KR101891415B1 - Apparatus and method for inline inspection of welds - Google Patents

Abstract

The present invention relates to a defect detection system and method that can occur in a welded portion of a plate material or a pipe, and a defect detection system of the welded portion according to the first embodiment of the present invention is disposed on one side of a test object including a weld portion, A plurality of electromagnetic acoustic sensors provided on left and right sides of the welded portion, respectively; And a control unit for generating guided ultrasonic waves through the first electromagnetic acoustic sensor among the plurality of electromagnetic acoustic sensors and receiving the guided ultrasonic waves reflected by the welding unit from the plurality of second electromagnetic acoustic sensors to detect defects in the welded part . Each of the plurality of electromagnetic acoustic sensors includes a coil for generating the guided ultrasonic wave into the inspecting body, a coil for receiving the guided ultrasonic wave reflected and returned, and a magnet disposed on the upper portion of the coil, And a second meander coil arranged to face the first meander coil, wherein the induced ultrasound is applied to the first meander coil and the second meander coil of the first electromagnetic acoustic sensor, And is focused on the welding portion of the inspection object by a coil.

Description

[0001] APPARATUS AND METHOD FOR INLINE INSPECTION OF WELDS [0002]

FIELD OF THE INVENTION The present invention relates to a defect detection system and method that can occur in a weld of a plate or pipe.

Welding is widely applied as a technology for joining plate or pipe in all industries such as shipbuilding, petrochemical, power generation, and infrastructure.

However, since welding is locally bonded by atomic bonding of two sheets within a short time, defects may be caused by various external influences such as material, rod, electrode, and current. Therefore, it is required to develop an inspection apparatus which detects the defects of the welds, which deteriorates the durability of such structures and loses strength against the stresses of the joints.

Korean Patent Application No. 10-2011-0004393 (entitled " Nondestructive Ultrasonic Inspection Method and Detection System for Detecting Internal Defects in Semiconductor Materials ") discloses a method for detecting relative motion between a semiconductor material and a semiconductor material, Wherein the ultrasonic device emits ultrasonic waves toward the semiconductor material during the generation of relative motion between the side of the semiconductor material and the ultrasonic device, and at the same time, the ultrasonic-echo signal from the inside of the semiconductor material to the ultrasonic pulse, Discloses a non-destructive inspection method for detecting defects in a semiconductor material having a length and a cross-sectional area for inspecting a defect inside the semiconductor material from the entire bulk of the semiconductor material.

Korean Patent Publication No. 10-2011-0004393

Disclosure of Invention Technical Problem [8] The present invention provides a defect detection system and method that can be applied to a plate or pipe weld.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are not intended to limit the invention to the precise form disclosed. It can be understood.

According to a first aspect of the present invention, there is provided a defect detection system for a weld according to the first aspect of the present invention, which is disposed on one side of an inspection body including a weld portion, A plurality of electromagnetic acoustic sensors each provided on the right side; And a control unit for generating guided ultrasonic waves through the first electromagnetic acoustic sensor among the plurality of electromagnetic acoustic sensors and receiving the guided ultrasonic waves reflected by the welding unit from the plurality of second electromagnetic acoustic sensors to detect defects in the welded part . Each of the plurality of electromagnetic acoustic sensors includes a coil for generating the guided ultrasonic wave into the inspecting body, a coil for receiving the guided ultrasonic wave reflected and returned, and a magnet disposed on the upper portion of the coil, And a second meander coil arranged to face the first meander coil, wherein the induced ultrasound is applied to the first meander coil and the second meander coil of the first electromagnetic acoustic sensor, And is focused on the welding portion of the inspection object by a coil.

Further, a defect detection system of a weld according to a second embodiment of the present invention includes a first electromagnetic acoustic sensor, a second electromagnetic acoustic sensor, a third electromagnetic acoustic sensor, a fourth electromagnetic acoustic sensor, Sensor and the first electromagnetic acoustic sensor to generate an induced ultrasound wave and to receive the induced ultrasound reflected by the welded part from the second electromagnetic acoustic sensor, the third electromagnetic acoustic sensor, and the fourth electromagnetic acoustic sensor And detecting a defect of the welded portion. Each of the first to fourth electromagnetic acoustic sensors includes a coil for generating the guided ultrasonic wave into the inspecting body, a coil for receiving the guided ultrasonic wave reflected and returned, and a magnet disposed on the coil, Wherein the coil includes a first meander coil of a meandering shape and a second meander coil arranged to face the first meander coil, wherein the induced ultrasound is applied to the first meander coil of the first electromagnetic acoustic sensor, 2 meander coil to the welding portion of the inspection object.

