CN202854097U - Magnetostriction sensor for round steel defect detection - Google Patents
Magnetostriction sensor for round steel defect detection Download PDFInfo
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- CN202854097U CN202854097U CN201220436376.3U CN201220436376U CN202854097U CN 202854097 U CN202854097 U CN 202854097U CN 201220436376 U CN201220436376 U CN 201220436376U CN 202854097 U CN202854097 U CN 202854097U
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Abstract
The utility model provides a magnetostriction sensor for round steel defect detection. The magnetostriction sensor comprises a plurality of magnetic loop assemblies, wherein the magnetic loop assemblies are uniformly arranged around the circumference along an axis direction of round steel, and form a closed ring-shaped magnetic path with the round steel. The magnetostriction sensor further comprises one or two coils, wherein the coil is sleeved on the round steel, and is located between the magnetic loop assemblies and an iron magnetic round rod structure part, such as the round steel and the like; each magnetic loop assembly comprises a permanent magnet array and two magnetic path elements; the magnetic path elements are L-shaped; one ends of the two magnetic path elements are opposite and are connected with each other to be a whole body through the permanent magnet array; the other ends of the two magnetic path elements are vertically connected with the outer surface of the round steel; the bottoms of the two magnetic path elements are inward-concave arc surfaces adapted with the outer surface of the round steel; each permanent magnet array 4 consists of a plurality of permanent magnets; and the directions of the magnetic fields of the permanent magnets are the same and are parallel to the axis direction of the round steel. The magnetostriction sensor provided by the utility model can be applied to the defect detection of the iron magnetic round rod structure part, such as the round steel, and has the advantages of convenience in installation and good integrality.
Description
Technical field
The utility model belongs to the supersonic guide-wave field of non destructive testing, is specifically related to utilize magnetostrictive effect excitation and receives the longitudinal ultrasonic guided wave, with the defects detection of the ferromagnetism round bar structure that is used for the round steel class such as grounded round steels ground wire, anchor pole, distaff etc.
Background technology
Now, the instrument that adopts for the defects detection of the ferromagnetism round bar structure members such as round steel mostly is piezoelectric transducer, this kind sensor need in use with the checked object end face polish flat, smooth, generally need special anchor clamps that piezoelectric sensor is fixed on endface position, and need at the end face daubing coupling agent, bring a lot of inconvenience for actual the detection in the testing process.
Adopt in addition magneto strictive sensor, magneto strictive sensor is owing to its noncontact, need not couplant, and need to not detect by end face, has broad application prospects in the detection of the ferromagnetism round bar structure members such as round steel.
Magnetostrictive effect refers to that its size can extend or shorten under the effect of ferromagnetic material outside magnetic field, remove external magnetic field after, recover again the phenomenon of the original length.Ferrimagnet is applied suitable alternating magnetic field, utilize magnetostrictive effect can produce ultrasound wave.The discontinuous interface of ultrasound wave in medium can produce repeatedly past interflection, thus and then complicated interference and how much disperse formation supersonic guide-waves of generation.Opposite, the mechanically deform meeting of ferrimagnet changes magnetic field, causes that the coil in the magnetic field produces induction current, and this phenomenon is called magnetostrictive reaction.Utilize this magnetic force transduction efficiency of ferrimagnet to carry out ultrasound examination to defective locations and the defect size of round steel.Ultrasonic guided wave detecting method based on magnetostrictive effect has following advantage: sensing range is large, need not coupling, non-contact detection, and accuracy of detection is high, and adapts to online detection and long-term status monitoring under the rugged surroundings such as high temperature corrosion.In addition, low frequency ultrasound guided wave velocity of propagation is very fast, can be along the tens of rice of round steel Propagation even rice up to a hundred.Because the performance of sensor directly has influence on the quality of detection signal, therefore, numerous domestic scholar conducts in-depth research magneto strictive sensor, for example:
China's application number 200710119319.6, applying date 2007-07-20, name is called＜＜a kind of magneto strictive sensor that detects for steel stranded wire supersonic guided wave patent, China's application number 200910083735.4, applying date 2009-05-08, the name be called＜＜a kind of high-performance mangneto telescoping sensor that adopts the multilayer winding coil patent, and Chinese application number 201020218119.3, applying date 2010-05-28, name is called＜＜based on the monomer magnetostrictive sensor that is used for steel strand detection of Pitch and catch technique patent.The magneto strictive sensor structural difference of above-mentioned patent is little, and it is basic identical that magnetic circuit consists of, and has low, the advantage such as good reproducibility when detecting of cost, but the Conversion of Energy one after another is low, and in addition, saddle sheet, magnet, yoke etc. need to install separately during assembling, operation inconvenience, globality is poor.And above-mentioned patent does not consider that closed magnetic circuit quantity and number of magnets are on the impact of magneto strictive sensor performance.Moreover, magnet in the magneto strictive sensor of above-mentioned patent is adsorbed in measured workpiece steel strand wires sustained height place around circumference, they and steel strand wires are at a distance of near and their homopolarities pair, when strengthening the magnetic force of magnet, can interfere with each other between the magnet, so the structure of the magneto strictive sensor in the above-mentioned patent has certain restriction to the magnetic field intensity of its magnet in fact, this restriction, cause when the magneto strictive sensor with above-mentioned patent is applied to large diameter round steel, often because enough energy can't be provided, and can't finish detection.
