WO2013038759A1 - Loop core for flux gate current sensor and flux gate current sensor - Google Patents

Loop core for flux gate current sensor and flux gate current sensor Download PDF

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Publication number
WO2013038759A1
WO2013038759A1 PCT/JP2012/064458 JP2012064458W WO2013038759A1 WO 2013038759 A1 WO2013038759 A1 WO 2013038759A1 JP 2012064458 W JP2012064458 W JP 2012064458W WO 2013038759 A1 WO2013038759 A1 WO 2013038759A1
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Prior art keywords
core
outer leg
current sensor
outer legs
contact
Prior art date
Application number
PCT/JP2012/064458
Other languages
French (fr)
Japanese (ja)
Inventor
孔恵 余
小林　正和
田中　裕士
憲弘 稲田
康紀 伊藤
Original Assignee
株式会社タムラ製作所
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Priority claimed from JP2011201976A external-priority patent/JP5926911B2/en
Priority claimed from JP2011201977A external-priority patent/JP5926912B2/en
Application filed by 株式会社タムラ製作所 filed Critical 株式会社タムラ製作所
Publication of WO2013038759A1 publication Critical patent/WO2013038759A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/146—Measuring arrangements for current not covered by other subgroups of G01R15/14, e.g. using current dividers, shunts, or measuring a voltage drop
    • G01R15/148—Measuring arrangements for current not covered by other subgroups of G01R15/14, e.g. using current dividers, shunts, or measuring a voltage drop involving the measuring of a magnetic field or electric field
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers
    • G01R15/183—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers using transformers with a magnetic core
    • G01R15/185—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers using transformers with a magnetic core with compensation or feedback windings or interacting coils, e.g. 0-flux sensors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F3/00—Cores, Yokes, or armatures
    • H01F3/10—Composite arrangements of magnetic circuits

Definitions

  • the present invention relates to a fluxgate current sensor for measuring a current flowing through a measurement object and a loop core for the fluxgate current sensor.
  • a fluxgate current sensor is known as a sensor for measuring the current flowing through the measurement target and is in practical use.
  • a specific configuration of this type of fluxgate current sensor is described in, for example, Patent Document 1 (Japanese Patent Application Publication JP2011-510318A).
  • the fluxgate current sensor described in Patent Document 1 includes a magnetic field sensor (8) having a fluxgate core (18) around which a fluxgate coil (20) is wound. Moreover, it has the magnetic core (4) formed of two core parts (28a, 28b). The branch portions (32a, 32b) of the core portions (28a, 28b) are connected to the inner wall portions (40a, 40b) and the outer wall portions (42a, 42b) joined by the side wall portions (46a, 46b, 46a ′, 46b ′). have.
  • ') Is formed so as to partially surround the cavity (44) while leaving a predetermined air gap (54) between the free end edges (53a, 53b) of each other.
  • a magnetic field sensor (8) is accommodated and supported in the cavity (44).
  • the magnetic field sensor (8) may be unable to detect the current to be measured with high accuracy due to the influence of geomagnetism.
  • the magnetic field sensor (8) may be unable to detect the current to be measured with high accuracy due to the influence of geomagnetism.
  • the direction of geomagnetism is the major axis direction of the branch portions (32a, 32b)
  • the geomagnetism when the direction of geomagnetism is the long axis direction of the side branch portions (36, 34) of the core portions (28a, 28b), the geomagnetism is transferred from the side branch portions (36, 34) to the branch portion portions (32a, 32b) and flows in the air gap (54) through the magnetic field sensor (8) having a lower magnetic resistance than air.
  • the present invention has been made in view of the above circumstances, and the object thereof is a fluxgate current sensor that is not easily affected by geomagnetism, and a fluxgate current sensor suitable for such a fluxgate current sensor. It is to provide a loop core.
  • the loop core for a fluxgate current sensor has a pair of substantially 3-shaped cores in which two plate shapes bent in a substantially U-shape are integrally connected.
  • the pair of cores are in a state in which at least a part of each of the first outer legs is in contact with each other and at least a part of each of the second outer legs is overlapped in the thickness direction of the second outer legs. While being in contact with each other, a predetermined gap is maintained between the two substantially U-shaped connecting portions, and an annular loop with a halfway is formed so as to face each other.
  • the annular loop has a first ring portion that defines a space through which the electric wire to be measured is inserted and passed on the first outer leg side with the gap portion as a boundary, and the electric wire on the second outer leg side.
  • a second ring portion that defines a space for arranging a magnetic probe for detecting a magnetic field induced by a flowing current is provided.
  • the pair of second outer legs that constitute the second ring part that surrounds the magnetic probe are in contact with each other after being overlapped, and therefore, between the pair of second outer legs.
  • the magnetic resistance at the contact portion is suppressed to a small value. Therefore, the geomagnetism that has reached this contact portion flows through the contact portion having a lower magnetic resistance without passing through the magnetic probe. That is, the loop core for a fluxgate current sensor according to the present invention is suitably configured to suppress the influence of geomagnetism on the magnetic probe.
  • the loop core for a flux gate current sensor may include a close contact means for closely contacting at least a part of the second outer legs in a state of being overlapped in the plate thickness direction.
  • the contact means may include at least one of a claw part, a welded part, an adhesive part, a sandwiching part, a fitting part, and an embossed part.
  • the claw portion is formed at the tip of one second outer leg portion, for example, and engages with the other second outer leg portion when the pair of second outer leg portions are disposed opposite to each other.
  • the second outer legs are fixed to each other.
  • a welding part welds at least one part of the cores of the state arrange
  • an adhesion part is apply
  • the sandwiching portion is formed at the tip of one second outer leg portion, for example, and when the pair of second outer leg portions are arranged to face each other, the other second outer leg portion is sandwiched. By doing so, the second outer legs are fixed to each other.
  • a fitting part is formed in the other of the 2nd outer leg part, for example, and the convex part formed in one side of a 2nd outer leg part which fits when a pair of 2nd outer leg part is opposingly arranged. It consists of a recessed part.
  • the embossed portion is formed, for example, on one second outer leg portion, and is urged and applied to the other second outer leg portion when opposed to each other.
  • the loop core for the flux gate current sensor may have a soft magnetic insertion member having a higher magnetic permeability than the pair of cores.
  • at least a part of the second outer leg portions of the pair of cores is in contact with each other via the soft magnetic insertion member.
  • the soft magnetic insertion member is a soft material that deforms when inserted between, for example, a pair of second outer legs.
  • the soft magnetic insertion member has, for example, adhesiveness, and may be configured to adhere and fix the second outer legs.
  • At least a part of the second outer legs may be superposed with a soft magnetic insertion member interposed therebetween in the thickness direction of the second outer legs.
  • the loop core for a fluxgate current sensor may have a configuration in which at least a part of the first outer legs are in contact with each other in a state of being overlapped in the plate thickness direction.
  • a fluxgate current sensor includes an insulator in the fluxgate current sensor loop core, a magnetic probe disposed in a space surrounded by the second ring portion, and the fluxgate current sensor loop core. And a coil wound through the wire.
  • the insulator is, for example, a first bobbin that surrounds at least a part of the side surfaces of the pair of first outer legs overlapped in the thickness direction of the first outer legs.
  • the first outer leg portions may be configured to be in contact with each other and fixed by pressure contact holding by the first bobbin.
  • the insulator is, for example, a second bobbin that surrounds at least a part of the side surfaces of the pair of second outer legs overlapped in the thickness direction of the second outer legs.
  • the second outer leg portions may be in contact with each other and fixed by press-clamping by the second bobbin.