Further, a first electromagnetic acoustic sensor, a second electromagnetic acoustic sensor, a third electromagnetic acoustic sensor, a fourth electromagnetic acoustic sensor, and a second electromagnetic acoustic sensor, which are disposed on one side of the inspection body including the welded portion according to the third embodiment of the present invention, And a second electromagnetic acoustic sensor that receives the induced ultrasound reflected by the welded portion from the second electromagnetic acoustic sensor, the third electromagnetic acoustic sensor, and the fourth electromagnetic acoustic sensor, The method comprising: a first step of the ultrasonic wave mode being selected by the control unit according to the material and the thickness of the inspection object; A second step of the control unit having the first electromagnetic acoustic sensor to focus the guided ultrasonic wave of the selected mode on the welding portion of the inspection object; And a third step of the controller receiving guided ultrasonic waves reflected by the welded portion of the inspection object from the second electromagnetic acoustic sensor, the third electromagnetic acoustic sensor, and the fourth electromagnetic acoustic sensor to detect defects do. Wherein each of the first to fourth electromagnetic acoustic sensors includes a coil for generating the guided ultrasonic wave into the inspecting body, receiving the guided ultrasonic wave reflected and returned, and a magnet disposed on the coil, Shaped first meander coil and a second meander coil arranged to face the first meander coil.

According to any one of the above-mentioned objects of the present invention, it is possible to provide a system capable of detecting defects that can occur in a welded portion of a plate material or a pipe, and a defect detection method of a welded portion.

It should be understood, however, that the effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those skilled in the art to which the present invention belongs It will be possible.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing the configuration of a defect detection system of a weld according to an embodiment of the present invention; FIG.
2 is a block diagram schematically showing the configuration of a defect detection system of a weld according to an embodiment of the present invention.
3 is a schematic view of an electromagnetic acoustic sensor according to an embodiment of the present invention.
4 is a view showing a coil included in an electromagnetic acoustic sensor according to an embodiment of the present invention.
5 is an enlarged view of a part of the coil shown in Fig.
6 illustrates the types of acoustic waves generated according to the excitation of an electromagnetic acoustic sensor according to an embodiment of the present invention.
FIG. 7 is a flowchart illustrating a defect detection method of a defect detection system of a weld according to an exemplary embodiment of the present invention. Referring to FIG.
FIG. 8 is a view for explaining a detailed transmission / reception path of guided ultrasonic waves generated in a welding defect detection system 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, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "including" an element, it is to be understood that the element may include other elements as well as other elements, And does not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

In this specification, the term " part " includes a unit realized by hardware, a unit realized by software, and a unit realized by using both. Further, one unit may be implemented using two or more hardware, or two or more units may be implemented by one hardware.

In this specification, some of the operations or functions described as being performed by the terminal or the device may be performed in the server connected to the terminal or the device instead. Similarly, some of the operations or functions described as being performed by the server may also be performed on a terminal or device connected to the server.

Welding is widely applied as a technology for joining plates or pipes in all industries such as shipbuilding, petrochemical, power generation, and infrastructure.

However, since welding is locally bonded by atomic bonding of two sheets within a short time, defects may be caused by various external influences such as material, rod, electrode, and current. Therefore, it is required to develop an inspection apparatus which detects the defects of the welds, which deteriorates the durability of such structures and loses strength against the stresses of the joints.

SUMMARY OF THE INVENTION The present invention provides a defect detection system and method for a welding portion of a plate or pipe.

Hereinafter, a welding defect detection system and method according to an embodiment of the present invention will be described in detail with reference to the drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing the configuration of a defect detection system of a weld according to an embodiment of the present invention; FIG.

2 is a block diagram schematically showing the configuration of a defect detection system of a weld according to an embodiment of the present invention.

Referring to FIG. 1, a defect detection system of a weld according to an embodiment of the present invention includes a plurality of electromagnetic acoustic sensors 100a, 100b1 to 100b3; 100.

A defect detection system of a weld according to an embodiment of the present invention may preferably include four electromagnetic acoustic sensors. More specifically, the four electromagnetic acoustic sensors may be disposed symmetrically on the left and right sides of the welded portion 70, as shown in Fig.