The utility model content
Technical problem to be solved in the utility model is to provide a kind of and can be applied to the defects detection of the ferromagnetism round bar structure members such as round steel and the magneto strictive sensor of good integrity easy for installation.The utility model is on the theoretical foundation of magneto strictive sensor, the longitudinal ultrasonic guided wave magneto strictive sensor of a kind of defects detection for ferromagnetism round bar structure members such as round steel of developing, utilize magnetostrictive effect, in round steel, encourage and receive the L mode longitudinal wave guide of single mode, utilize flaw echo to judge corrosion position and extent of corrosion.
For solving the problems of the technologies described above the technical scheme that adopts be: a kind of magneto strictive sensor for the round steel defects detection, comprise several magnetic loop assemblies, described magnetic loop assembly around the even circumferential setting, consists of closed hoop magnetic circuit with described round steel along the axis direction of round steel;
Also comprise coil, described mounting coil forms a segment identifier on the described round steel and be between magnetic loop assembly and the round steel every a segment distance, whenever changes once through a segment identifier coil winding-direction;
It is characterized in that, described magnetic loop assembly comprises permanent magnet array and two magnetic circuit elements, described magnetic circuit element is L-type, two magnetic circuit element one ends are connected as a single entity relatively and by described permanent magnet array, the other end all with vertical linking to each other of outside surface of round steel, the bottom is and the cambered surface of the suitable indent of the outside surface of described round steel, and described permanent magnet array is made of some permanent magnets, and each piece magnetic direction is identical and all be parallel to the axis direction of described round steel.
The utility model places magnetic loop assembly middle part with permanent magnet, and pole orientation is parallel with the axis direction of round steel, so can adopt the stronger permanent magnet array of magnetic.The absorption affinity of the magnetic loop assembly of prior art generally only has about 3Kg, the absorption affinity of the magnetic loop assembly of permanent magnet array that adopted of the present utility model can arrive about 10Kg, increased the magnetic field intensity of magnet, improved the energy conversion efficiency of magneto strictive sensor, and then improved the sensing range of magneto strictive sensor, can adapt to the defects detection of the ferromagnetism round bar structure members such as larger-diameter round steel.
As specific embodiment of the utility model, described magnetic circuit element is for being processed by No. 20 steel or other low-carbon steel materials.
Magnetic loop assembly of the present utility model is chosen as 2 ~ 4, and preferred embodiments is 4, thereby the quantity that increases the magnetic loop assembly has increased closed magnetic circuit quantity, is conducive to further improve the energy conversion efficiency of magneto strictive sensor.
As preferred implementation of the present utility model, described permanent magnet array is made of 2 ~ 4 permanent magnets.Evidence suitably increases permanent magnet quantity, is conducive to improve the energy conversion efficiency of magneto strictive sensor, acquires a certain degree but work as permanent magnet quantity, when continuing to increase, presents state of saturation.Described permanent magnet adopts Nd-Fe-B permanent magnet.
The utility model can adopt one deck coil or two-layer above coil, and coil is two-layer when above, and interior each layer coil winding-direction of same segment identifier is identical.The utility model can adopt the single layer coil autoexcitation from receiving because energy conversion efficiency is higher, can certainly select two-layer above loop construction, when coil is two-layer when above, can separate drive coil and receiving coil.Described coil adopts PCB flexible coil or manual coiling.
Described magneto strictive sensor also comprises the coupling sleeve of being made by the metal material of electromagnetic screen, described coupling sleeve is sleeved on the described magnetic loop assembly, two ends are fixedly connected with the magnetic circuit element that is in magnetic loop assembly both sides respectively, it is inner that the permanent magnet array of magnetic loop assembly is wrapped in described coupling sleeve, and the end that described magnetic circuit element is connected with round steel passes in described coupling sleeve.Described connection coupling sleeve is aldary.Adopt the metal material of electromagnetic screen to make coupling sleeve and wrap permanent magnet array and magnetic circuit element, reduce coil magnetic field with the interference in magnetic loop component internal magnetic field.