  • the second outer leg portions may be configured to be fixed to each other via a soft magnetic insertion member by pressure contact holding by the second bobbin.
  • a fluxgate current sensor that is not easily affected by geomagnetism and a loop core for a fluxgate current sensor suitable for such a fluxgate current sensor are provided.
  • the circuit diagram of the fluxgate current sensor which concerns on embodiment of this invention is shown.
  • 1 shows a cross-sectional view of a fluxgate current sensor according to an embodiment of the present invention.
  • unit with which the fluxgate current sensor which concerns on embodiment (this Example 1) of this invention is provided is shown. It is a figure explaining the assembly of the fluxgate current sensor of Example 1 of this invention. Sectional drawing of the feedback core single-piece
  • unit with which the fluxgate current sensor which concerns on Example 4 of this invention is provided is shown.
  • unit with which the fluxgate current sensor which concerns on Example 5 of this invention is provided is shown.
  • unit with which the fluxgate current sensor which concerns on Example 6 of this invention is provided is shown.
  • unit with which the fluxgate current sensor which concerns on Example 7 of this invention is provided is shown.
  • unit with which the fluxgate current sensor which concerns on Example 8 of this invention is provided is shown.
  • Sectional drawing of the fluxgate current sensor which concerns on Example 9 of this invention is shown.
  • unit with which the fluxgate current sensor which concerns on Example 9 of this invention is provided is shown. It is a figure explaining the assembly of the fluxgate current sensor of Example 9 of this invention. Sectional drawing of the feedback core single-piece
  • FIG. 1 shows a circuit diagram of a fluxgate current sensor 1 according to an embodiment of the present invention.
  • the fluxgate current sensor 1 of this embodiment has a structure in which a probe 10 and a feedback coil 20 are attached to a feedback core 30.
  • the feedback core 30 is made of, for example, PC permalloy that is one of soft magnetic alloys having high magnetic permeability.
  • a cable CL through which a current to be measured flows is disposed close to the feedback core 30.
  • the fluxgate current sensor 1 measures the magnitude of the current flowing through the cable CL by detecting the magnitude of the magnetic field generated in the feedback core 30 by the current flowing through the cable CL.
  • FIG. 2A shows a cross-sectional view of the main part of the fluxgate current sensor 1 including the probe 10, the feedback coil 20, and the feedback core 30.
  • FIG. 2B shows the AA cross section of FIG. 2A
  • FIG. 2C shows the BB cross section of FIG. 2A.
  • FIG. 3 shows a perspective view of the feedback core 30 alone.
  • the feedback core 30 forms a loop by combining the first core portion 31 and the second core portion 32.
  • Each of the first core portion 31 and the second core portion 32 has bent portions 31 a and 32 a that are largely bent toward the inner side of the loop of the feedback core 30, and two wide plate materials bent into a substantially U-shape. Is formed in a shape of approximately three. As shown in FIG.
  • the loop shape of the feedback core 30 includes a first ring portion 33 and a second ring portion 34 by bent portions 31 a and 32 a including a connecting portion that connects two substantially U-shaped shapes. In the middle, it is a ring (substantially 8 characters).
  • the probe 10 is a magnetic probe in which a winding 12 is wound around a fluxgate core 11.
  • the fluxgate core 11 is made of, for example, an amorphous material having a high magnetic permeability and is one of soft magnetic alloys.
  • the fluxgate core 11 and the winding 12 are insulated by an insulator not shown.
  • the probe 10 is arranged in a space surrounded by the feedback core 30 in the second ring portion 34. When a current is passed through the winding 12, a magnetic field is generated in the fluxgate core 11.
  • the feedback coil 20 has a first winding 21 and a second winding 22.
  • the first winding 21 is disposed so as to surround a part of the first ring portion 33 (the first outer leg portion 31c of the first core portion 31 and the first outer leg portion 32c of the second core portion 32). It is wound around a first bobbin 41 having insulating properties.
  • the second winding 22 is wound around a second bobbin 42 having insulation properties, which is disposed so as to surround the second ring portion 34 and the bent portions 31a and 32a.
  • the first winding 21 and the second winding 22 are connected to each other so as to be electrically in series.
  • a pulse power source 51 is connected to the winding 12 of the probe 10.
  • a pulsed high-frequency rectangular wave current is supplied from the pulse power source 51 to the winding 12.
  • the magnetic flux density in the fluxgate core 11 is periodically saturated. Therefore, when a magnetic field is generated in the feedback core 30 by the current flowing through the cable CL, the waveform of the voltage applied to the winding 12 is distorted by an external magnetic field (a magnetic field generated in the feedback core 30). .
  • the winding 12 is connected to the interface circuit 52.
  • the interface circuit 52 converts the voltage between the windings 12 into a PWM signal.
  • the PWM signal output from the interface circuit 52 is a signal having a duty ratio of 50% when an external magnetic field is not applied to the fluxgate core 11 (that is, when no current flows through the cable CL).
  • the duty ratio of the PWM signal changes according to the external magnetic field applied to the fluxgate core 11.
  • the PWM signal output from the interface circuit 52 is input to the low pass filter 53.
  • the low-pass filter 53 converts the PWM signal into an analog signal (output voltage corresponding to the duty ratio), and outputs the converted output voltage to the driver 54.
  • the driver 54 includes an error amplifier and a feedback circuit.
  • the feedback coil 20 is connected to the output stage of the driver 54.
  • the error amplifier detects the difference between the output voltage from the low-pass filter 53 and a predetermined reference voltage Vref .
  • the feedback circuit causes a current having a magnitude based on the detected difference to flow through the feedback coil 20.
  • the fluxgate current sensor 1 measures the magnitude of the current flowing through the cable CL by measuring the current flowing through the feedback coil 20 (in other words, the output voltage V OUT ) with the shunt resistor Rs. Note that the current flowing through the feedback coil 20 periodically changes at a high speed by the negative feedback. However, the differential amplifier 55 has a response speed several orders of magnitude lower than that of the driver 54. Therefore, the waveform of the output voltage V OUT coincides with the current waveform to be measured, and is substantially a value correlated with the magnitude of the current flowing through the cable CL.
  • the fluxgate current sensor 1 of the present embodiment effectively connects the first core portion 31 and the second core portion 32 so that the magnetic resistance of the feedback core 30 is reduced in order to effectively suppress current measurement errors based on geomagnetism. It is made to adhere to.
  • a plurality of specific examples of the fluxgate current sensor 1 will be described.
  • Example 1 2 also serves as a cross-sectional view of the fluxgate current sensor 1 according to the first embodiment
  • FIG. 3 also serves as a perspective view of the feedback core 30 according to the first embodiment
  • 4 (a) to 4 (c) are diagrams illustrating the assembly of the fluxgate current sensor 1 of the first embodiment.
  • the feedback core 30 has a second outer leg portion 31b of the first core portion 31 and a second core as viewed from the middle constricted position side.
  • the second outer leg portions 32b of the portion 32 are arranged in this order, and the upper surface 31bU of the second outer leg portion 31b and the lower surface 32bD of the second outer leg portion 32b are overlapped with each other.
  • the feedback core 30 has a first outer leg portion 31c of the first core portion 31 as viewed from the middle constricted position side. It arrange
  • the second outer leg portion 31 b of the first core portion 31 is inserted into and passed through the second bobbin 42, and the first core portion
  • the 31st 1st outer leg part 31c is inserted inside the 1st bobbin 41, and is penetrated (refer Fig.4 (a)).
  • the second outer leg portion 32b of the second core portion 32 is the second bobbin.
  • the first outer leg portion 32c of the second core portion 32 is inserted into and passed through the remaining space in the first bobbin 41 (see FIG. 4C). .
