WO1996000386A1 - Procede et dispositif de detection de defauts au moyen d'un flux de fuite, et detecteur de defauts utilisant un flux de fuite - Google Patents

Procede et dispositif de detection de defauts au moyen d'un flux de fuite, et detecteur de defauts utilisant un flux de fuite Download PDF

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Publication number
WO1996000386A1
WO1996000386A1 PCT/JP1995/001254 JP9501254W WO9600386A1 WO 1996000386 A1 WO1996000386 A1 WO 1996000386A1 JP 9501254 W JP9501254 W JP 9501254W WO 9600386 A1 WO9600386 A1 WO 9600386A1
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WO
WIPO (PCT)
Prior art keywords
defect
magnetic flux
sensor
magnets
leakage
Prior art date
Application number
PCT/JP1995/001254
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English (en)
Japanese (ja)
Inventor
Toshiyuki Suzuma
Original Assignee
Sumitomo Metal Industries Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP13340895A external-priority patent/JPH08327602A/ja
Priority claimed from JP13779895A external-priority patent/JPH0868778A/ja
Priority claimed from JP14369595A external-priority patent/JPH08334495A/ja
Application filed by Sumitomo Metal Industries Limited filed Critical Sumitomo Metal Industries Limited
Priority to DE19580847T priority Critical patent/DE19580847T1/de
Priority to US08/549,674 priority patent/US5747988A/en
Publication of WO1996000386A1 publication Critical patent/WO1996000386A1/fr

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
    • G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws

Definitions

  • the present invention relates to a method and apparatus for detecting magnetic flux leakage and a magnetic flux detection sensor.
  • the present invention relates to a magnetic flux leakage detection method and a magnetic flux leakage detection apparatus for magnetizing a magnetic material to be inspected and detecting a magnetic flux generated based on the defect to inspect the material to be inspected.
  • the present invention relates to a sensor for detecting a leakage magnetic flux generated due to a defect of a magnetized test piece.
  • FIG. 1 is a schematic side view showing a conventional rotary type magnetic flux leakage inspection device
  • FIG. 2 is a schematic partial enlarged view of FIG.
  • Feeding devices 81, 81 having a pair of upper and lower rolls for holding the flaw-detected material P and transporting the flaw-detected material P in the arrow direction are provided in the transport area of the rod-shaped or tubular flaw-detected material P which is a ferromagnetic material. It is located at a distance.
  • An annular rotary head 71 is disposed between the two feeders 81, 81, and the material P to be inspected passes through the rotary head 71.
  • a pair of electromagnets 72.72 for magnetizing the material to be inspected P are mounted on the rotary head 71 at a predetermined distance in the circumferential direction of the rotary head 71, and are located approximately at the center of the two electromagnets 72, 72. Is equipped with a sensor 73, such as a magnetic-sensitive element that detects changes in magnetic flux density due to defects and a search coil.
  • the rotating head 71 is mounted coaxially with the central axis of the rotating device 80 on the entry side of the material to be detected P of the ring-shaped rotating device 80 for driving the rotating head 71 to rotate.
  • the output signal of the sensor 73 is supplied to the defect signal analyzer 82 via the rotating device 80.
  • the output side of the rotating device 80 A marking device 83 for marking the position of the issued defect is provided, and the surface of the material P to be inspected is marked according to a command from the defect signal analyzing device 82.
  • the defect signal analyzer 82 When the output signal provided from the sensor 73 is equal to or greater than a predetermined value, the defect signal analysis device 82 gives a command to the marking device 83 to cause marking around the corresponding portion of the material P to be inspected. As a result, the entire circumference and the entire length of the material P to be inspected are inspected.
  • the conventional apparatus for magnetizing the material to be inspected by a pair of magnets has a problem that the detection sensitivity is reduced when the direction of the defect generated in the material to be inspected is close to the magnetization directions of both magnets.
  • Fig. 3 is a graph showing the relationship between the direction of the defect and the output of the sensor.
  • the abscissa indicates the inclination angle 0 of the defect with respect to the central axis of the material to be inspected, and the ordinate indicates the output of the sensor.
  • the sensor 73 used for detecting the leakage magnetic flux is usually a magnetic sensor including a magnetic element such as a hall element or a magnetoresistive element, or a ferrite core.
  • a coil sensor in which a conductive wire is wound.
  • the conventional sensor 73 has a rectangular cross section of the magnetic sensing part in order to increase the detection sensitivity in response to the linear defect K that occurs frequently in the longitudinal direction of the material P to be inspected. It is formed so that its long side is parallel to the extension direction of the defect K.
  • the length of defect K is approximately 8 mm to 14 mm, and is often a heavy defect that degrades product quality.
  • the noise generated by the vibration caused by the transport of the material P to be inspected and the rotation of the rotary head 71 cannot be reduced, so that the SZN is low. there were. Therefore, sensors with the following two magnetically sensitive parts have been put to practical use.
  • FIG. 4 is a schematic plan view showing a conventional leakage magnetic flux detection sensor.
  • the sensor 76 has two magnetic sensing parts 75, 75 facing each other, and the two magnetic sensing parts 75, 75 are arranged at a predetermined distance in a flaw detection direction indicated by an outline arrow in the figure.
  • the shape of both magneto-sensitive portions 75, 75 is a rectangle that is long in the direction perpendicular to the flaw detection direction, and the length L is about 3 mm.
  • both the magneto-sensitive portion 75, 75 of the center 0!, The distance d between 0 2 is about 1 mm.
  • FIG. 5 is a plan view showing a state in which a defect is detected by the sensor 76 shown in FIG. 4, and FIG. 6 is a side sectional view thereof.
  • the defect K often occurs in the longitudinal direction, and in order to detect the defect K in such a direction with high sensitivity, the sensor 76 applies the magnetically sensitive portions 75, 75 to the material to be inspected. Inspection is performed in a direction perpendicular to the longitudinal direction of the material P to be inspected, as indicated by the white arrow in the figure, so as to be parallel to the longitudinal direction of P.