At this time, among the four electromagnetic acoustic sensors, the first electromagnetic acoustic sensor 100a can operate as an excitation sensor, and the remaining second electromagnetic acoustic sensor 100b1, the third electromagnetic acoustic sensor 100b2, (100b3) can operate as a receiving sensor.

At this time, each of the electromagnetic acoustic sensors 100 may generate guided ultrasonic waves to detect defects that may occur in the welded portion 70 of the plate material or the pipe, or may detect guided ultrasonic waves reflected and returned.

Each of the plurality of electromagnetic acoustic sensors 100 includes an excitation unit 140 and a receiving unit 150 and each excitation unit 140 and the receiving unit 150 includes a controller 200 ). ≪ / RTI > In addition, each exciter 140 may include a mode selector 142 to select the mode of the guided ultrasound applied to the inspector.

Specifically, the defect detection system of the weld according to an embodiment of the present invention can select the guided ultrasonic mode after first measuring the material and the thickness of the pipe or the plate material. At this time, the induced ultrasound excited can be a surface wave or a LAMB wave (Lamb wave).

Meanwhile, although not shown, the defect detection system of the weld according to the embodiment of the present invention may further include an input device capable of receiving the material and the thickness of the pipe or the plate material from the user.

Accordingly, the control unit 200 can automatically select the guided ultrasonic mode considering the material and thickness of the pipe or plate input from the user and the exciting frequency to be applied to the electromagnetic acoustic sensor 100. At this time, the excitation frequency may be about 500 KHz to 5 MHz, but is not limited thereto.

In other words, in the defect detection system of the weld according to the embodiment of the present invention, the plurality of electromagnetic acoustic sensors 100 each include the excitation unit 140 and the receiving unit 150, It can operate as a receiving sensor.

Therefore, the controller 200 can generate the guided ultrasonic wave by controlling the excitation unit 140 of the electromagnetic acoustic sensor 100 operating as the excitation sensor, and can generate the guided ultrasonic wave by using the induction received from the electromagnetic acoustic sensor 100, The defect of the welded portion 70 can be detected through the ultrasonic waves. The control unit 200 may output the change of the guided ultrasonic wave received from the electromagnetic acoustic sensor 100 acting as the receiving sensor or the defect detection result of the welding unit 70 through the output unit 300.

For example, as described above, when the first electromagnetic acoustic sensor 100a operates as a sensor and the second electromagnetic acoustic sensor 100b1 through the fourth electromagnetic acoustic sensor 100b3 operate as a reception sensor, The controller 200 can control the excitation unit 140 of the electromagnetic acoustic sensor 100a operating as an excitation sensor to generate guided ultrasonic waves.

More specifically, each of the electromagnetic acoustic sensors 100 includes a coil and a magnet formed on an upper portion of the coil. When a current is supplied by applying a voltage to the coil, a magnetic field is generated by electromagnetic induction. By the static magnetic field generated by the magnet Guided ultrasonic waves can be generated inside the plate material or the welded portion 70. That is, the control unit 200 can generate a magnetic field by applying a pulse signal through the excitation unit of the first electromagnetic acoustic sensor 100a operating as an excitation sensor, and can control the strength of the excitation magnetic field.

The control unit 200 also detects whether or not a defect has occurred in the welded portion 70 from the induced ultrasonic waves received from the second electromagnetic acoustic sensor 100b1, the second electromagnetic acoustic sensor 100b2, and the third electromagnetic acoustic sensor 100b3 can do. In this case, although not shown, the controller 200 may include an oscilloscope or a signal amplifier to detect a signal of the guided ultrasound wave received from the receiver 150. [

The control unit 300 receives the induced ultrasonic waves and the welding unit 70 received from the second electromagnetic acoustic sensor 100b1, the second electromagnetic acoustic sensor 100b2, and the third electromagnetic acoustic sensor 100b3 via the output unit 400, Can be output in real time. In this case, the output unit 400 may include a display, which may be a light emitting diode (LED), a liquid crystal display (LCD), a thin film transistor-liquid crystal display , A TFT LCD, an organic light emitting diode (OLED), a flexible display, a 3D display, and an electronic paper. However, the present invention is not limited thereto.

3 to 6, an electromagnetic acoustic sensor 100 included in a defect detection system of a weld according to an embodiment of the present invention will be described in more detail.

3 is a schematic view of an electromagnetic acoustic sensor according to an embodiment of the present invention.