  • the first bobbin 41 and the second bobbin 42 have the first winding 21 and the second winding 22 so that the insulation between the first winding 21 and the second winding 22 and the feedback core 30 is secured. And the feedback core 30 are formed so as to surround at least a part thereof.
  • both the first bobbin 41 and the second bobbin 42 have a substantially square shape in cross section perpendicular to the major axis direction. ing.
  • w1 is substantially equal to the distance d1 between the opposing inner wall surfaces of the second bobbin 42.
  • the sum of the width w2 from the upper surface 31bU to the lower surface 31aD (or 32aD) of the second outer leg portion 31b of the first core portion 31 and the thickness t of the second outer leg portion 32b of the second core portion 32 is also the sum. Is substantially equal to the distance d1.
  • the width w1 (and the sum of the width w2 and the plate thickness t) and the distance d1 are defined by, for example, a fit tolerance (intermediate fit or interference fit). Therefore, when the second bobbin 42 is attached to the feedback core 30 (see FIG. 2A or FIG. 4C), the entire second ring portion 34, the bent portions 31a, and 32a are the inner wall surface of the second bobbin 42. It is sandwiched between and receives moderate tightening force. As a result, the upper surface 31bU of the second outer leg portion 31b and the lower surface 32bD of the second outer leg portion 32b are in close contact with each other and are in a fixed state.
  • the distance d2 between the opposing inner wall surfaces of the first bobbin 41 is the sum of the plate thicknesses of the first outer leg part 31c of the first core part 31 and the first outer leg part 32c of the second core part 32. Almost equal.
  • the total thickness and the distance d2 are defined by fit tolerance (intermediate fit or interference fit), for example. Therefore, when the first bobbin 41 is attached to the feedback core 30 (see FIG. 2A or 4C), the first outer leg portions 31c and 32c are sandwiched between the inner wall surfaces of the first bobbin 41, Receive moderate tightening force. As a result, the lower surface 31cD of the first outer leg portion 31c and the upper surface 32cU of the first outer leg portion 32c are in close contact with each other and are in a fixed state.
  • the upper surface 31bU of the second outer leg portion 31b of the first core portion 31 and the second outer leg portion 32b of the second core portion 32 by a simple construction method of nipping and pressing with the second bobbin 42. Is fixed in surface contact with the lower surface 32bD. Due to the close contact between the upper surface 31bU and the lower surface 32bD, the magnetic resistance at the contact portion between the first core portion 31 and the second core portion 32 is suppressed to a small value. For example, consider the case where the direction of geomagnetism is the long axis direction of the probe 10.
  • the geomagnetism that has reached the contact portion between the first core portion 31 and the second core portion 32 flows through the contact portion having a smaller magnetic resistance without passing through the flux gate core 11.
  • the direction of geomagnetism is orthogonal to the long axis direction of the probe 10.
  • the geomagnetism flows without being routed through the fluxgate core 11 and attracted into the feedback core 30 having a lower magnetic resistance.
  • the geomagnetism flows along the substantially 3 shape in the feedback core 30 having a smaller magnetic resistance without passing through the fluxgate core 11. Go.
  • the fluxgate core 11 is not substantially affected by the geomagnetism or becomes very difficult to receive. Therefore, the fluxgate current sensor 1 can accurately detect the current flowing through the cable CL. Further, the feedback core 30 has a two-piece configuration and has a small number of parts.
  • the flux gate current sensor 1 of each of Examples 2 to 8 has the same configuration as that of Example 1 except for the feedback core. Therefore, in Examples 2 to 8, only the single feedback core of each example will be described. Moreover, in each Example after this Example 2, the same name and code
  • FIG. 5 is a cross-sectional view of the feedback core 130 alone according to the second embodiment.
  • the feedback core 130 according to the second embodiment includes a first core portion 131 and a second core portion 132.
  • a claw portion 132 e is formed at the tip of the second outer leg portion 132 b of the second core portion 132.
  • the second core portion 132 is moved to the first core so that the lower surface 132bD of the second outer leg portion 132b of the second core portion 132 is superimposed on the upper surface 131bU of the second outer leg portion 131b of the first core portion 131.
  • the upper surface 131bU of the second outer leg portion 131b of the first core portion 131 and the lower surface of the second outer leg portion 132b of the second core portion 132 by a simple method of engagement by the claw portion 132e. It is fixed in a state of surface contact with 132bD. Since the magnetic resistance at the contact portion between the first core portion 131 and the second core portion 132 is suppressed to a small value due to the close contact between the upper surface 131bU and the lower surface 132bD, the flux gate core 11 is substantially affected by geomagnetism. No or very difficult to receive. Therefore, the fluxgate current sensor 1 according to the second embodiment can accurately detect the current flowing through the cable CL.
  • FIG. 6 shows a cross-sectional view of the feedback core 230 alone in the third embodiment.
  • the feedback core 230 according to the third embodiment includes a first core portion 231 and a second core portion 232.
  • the upper surface 231bU of the second outer leg portion 231b of the first core portion 231 and the lower surface 232bD of the second outer leg portion 232b of the second core portion 232 are brought into surface contact with each other, and the second outer leg The tip of the portion 231b is inserted into a hole (not shown) formed near the base of the second outer leg portion 232b, and then fixed by welding W.
  • the fluxgate current sensor 1 can accurately detect the current flowing through the cable CL.
  • FIG. 7 shows a cross-sectional view of the feedback core 330 alone of the fourth embodiment.
  • the feedback core 330 according to the fourth embodiment includes a first core portion 331 and a second core portion 332.
  • the first core portion 331 and the second core portion 332 are the lower surface 331bD of the second outer leg portion 331b of the first core portion 331 and the upper surface of the second outer leg portion 332b of the second core portion 332. It is contacted and fixed via the magnetic adhesive A applied between 332bU.
  • the lower surface 331bD and the upper surface 332bU are illustrated so as to be separated from each other. However, since the amount of the magnetic adhesive A applied is extremely thin, these surfaces are substantially in close contact with each other. Is in a state.
  • the lower surface 331bD of the second outer leg portion 331b of the first core portion 331 and the upper surface 332bU of the second outer leg portion 332b of the second core portion 332 are brought into close contact with the first core portion 331. Since the magnetic resistance at the contact portion with the second core portion 332 is suppressed to a small value, the fluxgate core 11 is not substantially affected by the geomagnetism or very difficult to receive. Therefore, the fluxgate current sensor 1 according to the fourth embodiment can accurately detect the current flowing through the cable CL. In the fourth embodiment, it is more preferable that the lower surface 331bD and the upper surface 332bU are brought into close contact with each other by using the pressure contact holding by the second bobbin 42 together.
  • FIG. 8 shows a cross-sectional view of the feedback core 430 alone of the fifth embodiment.
  • the feedback core 430 according to the fifth embodiment includes a first core portion 431 and a second core portion 432.
  • the tip of the second outer leg portion of the second core portion 432 is formed in a clip shape.
  • the clip shape includes a clip upper part 432f and a clip lower part 432g.
  • the clip upper portion 432f and the clip lower portion 432g are elastically deformed, and the tip of the second outer leg portion 431b of the first core portion 431 is pinched. Thereby, the lower surface 431bD of the second outer leg portion 431b and the clip lower portion 432g are brought into close contact with each other, and are fixed.
  • the lower surface 431bD of the second outer leg portion 431b of the first core portion 431 and the clip are formed by a simple method of holding the tip of the first core portion 431 with the tip of the second core portion 432.
  • the lower portion 432g is fixed in surface contact.
  • FIG. 9 is a cross-sectional view of the feedback core 530 according to the sixth embodiment.