Principle explanation: when the utility model uses, directly be adsorbed in by the magnetic loop assembly on the ferromagnetism round bar structure members such as round steel, coil links to each other with extraneous ultrasonic action receiving instrument such as ultrasonic card, the pulse signal of ultrasonic action receiving instrument Energizing cycle, magneto strictive sensor becomes supersonic guide-wave with this electroporation, guided wave is propagated in round steel, reflection echo appears when meeting defective or end face, the coil of magneto strictive sensor converts thereof into electric pulse after receiving supersonic guide-wave, and further output to receiver module and analog-to-digital conversion module on the ultrasonic card, through filtering, signal is transferred to industrial computer by data line after amplifying, under the LabVIEW program, carry out waveform demonstration and data storage, determine endface position or defect size by time and the amplitude of echo, the position.
Result of use of the present utility model is: magneto strictive sensor of the present utility model adopts pole orientation to be parallel to the round steel axis, the permanent magnet array that magnetic is stronger, be conducive to improve the energy conversion efficiency of magneto strictive sensor, enlarge the sensing range of magneto strictive sensor, magneto strictive sensor of the present utility model contacts with round steel and need not couplant, the magnetic loop assembly directly is adsorbed on the round steel, good integrity easy for installation, theoretical and experiment shows, this magneto strictive sensor can carry out defects detection to the ferromagnetism round bar of round steel class, and testing process is simple, efficiently, adapt to the requirement that engineering site detects; In addition, the utility model adopts many closed magnetic circuits, can further improve the energy conversion efficiency of magneto strictive sensor.
Description of drawings
Fig. 1 is the assembling product synoptic diagram of the magneto strictive sensor of the utility model preferred embodiment;
Fig. 2 is the decomposing schematic representation of the magnetic loop assembly of the utility model preferred embodiment;
Fig. 3 is the connection diagram of the magneto strictive sensor of the utility model preferred embodiment when detecting the round steel defective;
Fig. 4 is the dispersion curve figure of the round steel of diameter 22mm;
Fig. 5 is that magneto strictive sensor detects 2m length with the received oscillogram of the round steel of corrosion default;
Among the figure: 1, magnetic circuit element, 2, coupling sleeve, 3, screw, 4, permanent magnet array, 5, coil, 6, round steel, 7, magneto strictive sensor, 8, impedance matching, 9, the ultrasonic action receiving instrument, 10, industrial computer, A represents the left side, and B represents defective locations, and C represents the right side.
Embodiment
Such as Fig. 1, Fig. 2, magneto strictive sensor of the present utility model, comprise 4 magnetic loop assemblies and autoexcitation from the single layer coil 5 that receives, the magnetic loop assembly around the even circumferential setting, consists of closed hoop magnetic circuits with round steel 6 along the axis direction of round steel 6, coil 5 be sleeved on the round steel 6 and be in the magnetic loop assembly and round steel 6 between, coil 5 total lengths are 1.5 times of the excitation guide wavelength, and 0.5 wavelength coil winding-direction of every experience changes once, adopts manual coiling to form.
Each magnetic loop assembly comprises permanent magnet array 4, two magnetic circuit elements 1 and a coupling sleeve 2, magnetic circuit element 1 is L-type, two magnetic circuit element 1 one ends are connected as a single entity relatively and by permanent magnet array 4, the other end all with vertical linking to each other of outside surface of round steel 6, the bottom is the cambered surface with the suitable indent of the outside surface of round steel 6, permanent magnet array 4 is made of two square permanent magnets, and the magnetic direction of each piece permanent magnet is identical and all be parallel to the axis direction of round steel 6.The magnetic circuit element 1 of present embodiment is processed by No. 20 steel, and permanent magnet adopts Nd-Fe-B permanent magnet, and Surface field reaches 4500 Gausses.
Fig. 3 is the connection diagram when utilizing the utility model to detect the round steel defective, in order to realize better signal to noise ratio (S/N ratio), has added impedance matching 8 for magneto strictive sensor 7, and present embodiment is selected the impedance matching electric capacity to coil 53 nF in parallel.
As shown in Figure 3, magneto strictive sensor 7 is installed in the left end head of round steel 6, and adopts ultrasonic card USB-UT350 with impedance matching 8, ultrasonic action receiving instrument 9(the utility model successively), industrial computer 10 connects.