FIG. 4 is a view showing a coil included in an electromagnetic acoustic sensor according to an embodiment of the present invention, and FIG. 5 is an enlarged view of a portion of the coil shown in FIG.

6 shows the types of acoustic waves generated according to the excitation of an electromagnetic acoustic sensor according to an embodiment of the present invention.

Referring to FIG. 3, each electromagnetic acoustic sensor 100 included in a defect detection system of a weld according to an embodiment of the present invention includes a magnet 110 and a pair of coils 120 and 130.

The magnet 110 may be an electromagnet or a permanent magnet and is disposed on top of the coils 120 and 130. Therefore, the magnet 110 generates a static magnetic field in the direction perpendicular to the coils 120 and 130 and the surface of the inspection object 50 to detect defects. At this time, the inspection object 50 may be a plate material or a pipe.

The pair of coils 120 and 130 are disposed between the magnet 110 and the inspection object 50 to generate guided ultrasonic waves into the inspection object 50 or reflected by the inspection object 50 And receives the returned guided ultrasonic wave. The pair of coils includes a first coil and a second coil spaced apart from the first coil by a predetermined distance.

The coils 120 and 130 may be meander coils having a fan shape, as shown in FIGS.

Specifically, the sector-shaped meander coils 120 and 130 may be formed so that the arc length decreases from the first vector R1 to the second vector R2, and the first vector R1 and the second vector R1 It is possible to concentrate the guided ultrasound waves at the center 10 of the center R2.

In other words, since the coils 120 and 130 constituting the electromagnetic acoustic sensor 100 are formed as sector-shaped meander coils, the induction ultrasonic waves can be focused on a specific portion of the surface of the inspection object 50.

As described above, in the weld defect detection system according to the embodiment of the present invention, the mode of the induced ultrasound generated is selected through the mode selection unit 142, and the induced ultrasound is applied to the welded portion 70 of the plate material or the pipe So that the effect of improving the detection resolution is exhibited.

More specifically, referring to FIG. 6, the electromagnetic acoustic sensor 100 generates various acoustic waves such as a surface wave, a volume longitudinal wave, and a volume shear wave by excitation. At this time, frequency setting, sound field distribution, and ultrasonic mode can be selected according to the design of the interval and shape of the coils 120 and 130. Further, the propagation angle of the volume longitudinal wave and the volume shear wave can be determined according to the excitation frequency as shown in Equation (1) below.

Where c is the velocity of the wave, l is the spacing between the points of excitation (the spacing between the coils), f is the excited frequency, and θ is the propagation angle of the wave.

That is, according to an embodiment of the present invention, it is possible to control the angle of the guided ultrasonic wave by controlling the interval and shape of the coils 120 and 130. Therefore, the spacing and shape of the coils 120 and 130 are not limited to the shapes shown in Figs. 3 to 5, and can be changed according to the design of the user.

Hereinafter, with reference to FIGS. 7 and 8, a defect detection method of a defect detection system of a welded portion according to an embodiment of the present invention will be described in detail.

FIG. 7 is a flowchart illustrating a defect detection method of a defect detection system of a weld according to an exemplary embodiment of the present invention. Referring to FIG.

FIG. 8 is a view for explaining a detailed transmission / reception path of guided ultrasonic waves generated in a welding defect detection system according to an embodiment of the present invention.

Referring to FIG. 7, a defect detection method of a defect detection system of a weld according to an exemplary embodiment of the present invention includes: (S100) selecting an ultrasound mode according to a material and a thickness of a test object; The control unit having the first electromagnetic acoustic sensor to generate the induced ultrasound of the selected mode (S200); And a step (S300) of receiving a guided ultrasonic wave reflected by the welded portion of the inspection object from the second electromagnetic acoustic sensor to the fourth electromagnetic acoustic sensor to detect defects. At this time, the inspection object 50 may be any one of a plate material and a pipe, but is not limited thereto.

First, in step S100 of selecting an ultrasonic mode according to the material and thickness of the inspection object 50, the thickness of the inspection object 50, that is, the thickness of the plate or the pipe, can be measured. Alternatively, the material and thickness of the sheet material or pipe can be input from the user. Accordingly, the mode selection unit 142 can select the ultrasonic mode according to the material and thickness of the inspection object, and the control unit 200 can control the excitation frequency applied to the coils 120 and 130 according to the selected ultrasonic mode have. At this time, the ultrasonic mode may be any one of surface wave and LAMB wave.