  • the material to be inspected P is magnetized so as to face the inspection direction of the sensor 76. As shown in FIG. 6, near the defect K, the magnetic flux J leaks from the material to be inspected P to above the defect K. It returns to the material to be inspected P again. Therefore, when the two magnetic sensing parts 75, 75 of the sensor 76 are located at the position sandwiching the defect K, the magnetic sensing part 75 and the magnetic sensing part 75 detect magnetic fluxes of opposite polarities to each other. The defect signal is amplified by subtracting the 75 and 75 detection signals.
  • the noise generated by the vibration caused by the transport of the material to be inspected P and the scanning of the sensor 76 is detected as the same polarity by the magnetic sensing units 75, 75, and thus the detected noise signal is subjected to the subtraction processing described above.
  • the level is reduced and a high SZN is obtained.
  • FIG. 7 is a graph showing a detection signal of each of the magnetic sensing units 75 and 75 of the sensor 76 shown in FIG. 6 and a signal obtained by subtracting both detection signals.
  • the detection signal of the magneto-sensitive section 75 in front of Indicates a detection signal of the magneto-sensitive section 75 on the rear side, and (c) indicates a signal subjected to subtraction processing.
  • the magneto-sensitive part 75 in front of the flaw detection direction detects an upward defect signal following a downward defect signal.
  • the magneto-sensitive section 75 at the rear detects the downward defective signal.
  • the base lines of the detection signals of both magneto-sensitive sections 75, 75 have irregularities due to the noise signal ⁇ , as is clear from Figs. 7 (a) and (b), the directions are the same. . Therefore, as is clear from FIG. 7 (c), when the detection signals of the two magnetic sensing units 75, 75 are subtracted, the defective signal is amplified and its amplitude is large, the noise signal is reduced, and the baseline is substantially reduced. It is straight. As a result, the SZN is increased and the defect detection sensitivity is improved.
  • FIG. 8 is a plan view showing the relationship between a sensor that moves two magnetically sensitive parts and the inclination of the defect.
  • reference numeral 76 denotes a sensor.
  • the sensor 76 for detecting a flaw-detected material P in the outline arrow direction in the drawing includes the magnetic sensing portions 75, 75 that are long in a direction orthogonal to the flaw detection direction.
  • the defect K 1 in a direction parallel to the magneto-sensitive portions 75, 75 the defect K 2 shown by the broken line is inclined by 0 from the direction of the reference defect K 1.
  • Fig. 9 is a graph showing the relationship between the defect inclination angle 0 and the defect signal amplitude by the conventional leakage magnetic flux detection sensor.
  • the vertical axis shows the defect signal amplitude
  • the horizontal axis shows the inclination angle 0. I have.
  • the tilt angle 0 0 °
  • the amplitude of the defective signal is maximum, and the amplitude is almost the same up to the tilt angle of 0 ⁇ 18 °. Beyond that, the amplitude of the defect signal sharply diminishes.
  • the tilt angle 0 ⁇ 18 ° is a critical tilt angle.
  • the length L of the magnetic sensing part 75, 75 is 3 mm, and the distance d is 1 mm.
  • the angle 0 c critical slope between the line connecting the center of one end of the part 75 and the center of the other end of the other part 75 and the central axes u, (u 2 ) in the longitudinal direction of the part 75 (75) The angle is about 18 °. Therefore, for the defect K having the inclination angle 0 of about 18 ° or more, the defect signal is detected simultaneously by the two magnetic sensing units 75, 75, and the amplitude of the defect signal is reduced by the subtraction processing.
  • the critical tilt angle is small, so that even a defect with a relatively small tilt angle 0 exceeds the critical tilt angle 0 c, and the amplitude of the defect detection signal is small. And the possibility of erroneous determination was high.
  • the following method can be used to detect the defect with high sensitivity. Conceivable. That is, as shown in FIG. 11, a magnetic sensing part 80 having a circular cross section is used alone, and the magnetic sensing part 80 is scanned in a direction orthogonal to the reference direction. . In this case, as shown in FIGS. 12 (A) and (B), the relative positional relationship between the magneto-sensitive part 80 and the defect K in the plane is magneto-sensitive regardless of the inclination angle of the defect K being 0.
  • the linear defect K can be detected with high sensitivity without being affected by the tilt angle 0.
  • two magnetic sensing units 80 are arranged side by side in the scanning direction, and the two magnetic sensing units are differentially connected to each other to perform subtraction.
  • the sensor is used as a sensor, the same phenomenon occurs when two magnetic sensing units 75 with a rectangular cross section are arranged side by side as described above.
  • An existing defect that is inclined in a direction different from the direction cannot be detected with the same sensitivity as an existing defect that extends in the reference direction.
  • An object of the present invention is to provide a method and an apparatus for detecting a magnetic flux leakage which can direct-magnetize a defect in a different direction without lowering the inspection speed.
  • Still another object of the present invention is to provide a method and apparatus for detecting a magnetic flux leakage, which can increase the magnetic flux leakage from the defect and detect the defect with high sensitivity.
  • Still another object of the present invention is to be able to use as a subtraction sensor adopting an inexpensive, simple and effective subtraction process as a noise suppression means, and to reduce the depth of existing defects inclined in a direction other than the reference direction.
  • An object of the present invention is to provide a sensor for detecting a magnetic flux leakage with a constant sensitivity and high accuracy as long as the magnetic flux is the same. Disclosure of the invention
  • the magnetic flux leakage inspection apparatus magnetizes the material to be inspected by a pair of magnets, and detects the magnetic flux to be leaked by a sensor provided between the two magnets.
  • a sensor provided between each of the two pairs of magnets for magnetizing the material to be inspected in a direction different from the above. Magnetized region
  • the target material is magnetized in different directions with respect to the flaw detection direction by two pairs of magnets arranged at a predetermined distance in the flaw detection direction.
  • the defect generated in the material to be inspected crosses either of the magnetization directions in any direction, and a leakage magnetic flux is generated.