The present embodiment detected object adopt diameter 22mm, 2m long round steel, density is 7.9g/cm
3, Poisson ratio is 0.31.Artificial corrosion default B(adopts the chloroazotic acid corrosion, and the section miss rate is about 5%) apart from round steel left end head 0.5m place.
Fig. 4 has provided diameter 22mm round steel dispersion curve.This magneto strictive sensor frequency of operation can encourage single L mode longitudinal mode guided wave (because the mode selectivity characteristic of sensor symmetric design and bias magnetic field, F mode guided wave is suppressed when excitation) in 0 ~ 0.3MHz low-frequency range.Consider on the Dispersion of sensor construction, guided wave and the group velocity curve group velocity maximum value correspondence and the minimizing characteristic of guided wave propagation attenuation, corresponding to diameter 22mm round steel, sensor frequency is selected the L(0 with 50kHz, 1) L(0 of longitudinal wave guide mode and 235kHz, 2) longitudinal wave guide mode is advisable.Detecting the structures such as other round steel, anchor pole can adjust accordingly sensor parameters according to this example.
It is adjustable in 1 ~ 32 scope to produce one-period by ultrasonic action receiving instrument 9, centre frequency adjustable pulse signal in 0 ~ 300kHz scope, in this scope, change frequency, make magneto strictive sensor 7 produce the pumping signal energy and be in maximal value, the frequency of corresponding this moment is 235kHz, then is chosen for frequency of operation.The intensity of pulse signal and gain etc. all can exert an influence to supersonic guide-wave.In example, produce driving voltage 250V by ultrasonic action receiving instrument 9, gain 70dB, frequency is the pulse signal in 20 cycles of 235kHz, after impedance matching 8, magneto strictive sensor 7 changes into the longitudinal mode supersonic guide-wave with this pulse signal, guided wave is propagated in round steel, reflection echo appears when meeting defective or end face, again by impedance matching 8, convert thereof into electric pulse after receiving supersonic guide-wave by sensor, through filtering, signal is transferred to industrial computer 10 by data line after amplifying, and carries out waveform demonstration and data storage under the LabVIEW program that it weaves.
Arrive the time of acceptance point by analyzing the reflection echo that receives in the signal, determine corrosion default position in the round steel 6, setting the position, left side is A, and defective locations is B, and the position, right side is C.Telling for the first time among Fig. 5, echo is the corrosion default echo, experience distance A-B-A, under this experiment condition of crest time location 0.232ms(with each ripple bag time to peak as signal initial and time of arrival the position, because be that radiofrequency signal plays a some zero point in the oscillogram, it is not time to peak, during actual computation, get radiofrequency signal and delay about 0.03ms as actual leading zero's position, the above-mentioned crest time is through revising, together lower), echo is round steel right side echo for the second time, experience distance A-C-A, crest time location 0.944ms, echo is the second trip echo of defective after the reflection of left side for the third time, experience distance A-B-A-C-A, crest time location 1.177ms, the 4th echo is the second trip echo of defective after the reflection of right side, experience distance A-C-B-C-A, crest time location 1.640ms, the 5th echo are the second trip echo through the right side, experience distance A-C-A-C-A, crest time location 1.884ms.(crest is obvious by the 5th right side second trip echo, be convenient to differentiate) and poor 2.218ms of the right side echo time second time, and corresponding path length difference 4000mm, can calculate and this time test actual velocity of wave is 4255m/s, be L(0,2) longitudinal mode guided wave, with theoretical velocity of wave (4440m/s) relative error be 4.2%.By actual velocity of wave and the anti-defective locations that pushes away of echo time for the first time, (0.232ms * 4255m/s)/2, record defective apart from left side 494mm, with actual range 500mm relative error only be 1.2%.In like manner, also can be by the checking of echo time for the third time defective locations---apart from left side 508mm, with actual range 500mm relative error only be 1.6%.Utilize the decay of guided wave reflection echo strong and weak, can also differentiate defect size according to the amplitude of defect waves bag.
By experiment checking, this supersonic guide-wave magneto strictive sensor can rapidly and efficiently detect the round steel defective, and this sensor cost is low, good stability and can reusing, the measurement result accuracy is high, favorable repeatability, testing process is convenient and swift, adapts to the requirement of Practical Project Site Detection.
