves are generated from the ultrasonic sensor 120 at a predetermined time T0, and the generated ultrasonic waves propagate to the circular wire rod S (see FIG. 3A).

In the case of the ultrasonic waves 213 incident on the normal line perpendicular to the circumferential direction of the circular wire S, the ultrasonic waves 213 are reflected by the circular wire S (hereinafter, referred to as first reflected wave) (See FIG. 3B).

On the other hand, in the case of the ultrasonic waves 211 and 212 incident on the surface of the circular wire rod S with a normal line perpendicular to the circumferential direction of the circular wire rod S and a critical angle? C, And then moves along the outer circumferential surface of the circular wire rod S (see Figs. 3C and 3D). It is reflected by the surface defect DF (hereinafter referred to as 'second reflected wave') and can be returned to the same path along the outer circumferential surface of the circular wire rod S. The second reflected wave may include a reflected wave 212 that is reflected in the clockwise direction along the outer circumferential surface of the circular wire rod S after being reflected by the surface defect DF and a reflected wave 211 that is returned in the counterclockwise direction.

In the case of the ultrasonic wave 212 incident on the side closer to the surface defect DF, as shown in Fig. 3C, in the case of the ultrasonic wave 211 moving on the short path and incident on the side farther from the surface defect DF, It is possible to move back a relatively long path as shown in Fig. Therefore, the ultrasonic wave 212 can be detected at the time T2 and the ultrasonic wave 211 can be detected at the time T4.

On the other hand, when the surface defect DF exists but the size thereof is too small, the ultrasonic waves can not be blocked. Therefore, as shown in FIG. 3E, the ultrasonic waves 211 and 212 can pass through the surface defect DF In this case, the reception time of the received reflected wave may be the time point T3 between the reception time (T2) of the ultrasonic wave (212) and the reception time (T4) of the ultrasonic wave (211). The reflected waves 211 and 212 transmitting the surface defect DF are signals unnecessary for detecting the position of the surface defect DF and can be removed.

Hereinafter, a concrete procedure for calculating the position of the surface defect (DF) in the controller 140 will be described in detail with reference to FIG.

As shown in FIGS. 1A, 3B, 3C, 3D and 4, the controller 140 calculates the radius R of the circular wire rod S, the reception time T1 of the first reflected wave, The position [theta] of the surface defect DF can be calculated based on the time difference [Delta] t between the reception times T2 and T4 according to the following expression (1). FIG. 4 shows the ultrasonic waves 212 incident on the side closer to the surface defect DF as a reference.

[Equation 1]

은 선재에서의 초음파 표면파의 속도,

는 물에서의 초음파 종파의 속도, R은 원형 선재의 반경, θ는 표면 결함(DF)의 각도, θc는 임계각일 수 있다. 각도 θ 및 θc의 단위는 라디안(radian)일 수 있다. Here,? T is a time difference between the reception time (T1) of the first reflected wave and the reception time (T2) of the second reflected wave,

The velocity of ultrasonic surface waves in the wire rod,

R is the radius of the circular wire,? Is the angle of the surface defects (DF), and? C is the critical angle. The units of the angles? And? C may be radians.

On the other hand, d1 and d2 can be calculated according to the following equation (2).

&Quot; (2) "

Here, d1 may be a difference between a straight path of the first reflected wave and a second reflected wave, d2 may be a curved path of the second reflected wave, R may be a radius of a circular wire, and? May be an angle of a surface defect (DF).

As described above, according to the embodiment of the present invention, ultrasonic waves are incident on a circular wire rod submerged in a certain medium, and the surface defects of the circular wire rod are detected based on the reception time difference of the reflected wave reflected by the circular wire rod, Can be detected.

5 is a flowchart for explaining a surface defect detection method of a circular wire using ultrasonic waves according to an embodiment of the present invention.

Hereinafter, a surface defect detection method of a circular wire using ultrasonic waves according to an embodiment of the present invention will be described with reference to FIGS. However, in order to simplify the invention, the description of the overlapping portions with respect to FIGS. 1A to 4 will be omitted.

