CN108918653B - Nondestructive testing device and method for ferromagnetic slender component - Google Patents
Nondestructive testing device and method for ferromagnetic slender component Download PDFInfo
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Abstract
The invention provides a nondestructive testing device for a ferromagnetic elongated member, which comprises a nondestructive testing main body and an induction coil, and further comprises a coil mounting framework, wherein a protruding part is arranged on the coil mounting framework, and the induction coil is mounted on the protruding part. The invention also provides a nondestructive testing method for the ferromagnetic elongated member, which adopts the nondestructive testing device for the ferromagnetic elongated member to perform nondestructive testing on the loss of the sectional area of the metal. The invention has the beneficial effects that: the induction coil is additionally provided with the coil mounting framework and the non-magnetic-conduction winding framework, the induction coil is wound on the non-magnetic-conduction winding framework, the coil mounting framework provides a specific path for defect magnetic flux, the signal-to-noise ratio of the induction coil for LMA detection signals can be effectively improved, and the induction coil is simple in structure and convenient to wind and install.
Description
Technical Field
The invention relates to a detection device, in particular to a ferromagnetic slender component nondestructive detection device and a method.
Background
The nondestructive testing research of the steel wire rope is mainly divided into two categories: loss of metal cross-sectional Area (LMA, Loss of Metallic Area) and Localized damage (LF, Localized Flaw). LMA mainly refers to large-area metal loss of the steel wire rope caused by factors such as abrasion, corrosion and rust, reduction of the diameter of the steel wire rope and the like; LF mainly refers to damage in local areas such as wire breakage, pitting corrosion, etc. of the steel wire rope. The LMA detection result can intuitively reflect the loss of the section area of the steel wire rope and is the main basis for regular detection and elimination of the steel wire rope. The induction coil is a preferred sensor for LMA detection due to the characteristics of low cost, simple manufacture, durability and the like and the matching of the long-time low-drift integrator. Prior patent document 1: chinese patent publication No. 107328851a proposes an improved coil design for simplifying coil winding and improving signal-to-noise ratio of detection signals, in which the detection result of defects is more similar to LF detection result, so that the LF analysis mode referred to for quantitative analysis of defects.
Therefore, how to provide another improved coil design for the use of an induction coil for LMA quantitative detection, which simplifies the winding of the induction coil and obtains an LMA detection result with a higher signal-to-noise ratio, is a technical problem to be solved by those skilled in the art.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a nondestructive testing device and a nondestructive testing method for a ferromagnetic elongated member.
The invention provides a nondestructive testing device for a ferromagnetic elongated member, which comprises a nondestructive testing main body and an induction coil, and further comprises a coil mounting framework, wherein a protruding part is arranged on the coil mounting framework, and the induction coil is mounted on the protruding part.
As a further improvement of the invention, at least two convex parts are arranged on the coil mounting framework, and the induction coils are connected in series in the same direction on the convex parts.
As a further improvement of the invention, the convex parts are uniformly arranged along the circumferential direction of the detection axis of the nondestructive testing main body at intervals, and the convex parts are convex along the direction of the detection axis of the nondestructive testing main body.
As a further improvement of the invention, the nondestructive testing device for the ferromagnetic elongated member further comprises a non-magnetic winding framework, the induction coil is wound on the non-magnetic winding framework, and the non-magnetic winding framework is fixedly installed on the protruding part.
As a further improvement of the invention, the coil mounting framework is a high-permeability material framework, the bulge part is a rectangular bulge, and the non-magnetic winding framework is a rectangular frame.
As a further improvement of the invention, the coil installation framework comprises at least two split frameworks which are spliced into a circular ring shape.
As a further improvement of the invention, the split type framework comprises two high-magnetic-permeability arc-shaped flat plates, and the protruding part is arranged between the two high-magnetic-permeability arc-shaped flat plates.