  • the feedback core 530 according to the sixth embodiment includes a first core portion 531 and a second core portion 532.
  • a convex portion 531h is formed on the upper surface 531bU of the second outer leg portion 531b of the first core portion 531, and a concave portion 532h is formed on the lower surface 532bD of the second outer leg portion 532b of the second core portion 532. .
  • the tip of the second outer leg portion 532b becomes the convex portion 531h.
  • the convex portion 531h and the concave portion 532h are fitted.
  • the first core portion 531 and the second core portion 532 are connected to each other in a fixed state in a state where the upper surface 531bU and the lower surface 532bD are in close contact with each other.
  • the upper surface 531bU of the second outer leg portion 531b of the first core portion 531 and the second outer leg of the second core portion 532 are simply formed by fitting the convex portion 531h and the concave portion 532h.
  • the lower surface 532bD of the part 532b is fixed in a state of surface contact. Since the magnetic resistance at the contact portion between the first core portion 531 and the second core portion 532 is suppressed to a small value due to the close contact between the upper surface 531bU and the lower surface 532bD, the flux gate core 11 is substantially affected by geomagnetism. No or very difficult to receive. Therefore, the fluxgate current sensor 1 of the sixth embodiment can accurately detect the current flowing through the cable CL. Note that the object of the present invention is suitably achieved if there is at least one set of the convex portion 531h and the concave portion 532h.
  • FIG. 10 is a sectional view of the feedback core 630 alone according to the seventh embodiment.
  • the feedback core 630 of the seventh embodiment includes a first core portion 631 and a second core portion 632.
  • the second outer leg portion of the second core portion 632 is formed in a bifurcated shape including a second outer leg portion 632f and a second outer leg portion 632g.
  • the gap between the second outer leg portion 632f and the second outer leg portion 632g and the plate thickness of the second outer leg portion 631b of the first core portion 631 are defined by, for example, a fit tolerance (intermediate fit or interference fit). ing.
  • the second outer leg portion 631b is located between the second outer leg portion 632f and the second outer leg portion 632g. Inserted into and receives an appropriate tightening force. Accordingly, the upper surface 631bU of the second outer leg portion 631b and the second outer leg portion 632f are in close contact with each other, and the lower surface 631bD of the second outer leg portion 631b and the second outer leg portion 632g are in close contact with each other.
  • the first core part 631 and the second core part 632 are connected to be in a fixed state.
  • the fluxgate current sensor 1 since the magnetic resistance at the contact portion between the first core portion 631 and the second core portion 632 is suppressed to a small value due to the close contact on the two surfaces, the flux gate core 11 It is virtually unaffected or very difficult to be affected. Therefore, the fluxgate current sensor 1 according to the seventh embodiment can accurately detect the current flowing through the cable CL. In the seventh embodiment, it is more preferable that the two surfaces are brought into close contact with each other by using the press-contacting / holding by the second bobbin 42 together.
  • FIG. 11 is a sectional view of the feedback core 730 according to the eighth embodiment.
  • the feedback core 730 according to the eighth embodiment includes a first core portion 731 and a second core portion 732.
  • a substantially hemispherical embossed portion 732 i is formed on the second outer leg portion 732 b of the second core portion 732.
  • the bent portion D at the base of the second outer leg portion 732b is bent at a slightly acute angle. Therefore, the embossed portion 732i contacts the upper surface 731bU of the second outer leg portion 731b of the first core portion 731 with an appropriate urging force.
  • the first core portion 731 and the second core portion 732 are connected and in a fixed state in a state where the upper surface 731bU and the embossed portion 732i are in close contact with each other.
  • the vicinity of the apex of the embossed portion 732i may be formed in a planar shape in order to increase the contact area with the upper surface 731bU.
  • the upper surface 731bU and the embossed portion 732i are brought into close contact with each other by using the press-contact clamping by the second bobbin 42 together. Further, if there is at least one embossed portion 732i, the object of the present invention is preferably achieved.
  • FIGS. 12A to 12C are views similar to FIGS. 2A to 2C, and show cross-sectional views of the fluxgate current sensor 1 of the ninth embodiment.
  • the fluxgate current sensor 1 of the ninth embodiment includes a probe 10, a feedback coil 20, and a feedback core 830.
  • FIG. 13 is a perspective view of the feedback core 830 alone of the ninth embodiment.
  • the feedback core 830 forms a loop by combining the first core portion 831, the second core portion 832, and the soft magnetic insertion member 835.
  • the fluxgate current sensor 1 according to the ninth embodiment is configured such that the magnetic resistance of the contact portion between the first core portion 831 and the second core portion 832 is reduced in order to effectively suppress a current measurement error based on geomagnetism. Yes.
  • the feedback core 830 includes a second outer leg portion 831b of the first core portion 831 and a soft magnetic medium, as viewed from the constricted position side.
  • the insertion member 835 and the second outer leg portion 832b of the second core portion 832 are arranged in this order, and the upper surface 831bU of the second outer leg portion 831b and the lower surface 832bD of the second outer leg portion 832b are soft magnetic insertion members. Overlaid on each other via 835.
  • the soft magnetic insertion member 835 is a soft magnetic material having a higher magnetic permeability than the first core portion 831 and the second core portion 832 and is, for example, a permalloy tape made of a magnetic material mainly made of a nickel alloy in a foil shape.
  • the soft magnetic insertion member 835 has flexibility and one surface is an adhesive surface having adhesiveness.
  • FIG. 14 (a) to 14 (c) are diagrams illustrating the assembly of the fluxgate current sensor 1 of the ninth embodiment.
  • the soft magnetic insertion member 835 is bonded and fixed to the upper surface 831bU of the second outer leg portion 831b of the first core portion 831.
  • the second outer leg portion 831b is inserted and passed through the inside of the second bobbin 42, and the first outer leg portion 831c of the first core portion 831 is inserted and passed through the inside of the first bobbin 41 (FIG. 14A). )reference).
  • the second outer leg portion 832b of the second core portion 832 is the second bobbin.
  • the first outer leg portion 832c of the second core portion 832 is inserted into and passed through the remaining space in the first bobbin 41 (see FIG. 14C).
  • the soft magnetic insertion member 835 is in surface contact with each surface of the upper surface 831bU of the second outer leg portion 831b of the first core portion 831 and the lower surface 832bD of the second outer leg portion 832b of the second core portion 832. Inserted in the state.
  • the soft magnetic insertion member 835 may have an adhesive surface on the side in surface contact with the lower surface 832bD.
  • w1 is substantially equal to the distance d1 between the opposing inner wall surfaces of the second bobbin 42.
  • the width w2 from the upper surface 831bU to the lower surface 831aD (or 832aD) of the second outer leg portion 831b of the first core portion 831, the plate thickness t1 of the second outer leg portion 832b of the second core portion 832, and soft magnetism is also substantially equal to the distance d1.
  • the width w1 (and the sum of the width w2, the plate thickness t1, and the layer thickness t2) and the distance d1 are defined by fit tolerance (intermediate fit or interference fit), for example. Therefore, when the second bobbin 42 is attached to the feedback core 830 (see FIG.
  • the entire second ring portion 834, the bent portions 831a, and 832a are the inner wall surface of the second bobbin 42. It is sandwiched between and receives moderate tightening force. As a result, the upper surface 831bU of the second outer leg portion 831b and the lower surface 832bD of the second outer leg portion 832b are in close contact with each other with the soft magnetic insertion member 835 interposed therebetween, thereby achieving a fixed state.
  • the first core is formed so as to fill a gap between the upper surface 831bU of the second outer leg portion 831b of the first core portion 831 and the lower surface 832bD of the second outer leg portion 832b of the second core portion 832.
