阅读说明：本技术 一体式激光声磁金属缺陷探伤装置与方法 (Integrated laser acousto-magnetic metal defect flaw detection device and method ) 是由 袁伟 刘泽 于 2021-08-25 设计创作，主要内容包括：本发明提供了一种一体式激光声磁金属缺陷探伤装置与方法,包括：两个电磁铁、两个磁芯、检测线圈、激光发射器和聚焦透镜；两个电磁铁为C型电磁铁且开口处对向放置,每个磁芯两端分别与两个C型电磁铁的一个端部接触,且两个磁芯相互平行,磁芯的接触面宽度大于或等于C型电磁铁接触面,高度大于C型电磁铁,磁芯底部低于磁铁一定距离,使C型电磁铁与被测金属之间有一定的提离距离；检测线圈固定于两个磁芯中间,且与每个磁芯之间设置有缝隙,检测线圈的底面与两个磁芯的底面在同一水平面上；激光发射器和聚焦透镜设置于检测线圈的中心处,激光发射器用于发出激光脉冲,聚焦透镜用于将激光脉冲聚焦成线状。可以一次扫描定量探测钢轨缺陷。(The invention provides an integrated laser acousto-magnetic metal defect flaw detection device and method, which comprises the following steps: the device comprises two electromagnets, two magnetic cores, a detection coil, a laser emitter and a focusing lens; the two electromagnets are C-shaped electromagnets, the openings of the two electromagnets are oppositely arranged, two ends of each magnetic core are respectively contacted with one end part of the two C-shaped electromagnets, the two magnetic cores are parallel to each other, the width of the contact surface of each magnetic core is larger than or equal to that of the C-shaped electromagnet, the height of the contact surface of each magnetic core is larger than that of the C-shaped electromagnet, the bottom of each magnetic core is lower than the magnets by a certain distance, and a certain lifting distance is reserved between each C-shaped electromagnet and the metal to be detected; the detection coil is fixed between the two magnetic cores, a gap is arranged between the detection coil and each magnetic core, and the bottom surface of the detection coil and the bottom surfaces of the two magnetic cores are on the same horizontal plane; the laser emitter and the focusing lens are arranged at the center of the detection coil, the laser emitter is used for emitting laser pulses, and the focusing lens is used for focusing the laser pulses into a line shape. The rail defect can be detected quantitatively by one-time scanning.)

1. The utility model provides an integral type laser acoustomagnetic metal defect inspection device which characterized in that includes: the device comprises two electromagnets, two magnetic cores (3), a detection coil (4), a laser emitter and a focusing lens (5);

the two electromagnets are C-shaped electromagnets, the openings of the two electromagnets are oppositely arranged, two ends of each magnetic core (3) are respectively contacted with one end part of the two C-shaped electromagnets, the two magnetic cores (3) are parallel to each other, the width of the contact surface of each magnetic core (3) is larger than or equal to that of the contact surface of the C-shaped electromagnet, the height of the contact surface of each magnetic core is larger than that of the C-shaped electromagnet, the bottom of each magnetic core (3) is lower than the corresponding magnet by a certain distance, and a certain lifting distance is reserved between the C-shaped electromagnet and the metal to be detected;

the detection coil (4) is fixed between the two magnetic cores (3), a gap is formed between the detection coil and each magnetic core (3), and the bottom surface of the detection coil (4) and the bottom surfaces of the two magnetic cores (3) are on the same horizontal plane;

the laser emitter and the focusing lens (5) are arranged at the center of the detection coil (4), the laser emitter is used for emitting laser pulses, and the focusing lens is used for focusing the laser pulses into a linear shape.

2. The device according to claim 1, characterized in that said C-shaped electromagnet comprises an electromagnet coil (1) and a C-shaped electromagnet core (2), the electromagnet coil being uniformly wound on two coil bobbins respectively provided at the two ends of the C-shaped electromagnet core (2).

3. Device according to claim 1, characterized in that the magnetic core (3) is of rectangular parallelepiped shape.

4. A device according to claim 1, characterized in that the coils of the two ends of the C-shaped electromagnet are energized in opposite directions, and that the coil current of each end is energized in opposite directions to the end coil corresponding to the other C-shaped electromagnet to which it is connected via the magnetic core (3).