As a further improvement of the present invention, the nondestructive testing main body comprises a housing, a magnetic yoke, a guide wheel, an encoder, a signal collecting and processing unit and an integrator, wherein the magnetic yoke is arranged in the housing, the magnetic yoke is provided with a permanent magnet, the encoder is connected with the guide wheel, the guide wheel is connected with the housing, an output end of the encoder and an output end of the integrator are respectively connected with an input end of the signal collecting and processing unit, and an input end of the integrator is connected with the induction coil
The invention also provides a nondestructive testing method for the ferromagnetic elongated member, which adopts the nondestructive testing device for the ferromagnetic elongated member to perform nondestructive testing on the loss of the sectional area of the metal.
As a further improvement of the invention, when the ferromagnetic slender component and the nondestructive testing device of the ferromagnetic slender component move relatively, the induction coil outputs the voltage as follows:
n is the number of turns of the induction coil;
s-curved surface enclosed by induction coil;
Φ — the magnetic flux through a closed coil of area s;
b-magnetic induction in the curved surface s;
ds-Unit integral bin on surface s;
after integrating equation (1) with an integrator, we can obtain:
in the formula phi def -a defect leakage flux through the induction coil;
Φ 0 -a background magnetic field flux through the induction coil;
after the induction coil is integrated by a formula (2), the output voltage value of the induction coil is in direct proportion to the number of turns of the coil, the leakage flux of the defect and the magnetic flux of a background magnetic field and in inverse proportion to the integral constant of the integrator; for the wound induction coil and the designed integrator, N/RC is a constant; the integral output voltage and the defect leakage flux are in a proportional relation, and the defect size of the steel wire rope can be inverted through the integral output voltage
The beneficial effects of the invention are: through the scheme, the coil mounting framework and the non-magnetic-conduction winding framework are additionally arranged, the induction coil is wound on the non-magnetic-conduction winding framework, the coil mounting framework provides a specific path for defect magnetic flux, the signal-to-noise ratio of the induction coil for LMA detection signals can be effectively improved, and the induction coil is simple in structure and convenient to wind and install.
Drawings
Fig. 1 is a schematic view of a non-destructive testing apparatus for ferromagnetic elongated members according to the present invention.
Fig. 2 is a schematic view of a coil mounting skeleton of a nondestructive testing device for ferromagnetic elongated members of the present invention.
FIG. 3 is a schematic view of a non-magnetic conducting bobbin of a nondestructive testing apparatus for ferromagnetic elongated members of the present invention.
Fig. 4 is a schematic view of a single-sided coil-mounting bobbin of a nondestructive testing apparatus for ferromagnetic elongated members of the present invention.
Fig. 5 is a schematic layout of a non-magnetic winding skeleton of the nondestructive testing device for ferromagnetic elongated members in accordance with the present invention.
FIG. 6 is a schematic view of another arrangement of the non-magnetic winding skeleton of the nondestructive testing device for ferromagnetic slender members in accordance with the present invention.
Fig. 7 is a diagram of the detection result of the nondestructive detection method for ferromagnetic elongated members.
Detailed Description
The invention is further described with reference to the following description and embodiments in conjunction with the accompanying drawings.
As shown in fig. 1 to 7, a ferromagnetic slender component nondestructive testing apparatus includes a nondestructive testing main body and an induction coil 10, the ferromagnetic slender component nondestructive testing apparatus further includes a coil mounting framework 1, a protrusion 8 is provided on the coil mounting framework 1, and the induction coil 10 is mounted on the protrusion 8.
As shown in fig. 1 to 7, at least two protrusions 8 are provided on the coil mounting frame 1, and the induction coils 10 are installed in series on the protrusions 8 in the same direction.
As shown in fig. 1 to 7, the protrusions 8 are uniformly arranged along the circumferential direction of the detection axis of the nondestructive testing main body at intervals, and the protrusions 8 protrude along the detection axis direction of the nondestructive testing main body, and the steel wire rope 7 is used as a detected member in the present invention, so that the detection axis direction of the nondestructive testing main body is the axis of the steel wire rope 7 during detection.