  • a soft magnetic insertion member 835 having a higher magnetic permeability than the portion 831 and the second core portion 832 is bonded and inserted. Therefore, the magnetic resistance at the contact portion (via the soft magnetic insertion member 835) between the first core portion 831 and the second core portion 832 is suppressed to a small value. Therefore, the fluxgate core 11 is not substantially affected by the geomagnetism or becomes very difficult to receive. Therefore, the fluxgate current sensor 1 of the ninth embodiment can accurately detect the current flowing through the cable CL.
  • the second outer leg portion 831b and the soft magnetic material are formed by the second bobbin 42 in order to further improve the adhesion between the respective surfaces of the upper surface 831bU and the lower surface 832bD and the soft magnetic insertion member 835.
  • the three members of the insertion member 835 and the second outer leg portion 832b are pressed and sandwiched. Thereby, the magnetic resistance in the contact part of the 1st core part 831 and the 2nd core part 832 is suppressed to the still smaller value.
  • Example 10 The configuration of the flux gate current sensor 1 of the tenth embodiment is the same as that of the ninth embodiment except for the feedback core. Therefore, in the tenth embodiment, only the feedback core alone will be described.
  • FIG. 15 is a cross-sectional view of the feedback core 930 according to the tenth embodiment.
  • the feedback core 930 of the tenth embodiment includes a first core portion 931, a second core portion 932, and a soft magnetic insertion member 935.
  • the soft magnetic insertion member 935 is a soft magnetic material having a higher magnetic permeability than the first core portion 931 and the second core portion 932, and is, for example, an amorphous ribbon having flexibility.
  • the soft magnetic insertion member 935 has one end near the tip of the second outer leg portion 931 b of the first core portion 931 and the side leg portion 932 s of the second core portion 932.
  • the remaining portion is sandwiched between the upper surface 931bU of the second outer leg portion 931b and the lower surface 932bD of the second outer leg portion 932b via the pressure contact by the second bobbin 42. .
  • the soft magnetic insertion member 935 is inserted between the first core portion 931 and the second core portion 932 while being bent in a substantially L shape as a whole.
  • the second outer leg A soft magnetic insertion member 935 having a higher magnetic permeability than the first core portion 931 and the second core portion 932 is interposed so as to fill a gap between the tip of the portion 931b and the side leg portion 932s of the second core portion 932.
  • the magnetic resistance at the contact portion between the first core portion 931 and the second core portion 932 is further suppressed, and the fluxgate core 11 is not substantially affected by the geomagnetism or is very difficult to receive. Therefore, the fluxgate current sensor 1 of the tenth embodiment can accurately detect the current flowing through the cable CL.
  • the contact means shown in each embodiment pressure clamping by the second bobbin 42, engagement by the claw 132e, welding by the welding W, adhesion by the magnetic adhesive A, clamping by the clip shape, the convex portion 531h and the concave portion
  • the first core portion and the second core portion may be connected and fixed by appropriately combining the engagement with 532h, the holding by the bifurcated shape, and the urging by the embossed portion 732i.
  • the soft magnetic insertion member 835 or 935 may be provided. Further, the insertion positions and materials of the soft magnetic insertion members 835 and 935 are not limited to those exemplified in the ninth and tenth embodiments.

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Abstract

A loop core for a flux gate current sensor has a pair of substantially 3-shaped cores in which two plate shapes each bent in a substantial U-shape are integrally coupled to each other. The pair of cores are disposed facing each other so that: the first outer leg portions thereof at least partially contact each other; the second outer leg portions thereof contact each other while being at least partially overlapped with each other in the plate thickness direction of the second outer leg portions; and a ring-shaped loop, certain parts of which are narrowed while maintaining a predetermined gap, is formed between the mutual coupling portions of the two U-shapes. Taking the gap portion as a boundary, the ring-shaped loop has a first ring portion on the first outer leg portion side and a second ring portion on the second outer leg portion side, the first ring portion specifying a space through which a wire to be measured is inserted and made to pass, the second ring portion specifying a space in which a magnetic probe for detecting a magnetic field induced by the current flowing through the wire is disposed.

Description

フラックスゲート電流センサ用ループコア、及びフラックスゲート電流センサLoop core for fluxgate current sensor and fluxgate current sensor
　本発明は、測定対象に流れる電流を測定するためのフラックスゲート電流センサ、及びフラックスゲート電流センサ用のループコアに関する。 The present invention relates to a fluxgate current sensor for measuring a current flowing through a measurement object and a loop core for the fluxgate current sensor.
　測定対象に流れる電流を測定するためのセンサとして、フラックスゲート電流センサが知られており、実用に供されている。この種のフラックスゲート電流センサの具体的構成は、例えば特許文献１（日本特許出願公開公報ＪＰ２０１１－５１０３１８Ａ）に記載されている。 A fluxgate current sensor is known as a sensor for measuring the current flowing through the measurement target and is in practical use. A specific configuration of this type of fluxgate current sensor is described in, for example, Patent Document 1 (Japanese Patent Application Publication JP2011-510318A).
　特許文献１に記載のフラックスゲート電流センサは、フラックスゲートコア（１８）を有し、その周囲にフラックスゲートコイル（２０）が巻回された磁界センサ（８）を備えている。また、二つのコア部分（２８ａ、２８ｂ）により形成される磁気コア（４）を有している。コア部分（２８ａ、２８ｂ）の枝部部分（３２ａ、３２ｂ）は、側壁部（４６ａ、４６ｂ、４６ａ’、４６ｂ’）によって結合された内壁部（４０ａ、４０ｂ）と外壁部（４２ａ、４２ｂ）を有している。コア部分（２８ａ）の枝部部分（３２ａ）の壁部（４０ａ、４２ａ、４６ａ、４６ａ’）と、コア部分（２８ｂ）の枝部部分（３２ｂ）の壁部（４０ｂ、４２ｂ、４６ｂ、４６ｂ’）は、互いの自由端縁部（５３ａ、５３ｂ）間に所定のエアギャップ（５４）を空けつつ、空洞部（４４）を部分的に囲うように形成されている。空洞部（４４）には、磁界センサ（８）が収容され支持されている。 The fluxgate current sensor described in Patent Document 1 includes a magnetic field sensor (8) having a fluxgate core (18) around which a fluxgate coil (20) is wound. Moreover, it has the magnetic core (4) formed of two core parts (28a, 28b). The branch portions (32a, 32b) of the core portions (28a, 28b) are connected to the inner wall portions (40a, 40b) and the outer wall portions (42a, 42b) joined by the side wall portions (46a, 46b, 46a ′, 46b ′). have. The wall part (40a, 42a, 46a, 46a ′) of the branch part (32a) of the core part (28a) and the wall part (40b, 42b, 46b, 46b) of the branch part (32b) of the core part (28b). ') Is formed so as to partially surround the cavity (44) while leaving a predetermined air gap (54) between the free end edges (53a, 53b) of each other. A magnetic field sensor (8) is accommodated and supported in the cavity (44).