5. A device according to claim 1, characterized in that said detection coil (4) is a spiral, butterfly or meander coil, positioned between two magnetic cores (3) and between the two end points of the same magnetic core (3) when it belongs to one of the above-mentioned coils.

6. A device according to claim 3, characterized in that the detection coil (4) is a racetrack-type coil, the non-circular arc-shaped sides of which are parallel to the magnetic core and have the same length, and the two ends of each of the two non-circular arc-shaped sides of which are located at the two ends of the connection of the same magnetic core (3) with the two C-type electromagnets.

7. The apparatus of claim 1, wherein the central axes of the laser emitter and the focusing lens are collinear.

8. The apparatus of claim 1, wherein the laser transmitter apparatus is a pulsed laser transmitter.

9. The device of claim 1, wherein the focusing lens is a line lens, and the focusing lens is fixed inside or outside the integrated device according to the structure of the laser emitter device.

10. A method of metal defect inspection using the apparatus of any of claims 1-9, comprising the steps of:

the bottom of the laser acousto-magnetic metal defect flaw detection device is arranged on the top of a metal to be detected, laser pulses are excited by a laser emitter device and are focused into a linear light source through a focusing lens to be radiated to the surface of the metal to be detected, and different types of ultrasonic waves are generated; meanwhile, currents with opposite directions are respectively introduced into two tail end electromagnet coils of a first C-shaped electromagnet, and the currents which are opposite to the tail end electromagnet coils (1) of a second C-shaped electromagnet connected with the first C-shaped electromagnet through a magnetic core (3) are respectively introduced into the tail end electromagnet coils (1) of the first C-shaped electromagnet, so that magnetic fields with different polarities are formed in the two magnetic cores (3), and a uniform radial magnetic field is generated in the detected metal body right below the detection coil (4); for forming a closed magnetic circuit; after the different types of ultrasonic waves encounter metal defects, the ultrasonic waves immediately return to the surface of the metal to be detected according to the original path, so that particles in the metal to be detected right below the detection coil (4) vibrate, and a voltage signal is induced through the detection coil (4), so that the information of the position and the size type of the metal defects is determined.

Technical Field

The invention relates to the technical field of ultrasonic nondestructive testing, in particular to an integrated laser acousto-magnetic metal defect flaw detection device and method.

Background

The laser ultrasonic and electromagnetic ultrasonic technology belongs to the non-contact ultrasonic nondestructive detection technology without a coupling agent, and has wide application prospect in the fields of industrial production, medical diagnosis, aerospace and the like.

The principle of generating ultrasonic waves by laser ultrasound is to apply laser to locally heat the surface of a detected body so as to generate thermal expansion and generate micro vibration. The laser ultrasonic method has the characteristics of good sensitivity, high precision and the like, and can realize the detection of the micro defects. And the receiving of the ultrasonic wave usually needs to be realized by accurately measuring the displacement of the surface of the measured object by using a laser interferometer. The laser interferometer not only has a complex structure, but also has high manufacturing cost, large volume and higher requirement on the surrounding working environment, and is not suitable for the on-line steel rail flaw detection which is a severe on-site environment.

Electromagnetic ultrasound has a very low requirement for surface defects, and can excite multiple wave modes according to different structures, but the low transduction efficiency is still an unsolved problem at present, and particularly, a longitudinal wave sensor for generating and receiving out-of-plane vibration velocity needs a uniform radial (transverse) magnetic field which is difficult to generate to be combined with a coil for realization.

Traditional laser-electromagnetic ultrasonic composite devices are also proposed, but some of the devices are provided with an excitation device and a receiving device which are arranged at different positions, so that errors are easily caused to the system; some devices, although they are integrated, require a hole to be drilled in the permanent magnet to facilitate the smooth passage of the laser source. The holes seriously affect the uniform distribution of the magnetic field and the signal-to-noise ratio of the signal. Meanwhile, some people do not fully utilize the advantage that laser can excite multiple types of waves at the same time, only one wave mode is used and other waves are filtered, so that energy loss and waste are caused.

According to the current application situation of laser ultrasound and electromagnetic ultrasound at the present stage, the electromagnetic ultrasound technology and the laser ultrasound technology are used for the research of metal defects, thickness and residual stress measurement, but because the excitation energy conversion efficiency of the electromagnetic ultrasound sensor is low, the laser ultrasound receiving device has high manufacturing cost and complex structure and is seriously influenced by the environment, and the electromagnetic ultrasound receiving device and the laser ultrasound receiving device are not widely popularized and used for a while. With the development of high-speed railways, as one of important guarantees of track safety, rail flaw detection is always a hot topic. At present, the traditional piezoelectric type ultrasonic flaw detection vehicle is still used for detecting on the railway. Although the eddy current method and the electromagnetic tomography method are technically studied in the aspect of rail flaw detection, no report about the practical application of the method is found yet due to the influence of the skin effect.