Claims (9)
1. a magneto strictive sensor that is used for the round steel defects detection comprises several magnetic loop assemblies, and described magnetic loop assembly around the even circumferential setting, consists of closed hoop magnetic circuit with described round steel along the axis direction of round steel; Also comprise coil, described mounting coil forms a segment identifier on the described round steel and be between the ferromagnetism round bar structural portion such as magnetic loop assembly and round steel every a segment distance, whenever changes once through a segment identifier coil winding-direction;
It is characterized in that, described magnetic loop assembly comprises permanent magnet array and two magnetic circuit elements, described magnetic circuit element is L-type, two magnetic circuit element one ends are connected as a single entity relatively and by described permanent magnet array, the other end all with vertical linking to each other of outside surface of round steel, the bottom is and the cambered surface of the suitable indent of the outside surface of described round steel, and described permanent magnet array is made of some permanent magnets, and each piece magnetic direction is identical and all be parallel to the axis direction of described round steel.
2. the magneto strictive sensor for the round steel defects detection according to claim 1 is characterized in that, described magnetic loop assembly is 2 ~ 4.
3. the magneto strictive sensor for the round steel defects detection according to claim 2 is characterized in that, described magnetic loop assembly is 4.
4. the magneto strictive sensor for the round steel defects detection according to claim 1 is characterized in that, described permanent magnet array is made of 2 ~ 4 permanent magnets.
5. the magneto strictive sensor for the round steel defects detection according to claim 4 is characterized in that, described permanent magnet adopts Nd-Fe-B permanent magnet.
6. the magneto strictive sensor for the round steel defects detection according to claim 1 is characterized in that, described coil be one deck or two-layer more than, coil is two-layer when above, each layer coil winding-direction is identical in the same segment identifier.
7. the magneto strictive sensor for the round steel defects detection according to claim 6 is characterized in that, coil adopts PCB flexible coil or manual coiling.
8. each described magneto strictive sensor for the round steel defects detection according to claim 1 ~ 7, it is characterized in that, described magneto strictive sensor also comprises the coupling sleeve of being made by the metal material of electromagnetic screen, described coupling sleeve is sleeved on the described magnetic loop assembly, two ends are fixedly connected with the magnetic circuit element that is in magnetic loop assembly both sides respectively, it is inner that the permanent magnet array of magnetic loop assembly is wrapped in described coupling sleeve, and the end that described magnetic circuit element is connected with round steel passes in described coupling sleeve.
9. the magneto strictive sensor for the round steel defects detection according to claim 8 is characterized in that, described coupling sleeve is the cylindrical shell of aldary.
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| CN201220436376.3U CN202854097U (en) | 2012-08-30 | 2012-08-30 | Magnetostriction sensor for round steel defect detection |
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| CN201220436376.3U CN202854097U (en) | 2012-08-30 | 2012-08-30 | Magnetostriction sensor for round steel defect detection |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103206912A (en) * | 2013-04-24 | 2013-07-17 | 四川大学 | Magnetostrictive displacement sensor detection device |
| CN103529131A (en) * | 2013-10-18 | 2014-01-22 | 国家电网公司 | Adjustable magnetostrictive waveguide sensor |
| CN104569142A (en) * | 2013-10-29 | 2015-04-29 | 中国石油天然气集团公司 | U-shaped detection probe based on AC magnetic field detection and detection method |
| US10175200B2 (en) | 2014-05-30 | 2019-01-08 | Prime Photonics, Lc | Methods and systems for detecting nonuniformities in a material, component, or structure |
| CN109870389A (en) * | 2019-04-12 | 2019-06-11 | 长春工程学院 | Based on magnetostrictive displacement sensor irrigation water coefficient of viscosity detection device and method |
-
2012
- 2012-08-30 CN CN201220436376.3U patent/CN202854097U/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103206912A (en) * | 2013-04-24 | 2013-07-17 | 四川大学 | Magnetostrictive displacement sensor detection device |
| CN103529131A (en) * | 2013-10-18 | 2014-01-22 | 国家电网公司 | Adjustable magnetostrictive waveguide sensor |
| CN103529131B (en) * | 2013-10-18 | 2015-12-02 | 国家电网公司 | A kind of adjustable magnetostrictive waveguide sensor |
| CN104569142A (en) * | 2013-10-29 | 2015-04-29 | 中国石油天然气集团公司 | U-shaped detection probe based on AC magnetic field detection and detection method |
| US10175200B2 (en) | 2014-05-30 | 2019-01-08 | Prime Photonics, Lc | Methods and systems for detecting nonuniformities in a material, component, or structure |
| CN109870389A (en) * | 2019-04-12 | 2019-06-11 | 长春工程学院 | Based on magnetostrictive displacement sensor irrigation water coefficient of viscosity detection device and method |
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Granted publication date: 20130403 |