　特許文献１に記載のフラックスゲート電流センサでは、磁界センサ（８）が地磁気の影響を受けることにより、測定対象の電流を精度良く検出できないことがある。特許文献１に記載のフラックスゲート電流センサにおいては、例えば地磁気の向きが枝部部分（３２ａ、３２ｂ）の長軸方向の場合、エアギャップ（５４）にて、空気よりも磁気抵抗の低い磁界センサ（８）を介して地磁気が流れる。また、例えば地磁気の向きがコア部分（２８ａ、２８ｂ）の側方枝部（３６、３４）の長軸方向の場合、地磁気は、側方枝部（３６、３４）から枝部部分（３２ａ、３２ｂ）に流れ、エアギャップ（５４）にて、空気よりも磁気抵抗の低い磁界センサ（８）を介して流れる。 In the fluxgate current sensor described in Patent Document 1, the magnetic field sensor (8) may be unable to detect the current to be measured with high accuracy due to the influence of geomagnetism. In the fluxgate current sensor described in Patent Document 1, for example, when the direction of geomagnetism is the major axis direction of the branch portions (32a, 32b), a magnetic field sensor having a lower magnetic resistance than air at the air gap (54). The geomagnetism flows through (8). Further, for example, when the direction of geomagnetism is the long axis direction of the side branch portions (36, 34) of the core portions (28a, 28b), the geomagnetism is transferred from the side branch portions (36, 34) to the branch portion portions (32a, 32b) and flows in the air gap (54) through the magnetic field sensor (8) having a lower magnetic resistance than air.
　このように、従来のフラックスゲート電流センサは、地磁気の影響を受けやすいため、測定対象の電流を精度良く検出できないという問題を抱えていた。本発明は上記の事情に鑑みてなされたものであり、その目的とするところは、地磁気の影響を受けにくいフラックスゲート電流センサ、及び、このようなフラックスゲート電流センサに適したフラックスゲート電流センサ用ループコアを提供することである。 Thus, since the conventional fluxgate current sensor is easily affected by geomagnetism, it has a problem that the current to be measured cannot be accurately detected. The present invention has been made in view of the above circumstances, and the object thereof is a fluxgate current sensor that is not easily affected by geomagnetism, and a fluxgate current sensor suitable for such a fluxgate current sensor. It is to provide a loop core.
　本発明の一形態に係るフラックスゲート電流センサ用ループコアは、略コの字形状に曲折された２つの板形状を一体に連ねた、略３の字状のコアを一対有している。一対のコアは、互いの第１外脚部同士の少なくとも一部が接触するとともに、互いの第２外脚部同士の少なくとも一部が第２外脚部の板厚方向に重ね合わせられた状態で接触しつつ、２つの略コの字形状の互いの連結部分の間に所定のギャップが保たれて、中途が括れた環状ループが形成されるように、対向配置されている。環状ループは、ギャップ部分を境に、第１外脚部側に、測定対象の電線が挿入され通されるスペースを規定する第１環部を有し、第２外脚部側に、電線に流れる電流により誘導される磁界を検出するための磁気プローブを配置するスペースを規定する第２環部を有している。 The loop core for a fluxgate current sensor according to an embodiment of the present invention has a pair of substantially 3-shaped cores in which two plate shapes bent in a substantially U-shape are integrally connected. The pair of cores are in a state in which at least a part of each of the first outer legs is in contact with each other and at least a part of each of the second outer legs is overlapped in the thickness direction of the second outer legs. While being in contact with each other, a predetermined gap is maintained between the two substantially U-shaped connecting portions, and an annular loop with a halfway is formed so as to face each other. The annular loop has a first ring portion that defines a space through which the electric wire to be measured is inserted and passed on the first outer leg side with the gap portion as a boundary, and the electric wire on the second outer leg side. A second ring portion that defines a space for arranging a magnetic probe for detecting a magnetic field induced by a flowing current is provided.
　本発明の一形態によれば、磁気プローブを囲う第２環部を構成する一対の第２外脚部が、重ね合わせられたうえで接触しているため、一対の第２外脚部間の接触部分における磁気抵抗が小さい値に抑えられる。そのため、この接触部分に達した地磁気は、磁気プローブを経由することなく、磁気抵抗のより小さい接触部分を経由して流れていく。すなわち、本発明に係るフラックスゲート電流センサ用ループコアは、磁気プローブに対する地磁気の影響を抑えるのに好適に構成されている。 According to one aspect of the present invention, the pair of second outer legs that constitute the second ring part that surrounds the magnetic probe are in contact with each other after being overlapped, and therefore, between the pair of second outer legs. The magnetic resistance at the contact portion is suppressed to a small value. Therefore, the geomagnetism that has reached this contact portion flows through the contact portion having a lower magnetic resistance without passing through the magnetic probe. That is, the loop core for a fluxgate current sensor according to the present invention is suitably configured to suppress the influence of geomagnetism on the magnetic probe.
　また、本発明の一形態において、フラックスゲート電流センサ用ループコアは、第２外脚部同士の少なくとも一部を板厚方向に重ね合わせた状態で密着させる密着手段を有した構成としてもよい。 Further, in one embodiment of the present invention, the loop core for a flux gate current sensor may include a close contact means for closely contacting at least a part of the second outer legs in a state of being overlapped in the plate thickness direction.
　密着手段は、爪部、溶接部、接着部、狭持部、嵌合部、エンボス部の少なくとも一つを含む構成としてもよい。なお、爪部は、例えば、一方の第２外脚部の先端に形成されたものであり、一対の第２外脚部を対向配置したときに、他方の第２外脚部に係合することにより、第２外脚部同士を固定するものである。また、溶接部は、例えば、対向配置された状態のコア同士の少なくとも一部を溶接したものである。また、接着部は、例えば、対向配置された一対の第２外脚部の間に塗布されたものである。また、狭持部は、例えば、一方の第２外脚部の先端に形成されたものであり、一対の第２外脚部を対向配置したときに、他方の第２外脚部を狭持することにより、第２外脚部同士を固定するものである。また、嵌合部は、例えば、一対の第２外脚部を対向配置したときに嵌合する、第２外脚部の一方に形成された凸部と、第２外脚部の他方に形成された凹部からなるものである。また、エンボス部は、例えば、一方の第２外脚部に形成されており、対向配置時に、他方の第２外脚部に付勢されて当て付くものである。 The contact means may include at least one of a claw part, a welded part, an adhesive part, a sandwiching part, a fitting part, and an embossed part. The claw portion is formed at the tip of one second outer leg portion, for example, and engages with the other second outer leg portion when the pair of second outer leg portions are disposed opposite to each other. Thus, the second outer legs are fixed to each other. Moreover, a welding part welds at least one part of the cores of the state arrange | positioned facing, for example. Moreover, an adhesion part is apply | coated between a pair of 2nd outer leg part arrange | positioned facing, for example. Further, the sandwiching portion is formed at the tip of one second outer leg portion, for example, and when the pair of second outer leg portions are arranged to face each other, the other second outer leg portion is sandwiched. By doing so, the second outer legs are fixed to each other. Moreover, a fitting part is formed in the other of the 2nd outer leg part, for example, and the convex part formed in one side of a 2nd outer leg part which fits when a pair of 2nd outer leg part is opposingly arranged. It consists of a recessed part. Further, the embossed portion is formed, for example, on one second outer leg portion, and is urged and applied to the other second outer leg portion when opposed to each other.
　また、本発明の一形態において、フラックスゲート電流センサ用ループコアは、一対のコアよりも透磁率の高い軟磁性介挿部材を有した構成としてもよい。この場合、一対のコアの互いの第２外脚部同士は、少なくとも一部が軟磁性介挿部材を介して接触している。 Further, in one embodiment of the present invention, the loop core for the flux gate current sensor may have a soft magnetic insertion member having a higher magnetic permeability than the pair of cores. In this case, at least a part of the second outer leg portions of the pair of cores is in contact with each other via the soft magnetic insertion member.
　軟磁性介挿部材は、例えば一対の第２外脚部の間に介挿されたときに変形する軟性材である。 The soft magnetic insertion member is a soft material that deforms when inserted between, for example, a pair of second outer legs.