Therefore, a flaw detection device capable of receiving multiple types of ultrasonic waves of particles generated by laser in an out-of-plane vibration direction is needed to represent mechanical vibration conditions of different types of defect echoes, and further quantitative nondestructive flaw detection of a rail head of a steel rail is achieved.

Disclosure of Invention

The invention provides an integrated laser acousto-magnetic metal defect flaw detection device and method, which aim to solve the defects in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme.

An integrated laser acousto-magnetic metal defect inspection device, comprising: the device comprises two electromagnets, two magnetic cores 3, a detection coil 4, a laser emitter and a focusing lens 5;

the two electromagnets are C-shaped electromagnets, the openings of the two electromagnets are oppositely arranged, two ends of each magnetic core 3 are respectively contacted with one end part of the two C-shaped electromagnets, the two magnetic cores 3 are parallel to each other, the width of the contact surface of each magnetic core 3 is larger than or equal to that of the C-shaped electromagnet, the height of the contact surface of each magnetic core is larger than that of the C-shaped electromagnet, the bottom of each magnetic core 3 is lower than the magnet by a certain distance, and a certain lifting distance is formed between each C-shaped electromagnet and the metal to be detected;

the detection coil 4 is fixed between the two magnetic cores 3, a gap is formed between the detection coil 4 and each magnetic core 3, and the bottom surface of the detection coil 4 and the bottom surfaces of the two magnetic cores 3 are on the same horizontal plane;

the laser emitter and the focusing lens 5 are arranged at the center of the detection coil 4, the laser emitter is used for emitting laser pulses, and the focusing lens is used for focusing the laser pulses into a linear shape.

Preferably, the C-type electromagnet includes an electromagnet coil 1 and a C-type electromagnet core 2, and the electromagnet coils are uniformly wound around two bobbin members respectively provided at both ends of the C-type electromagnet core 2.

Preferably, the magnetic core 3 has a rectangular parallelepiped shape.

Preferably, the coils of the two ends of the C-shaped electromagnet are energized in opposite directions, and the coil current of each end is energized in opposite directions to the current of its corresponding end coil of the other C-shaped electromagnet connected by the magnetic core 3.

Preferably, the detection coil 4 is a spiral coil, a butterfly coil or a meander coil, and when the detection coil belongs to one of the above coils, the position thereof is located between the two magnetic cores 3 and between the two end points of the same magnetic core 3.

Preferably, the detection coil 4 is a runway-type coil, the non-circular-arc-shaped sides of the runway-type coil are parallel to the magnetic core and have the same length, and the positions of two tail ends of each of the two non-circular-arc-shaped sides of the runway-type coil correspond to the two ends of the same magnetic core 3 connected with the two C-type electromagnets.

Preferably, the central axes of the laser emitter and the focusing lens are located on the same straight line.

Preferably, the laser transmitter means is a pulsed laser transmitter.

Preferably, the focusing lens is a straight lens, and the focusing lens is fixed in the integrated device or outside the device according to the structure of the laser emitter device.

The embodiment of the invention also provides a method for detecting the metal defects by adopting the device, which comprises the following steps:

the bottom of the laser acousto-magnetic metal defect flaw detection device is arranged on the top of a metal to be detected, laser pulses are excited by a laser emitter device and are focused into a linear light source through a focusing lens to be radiated to the surface of the metal to be detected, and different types of ultrasonic waves are generated; meanwhile, currents with opposite directions are respectively introduced into two tail end electromagnet coils of a first C-shaped electromagnet, and currents with opposite directions corresponding to the tail end electromagnet coil 1 of the first C-shaped electromagnet are respectively introduced into a tail end electromagnet coil 1 of a second C-shaped electromagnet connected with the first C-shaped electromagnet through a magnetic core 3, so that magnetic fields with different polarities are formed in the two magnetic cores 3, and a uniform radial magnetic field is generated in a detected metal body right below a detection coil 4; for forming a closed magnetic circuit; after the different types of ultrasonic waves encounter metal defects, the ultrasonic waves immediately return to the surface of the metal to be detected according to the original path, so that particles in the metal to be detected right below the detection coil 4 vibrate, and a voltage signal is induced by the detection coil 4, so that the position and size type information of the metal defects is determined.

