CN102269734B - Method and device for detecting loss of metal cross section area of ferromagnetic cable rope - Google Patents

Abstract

The invention discloses a method and device for detecting loss of metal cross section area of a ferromagnetic cable rope. The method provided by the invention comprises the following steps of: winding a cable which is connected with a direct-current power supply on a detected cable rope to be used as a direct-current magnetizing coil; distributing an armature group and a magnetism-sensitive element along the circumferential direction of the cable rope; switching on a direct-current power supply and magnetizing the cable rope by a direct-current coil to form a magnetic circuit with the armature group; measuring a magnetic induction intensity value in the circuit by the magnetism-sensitive element which is placed in the magnetic circuit and outputting the value in the form of voltage; obtaining a measuring coefficient through comparing the change of voltages which are output by the magnetism-sensitive element before and after a standard sample is inserted so that the detection of the loss of the metal cross section area of the cable rope is realized. The device provided by the invention comprises the magnetism-sensitive element, the magnetizing coil, a data processor and one or more armature groups; and each armature group is composed of two symmetrical inverted-L-shaped armatures. By utilizing a way of internally placing a magnetic source, a magnetic field generated by the magnetizing coil is directly acted on the detected cable rope so that a magnetic system needed by the detection method has the advantages of small volume, light weight and convenience for adjusting.

Description

The long-pending loss detection method of ferromagnetism cable cross section metal and device thereof

Technical field

The invention belongs to Dynamic Non-Destruction Measurement, relate to the long-pending loss detection method of a kind of ferromagnetism cable cross section metal and device thereof, be used for the detection to the wearing and tearing of the ferromagnetism cables such as wire rope, suspension cable, etch state.

Background technology

The ferromagnetism cable comprises wire rope, bridge cable, recreation facility drag-line etc., as a kind of crucial load bearing component, be widely used in the industries such as colliery, metallurgy, building, traffic, tourism, in use, can generation wear and tear because cable contacts with drive disk assembly, perhaps because the external environment factor causes the cable corrosion, above-mentioned two situations all can cause the long-pending minimizing of cable cross section metal, thereby the effective bearing cross-section that reduces cable is long-pending, to the safe operation generation harm of equipment.Therefore, must take effective ways that the cable section loss is detected, guarantee the device security operation.

At present, the method that long-pending loss detects for the cable cross section metal, mainly contain the magnetic flux method, magnetic bridge road detection method, the magnetic flux method is to adopt direct current or permanent magnet mode cable to be magnetized into saturated, in cable because wearing and tearing, corrosion causes that its cross section metal is long-pending and changes, then the magnetic circuit state can change, if directly measure magnetic flux in the cable by coiling, then be called the main flux method, if in the loop, measure magnetic flux, then be called back the magnetic flux method (Yang Shuzi, Kang Yihua. steel rope fault quantitatively detects philosophy and technique. Beijing: National Defense Industry Press, 1995).The magnetic bridge path method then be by measure on whole magnetic loop build up outside magnetic bridge road (Wu Xinjun, Kang Yihua, Xie Yueyun. Three-Gorges Ship-lift steel rope fault and abrasion detection principle and realization. hi-tech communication .1998,5,44-47).In above-mentioned detection method, the flux detection method is because magnetic source is external, be that the magnetic field that permanent magnet or dc coil produce does not act directly on the measured cable, but by certain magnetic Circuit Design magnetic flux is imported in the cable, because the existence of leakage flux, will inevitably cause the magnetic energy loss, for satisfying the magnetization requirement of detection method, must improve magnetic energy, thereby whole magnetizing system volume is increased, and weight increases, and in the main flux detection method, owing to can only adopt coil mode induced field to change, thereby examined rate is larger; The magnetic bridge path method is owing to adopt mutually integration between a plurality of magnetic circuits, and for reaching the linear work point of magnetic circuit, the adjustment of whole magnetic circuit is complicated.

Summary of the invention

The object of the invention is to the deficiency for above-mentioned detection method, provide a kind of ferromagnetism cable cross section metal to amass loss detection method, the method is simple and easy effectively, is easy to realize; The present invention also provides the device of realizing the method, and this device has little, the lightweight characteristics of volume.