  • the defect is generated by a sensor arranged between each of the two pairs of magnets. Detects leaked magnetic flux. Since the magnetized regions of the two pairs of magnets are separated from each other, DC magnetization can be performed, and the direction and depth of the defect can be quantitatively detected.
  • the magnets of the pair are each capable of changing the direction of magnetization, and the two sensors are each capable of changing the detection area. Therefore, by changing the position of one of the paired magnets or by changing the IS separation between the two magnets, the direction in which the material to be inspected is magnetized is changed to the inclination angle of the defect that frequently occurs. Adjust to. This makes it possible to increase the leakage flux from the defect.
  • the detection area of the sensor can be changed, the detection area is appropriately adjusted according to the adjustment of the magnetization direction.
  • Another leakage magnetic flux flaw detection device of the present invention is a leakage magnetic flux flaw detector that magnetizes a pipe with a pair of magnets, detects a magnetic flux leakage with a sensor provided between the two magnets, and flaws the pipe in the circumferential direction.
  • both magnets are arranged so that two magnetized regions are formed on the circumferential surface of the tube in a direction different from the circumferential direction, and sensors are provided in both magnetized regions.
  • the pair of magnets magnetizes the tube in two different directions from the circumferential direction, which is the flaw detection direction.
  • any defect in the tube material regardless of the direction in which it crosses, will intersect with either of the magnetization directions, causing leakage flux, and the leakage flux generated by the sensors arranged in the two magnetization regions will be reduced.
  • To detect In the case of tubing, it is possible to perform DC magnetization in two directions with a pair of magnets, whereby the direction and depth of the defect can be quantitatively detected.
  • both magnets can change the direction of magnetization, and the two sensors can change the detection area. Therefore, by changing the position of one of the paired magnets or by changing the distance between the two magnets, the direction of magnetizing the tube is adjusted to the inclination angle of the defect that frequently occurs. As a result, the leakage flux from the defect can be increased.
  • the detection area of the sensor can be changed, the detection area is appropriately adjusted according to the adjustment of the magnetization direction.
  • means for calculating an output ratio between the two sensors, a relationship between a predetermined output ratio and a tilt angle of a defect, and a calculated output Means for determining the tilt angle of the defect based on the ratio, and a relationship between a predetermined tilt angle of the defect and a change rate of the amplitude of the output signal of the sensor and the determined tilt angle of the defect. Means for correcting the amplitudes of the output signals of both sensors, and means for calculating the depth of the defect based on the corrected amplitudes of the output signals are provided.
  • the sensor for detecting magnetic flux leakage is generated by a defect of a material to be inspected magnetized by two magnetic sensing parts disposed opposite to the material to be inspected and separated by a predetermined distance in the inspection direction.
  • a sensor for detecting the leakage magnetic flux in which the dimension d between the centers of the two magnetic sensing parts is 4 mm or less, the dimension L in the direction perpendicular to the flaw detection direction is 0.5 mm or more, and d ZL Is greater than or equal to 1. If the distance d between the centers of both magneto-sensitive sections is within 4 mm or less, the defect signal is amplified by subtracting the detection signal from both magneto-sensitive sections, and the defect can be detected with high sensitivity. .
  • the dimension L in the direction perpendicular to the flaw detection direction of the magnetic sensing part can be reduced to 0.5 mm. If d ZL is 1 or more, the critical inclination angle is 0 even if the dimension L is 0.5 mm. c is about 45 ° and the inclination angle 0 is relatively large Can be detected in degrees.
  • both magnetic sensing portions are formed regardless of the inclination angle of the defect. Are substantially the same.
  • Another sensor for detecting magnetic flux leakage is a sensor for detecting magnetic flux leaking from a defect of a magnetized material to be inspected, and has a circular cross-sectional shape and two different cross-sectional areas.
  • the magneto-sensitive parts are arranged concentrically. Since two magneto-sensitive parts with circular cross-sectional shapes with different cross-sectional areas are arranged concentrically, even when detecting magnetic flux leaking from an existing defect by tilting in a direction other than the reference direction, The relative relationship between the two magnetosensitive portions and the defect in the horizontal plane is constant around its axis. C As a result, the output is always constant without being affected by the inclination angle of the defect. Therefore, it is possible to detect a defect existing in a direction other than the reference direction with high accuracy.
  • Fig. 1 is a schematic side view showing a conventional rotary type magnetic flux leakage detector
  • Fig. 2 is a schematic partial enlarged view of Fig. 1
  • Fig. 3 shows the relationship between the inclination angle of the defect and the sensor output.
  • Fig. 4 is a schematic plan view showing a conventional sensor for detecting leakage magnetic flux
  • Fig. 5 is a plan view showing a state where a defect is detected by the sensor shown in Fig. 4
  • Fig. 7 is a side view showing a state where a defect is detected by the sensor shown in Fig. 4, and Fig. 7 is a process of subtracting the detection signal of each magnetic sensing part of the sensor shown in Fig. 6 and both detection signals.
  • FIG. 4 is a schematic plan view showing a conventional sensor for detecting leakage magnetic flux
  • Fig. 5 is a plan view showing a state where a defect is detected by the sensor shown in Fig. 4
  • Fig. 6 is a side view showing
  • FIG. 8 is a plan view showing the relationship between the sensor having two magnetically sensitive parts and the inclination of the defect
  • FIG. 9 is a graph showing the inclination angle of the defect by the conventional sensor for detecting magnetic flux leakage.
  • FIG. 10 is a graph showing a relationship with a defect signal amplitude
  • FIG. 10 is a schematic plan view showing a conventional sensor for detecting a magnetic flux leakage
  • FIG. Fig. 12 illustrates a conventional method for preventing the signal amplitude from decreasing due to the inclination angle of a defect.
  • Figs. 12 (A) and (B) use a magnetic sensing part with a circular cross section.
  • FIG. 13 is a view for explaining that a reduction in signal amplitude can be prevented by the conventional method.
  • FIG. 13 is a view for explaining that a reduction in signal amplitude can be prevented by the conventional method.
  • FIG. 13 is a schematic side view showing a magnetic flux leakage inspection apparatus according to the present invention.