　また、軟磁性介挿部材は、例えば接着性を有しており、第２外脚部同士を接着固定する構成としてもよい。 Further, the soft magnetic insertion member has, for example, adhesiveness, and may be configured to adhere and fix the second outer legs.
　第２外脚部同士の少なくとも一部は、第２外脚部の板厚方向に、軟磁性介挿部材を間に介挿したうえで重ね合わせられている構成としてもよい。 At least a part of the second outer legs may be superposed with a soft magnetic insertion member interposed therebetween in the thickness direction of the second outer legs.
　本発明の一形態において、フラックスゲート電流センサ用ループコアは、第１外脚部同士の少なくとも一部がその板厚方向に重ね合わせられた状態で接触している構成としてもよい。 In one embodiment of the present invention, the loop core for a fluxgate current sensor may have a configuration in which at least a part of the first outer legs are in contact with each other in a state of being overlapped in the plate thickness direction.
　また、本発明の一形態に係るフラックスゲート電流センサは、上記フラックスゲート電流センサ用ループコアと、その第２環部によって囲われるスペースに配置される磁気プローブと、フラックスゲート電流センサ用ループコアに絶縁体を介して巻回されたコイルとを有することを特徴としたものである。 A fluxgate current sensor according to an aspect of the present invention includes an insulator in the fluxgate current sensor loop core, a magnetic probe disposed in a space surrounded by the second ring portion, and the fluxgate current sensor loop core. And a coil wound through the wire.
　上記絶縁体は、例えば、第１外脚部の板厚方向に重ね合わせられた一対の第１外脚部の側面の少なくとも一部を囲う第１のボビンである。この場合、第１外脚部同士は、第１のボビンによる圧接狭持により、互いに接触し固定されている構成としてもよい。 The insulator is, for example, a first bobbin that surrounds at least a part of the side surfaces of the pair of first outer legs overlapped in the thickness direction of the first outer legs. In this case, the first outer leg portions may be configured to be in contact with each other and fixed by pressure contact holding by the first bobbin.
　また、上記絶縁体は、例えば、第２外脚部の板厚方向に重ね合わせられた一対の第２外脚部の側面の少なくとも一部を囲う第２のボビンである。この場合、第２外脚部同士は、第２のボビンによる圧接狭持により、互いに接触し固定されている構成としてもよい。 Further, the insulator is, for example, a second bobbin that surrounds at least a part of the side surfaces of the pair of second outer legs overlapped in the thickness direction of the second outer legs. In this case, the second outer leg portions may be in contact with each other and fixed by press-clamping by the second bobbin.
　第２外脚部同士は、第２のボビンによる圧接狭持により、軟磁性介挿部材を介して互いが固定されている構成としてもよい。 The second outer leg portions may be configured to be fixed to each other via a soft magnetic insertion member by pressure contact holding by the second bobbin.
　本発明の一形態によれば、地磁気の影響を受けにくいフラックスゲート電流センサ、及び、このようなフラックスゲート電流センサに適したフラックスゲート電流センサ用ループコアが提供される。 According to one aspect of the present invention, a fluxgate current sensor that is not easily affected by geomagnetism and a loop core for a fluxgate current sensor suitable for such a fluxgate current sensor are provided.
本発明の実施形態に係るフラックスゲート電流センサの回路図を示す。The circuit diagram of the fluxgate current sensor which concerns on embodiment of this invention is shown. 本発明の実施形態に係るフラックスゲート電流センサの断面図を示す。1 shows a cross-sectional view of a fluxgate current sensor according to an embodiment of the present invention. 本発明の実施形態（本実施例１）に係るフラックスゲート電流センサが備えるフィードバックコア単体の斜視図を示す。The perspective view of the feedback core single-piece | unit with which the fluxgate current sensor which concerns on embodiment (this Example 1) of this invention is provided is shown. 本発明の実施例１のフラックスゲート電流センサの組立を説明する図である。It is a figure explaining the assembly of the fluxgate current sensor of Example 1 of this invention. 本発明の実施例２に係るフラックスゲート電流センサが備えるフィードバックコア単体の断面図を示す。Sectional drawing of the feedback core single-piece | unit with which the fluxgate current sensor which concerns on Example 2 of this invention is provided is shown. 本発明の実施例３に係るフラックスゲート電流センサが備えるフィードバックコア単体の断面図を示す。Sectional drawing of the feedback core single-piece | unit with which the fluxgate current sensor which concerns on Example 3 of this invention is provided is shown. 本発明の実施例４に係るフラックスゲート電流センサが備えるフィードバックコア単体の断面図を示す。Sectional drawing of the feedback core single-piece | unit with which the fluxgate current sensor which concerns on Example 4 of this invention is provided is shown. 本発明の実施例５に係るフラックスゲート電流センサが備えるフィードバックコア単体の断面図を示す。Sectional drawing of the feedback core single-piece | unit with which the fluxgate current sensor which concerns on Example 5 of this invention is provided is shown. 本発明の実施例６に係るフラックスゲート電流センサが備えるフィードバックコア単体の断面図を示す。Sectional drawing of the feedback core single-piece | unit with which the fluxgate current sensor which concerns on Example 6 of this invention is provided is shown. 本発明の実施例７に係るフラックスゲート電流センサが備えるフィードバックコア単体の断面図を示す。Sectional drawing of the feedback core single-piece | unit with which the fluxgate current sensor which concerns on Example 7 of this invention is provided is shown. 本発明の実施例８に係るフラックスゲート電流センサが備えるフィードバックコア単体の断面図を示す。Sectional drawing of the feedback core single-piece | unit with which the fluxgate current sensor which concerns on Example 8 of this invention is provided is shown. 本発明の実施例９に係るフラックスゲート電流センサの断面図を示す。Sectional drawing of the fluxgate current sensor which concerns on Example 9 of this invention is shown. 本発明の実施例９に係るフラックスゲート電流センサが備えるフィードバックコア単体の斜視図を示す。The perspective view of the feedback core single-piece | unit with which the fluxgate current sensor which concerns on Example 9 of this invention is provided is shown. 本発明の実施例９のフラックスゲート電流センサの組立を説明する図である。It is a figure explaining the assembly of the fluxgate current sensor of Example 9 of this invention. 本発明の実施例１０に係るフラックスゲート電流センサが備えるフィードバックコア単体の断面図を示す。Sectional drawing of the feedback core single-piece | unit with which the fluxgate current sensor which concerns on Example 10 of this invention is provided is shown.
　以下、図面を参照して、本発明の実施形態に係るフラックスゲート電流センサについて説明する。 Hereinafter, a fluxgate current sensor according to an embodiment of the present invention will be described with reference to the drawings.
　図１は、本発明の実施形態に係るフラックスゲート電流センサ１の回路図を示す。本実施形態のフラックスゲート電流センサ１は、フィードバックコア３０に、プローブ１０及びフィードバックコイル２０を取り付けた構造を有している。フィードバックコア３０は、例えば、透磁率の高い、軟磁性合金の一つであるＰＣパーマロイによって形成されている。フィードバックコア３０には、測定対象となる電流が流れるケーブルＣＬが近接して配置されている。フラックスゲート電流センサ１は、ケーブルＣＬを流れる電流によってフィードバックコア３０内に発生する磁界の大きさを検出することにより、ケーブルＣＬを流れる電流の大きさを測定する。 FIG. 1 shows a circuit diagram of a fluxgate current sensor 1 according to an embodiment of the present invention. The fluxgate current sensor 1 of this embodiment has a structure in which a probe 10 and a feedback coil 20 are attached to a feedback core 30. The feedback core 30 is made of, for example, PC permalloy that is one of soft magnetic alloys having high magnetic permeability. In the feedback core 30, a cable CL through which a current to be measured flows is disposed close to the feedback core 30. The fluxgate current sensor 1 measures the magnitude of the current flowing through the cable CL by detecting the magnitude of the magnetic field generated in the feedback core 30 by the current flowing through the cable CL.