A kind of ferromagnetism cable cross section metal provided by the invention amasss loss detection method, comprises the steps:

It is S that the 1st step was selected one section known metal sectional area in measured cable ₀The prime area, the cable winding that will be connected with direct supply on it as the dc magnetization coil;

The 2nd step is along the one or more armature groups of cable circumferential directions, and each armature group is by two symmetries

The type armature block forms, and each armature group is all across magnetizing coil;

The 3rd step was arranged symmetrically with two of each armature group

The gap of reserving between the type armature block is arranged a magneto sensor or is arranged a magneto sensor at the gap location of armature group end and cable hold;

The 4th step was obtained the output voltage signal U of magneto sensor when direct current is passed into magnetizing coil ₀

The 5th step was S with a known sectional area _aMaterial behavior is identical with measured cable, length is put into magnetizing coil greater than the standard specimen steel wire of armature length, make standard specimen steel wire axle line parallel measured cable axis when putting into, standard specimen steel wire and measured cable all are magnetized, and put into the output voltage signal U that obtains magneto sensor behind the steel wire _a

The 6th step calculated detection coefficient according to following formula

$P=\left(\frac{U_a-U_0}{U_a}\right)/\left(\frac{S_a-S_0}{S_a}\right)$

The 7th step was taken out the standard specimen steel wire, begins to detect, and be S when detecting a certain sectional area _iWhen zone to be detected, the magneto sensor output signal U _i

The 8th step obtained the sectional area S in each zone to be detected according to following formula _iWith respect to prime area sectional area S ₀The long-pending loss amount of cross section metal:

$\mathrm{\Δ}{\mathrm{Sp}}_i=\frac{1}{P}\·\frac{U_0-U_i}{U_0}$

And obtain the sectional area S of this surveyed area _iFor:

S _i＝(1-ΔSp _i)·S ₀。

Realize the device of said method, it is characterized in that this device comprises magneto sensor, magnetizing coil, data processor and one or more armature group, each armature group is by two symmetries

The type armature block forms; During use, each armature group is all across magnetizing coil, and magneto sensor is identical with armature group quantity, is placed on two of each armature group

The gap of reserving between the type armature block or at the gap location of armature group end and cable hold; Magnetizing coil is made of in measured cable the cable winding that is connected with direct supply; Data processor links to each other with magneto sensor, obtains required result after the output valve of magneto sensor is processed.

When adopting method of the present invention and device thereof to carry out the long-pending loss detection of cable cross section metal, because the magnetic field that dc coil produces acts directly on the measured cable, do not exist because the magnetic energy that magnetic Circuit Design causes loses, magnetization efficient is high, thereby make the magnetizing system smaller volume, weight reducing; On the other hand, owing to adopt the dc magnetization mode, thus can conveniently regulate the magnetic circuit working point by regulating magnetization current, easy to adjust.Therefore, adopt method of the present invention can realize easily the detection of the long-pending loss of ferromagnetism cable cross section metal.

Description of drawings

Fig. 1 is the long-pending loss detection method of cross section metal provided by the invention and apparatus structure synoptic diagram;

Fig. 2 is the schematic diagram of the long-pending loss detection method of cross section metal provided by the invention;

Fig. 3 is the equivalent magnetic circuit modeling of the long-pending loss detection method of cross section metal provided by the invention.

Embodiment

Below by by embodiment the present invention being described in further detail, but following examples only are illustrative, and protection scope of the present invention is not subjected to the restriction of these embodiment.

As shown in Figure 1, the cable winding that will be connected with direct supply on measured cable 1 as dc magnetization coil 2, along the one or more armature groups 3 of cable 1 circumferential directions (quantity of armature group can be 1～32), each armature group 3 is arranged symmetrically with by two

The type armature block forms, and each armature group 3 is all across magnetizing coil 2, is arranged symmetrically with two of each armature group 3

A magneto sensor 4 is arranged or at magneto sensor 4 ' of gap location layout of 1 of armature group 3 ends and cable in the gap reserved between the type armature block; Open direct supply, cable 1 will be magnetized by dc coil 2, armature group 3 and armature group 3 across cable sections between form magnetic loop, be arranged in the magnetic induction density value of this magnetic loop magneto sensor 4 or magneto sensor 4 ' its present position of energy measuring circuit, and with the formal output of voltage, data processor 5 links to each other with magneto sensor 4 or magneto sensor 4 ', obtains required result after the output valve of magneto sensor is processed.

When the sectional area of cable changes, magnetic flux in the magnetic loop can change, cause magneto sensor 4 or magneto sensor 4 ' present position magnetic induction density value generation respective change in the loop, therefore the variation of magneto sensor 4 or magneto sensor 4 ' output voltage can reflect the variation of cable sectional area, the method can realize the detection of cable section loss, and its concrete realization principle is as follows.