According to the technical scheme provided by the integrated laser acousto-magnetic metal defect flaw detection device and method, the flaw detection device detects the components of different types of ultrasonic wave generated by laser in the out-of-plane vibration direction, and observes the received voltage change characteristics of the coil of the electromagnetic ultrasonic sensor, so that the mechanical vibration conditions of different types of flaw echoes are represented, and quantitative nondestructive flaw detection is further realized. The device has the characteristics of high detection precision and good structural stability, can quantitatively detect the defects inside and on the surface of the metal simultaneously through one-time scanning, meets the high-efficiency, quick and comprehensive positioning and quantitative detection capability of the metal, and can be applied to the condition of severe environment.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an integrated laser acousto-magnetic metal defect inspection apparatus according to an embodiment;

FIG. 2 is a top view of the integrated laser acousto-magnetic metal defect inspection apparatus provided in the embodiments;

FIG. 3 is a schematic view of the magnetic path of the integrated laser acousto-magnetic metal defect flaw detection device;

FIG. 4 is a schematic view of the core position;

FIG. 5 is a flaw detection schematic diagram of the integrated laser acousto-magnetic metal flaw detection device;

description of reference numerals:

1 electromagnet coil, 2C type electromagnet core, 3 magnetic core, 4, detects coil 5 laser emitter and focusing lens 6 steel rail.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It should be understood that the term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

For the convenience of understanding of the embodiments of the present invention, the following description will be further explained by taking specific embodiments as examples with reference to the drawings, and the embodiments of the present invention are not limited thereto.

Examples

Fig. 1 is a schematic structural diagram of an integrated laser acoustic-magnetic metal defect inspection device provided in this embodiment, fig. 2 is a top view of the integrated laser acoustic-magnetic metal defect inspection device provided in this embodiment, and referring to fig. 1 and fig. 2, the device is a structure similar to a "ceiling type" and is applied to a steel rail 6, and the device includes: two electromagnets, two magnetic cores 3, a detection coil 4, a laser emitter device and a focusing lens 5.

Two electro-magnets are C type electro-magnet and opening part subtend and place, 3 both ends of every magnetic core respectively with the tip contact of two C type electro-magnets, and two magnetic cores 3 are parallel to each other, the contact surface width of magnetic core is more than or equal to C type electro-magnet contact surface, highly be greater than C type electro-magnet, the bottom of magnetic core is less than magnet certain distance, make C type electro-magnet and surveyed have certain lift-off distance between the metal, an effective area for increasing the magnetic core, make the magnetic resistance reduce, guarantee that the magnetic circuit passes through from the electro-magnet magnetic core completely, as shown in figure 4. The C-shaped electromagnet comprises an electromagnet coil 1 and a C-shaped electromagnet core 2, wherein the electromagnet coil 1 is uniformly wound on two coil frameworks which are respectively arranged at two tail ends of the C-shaped electromagnet core 2. The magnetic core 3 is in a rectangular parallelepiped shape.

The detection coil 4 is fixed between the two magnetic cores 3, a gap is arranged between the detection coil 4 and each magnetic core 3, and the bottom surface of the detection coil 4 and the bottom surfaces of the two magnetic cores 3 are on the same horizontal plane. As can be seen from fig. 2, the detection coil in this embodiment is a track-type coil, wherein the non-circular arc-shaped sides of the track-type coil are parallel to the magnetic core 3 and have the same length, and the positions of the two ends of each of the two non-circular arc-shaped sides of the track-type coil correspond to the connection ends of the same magnetic core 3 and the two C-type electromagnets.

A laser emitter device for emitting laser pulses and a focusing lens 5 for focusing the laser pulses into a line are provided at the center of the detection coil 4.

The current passing directions of the coils at the two tail ends of the C-shaped electromagnet are opposite to ensure that the magnetic field generated in the C-shaped electromagnet is the maximum, the magnetic field direction is from one end of the C-shaped electromagnet to the other end, the current passing direction of the coil at each tail end is opposite to the current passing direction of the tail end coil corresponding to the other C-shaped electromagnet which is oppositely connected through the magnetic core, so that the polarities of the two corresponding sides of the magnetic core 3 and the C-shaped electromagnet are same, and the polarities of the two opposite sides of the two magnetic cores 3 are opposite.