As shown in fig. 1 to 7, the nondestructive testing device for ferromagnetic slender components further includes a non-magnetic winding bobbin 9, the induction coil 10 is wound around the non-magnetic winding bobbin 9, and the non-magnetic winding bobbin 9 is fixed on the protruding portion 8.
As shown in fig. 1 to 7, the coil mounting frame 1 is a frame made of a high magnetic permeability material, the protruding portion 8 is a rectangular protrusion, and the non-magnetic conductive winding frame 9 is a rectangular frame.
As shown in fig. 1 to 7, the coil mounting frame 1 includes at least two split type frames, the split type frames are spliced into a circular ring shape, two split type frames are preferably provided in the present invention, each split type frame is in an arc shape of 180 degrees, and the split type frames are butted into a circular ring shape at the upper side and the lower side.
As shown in fig. 1 to 7, the split-type framework includes two high magnetic conductivity arc-shaped flat plates, and the protruding portion 8 is disposed between the two high magnetic conductivity arc-shaped flat plates.
As shown in fig. 1 to 7, the nondestructive testing main body comprises a housing, a magnetic yoke 2, a guide wheel 4, an encoder, a signal acquisition and processing unit 5 and an integrator 6, wherein the magnetic yoke 2 is arranged in the housing, a permanent magnet 3 is arranged on the magnetic yoke 2, the encoder is connected with the guide wheel 4, the guide wheel 4 is connected with the housing, the output end of the encoder and the output end of the integrator 6 are respectively connected with the input end of the signal acquisition and processing unit 5, and the input end of the integrator 6 is connected with an induction coil 10
As shown in fig. 1 to 7, the coil mounting frame 1 is made of a material having a high magnetic permeability, such as permalloy, industrial pure iron, or the like. The coil installation framework 1 adopts 4 split structures as shown in figure 2 to splice into two structures as shown in figure 4, and the two structures are respectively installed between the upper detection device and the lower detection device, so that the installation and the disassembly are convenient. Two bosses 8 on the coil mounting framework 1 provide a path with smaller magnetic resistance for defect magnetic flux, so that the induction coil 10 is wound on the two bosses 8 in series in the same direction, the defect leakage magnetic flux can be detected to the maximum extent, and the LMA detection of the defect is realized. In order to facilitate winding and installation of the coil, the induction coil 10 is wound on the non-magnetic winding framework 9 shown in fig. 3, and is fixed on the convex part 8 of the coil installation framework 1 after being wound for a plurality of turns.
The invention also provides a nondestructive testing method for the ferromagnetic elongated member, which adopts the nondestructive testing device for the ferromagnetic elongated member to carry out nondestructive testing on the loss of the metal sectional area (LMA), wherein the ferromagnetic elongated member is preferably a steel wire rope 7.
The invention provides a nondestructive testing method for a ferromagnetic elongated member, which comprises the following steps:
when the steel wire rope 7 and the ferromagnetic slender component nondestructive testing device move relatively, the output voltage of the induction coil 10 is as follows:
n is induction coil turn number;
s-curved surface enclosed by induction coil;
Φ — the magnetic flux through a closed coil of area s;
b-magnetic induction in the curved surface s;
ds-the unit integral bin over a surface s.
The coil mounting skeleton 1 is added to make the magnetic flux phi pass through the convex part 8 basically, so s in the formula (1) is mainly related to the size of the convex part 8 and is not related to the area of the induction coil 10 basically, and B is also mainly the magnetic induction intensity passing through the convex part 8.