Fig. 2 is the schematic diagram of the long-pending loss detection method of cross section metal provided by the invention, and its equivalent magnetic circuit modeling as shown in Figure 3.The implication of each parameter is among the figure: F---the mmf that magnetizing coil provides; R _a---the magnetic resistance of air in the magnetizing coil; R _c---the magnetic resistance of cable; R _g---the magnetic resistance of armature group and cable hold air-gap; R _l---the magnetic resistance of armature group; R _b---the magnetic resistance at magneto sensor measurement clearance place; Φ _a---the magnetic flux of air in the magnetizing coil; Φ _c---the magnetic flux in the cable; Φ _t---magnetic flux summation in the magnetizing coil; Φ _b---the magnetic flux at magneto sensor measurement clearance place;

Analyze magnetic circuit model shown in Figure 3, can get following 4 equatioies:

$\left\{\begin{array}{c}(2R_g+2R_l)\·{\mathrm{\Φ}}_t+R_b{\mathrm{\Φ}}_b+R_c{\mathrm{\Φ}}_c=F\left(1\right)\\ {\mathrm{\Φ}}_b={\mathrm{\Φ}}_t\left(2\right)\\ {\mathrm{\Φ}}_t={\mathrm{\Φ}}_a+{\mathrm{\Φ}}_c\left(3\right)\\ R_a{\mathrm{\Φ}}_a=R_c{\mathrm{\Φ}}_c\left(4\right)\end{array}\right.$

Formula (2), (3), (4) substitution formula (1) and abbreviation are got

$(2R_g+2R_l)\·{\mathrm{\Φ}}_b+R_b{\mathrm{\Φ}}_b+\frac{R_c{R}_a}{R_c+R_a}{\mathrm{\Φ}}_b=F---\left(5\right)$

The magnetic resistance of air in the magnetizing coil L in the formula _a, μ _a, S _aBe respectively the length of air magnetised section in the magnetizing coil, the magnetic permeability of air and the sectional area of the interior air of magnetizing coil; The magnetic resistance of cable

L in the formula _c, μ _c, S _cBe respectively the length of the cable section of being magnetized, the magnetic permeability of cable and the sectional area of cable; Because L _aAnd L _cSizableness, S _aAnd S _cSizableness, and μ _a＜＜μ _cSo, R _a＞＞R _c,

Formula (5) can be reduced to:

(2R _g+2R _l+R _b+R _c)·Φ _b＝F

Make R _s=2R _g+ 2R _l+ R _b, have

(magnetic permeability of material is μ for two sections same materials _c), (it on average magnetizes length is L to equal length _c) and sectional area is respectively S _C1, S _C2Cable C ₁, C ₂Have:

${\mathrm{\Φ}}_{b1}=\frac{F}{R_s+R_{c1}}---\left(6\right)$

${\mathrm{\Φ}}_{b2}=\frac{F}{R_s+R_{c2}}---\left(7\right)$

Φ in formula (6), (7) _B1, Φ _B2For detecting respectively cable C ₁, C ₂The time, the magnetic flux at magneto sensor measurement clearance place; R _C1, R _C2Be difference cable C ₁, C ₂Magnetic resistance; Formula (7) gets divided by formula (6):

$\frac{{\mathrm{\&Phi;}}_{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="110429142656.png"\; state="\{\{state\}\}">b</figure-callout>}2}}{{\mathrm{\&Phi;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="110429142656.png"\; state="\{\{state\}\}">b</figure-callout>}1}}=\frac{R_s+R_{c1}}{R_s+{\mathrm{<figure-callout\; id="2"\; label="R\; c"\; filenames="110429142656.png"\; state="\{\{state\}\}">R</figure-callout>}}_c}$

Conversion, $\frac{{\mathrm{\&Phi;}}_{b2}-{\mathrm{\&Phi;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="110429142656.png"\; state="\{\{state\}\}">b</figure-callout>}1}}{{\mathrm{\&Phi;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="110429142656.png"\; state="\{\{state\}\}">b</figure-callout>}1}}=\frac{R_{c1}-R_{c2}}{R_s+{\mathrm{<figure-callout\; id="2"\; label="R\; c"\; filenames="110429142656.png"\; state="\{\{state\}\}">R</figure-callout>}}_c}$

Because of R _s＞＞R _C2, R _s≈ R _s+ R _C2

So:

$\frac{{\mathrm{\&Phi;}}_{b2}-{\mathrm{\&Phi;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="110429142656.png"\; state="\{\{state\}\}">b</figure-callout>}1}}{{\mathrm{\&Phi;}}_{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="110429142656.png"\; state="\{\{state\}\}">b</figure-callout>}1}}=\frac{R_{c1}-R_{c2}}{R_s}---\left(8\right)$

With Φ _B1=B _B1S _b, Φ _B2=B _B2S _b,

Substitution formula (8):