The control unit 200 controls the coil 120 (130, 130) through the excitation part of the first electromagnetic acoustic sensor 100a in step S200, in which the control unit has the first electromagnetic acoustic sensor and generates the guidance ultrasonic wave in the selected mode ), Thereby generating guided ultrasonic waves in the selected ultrasonic mode.

More specifically, when the controller 200 applies a pulse signal to the conductors of the coils 120 and 130 via the excitation part of the first electromagnetic acoustic sensor 100a, an eddy current is generated on the inner surface of the inspection object 50, Due to the eddy current and the static magnetic field generated by the magnet 110, a Lorentz force is generated in accordance with the left hand rule of flashing. Therefore, induced ultrasound waves are generated in the inspecting body 50 by the Lorentz force described above, and the induced ultrasound waves are generated by the pair of fan call-shaped meander coils 120 and 130, As shown in FIG. That is, in the embodiment of the present invention, the guided ultrasonic wave is focused on the welding portion 70 of the plate material or the pipe.

Next, in step S300, in which the controller receives the guided ultrasonic wave reflected by the welded portion of the inspection object from the second electromagnetic acoustic sensor 100b1 to the fourth electromagnetic acoustic sensor 100b3 to detect defects, 200 detects whether or not a defect exists in the welded portion 70 through the guided ultrasonic wave received from the second electromagnetic acoustic sensor through the fourth electromagnetic acoustic sensor.

As shown in FIGS. 1 and 8, a defect detection system for a weld according to an embodiment of the present invention includes a plurality of electromagnetic acoustic sensors 100 symmetrically on the left and right sides of a weld portion 70 . Therefore, the guided ultrasound generated from the first electromagnetic acoustic sensor 100a is focused on the welded portion 70 and then reflected to be reflected by the second electromagnetic acoustic sensor 100b1, the third electromagnetic acoustic sensor 100b2, And the sensor 100b3.

Specifically, if there is no defect in the welded portion 70, the induced ultrasonic wave generated from the first electromagnetic acoustic sensor 100a goes straight through the welded portion 70 according to the nature of the wave, Lt; RTI ID = 0.0 > 100b2. ≪ / RTI > Therefore, the amplitude of the guided ultrasonic wave received from the third electromagnetic acoustic sensor 100b2 is the largest, and the induced ultrasonic waves of the low signal are detected from the second electromagnetic acoustic sensor 100b1 and the fourth electromagnetic acoustic sensor 100b3 Lt; / RTI >

On the other hand, when there is a defect in the welded portion 70, the guided ultrasonic wave generated from the first electromagnetic acoustic sensor 100a is reflected by a defect existing in the welded portion 70, and a part of the guided ultrasonic wave is reflected, Change.

Therefore, the size of the guided ultrasonic wave received by the second electromagnetic acoustic sensor 100b1 and the fourth electromagnetic acoustic sensor 100b3 is large, and conversely, the induced ultrasonic wave of the low signal is received from the third electromagnetic acoustic sensor 100b2 have.

In other words, the control unit 200 controls the first electromagnetic acoustic sensor 100a and the third electromagnetic acoustic sensor 100b2, which are in an origin-symmetrical position on the axis of the welding portion 70, When ultrasonic waves are received, it can be determined that there is no defect in the welded portion 70.

On the other hand, in the case of the second electromagnetic acoustic sensor 100b1 located at the x-axis symmetric position with respect to the first electromagnetic acoustic sensor 100a and the weld portion 70 or the fourth electromagnetic acoustic sensor 100b3 located at the y- When the guided ultrasound wave of the largest intensity is received, it can be judged that a defect exists in the welded portion 70.

 As described above, the defect detection system of the weld according to the embodiment of the present invention can detect the defect existing in the welded portion with high resolution by focusing the induction ultrasonic wave on the welded portion of the plate or pipe.

Meanwhile, the controller 200 according to the embodiment of the present invention refers to a hardware component such as software or an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and performs predetermined roles. However, 'component' is not meant to be limited to software or hardware, and each component may be configured to be in an addressable storage medium and configured to play back one or more processors.

Thus, as an example, a component may include components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, Microcode, circuitry, data, databases, data structures, tables, arrays, and variables, as will be appreciated by those skilled in the art.

In addition, the components and functions provided in the components may be combined into a smaller number of components or further separated into additional components.

The method for detecting defects in a defect detection system of a weld according to an embodiment of the present invention may also be implemented in the form of a recording medium including instructions executable by a computer such as a program module executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. The computer readable medium may also include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data.