After integrating equation (1) with an integrator, we can obtain:
in the formula phi def Passing through the induction lineThe defect leakage flux of the ring;
Φ 0 -a background magnetic field flux through the induction coil;
after the induction coil 10 is integrated by the formula (2), the output voltage value is in direct proportion to the number of turns of the coil, the leakage flux of the defect and the magnetic flux of the background magnetic field and in inverse proportion to the integral constant of the integrator. For a wound induction coil 10 and a designed integrator 6, N/RC is constant. The magnetic flux of the background magnetic field and the parameters of the probe are related to the diameter of the steel wire rope to be detected, and the background magnetic flux of the same probe and the same steel wire rope is not changed in the whole detection process, and the value can be eliminated through integral adjustment or subsequent data processing. Therefore, the integral output voltage and the defect leakage flux are in a proportional relation, and the size of the steel wire rope defect can be inverted through the integral output voltage.
For the steel wire rope 7 with different rope diameters, the number of the protrusions can be increased appropriately according to the diameter, for example, 6 or 8 protrusions or even more protrusions are arranged along the circumference of the steel wire rope 7, and the schematic plan view thereof is shown in fig. 5 and 6. For 19mm steel wire rope 7, through simulation and experimental verification, set up 6 protruding structures along 7 a week of steel wire rope, can obtain better detection effect, figure 7 is to 7 steel wire ropes 7 that have 7 damage, adopts a week coil installation skeleton 1 that has 4 bellying 8, and 50 circles induction coil 10 are wound respectively on every coil installation skeleton 1 to establish ties with induction coil 10 syntropy after, adopt integrator 6 to the testing result that its integration obtained. The detection result can better invert the corresponding defects on the steel wire rope 7.
The nondestructive testing device and method for the ferromagnetic slender component provided by the invention have the following advantages:
1. the coil mounting framework 1 with high magnetic permeability is added, and the protruding parts 8 are arranged on the coil mounting framework 1, so that a specific path is provided for defect magnetic flux, the winding of the induction coil can be effectively simplified, and the signal-to-noise ratio of a detection signal is increased.
2. The induction coil 10 is wound on the non-magnetic winding framework 9, and the non-magnetic winding framework 9 is fixed on the bulge part 8 of the coil mounting framework 1 and used for detecting the damage of the steel wire rope, so that the coil is convenient to manufacture and mount.
3. The induction coils 10 on the plurality of convex parts 8 are connected in series in the same direction, and the result after the induction coils are connected in series is integrated to obtain output voltage proportional to the defect magnetic flux for inverting the defects of the steel wire rope, so that the influence of the relative movement speed of the steel wire rope 7 and the detection device on the detection result is eliminated.
4. A plurality of magnetic conductivity coil mounting frameworks 1 are adopted for splicing detection, and the installation and the disassembly are convenient.
5. According to the different diameters of the steel wire ropes 7 to be measured, the number of the convex parts 8 on the coil mounting framework 1 can be increased or decreased, so that the detection effect is improved on the basis of less winding of the induction coils 10;
6. the device is not only suitable for nondestructive testing of the steel wire rope, but also has the same testing effect on nondestructive testing of all ferromagnetic slender components.
Through the points, the signal-to-noise ratio of the induction coil 10 for the steel wire rope LMA detection signal can be effectively improved, the coil is simple in structure and convenient to wind and install, and quantitative detection research on the steel wire rope LMA is facilitated.
The nondestructive testing device and method for the ferromagnetic elongated member are suitable for nondestructive testing of elongated structures such as steel wire ropes, ferromagnetic pipelines, stay cables and rails.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
Claims (3)
1. A ferromagnetic elongated member nondestructive testing device comprising a nondestructive testing main body and an induction coil, characterized in that: the nondestructive testing device for the ferromagnetic elongated component further comprises a coil mounting framework, wherein a protruding part is arranged on the coil mounting framework, the induction coil is mounted on the protruding part, at least two protruding parts are arranged on the coil mounting framework, the induction coil is mounted on the protruding part in a series connection mode in the same direction, the protruding parts are uniformly arranged along the circumferential interval of the detection axis of the nondestructive testing main body, the protruding parts protrude along the direction of the detection axis of the nondestructive testing main body, the nondestructive testing device for the ferromagnetic elongated component further comprises a non-magnetic winding framework, the induction coil is wound on the non-magnetic winding framework, the non-magnetic winding framework is mounted and fixed on the protruding parts, the coil mounting framework is a high-magnetic conductivity material framework, the protruding parts are rectangular protruding parts, and the non-magnetic winding framework is a rectangular framework, coil installation skeleton includes two at least split type skeletons, split type skeleton concatenation is the ring form, split type skeleton includes two convex dull and stereotypeds of high magnetic conductivity, the bellying sets up two between the convex dull and stereotyped of high magnetic conductivity, the nondestructive test main part includes casing, yoke, leading wheel, encoder, signal acquisition and processing unit and integrator, the yoke sets up in the casing, be equipped with the permanent magnet on the yoke, the encoder with the leading wheel is connected, the leading wheel with the casing is connected, the output of encoder, the output of integrator respectively with signal acquisition is connected with processing unit's input, the input of integrator with induction coil connects.