  • FIG. 14 is a view showing FIG. Fig. 5 is a cross-sectional view taken along line A-A in Fig. 14, and Fig. 16 is a cross-sectional view taken along line B-B in Fig. 14.
  • FIG. 17 is a cross-sectional view taken along the line C--C in FIG. 14,
  • FIG. 18 is a schematic plan view showing a main part of the magnetic flux leakage inspection apparatus of the present invention
  • FIG. FIG. 20 is a partially cutaway perspective view showing a main part of a leakage magnetic flux detection device according to another embodiment, FIG. 20 is a cross-sectional view taken along line D-D in FIG. 19, and FIG.
  • FIG. 22 is a graph showing the relationship between the inclination angle of the defect and the output ratio of both sensors.
  • Fig. 23 is a flowchart showing the processing procedure in the magnetic flux leakage inspection method of the present invention.
  • Fig. 24 (A ) And (B) are waveform diagrams showing the output signals of both sensors for a flaw-detected material having multiple defects with only different inclination angles, using the device shown in Fig. 13, and Fig. 25
  • FIG. 26 is a graph showing a test curve of the inclination angle of the defect
  • FIG. 26 is a waveform diagram showing the result of correcting the output of both sensors based on the inclination angle of the defect, and FIG.
  • FIG. 27 is a sensor for detecting magnetic flux leakage according to the present invention.
  • FIG. 28 is a schematic plan view showing a state in which a defect is detected using the first embodiment of FIG. 28,
  • FIG. 28 is a plan view showing the first embodiment of the leakage magnetic flux sensor, and
  • FIG. FIG. 28 is a sectional view taken along line E—E of FIG. 28.
  • FIG. 30 is a plan view showing a modification of the first embodiment of the leakage magnetic flux detection sensor.
  • FIG. 32 is a plan view showing another modified example of the leakage magnetic flux detection sensor according to the first embodiment;
  • FIG. 32 is a plan view showing a material to be inspected;
  • FIG. 33 is a side view showing an electromagnet for magnetizing the material to be inspected;
  • FIG. 34 is a waveform diagram of a signal obtained by subtracting both detection signals from a signal detected by a conventional sensor for detecting a magnetic flux leakage
  • FIG. 35 is a first embodiment of the sensor for detecting a magnetic flux leakage
  • FIG. 36 is a waveform diagram of a signal obtained by subtracting the two detection signals and a detection signal obtained by the above method.
  • FIG. 36 is a graph showing a relationship between the inclination angle of the defect and the amplitude of the defect signal. Is a longitudinal sectional view of a second embodiment of the sensor for detecting magnetic flux leakage according to the present invention, a sectional view taken along line FF of (A), and
  • FIGS. 2 is a diagram for explaining the relative positional relationship between the embodiment and the defect, FIG.
  • FIG. 39 is a waveform diagram of a detection signal of the second embodiment of the leakage magnetic flux sensor and a signal obtained by subtracting both detection signals
  • FIG. FIG. 40 is a plan view showing a modification of the second embodiment of the leakage magnetic flux detection sensor
  • FIGS. 41 (A) and (B) are other modifications of the second embodiment of the leakage magnetic flux detection sensor
  • Fig. 42 is a plan view showing the material to be inspected
  • Figs. 43 (A) and 43 (B) show the detection signals of the leakage magnetic flux detection sensor according to the second embodiment.
  • Detection signal The waveform diagram of the signal obtained by the arithmetic processing, the waveform diagram of the signal detected by the conventional sensor for detecting the leakage magnetic flux and the signal obtained by subtracting the two detection signals, and FIG. 44 shows the relationship between the inclination angle of the defect and the amplitude of the defect signal. It is a graph which shows a relationship.
  • FIG. 13 is a schematic side view showing a magnetic flux leakage inspection device according to the present invention, in which P is a bar-shaped or tube-shaped material to be inspected which is a ferromagnetic material.
  • feeders 23, 23 each having a pair of upper and lower rolls are arranged at a predetermined distance to hold the material P to be inspected and transport it in the direction of the arrow.
  • a ring-shaped rotating head 10 having a plurality of electromagnets for magnetizing the material to be inspected P and a sensor for detecting leakage magnetic flux is arranged. Material to be inspected P in 10 Is going to pass.
  • the rotating head 10 is mounted coaxially with the center axis of the rotating device 20 on the entry side of the annular rotating device 20 for driving the rotating head, and the material to be inspected P is rotated and driven.
  • the output signal from the sensor of the rotating head 10 is supplied to the defect signal analyzer 22 through the rotating device 20, and the output side of the rotating device 20 indicates the position of the detected defect.
  • a marking device 21 for attaching is provided. Then, when it is determined that a defect exists, the defect signal analyzer 22 gives a finger to the marking device 21 to make a marking around the corresponding portion of the material P to be detected.
  • FIG. 14 is a partially cutaway perspective view of the rotary head 10 shown in FIG. 13, and FIGS. 15, 16 and 17 are respectively the same as those in FIG. They are a cross-sectional view along line A-A, a cross-sectional view along line B-B, and a cross-sectional view along line CC.
  • the rotating head 10 has four sensors 3a, which detect the leakage magnetic flux of the first magnetic pole part 1, the magnetically sensitive element, the search coil, etc., where two electromagnets la and lb are attached to face each other.
  • the detector 3 on which 3b, 3c, and 3d are mounted, and the second magnetic pole in which two electromagnets 2a and 2b are mounted to face the electromagnet l a.lb of the first magnetic pole part 1 in a direction substantially orthogonal to the direction of lb. Part 2 is provided.
  • the sensors 3a, 3b, 3c, 3d are provided so as to be located at approximately the center of a line connecting the electromagnets la, lb of the first magnetic pole portion 1 and the electromagnets 2a, 2b of the second magnetic pole portion 2. .
  • the electromagnets la, lb, 2a, and 2b of the first magnetic pole part 1 and the second magnetic pole part 2 rotate their cores 12, 12, 12, and 12 by a predetermined length as shown in FIGS. 15 and 17.