$\frac{B_{b2}-B_{b1}}{{\mathrm{<figure-callout\; id="1"\; label="B\; b"\; filenames="110429142656.png"\; state="\{\{state\}\}">B</figure-callout>}}_b}=\frac{1}{R_s}(\frac{L_c}{{\mathrm{\&mu;}}_c{S}_{c1}}-\frac{L_c}{{\mathrm{\&mu;}}_c{S}_{c2}})=\frac{L_c}{{\mathrm{\&mu;}}_c{R}_s}(\frac{1}{S_{c1}}-\frac{1}{S_{c2}})$

Above-mentioned B _B1, B _B2For detecting respectively cable C ₁, C ₂The time, the magnetic induction density at magneto sensor measurement clearance place; S _b---the sectional area of the magnetic circuit at magneto sensor measurement clearance place.When long-pending loss detects to the cable cross section metal, might as well establish the long-pending rate of change of cable cross section metal and be

Then

$\frac{B_{b2}-B_{b1}}{{\mathrm{<figure-callout\; id="1"\; label="B\; b"\; filenames="110429142656.png"\; state="\{\{state\}\}">B</figure-callout>}}_b}=\frac{L_c}{{\mathrm{\&mu;}}_c{R}_s}(\frac{1}{S_{c1}}-\frac{1}{(1-\mathrm{\&Delta;Sp})S_{c1}})=\frac{L_c}{{\mathrm{\&mu;}}_c{R}_s{S}_{c1}}(1-\frac{1}{(1-\mathrm{\&Delta;Sp})})$

To formula

Carry out the second Taylor series by Δ Sp at Δ Sp=0 place

$\frac{1}{1-\mathrm{\&Delta;Sp}}=1+\mathrm{\&Delta;Sp}+\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="2"\; label="Sp"\; filenames="110429142656.png"\; state="\{\{state\}\}">Sp</figure-callout>}}^2+o\left(\mathrm{\&Delta;Sp}\right)$

$\frac{B_{b2}-B_{b1}}{{\mathrm{<figure-callout\; id="1"\; label="B\; b"\; filenames="110429142656.png"\; state="\{\{state\}\}">B</figure-callout>}}_b}=-\frac{L_c}{{\mathrm{\&mu;}}_c{R}_s{S}_{c1}}(\mathrm{\&Delta;Sp}+\mathrm{\&Delta;}{\mathrm{Sp}}^2)$

$\frac{B_{b1}-B_{b2}}{{\mathrm{<figure-callout\; id="1"\; label="B\; b"\; filenames="110429142656.png"\; state="\{\{state\}\}">B</figure-callout>}}_b}=\frac{L_c}{{\mathrm{\&mu;}}_c{R}_s{S}_{c1}}(\frac{S_{c1}-S_{c2}}{{\mathrm{<figure-callout\; id="1"\; label="S\; c"\; filenames="110429142656.png"\; state="\{\{state\}\}">S</figure-callout>}}_c}+{\left(\frac{S_{c1}-S_{c2}}{S_{c1}}\right)}^2)$

Note $\mathrm{\&Delta;Bp}=\frac{B_{b1}-B_{b2}}{B_{b1}},$ $P=\frac{L_c}{{\mathrm{\&mu;}}_c{R}_c{S}_{c1}}---\left(9\right)$

Δ Bp=P (Δ Sp+ Δ Sp then ²) (10).

Magneto sensor (such as Hall element) output voltage values U in its normal operation range is directly proportional with the measured place magnetic induction density B, that is:

U＝K _H·B

K in the formula _HSensitivity coefficient for Hall element.Xiang Yingyou:

ΔUp＝ΔBp＝P(ΔSp+ΔSp ²) (11)

Δ Up is the rate of change of hall element output voltage value in the formula.

Formula (10) expression be relation between magneto sensor measured place magnetic induction density rate of change and the cable sectional area rate of change.When the long-pending rate of change of cable cross section metal hour, namely Δ Sp hour, magneto sensor measured place magnetic induction density rate of change Δ Bp amasss rate of change Δ Sp with the cable cross section metal and is directly proportional; When the long-pending rate of change of cable cross section metal continues to increase, magnetic induction density rate of change Δ Bp and Δ Sp+ Δ Sp ²Or more the Δ Sp of high-order is directly proportional.For for the labour cable, the long-pending rate of change of its cross section metal is usually less, therefore the long-pending rate of change Δ Sp of cable cross section metal roughly is directly proportional with magneto sensor measured place magnetic induction density rate of change Δ Bp, by being set at the measurement incision position, magneto sensor can detect the long-pending loss percentage of cable cross section metal, as magneto sensor be Hall element then the long-pending rate of change Δ Sp of hall element output voltage rate of change Δ Up and cable cross section metal be directly proportional, suc as formula (11) expressed relation.