When the detection coil belongs to one of the coils, the detection coil is positioned between the two magnetic cores and between two end points of the same magnetic core. It should be noted that the central axes of the laser transmitter device and the focusing lens are located on the same straight line.

In this embodiment, the pulsed laser transmitter in the laser transmitter device is an yttrium aluminum garnet crystal laser, which is referred to as Nd: YAG laser for short. The focusing lens is a straight lens, the focusing lens is fixed in the integrated device or outside the device according to the structure of the laser emitter device, and no matter how the lens is fixed, the light path of the focusing lens is perpendicular to the surface of the tested piece and radiates at the center of the coil.

The method for detecting the metal defects by adopting the device of the embodiment comprises the following steps:

the bottom of the laser acousto-magnetic metal defect flaw detection device is arranged at the top of a steel rail head, laser pulses are excited by a laser emitter device and are focused into a linear light source through a focusing lens to be radiated onto the surface of the steel rail head, and different types of ultrasonic waves are generated; meanwhile, currents with opposite directions are respectively led into two tail end electromagnet coils of the first C-shaped electromagnet, and currents with opposite directions corresponding to the tail end electromagnet coils of the first C-shaped electromagnet are respectively led into tail end electromagnet coils of the second C-shaped electromagnet connected with the first C-shaped electromagnet through magnetic cores, so that magnetic fields with different polarities are formed in the two magnetic cores, as shown in fig. 3; in order to ensure the closure of the magnetic circuit, namely between the magnetic circuit and the detection coil, a uniform radial magnetic field is generated in the measured steel rail right below the detection coil; after the different types of ultrasonic waves encounter metal defects, the ultrasonic waves immediately return to the surface of the steel rail according to the original path, so that particles in the steel rail under the detection coil vibrate, and a voltage signal is induced by the detection coil, so that the position and size type information of the metal defects is determined.

Referring to fig. 3, the electromagnet coils around the two ends of the electromagnet are energized with opposite currents to ensure that the magnetic circuit is directed from one end of the C-shaped electromagnet to the other end pin. Two groups of electromagnet openings are oppositely arranged and are connected through a cuboid magnetic core 3. When the four groups of coils are electrified with corresponding currents, a magnetic circuit is formed in the C-shaped electromagnet magnetic cores 2 of the two groups of electromagnets, and magnetic poles with opposite polarities are formed in the two magnetic cores 3. In order to form a closed magnetic circuit, a radial magnetic field is formed inside the measured steel rail between the two magnetic cores 3. In order to identify the echo characteristics of the reflection of different types of ultrasonic waves generated by laser after encountering different defects, a runway type coil and a uniform radial magnetic field are combined to sense the change of particle vibration and determine the size and the position of the defects.

Referring to fig. 5, which is a schematic view of the flaw detection principle of the integrated laser acousto-magnetic metal flaw detection apparatus, different types of ultrasonic waves can be simultaneously generated by laser with reference to fig. 5. The Rayleigh wave propagates along the surface of the steel rail and is reflected when meeting the surface defect, so that the surface defect of the rail head on the surface can be detected. The transverse wave propagates along the normal direction of the excitation point at an angle of about 45 degrees, and the transverse wave is reflected when meeting the defects in the directions except the direction right below (90 degrees) the excitation source, so that the defects in the directions except the direction right below (90 degrees) the excitation source in the railhead can be detected. The longitudinal wave propagates in a diverging manner to the surroundings, but directly below (90 °), i.e. in the vertical direction, the energy is strongest, and the rest is slightly weaker. Therefore, it can detect the defects in the vertical direction and also assist in determining the defects in the remaining angles.

It will be appreciated by those skilled in the art that the number of elements shown in FIG. 1 for simplicity only may be less than that in an actual device, but such omissions are clearly not to be considered as a requirement for a clear and complete disclosure of embodiments of the invention.

The specific process of flaw detection by the apparatus of the embodiment of the present invention is similar to that of the method embodiment described above, and is not described herein again.

From the above description of the embodiments, it is clear to those skilled in the art that the present invention can be implemented by software plus necessary general hardware platform. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which may be stored in a storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the embodiments or some parts of the embodiments.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.