  • the magnetized coils 13, 13, 13, 13 and 13 are wound around the protruding portion of the head 10.
  • the two magnetic stones la and lb of the first magnetic pole part 1 are both excited to the N pole (S pole), and the two electromagnets of the second magnetic pole part 2 1 u
  • the material P to be inspected is magnetized in four directions that are oblique to the central axis and whose angles are symmetrical.
  • two electromagnets la, lb, 2a, and 2b are attached to the first magnetic pole portion 1 and the second magnetic pole portion 2, respectively, but at least one of the first magnetic pole portion I and the second magnetic pole portion 2 It is sufficient if one magnet is attached to the other and two magnets with opposite polarity magnetic poles are attached to the other. Further, in this embodiment, an electromagnet is attached to the rotating head 10 in order to detect a dedicated material or a tube material. However, it is needless to say that the configuration may be such that a material is detected.
  • FIG. 18 is a schematic plan view showing a main part of the magnetic flux leakage inspection apparatus of the present invention.
  • the electromagnet la of the first magnetic pole portion is disposed upstream of the material P to be transferred in the direction of the arrow, and the electromagnets 2a and 2b of the second magnetic pole portion are located downstream of the electromagnet la and 2b of the material P.
  • a first sensor 3a and a second sensor 3b are arranged at a substantially middle point between the electromagnet la of the first magnetic pole portion and the electromagnets 2a and 2b of the second magnetic pole portion.
  • the electromagnet la of the first magnetic pole portion is excited to the N pole, and the electromagnets 2a and 2b of the second magnetic pole portion are excited to the S pole.
  • a magnetization region having a magnetization angle ⁇ in a plan view with respect to an axis orthogonal to the central axis I of the material P to be inspected, and A magnetization region having a magnetization angle (one degree) symmetrical to the central axis I is generated.
  • the defect K having a tilt angle of 0 with respect to the central axis I of the material P to be inspected is magnetized by the above-mentioned two magnetized regions by flaw detection in the direction of the white arrow, and the leakage magnetic flux is generated. Is detected by both sensors 3a and 3b, respectively.
  • the rotating head 10 shown in FIG. 14 has spacers interposed between the first magnetic pole part 1 and the detecting part 3 and between the detecting part 3 and the second magnetic pole part 2, respectively. You can get it.
  • the spacers of various widths are prepared in advance, so that the above-mentioned magnetization angle ( ⁇ , -0) can be appropriately changed. Then, by changing the magnetization angle ( ⁇ , - ⁇ ) to a tilt angle of 0 that occurs frequently at a predetermined cycle, a high detection sensitivity can be maintained.
  • FIG. 19 is a partially cutaway perspective view showing another embodiment of the magnetic flux leakage inspection apparatus of the present invention, in which a pair of electromagnets la and lb magnetize the material P to be inspected in two directions different from the inspection direction. It has been done.
  • FIG. 20 is a sectional view taken along the line DD in FIG.
  • a groove 4 is formed in the inner peripheral wall of the cylindrical rotary head 10 in the longitudinal direction, and an electromagnet la is slidably fitted and fixed to one end of the groove 4.
  • An electromagnet lb is fixed to the inner peripheral wall at the other end of the rotating head 10 at a position substantially different from the electromagnet la by 180 °.
  • the test piece P is magnetized by the electromagnets la and lb in two directions that connect the centers of both electromagnets la and lb and pass through the peripheral surface of the test piece P.
  • the above-described magnetization angles (,-) can be changed. Therefore, high detection sensitivity can be maintained by changing the magnetization angle ( ⁇ , - ⁇ ) to the tilt angle 0, which frequently occurs, as in the above-described embodiment.
  • grooves 6a and 6b are formed on the inner peripheral wall between the two electromagnets la and lb of the rotary head 10, respectively.
  • Supporting rods for supporting the sensors 3a and 3b are provided at both ends of the grooves 6a and 6b.
  • 5a and 5b are slidably fitted and fixed. The position of the support rod 5a. It has been adjusted to be Thus, even when the position of the electromagnet la is changed, the sensors 3a and 3b can detect the leakage magnetic flux from the defect with high sensitivity. In this embodiment, it is needless to say that the position of the electromagnet la can be changed, and the position of the electromagnet lb can also be changed.
  • 21 is a graph showing the relationship between the inclination angle of the defect and the output of the sensor in the magnetic flux leakage inspection device of the present invention, and the solid line in the figure shows the output (amplitude) of the one sensor (first sensor) described above. , And the dashed line indicates the output (amplitude) of the other sensor (second sensor).
  • the outputs of both sensors change depending on the inclination angle 0 of the defect. The change of both outputs is symmetrical.
  • the output of the first sensor becomes maximum
  • the output of the second sensor becomes maximum.
  • the output of the sensor becomes maximum.
  • the output ratio of both sensors is obtained as follows.
  • FIG. 22 is a graph showing the output ratio of the first sensor and the second sensor.
  • the output ratio and the tilt angle 0 correspond one to one. Therefore, this curve can be used as a test curve, and by obtaining such a test curve in advance, the inclination angle 0 of the defect is calculated based on the detected output ratio of the first sensor and the second sensor. it can.
  • the amplitude of the output signal of the sensor can be corrected based on the graph of FIG. 21 described above. Since the amplitude of the corrected output signal is directly proportional to the depth of the defect, the depth of the defect can be determined by determining the relationship between the two by a test using an artificial defect whose depth is known in advance. It becomes possible.
  • FIG. 23 is a flowchart showing a procedure for processing the output signals of the first sensor 3a and the second sensor 3b shown in FIG. 18 based on such a viewpoint.
  • the output signals of the first sensor 3a and the second sensor 3b are fetched (step S1), and converted into digital signals (step S2). Then, the first sensor 3a and the second sensor 3b for the same defect
  • the detection time difference is corrected (step S3), and the output ratio of both sensors is calculated (step S4).