In formula (9), need known L _c, μ _c, R _s, S _C1Numerical value just can obtain parameter P value, and L _c, μ _c, R _sConcrete numerical value difficulty accurately obtain, but for definite cable cross section metal long-pending loss detecting sensor and drag-line, L _c, μ _c, R _sDefinite value, therefore can be by adopting one section sectional area known, material behavior is identical with measured cable, length comes calibrating parameters P value greater than the standard specimen steel wire of armature length, concrete grammar such as following step 1)～6).

During actual use the method, take successively following steps:

1) as shown in Figure 1, selecting one section known metal sectional area in measured cable 1 is S ₀The prime area, the cable winding that will be connected with direct supply on it as dc magnetization coil 2;

2) along the one or more armature groups 3 of cable 1 circumferential directions (quantity of armature group can be 1～32), each armature group 3 is arranged symmetrically with by two

The type armature block forms, and each armature group 3 is all across magnetizing coil 2;

3) be arranged symmetrically with two of each armature group 3

A magneto sensor 4 is arranged or at magneto sensor 4 ' of gap location layout of 1 of armature group 3 ends and cable in the gap reserved between the type armature block;

When 4) direct current being passed into magnetizing coil 2, obtain the output voltage signal U of magneto sensor 4 or magneto sensor 4 ' ₀

5) be S with a known sectional area _aMaterial behavior is identical with measured cable, length is put into magnetizing coil 2 greater than the standard specimen steel wire of armature length, make standard specimen steel wire axle line parallel measured cable axis when putting into, standard specimen steel wire and measured cable all are magnetized, and put into the output voltage signal U that obtains magneto sensor behind the steel wire _a

6) calculate detection coefficient according to following formula

$P=\left(\frac{U_a-U_0}{U_a}\right)/\left(\frac{S_a-S_0}{S_a}\right)$

7) taking out the standard specimen steel wire, begin to detect, is S when detecting a certain sectional area _iWhen zone to be detected, the magneto sensor output signal U _i

8) can obtain the sectional area S in each zone to be detected according to following formula _iWith respect to prime area sectional area S ₀The long-pending loss amount of cross section metal:

$\mathrm{\&Delta;}{\mathrm{Sp}}_i=\frac{1}{P}\&CenterDot;\frac{U_0-U_i}{U_0}$

And sectional area S that can this surveyed area _iFor:

S _i＝(1-ΔSp _i)·S ₀

The above is preferred embodiment of the present invention, but the present invention should not be confined to the disclosed content of this embodiment and accompanying drawing.So everyly do not break away from the equivalence of finishing under the spirit disclosed in this invention or revise, all fall into the scope of protection of the invention.

Claims (1)

1. the long-pending loss detection method of ferromagnetism cable cross section metal is characterized in that the method comprises the steps:

It is S that the 1st step was selected one section known metal sectional area in measured cable ₀The prime area, the cable winding that will be connected with direct supply on it as the dc magnetization coil;

The 2nd step is along the one or more armature groups of cable circumferential directions, and each armature group is by two symmetries

The type armature block forms, and each armature group is all across magnetizing coil;

The 3rd step was arranged symmetrically with two of each armature group

The gap of reserving between the type armature block is arranged a magneto sensor or is arranged a magneto sensor at the gap location of armature group end and cable hold;

The 4th step was obtained the output voltage signal U of magneto sensor when direct current is passed into magnetizing coil ₀

The 5th step was S with a known sectional area _aMaterial behavior is identical with measured cable, length is put into magnetizing coil greater than the standard specimen steel wire of armature length, make standard specimen steel wire axle line parallel measured cable axis when putting into, standard specimen steel wire and measured cable all are magnetized, and put into the output voltage signal U that obtains magneto sensor behind the steel wire _a

The 6th step calculated detection coefficient according to following formula

$P=\left(\frac{U_a-U_0}{U_a}\right)/\left(\frac{S_a-S_0}{S_a}\right)$

The 7th step was taken out the standard specimen steel wire, begins to detect, and be S when detecting a certain sectional area _iWhen zone to be detected, the magneto sensor output signal U _i

The 8th step obtained the sectional area S in each zone to be detected according to following formula _iWith respect to prime area sectional area S ₀The long-pending loss amount of cross section metal:

${\mathrm{\&Delta;Sp}}_i=\frac{1}{P}\&CenterDot;\frac{U_0-U_i}{U_0}$

And obtain the sectional area S of this surveyed area _iFor:

S _i＝(1-ΔSp _i)·S ₀。

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