For example, a ROM (Read Only Memory), a RAM (Random Access Memory), a magnetic tape, a magnetic disk, a flash memory, an optical data storage device, and the like. The computer-readable recording medium may also be stored and executed as a code that is distributed in a computer system connected to a computer network and readable in a distributed manner.

Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Electromagnetic sound sensor
110: Magnet
120, 130: coil
140:
150:
200:
300:

Claims (24)

In a defect detection system for a weld,
A plurality of electromagnetic acoustic sensors disposed on one side of a test body including a welded portion and provided on left and right sides of the welded portion around the welded portion; And
And a control unit for generating guided ultrasonic waves through the first electromagnetic acoustic sensor among the plurality of electromagnetic acoustic sensors and receiving the guided ultrasonic waves reflected by the welding unit from the plurality of second electromagnetic acoustic sensors to detect defects in the welded part However,
Wherein each of the plurality of electromagnetic acoustic sensors comprises:
A coil for generating the guided ultrasonic wave into the inspecting body and receiving the guided ultrasonic wave reflected and returned, and
And a magnet disposed on the upper portion of the coil,
Wherein the coil includes a first meander coil and a second meander coil disposed to face the first meander coil,
Wherein the first and second meander and the second meander coil are fan-shaped and symmetrical with respect to a center line therebetween, and a fan-like center point is formed on an extension line of the center line,
Wherein the guided ultrasound is focused on a weld of the inspected object by the first meander coil and the second meander coil of the first electromagnetic acoustic sensor,
Coil elements of the first and second washer coils are formed such that the length of the arc decreases from the first vector R1 to the second vector R2, and the first vector R1 and the second vector To concentrate the guided ultrasound at the center (10) of the probe (R2). delete delete The method according to claim 1,
Wherein the plurality of electromagnetic acoustic sensors includes a first electromagnetic acoustic sensor, a second electromagnetic acoustic sensor, a third electromagnetic acoustic sensor, and a fourth electromagnetic acoustic sensor,
Wherein the first electromagnetic acoustic sensor and the second electromagnetic acoustic sensor are disposed on a left side surface of the weld portion, the third electromagnetic acoustic sensor and the fourth electromagnetic acoustic sensor are disposed on a right side surface of the weld portion,
Wherein the second electromagnetic acoustic sensor is disposed at a position symmetrical to the first electromagnetic acoustic sensor in the x-axis, the third electromagnetic acoustic sensor is disposed at a position symmetrical to the origin of the first electromagnetic acoustic sensor, Wherein the acoustic sensor is disposed at a position symmetrical with respect to the y-axis with the first electromagnetic acoustic sensor. 5. The method of claim 4,
The control unit
Generating the induced ultrasound wave by exciting the first electromagnetic acoustic sensor,
And detects a defect of the welded portion based on the induced acoustic wave received from the second electromagnetic acoustic sensor, the third electromagnetic acoustic sensor, and the fourth electromagnetic acoustic sensor. 6. The method of claim 5,
When the size of the guided ultrasonic wave received from the third electromagnetic acoustic sensor is the largest,
The control unit
And judges that there is no defect in the welded portion.
Defect detection system of welds. 6. The method of claim 5,
When the magnitude of the guided ultrasonic wave received from any one of the second electromagnetic acoustic sensor and the fourth electromagnetic acoustic sensor is larger than the magnitude of the guided ultrasonic wave received from the third electromagnetic acoustic sensor,
The control unit
And judges that there is a defect in the welded portion.
Defect detection system of welds. The method according to claim 1,
The electromagnetic acoustic sensor
An excitation unit applying a pulse signal to the first and second washer coils and generating guided ultrasonic waves at a welding portion of the inspection target; And
Further comprising a receiving section for receiving a surface wave reflected by the welded portion of the inspection object and returning,
Wherein the excitation unit and the reception unit are controlled by the control unit.
Defect detection system of welds. 9. The method of claim 8,
The exciter
Further comprising a mode selection unit for selecting a mode of the guided ultrasonic wave based on the material and the thickness of the inspection object,
The control unit may control the mode selection unit
And controls the frequency of the pulse signal.
Defect detection system of welds. 9. The method of claim 8,
The receiving unit
Further comprising an output unit for outputting, as a graph, a change in size of the guided ultrasonic wave with respect to time,
Wherein the output comprises a display.
Defect detection system of welds. delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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