  • the inclination angle of the defect is determined based on the relationship between the predetermined inclination angle of the defect and the output ratio (see FIG. 22) and the output ratio calculated in the previous step S4 (step S5). ). Similarly, based on the relationship between the predetermined inclination angle of the defect and the change in the output signal amplitude of the sensor (see FIG. 21), and the inclination angle of the defect obtained in the previous step S5, the first cell is obtained. The amplitude of the output signal of the sensor 3a and the amplitude of the defect is corrected based on the relationship between the amplitude of the output signal and the depth of the defect and the amplitude of the corrected output signal (step S6). Is calculated (step S7). Then, the inclination angle of the defect obtained in step S5 and the depth of the defect obtained in step S7 are output to an external storage device or the like (step S8).
  • FIG. 24 is a waveform diagram showing the output signal of the sensor for a flaw-detected material formed with a plurality of defects having only different inclination angles using the apparatus shown in FIG. (B) shows the output signal of the second sensor, and (B) shows the output signal of the second sensor.
  • the first sensor and the second sensor use a magnetic diode element having a cross section of 1 mm x 3 mm for the magnetosensitive section, and the electromagnets are arranged so that the magnetization angle ⁇ thereof is ⁇ 25 °.
  • the sample was inspected for flaws.
  • FIG. 25 is a graph showing a test curve of the inclination angle of the defect obtained in advance, in which the vertical axis represents the output ratio and the horizontal axis represents the inclination angle.
  • the inclination angle of the defect is obtained based on the test curve and the output ratio of the first sensor and the second sensor described above, the inclination angle of the defect formed by machining and the test curve are obtained as shown in FIG. It was in good agreement with the inclination angle obtained.
  • FIG. 26 is a waveform diagram showing the result of correcting the outputs of the first sensor and the second sensor based on the inclination angle of the defect. The output signals of both sensors with respect to the inclination angle of the defect are obtained in advance, and the output signals of Fig.
  • FIG. 27 is a schematic plan view showing a main part of a leakage magnetic flux detection device using the first embodiment of the leakage magnetic flux detection sensor.
  • the same or similar parts as those in FIG. 18 are denoted by the same reference numerals and description thereof will be omitted.
  • Each of the first sensor 3a and the second sensor 3b includes two columnar magneto-sensitive portions 33a, 33a and 33b, 33b arranged at a predetermined distance in the flaw detection direction (the direction of the white arrow). Then, the magnetic flux leakage due to the defect K is detected by the magnetic sensing portions 33a. 33a, 33b. 33b of both sensors 3a, 3b, respectively.
  • FIG. 28 is a plan view showing a first embodiment of a sensor for detecting magnetic flux leakage
  • FIG. 29 is a cross-sectional view taken along line EE of FIG.
  • the sensor 3a (3b) includes the two magnetic sensing units 33, 33 as described above.
  • the two magnetic sensing parts 33, 33 are arranged at a predetermined distance from each other by erecting cylindrical cores 34, 34 made of ferrite, and coils 35, 35 are provided near the lower ends of the respective cores 34, 34. Is wound.
  • the dimensions of the sensitive portion 33, 33, centers of the magnetic sensitive sections 33, 33, 0 dimension d between the two is at 4 mm or less, 0.5 mm in diameter in the direction of dimension L perpendicular to the flaw detection direction D ZL is 1 or more.
  • both magnetic sensing parts 33. 33 are arranged so as to have a dimension d in the flaw detection direction, and the critical inclination angle 0 c of the sensor 3a (3b) is 45. ⁇ 83. It is.
  • the magnetic sensing portions 33, 33 are coil sensors, but it goes without saying that a Hall element or a magneto-resistive element may be used.
  • FIG. 30 and FIG. 31 are plan views showing modified examples of the first embodiment of the leakage magnetic flux detection sensor.
  • the shape of the magneto-sensitive portions 33, 33 in plan view may be a circle as shown in FIG. 28, a square as shown in FIG. 30, or a regular hexagon such as a regular hexagon as shown in FIG. It may be square. In this way, by making the shape of the magneto-sensitive portions 33, 33 in a plan view circular or regular polygon, the level of the detection signal of the magneto-sensitive portions 33, 33 regardless of the inclination angle 0 of the defect. Are approximately the same.
  • FIG. 32 is a plan view showing the material to be inspected.
  • notch-shaped defects Kl and K2 with a length of 20 mm, a width of 0.5 mm and a depth of 0.5 mm were formed by electric discharge machining on the surface of a rectangular carbon steel plate with a thickness of 5 mm.
  • FIG. 33 is a side view showing an electromagnet for magnetizing the material to be inspected, in which 31 is a U-shaped core.
  • the U-shaped core 31 is formed in a U-shape by layering gay steel plates (outer leg dimension 60 mm x inner leg dimension 40 mm x height 60 mm x length 65 mm), and copper conductors are provided on both legs.
  • FIG. 34 is a graph showing a detection signal from the conventional sensor
  • FIG. 35 is a graph showing a detection signal from the sensor of this embodiment.
  • a 1 shows the result of the sensor of the present embodiment described above.
  • FIG. 37 is a diagram showing an example of the second embodiment of the leakage magnetic flux detection sensor, wherein FIG. 37 (A) is a longitudinal sectional view, and FIG. 37 (B) is a cross-sectional view of FIG. It is sectional drawing of a line.
  • the leakage magnetic flux detection sensor 41 is arranged such that its axes are aligned with the hollow portions of the first cylindrical magneto-sensitive city 42 and the first magneto-sensitive city 42. And a solid columnar second magnetic sensing part 43.
  • the first magnetic sensing part 42 is a conductive wire 42b (0.5 mm in outer diameter) made of copper or the like on the outer periphery of the cylindrical ferrite core 42a (outer diameter 6 mm, inner diameter 5 mm, height 5 mm) at the center in the axial direction. ) Is wound (20 times).
  • the second magnetically sensitive part 43 has a solid cylindrical shape (shaft outer diameter 2 mm, height 5 mm including flange) with flanges 43c (outer diameter 4 mm, thickness 0.5 mm) formed at both ends.