2. A nondestructive testing method for a ferromagnetic elongated member is characterized by comprising the following steps: the nondestructive testing device for the ferromagnetic slender component of claim 1 is used for nondestructive testing of the loss of the metal cross-sectional area.
3. The nondestructive testing method for a ferromagnetic elongated member according to claim 2, characterized in that:
when the ferromagnetic slender component and the ferromagnetic slender component nondestructive testing device move relatively, the induction coil outputs the voltage as follows:
n is the number of turns of the induction coil;
s-curved surface enclosed by induction coil;
Φ — the magnetic flux through a closed coil of area s;
b-magnetic induction in the curved surface s;
ds-unit integral bin on curved surface s;
after integrating equation (1) with an integrator, we can obtain:
in the formula phi def -a defect leakage flux through the induction coil;
Φ 0 -a background magnetic field flux through the induction coil;
after the induction coil is integrated by a formula (2), the output voltage value of the induction coil is in direct proportion to the number of turns of the coil, the leakage flux of the defect and the magnetic flux of a background magnetic field and in inverse proportion to the integral constant of the integrator; for the wound induction coil and the designed integrator, N/RC is a constant; the integral output voltage and the defect leakage magnetic flux are in a proportional relation, and the size of the steel wire rope defect can be inverted through the integral output voltage.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| ZA871964B (en) * | 1986-03-25 | 1987-09-07 | ||
| JP4432476B2 (en) * | 2003-12-02 | 2010-03-17 | 株式会社Ｉｈｉ | Wire rope breakage detector |
| US8368395B2 (en) * | 2008-12-17 | 2013-02-05 | Ndt Technologies, Inc. | Magnetic inspection device and method for detecting loss in metallic cross section |
| CN103630723A (en) * | 2013-11-25 | 2014-03-12 | 北京航空航天大学 | Rogowski coil sensing head suitable for Rogowski coil current sensor |
| CN103760222A (en) * | 2014-01-18 | 2014-04-30 | 中国矿业大学 | Mining steel wire rope online detection device and method based on giant magnetoresistance sensor array |
| CN105588874A (en) * | 2014-10-19 | 2016-05-18 | 王帅 | Novel magnetic flux leakage sensor probe |
| CN104807879B (en) * | 2015-05-15 | 2017-12-05 | 徐州博联科技有限公司 | A kind of steel wire rope damage detection apparatus |
| CN205981091U (en) * | 2016-07-14 | 2017-02-22 | 无锡市河埒传感器有限公司 | Miniaturized differential transformer angle sensor |
| CN106290553B (en) * | 2016-08-02 | 2024-01-26 | 济南大学 | Novel electromagnetic sensor system for detecting defects of steel wire rope |
| CN107167514A (en) * | 2017-06-19 | 2017-09-15 | 中国矿业大学 | A kind of Novel steel wire rope the cannot-harm-detection device and detection method |
| CN107328851B (en) * | 2017-07-12 | 2020-11-06 | 哈尔滨工业大学深圳研究生院 | Ferromagnetic slender component nondestructive testing device based on improved coil |
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