1A to 5, the ultrasonic sensor 120 receives an ultrasonic wave W1 into a surface of a circular wire rod S which is locked to a certain medium according to a pulse signal applied by the pulse generator 110, The incident ultrasonic wave W1 is reflected by the circular wire rod S and can receive the reflected wave W2 (S501). The received reflected wave W2 may be transmitted to the control unit 140 through the signal processing unit 130. [

Next, based on the radius R of the circular wire rod S, the time difference DELTA t between the reception time T1 of the first reflected wave and the reception time T2, T4 of the second reflected wave, The position [theta] of the surface defect DF can be calculated according to Equation (1).

As described above, according to the embodiment of the present invention, ultrasonic waves are incident on a circular wire rod submerged in a certain medium, and the surface defects of the circular wire rod are detected based on the reception time difference of the reflected wave reflected by the circular wire rod, Can be detected.

The present invention is not limited to the above-described embodiments and the accompanying drawings. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It will be self-evident.

100: Case 101: Water
110: Pulse generator 120: Ultrasonic sensor
130: signal processor 140:
W1: Ultrasonic W2: Reflected wave
DF: Surface defect of circular wire S: Circular wire
D, Z: Axial direction of the circular wire?: Angle of incidence of ultrasonic waves
θc: critical angle NL: normal line perpendicular to the circumferential direction of the circular wire
R; Radius of circular wire

Claims (16)

An ultrasonic sensor for receiving an ultrasonic wave into a circular wire rod immersed in a constant medium and receiving the reflected wave reflected from the circular wire rod by the incident ultrasonic wave; And
And a control unit for detecting a position of a surface defect of the circular wire on the basis of a reception time difference of the received reflected wave,
The reflected wave,
A first reflected wave that returns after the ultrasonic wave incident on the normal line perpendicular to the circumferential direction of the circular wire is reflected by the circular wire; And
And a second reflected wave reflected by the surface defect of the circular wire after the ultrasonic wave incident on the circular wire with an angle to the normal line moves along the outer circumferential surface of the circular wire, .
delete The method according to claim 1,
Wherein,
And calculates the position of the surface defect based on a time difference between the radius of the circular wire and the reception time of the first reflected wave and the reception time of the second reflected wave.
The method according to claim 1,
The surface defect detecting apparatus includes:
And a driving unit for moving the ultrasonic sensor along the axial direction of the circular wire.
The method according to claim 1,
Wherein the constant medium includes water.
The method according to claim 1,
Wherein the circular wire includes a linear shape or a curved shape.
The method according to claim 1,
Wherein the predetermined angle is an incident angle such that a refraction angle of the ultrasonic wave incident on the circular wire becomes 90 degrees.
The method according to claim 1,
The second reflected wave is reflected by the first reflection wave,
And a reflected wave that is reflected in the clockwise direction along the outer circumferential surface of the circular wire after being reflected by the surface defect and a reflected wave that is returned in the counterclockwise direction.
A first step in which an ultrasonic wave is incident on a circular wire rod immersed in a constant medium in an ultrasonic sensor and the incident ultrasonic waves are reflected by the circular wire rod to receive a returning reflected wave; And
And a second step of detecting, at the control unit, the position of the surface defect of the circular wire on the basis of the reception time difference of the received reflected wave,
The reflected wave,
A first reflected wave that returns after the ultrasonic wave incident on the normal line perpendicular to the circumferential direction of the circular wire is reflected by the circular wire; And
And a second reflected wave which is reflected by the surface defect of the circular wire after the ultrasonic wave incident on the circular wire with a predetermined angle with the normal line moves along the outer circumferential surface of the circular wire, .
delete 10. The method of claim 9,
The second step comprises:
Calculating a position of the surface defect based on a time difference between the radius of the circular wire and the reception time of the first reflected wave and the reception time of the second reflected wave.
10. The method of claim 9,
The surface defect detection method includes:
And moving the ultrasonic sensor along the axial direction of the circular wire at the driving unit.
10. The method of claim 9,
Wherein the predetermined medium comprises water.
10. The method of claim 9,
Wherein the circular wire includes a linear shape or a curved shape.
10. The method of claim 9,
Wherein the predetermined angle is an incident angle such that a refraction angle of the ultrasonic wave incident on the circular wire becomes 90 degrees.
10. The method of claim 9,
The second reflected wave is reflected by the first reflection wave,
And a reflected wave that is reflected in the clockwise direction along the outer circumferential surface of the circular wire after being reflected by the surface defect and a reflected wave that is returned in the counterclockwise direction.

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