  • the ferrite core 43a is formed by winding (20 times) a conductive wire 43b (outer diameter 0.5 mm) made of copper or the like on the outer periphery of the shaft of the ferrite core 43a.
  • the first magnetic sensing part 42 and the second magnetic sensing part 43 having a circular cross section extend in a predetermined direction predicted using the leakage magnetic flux detecting sensor 41 configured concentrically.
  • the direction of scanning is set to be orthogonal to the above-mentioned predetermined direction. Even if it occurs at an angle, the detection sensitivity will not decrease. As shown in FIGS.
  • the noise signal such as the material gas signal due to the fluctuation of the surface unevenness of the material to be inspected or the conveyance vibration is used by differentially connecting the two magnetic sensing parts 42 and 43 as in the conventional example and the above-described embodiment.
  • the output amplitude can be suppressed to a small value.
  • FIG. 39 shows an example of a defect signal waveform of each of the first magnetic sensing part 42 and the second magnetic sensing part 43 having the above-described configuration, the two magnetic sensing parts 42.43 being concentrically arranged, and the differential connection.
  • FIG. 31 is a diagram showing an example of a defect signal waveform when the sensor is surrounded by the sensor ( as is clear from FIG. 39, the defect signal waveforms of the first magnetic sensing unit 42 and the second magnetic sensing unit 43 are different from each other). Since the cross-sectional shape of the magnetic part is circular, it can be seen that a linear defect having a constant shape and a constant depth has a constant amplitude regardless of the extending direction of the defect. In addition, it can be seen that the defect signal waveform when the two magnetic sensing sections 42.43 are concentrically arranged and the differential contact gun suppresses noise signals due to material play signals and gradual magnetic field changes.
  • FIG. 40 is a plan view showing a modification of the second embodiment of the leakage magnetic flux detection sensor.
  • the leakage magnetic flux detection sensor 50 in this example is a large-diameter I-type coil in which a conductive wire 50a made of copper or the like is spirally wound a plurality of times at predetermined intervals.
  • a coil 51 and a second coil 52 having a small diameter are printed concentrically on a silicon wafer 53.
  • 51a and 52a indicate input terminals
  • 51b and 52b indicate output terminals.
  • the leakage magnetic flux detection sensor 50 of this example in which the large-diameter first coil 51 and the small-diameter second coil 52 are formed concentrically on a silicon concentrator 53, also has a third coil. It goes without saying that a defect signal waveform almost similar to that in Fig. 9 can be obtained.
  • 4 1 drawing is a diagram showing another modification of the second embodiment of the leakage magnetic flux detecting sensor, Fig. (A) is a plan view, FIG. (B) is a side sectional view (No. 4 As shown in Fig. 1, the leakage magnetic flux detection sensor 60 in this example shows an example in which a magnetic sensor composed of a magnetic element such as a Hall element or a magnetoresistive element is used.
  • the first magneto-sensitive portion 60a and the second magneto-sensitive portion 60b having different cross-sectional areas are formed so as to be stacked in the upper and lower directions with the insulating layer 60c interposed therebetween so that their axes are aligned.
  • the first magnetic sensing part 60a and the second magnetic sensing part 60b can be formed upside down.
  • the first magnetic sensing part 42 is a solid cylindrical sensing part having a large cross-sectional area, It can be formed by vertically stacking a solid second magnetic sensing portion 43 having a cross-sectional area.
  • the lift-off amounts R and R 2 (see Fig. 41 (B)) of the magnetically sensitive parts 60a and 60b with respect to the surface of the material P to be inspected differ (see Fig. 41 (B)). Since the detection sensitivities are linked together, it goes without saying that it is necessary to perform calibration processing so that signals from the same defect can be detected with the same sensitivity.
  • the tilt angle 0 is 15 ° from 0 ° to 90 ° in the counterclockwise direction from the extension direction of the leftmost one (K 1).
  • Notched artificial defects (length 20 mm x width 0.5 mm x depth 0.5 mm) K1 to K7 were prepared by electric discharge machining with a 100 mm pitch, and a 5 mm thick carbon steel sheet was prepared.
  • the material to be inspected was magnetized under the condition of z. Then, as shown in Fig. 37 Using the leakage magnetic flux detection sensor 41 of the present embodiment having the above-described dimensions and having the above-described dimensions, the scanning direction thereof is set to the direction indicated by the outline arrow in FIG. Inspection was performed. For comparison, a conventional leakage magnetic flux detection sensor having a rectangular cross-sectional shape with a long side of 4 mm and a short side of 1 mm in the configuration shown in Fig. 5 was used. Inspection was also conducted.
  • FIG. 43 shows the detection signal waveforms of each magneto-sensitive part for the artificial defect K1 having an inclination angle of 0 ° and the artificial defect K4 having an inclination angle of 45 ° among the test results.
  • the waveform of the detection signal after the subtraction processing is shown.
  • FIG. (A) shows the case of using the leakage magnetic flux detection sensor of the present embodiment
  • FIG. (B) shows the case of using the conventional leakage magnetic flux detection sensor. ing.
  • the outputs of both magneto-sensitive sections are the same, only the output of one magneto-sensitive section is shown in FIG.
  • the leakage magnetic flux detection sensor of the present embodiment no decrease in the defect signal amplitude is observed.
  • the conventional and the leakage magnetic flux detection sensors of the present embodiment although a noise signal caused by a gradual magnetic field fluctuation is recognized in the signal waveform of each magnetic sensing unit alone, the signal after the subtraction processing is performed. The above noise signal is hardly recognized in the waveform.
  • FIG. 44 shows that the sensor output when the inclination angle 0 is 0 ° is 1 and the leakage magnetic flux detection sensor of the present embodiment and the conventional leakage magnetic flux for the artificial defects K 1 to K 7 at each inclination angle 0 are shown.
  • FIG. 4 is a diagram showing a change in detection sensitivity with respect to a detection sensor. As can be seen from FIG. 44, the defect detection sensitivity of the conventional sensor for detecting magnetic flux leakage sharply decreases as the inclination angle 0 of the defect greatly inclines from the predicted direction (reference direction). On the other hand.
  • the defect detection sensitivity of the leakage magnetic flux detection sensor of this embodiment hardly decreases even when the inclination angle ⁇ of the defect is greatly inclined from the reference direction, and is substantially constant irrespective of the inclination angle 0 of the defect. It can be seen that it is possible to detect defects with a sensitivity of.
  • the test results of the sensor for detecting a magnetic flux leakage as described above are obtained when AC excitation is used, but it goes without saying that similar results can be obtained when DC excitation is used. ⁇ ⁇ Business availability
  • the defect generated in the material to be inspected is detected by the sensor in any direction, so that the inspection accuracy is high and the inspection speed is reduced.
  • DC magnetization can be performed without any need, so that the obtained data can be handled quantitatively and the throughput of flaw detection work is high.
  • the leakage magnetic flux inspection apparatus of the present invention since the direction of magnetization of the material to be inspected or the tube material is adjusted to the inclination angle of the defect that frequently occurs, the amount of leakage magnetic flux from the defect can be increased. Defects can be detected with high sensitivity.
  • the inclination angle and the depth of a defect in any direction can be quantitatively obtained. Can contribute to the improvement of
  • the sensor for detecting magnetic flux leakage of the present invention has a configuration in which the cross section is formed into a circle and the two sensors having different cross sections are arranged concentrically, so that the magnetization direction and the linear
  • flaw detection can be performed with constant sensitivity regardless of the direction in which the defect is generated.
  • differential connection is used for each magnetic sensing part, it is possible to suppress the generation of noise signals such as material signals and gradual magnetic field changes.

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Abstract

L'invention concerne un détecteur de défauts utilisant un flux de fuite, permettant de détecter un défaut (K) dans un matériau (P) dans un sens prédéterminé. Selon l'invention, le matériau (P) est magnétisé et le flux de fuite émanant d'un défaut (K) est détecté. Le détecteur comprend: une paire d'aimants (1a, 2a) qui magnétisent le matériau dans un sens différent du sens de détection de défauts; une paire d'aimants (1a, 2b) qui magnétisent le matériau dans un sens différent du sens de magnétisation et du sens de détection de défauts, ces aimants (1a, 2b) se trouvant à une distance prédéterminée, dans le sens de détection de défauts, des régions de magnétisation des deux aimants; et des capteurs de flux de fuite (3a, 3b) placés entre les deux paires d'aimants. Dans les capteurs de flux de fuite, lesquels détectent un flux de fuite émanant d'un défaut du matériau magnétisé, au moyen de deux parties magnétosensibles disposées de façon à faire face au matériau et situées à une distance prédéterminée l'une de l'autre, dans le sens de détection de défauts, la distance entre les centres des deux parties magnétosensibles est: d « 4 mm, leur longueur, mesurée perpendiculairement au sens de détection de défauts, est: L » 0,5 mm, et d/L » 1. La présente invention concerne également un capteur de flux de fuite dans lequel deux parties magnétosensibles circulaires, de différentes tailles, sont disposées concentriquement.
PCT/JP1995/001254 1994-06-23 1995-06-22 Procede et dispositif de detection de defauts au moyen d'un flux de fuite, et detecteur de defauts utilisant un flux de fuite WO1996000386A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE19580847T DE19580847T1 (de) 1994-06-23 1995-06-22 Verfahren und Vorrichtung zur Fehlererkennung durch Streufluß und Streuflußsensor
US08/549,674 US5747988A (en) 1994-06-23 1995-06-22 Method and apparatus for flaw detection by leakage fluxes and leakage flux sensor

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
JP6/142032 1994-06-23
JP14203294 1994-06-23
JP13340895A JPH08327602A (ja) 1995-05-31 1995-05-31 漏洩磁気検出用センサ
JP7/133408 1995-05-31
JP7/137798 1995-06-05
JP13779895A JPH0868778A (ja) 1994-06-23 1995-06-05 漏洩磁束探傷装置
JP7/143695 1995-06-09
JP14369595A JPH08334495A (ja) 1995-06-09 1995-06-09 漏洩磁束探傷用センサ

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112098508A (zh) * 2020-09-03 2020-12-18 南京博克纳自动化系统有限公司 一种漏磁探伤检测设备的旋转探头装置
CN113728226A (zh) * 2019-04-24 2021-11-30 杰富意钢铁株式会社 漏磁探伤装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008024394A1 (de) * 2008-05-15 2009-12-03 V&M Deutschland Gmbh Verfahren zur zerstörungsfreien Prüfung von Rohren

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5775562U (fr) * 1980-10-27 1982-05-10
JPS5922179B2 (ja) * 1976-01-19 1984-05-24 住友金属工業株式会社 磁性金属体の欠陥形状測定装置
JPH01154457U (fr) * 1988-04-18 1989-10-24
JPH0333363U (fr) * 1989-08-10 1991-04-02
JPH04120456A (ja) * 1990-09-11 1992-04-21 Hitachi Ltd Ｓｑｕｉｄによる非破壊検査装置
JPH0560730A (ja) * 1991-09-02 1993-03-12 Nkk Corp 金属帯の磁気探傷方法及び装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5922179B2 (ja) * 1976-01-19 1984-05-24 住友金属工業株式会社 磁性金属体の欠陥形状測定装置
JPS5775562U (fr) * 1980-10-27 1982-05-10
JPH01154457U (fr) * 1988-04-18 1989-10-24
JPH0333363U (fr) * 1989-08-10 1991-04-02
JPH04120456A (ja) * 1990-09-11 1992-04-21 Hitachi Ltd Ｓｑｕｉｄによる非破壊検査装置
JPH0560730A (ja) * 1991-09-02 1993-03-12 Nkk Corp 金属帯の磁気探傷方法及び装置

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113728226A (zh) * 2019-04-24 2021-11-30 杰富意钢铁株式会社 漏磁探伤装置
CN112098508A (zh) * 2020-09-03 2020-12-18 南京博克纳自动化系统有限公司 一种漏磁探伤检测设备的旋转探头装置

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