　図２（ａ）は、プローブ１０、フィードバックコイル２０、及びフィードバックコア３０を備えるフラックスゲート電流センサ１の主要部の断面図を示す。図２（ｂ）は、図２（ａ）のＡ－Ａ断面を示し、図２（ｃ）は、図２（ａ）のＢ－Ｂ断面を示す。図３は、フィードバックコア３０単体の斜視図を示す。図２又は図３に示されるように、フィードバックコア３０は、第１コア部３１と第２コア部３２とを組み合わせることにより、ループを形成している。第１コア部３１、第２コア部３２は、それぞれ、フィードバックコア３０のループの内側に向かって大きく屈曲する屈曲部３１ａ、３２ａを持ち、略コの字形状に曲折された２つの幅広の板材を一体に連ねた、略３の字形状を有している。図２に示されるように、フィードバックコア３０のループ形状は、２つの略コの字形状を連結する連結部分を含む屈曲部３１ａ及び３２ａによって、第１環部３３と第２環部３４からなる、中途で括れた環状（略８の字状）となっている。 FIG. 2A shows a cross-sectional view of the main part of the fluxgate current sensor 1 including the probe 10, the feedback coil 20, and the feedback core 30. FIG. 2B shows the AA cross section of FIG. 2A, and FIG. 2C shows the BB cross section of FIG. 2A. FIG. 3 shows a perspective view of the feedback core 30 alone. As shown in FIG. 2 or FIG. 3, the feedback core 30 forms a loop by combining the first core portion 31 and the second core portion 32. Each of the first core portion 31 and the second core portion 32 has bent portions 31 a and 32 a that are largely bent toward the inner side of the loop of the feedback core 30, and two wide plate materials bent into a substantially U-shape. Is formed in a shape of approximately three. As shown in FIG. 2, the loop shape of the feedback core 30 includes a first ring portion 33 and a second ring portion 34 by bent portions 31 a and 32 a including a connecting portion that connects two substantially U-shaped shapes. In the middle, it is a ring (substantially 8 characters).
　プローブ１０は、フラックスゲートコア１１の周囲に巻線１２が巻回された磁気プローブである。フラックスゲートコア１１は、例えば、透磁率の高い、軟磁性合金の一つであるアモルファスによって形成されている。フラックスゲートコア１１と巻線１２は、図示省略された絶縁体によって絶縁されている。図２に示されるように、プローブ１０は、第２環部３４内の、フィードバックコア３０によって囲われたスペースに配置されている。巻線１２に電流が流されると、フラックスゲートコア１１内に磁界が発生する。 The probe 10 is a magnetic probe in which a winding 12 is wound around a fluxgate core 11. The fluxgate core 11 is made of, for example, an amorphous material having a high magnetic permeability and is one of soft magnetic alloys. The fluxgate core 11 and the winding 12 are insulated by an insulator not shown. As shown in FIG. 2, the probe 10 is arranged in a space surrounded by the feedback core 30 in the second ring portion 34. When a current is passed through the winding 12, a magnetic field is generated in the fluxgate core 11.
　フィードバックコイル２０は、第１巻線２１及び第２巻線２２を有している。第１巻線２１は、第１環部３３の一部（第１コア部３１の第１外脚部３１ｃ、及び第２コア部３２の第１外脚部３２ｃ）を囲うよう配置された、絶縁性を有する第１ボビン４１に巻回されている。第２巻線２２は、第２環部３４及び屈曲部３１ａ、３２ａ全体を囲うように配置された、絶縁性を有する第２ボビン４２に巻回されている。第１巻線２１と第２巻線２２は、電気的に直列となるよう互いに接続されている。 The feedback coil 20 has a first winding 21 and a second winding 22. The first winding 21 is disposed so as to surround a part of the first ring portion 33 (the first outer leg portion 31c of the first core portion 31 and the first outer leg portion 32c of the second core portion 32). It is wound around a first bobbin 41 having insulating properties. The second winding 22 is wound around a second bobbin 42 having insulation properties, which is disposed so as to surround the second ring portion 34 and the bent portions 31a and 32a. The first winding 21 and the second winding 22 are connected to each other so as to be electrically in series.
　フラックスゲート電流センサ１の動作について、以下に説明する。なお、測定対象となる電流が流れるケーブルＣＬは、第１環部３３内の、第１巻線２１と第２巻線２２との間のスペースに挿入され通されている。 The operation of the fluxgate current sensor 1 will be described below. Note that the cable CL through which the current to be measured flows is inserted into and passed through the space between the first winding 21 and the second winding 22 in the first ring portion 33.
　図１に示されるように、プローブ１０の巻線１２には、パルス電源５１が接続されている。パルス電源５１から巻線１２には、パルス状の高周波の矩形波電流が供給される。高周波矩形波電流が巻線１２に供給されると、フラックスゲートコア１１内の磁束密度が周期的に飽和する。そのため、ケーブルＣＬを流れる電流によってフィードバックコア３０内に磁界が発生すると、巻線１２に印加される電圧の波形には、外部磁界（フィードバックコア３０内に発生した磁界）によって歪みが生じるようになる。 As shown in FIG. 1, a pulse power source 51 is connected to the winding 12 of the probe 10. A pulsed high-frequency rectangular wave current is supplied from the pulse power source 51 to the winding 12. When the high-frequency rectangular wave current is supplied to the winding 12, the magnetic flux density in the fluxgate core 11 is periodically saturated. Therefore, when a magnetic field is generated in the feedback core 30 by the current flowing through the cable CL, the waveform of the voltage applied to the winding 12 is distorted by an external magnetic field (a magnetic field generated in the feedback core 30). .
　巻線１２は、インターフェース回路５２に接続されている。インターフェース回路５２は、巻線１２間の電圧をＰＷＭ信号に変換する。インターフェース回路５２から出力されるＰＷＭ信号は、フラックスゲートコア１１に外部磁界が加えられていない状態（すなわち、ケーブルＣＬに電流が流れていない状態）ではデューティ比５０％の信号となる。ＰＷＭ信号のデューティ比は、フラックスゲートコア１１に加えられる外部磁界に応じて変化する。 The winding 12 is connected to the interface circuit 52. The interface circuit 52 converts the voltage between the windings 12 into a PWM signal. The PWM signal output from the interface circuit 52 is a signal having a duty ratio of 50% when an external magnetic field is not applied to the fluxgate core 11 (that is, when no current flows through the cable CL). The duty ratio of the PWM signal changes according to the external magnetic field applied to the fluxgate core 11.
　インターフェース回路５２から出力されたＰＷＭ信号は、ローパスフィルタ５３に入力する。ローパスフィルタ５３は、ＰＷＭ信号をアナログ信号（デューティ比に応じた出力電圧）に変換し、変換した出力電圧をドライバ５４に出力する。 The PWM signal output from the interface circuit 52 is input to the low pass filter 53. The low-pass filter 53 converts the PWM signal into an analog signal (output voltage corresponding to the duty ratio), and outputs the converted output voltage to the driver 54.
　ドライバ５４は、エラーアンプとフィードバック回路を備えている。ドライバ５４の出力段には、フィードバックコイル２０が接続されている。エラーアンプは、ローパスフィルタ５３からの出力電圧と所定の基準電圧Ｖrefとの差分を検出する。フィードバック回路は、検出された差分に基づく大きさの電流をフィードバックコイル２０に流す。フィードバックコイル２０を流れる電流によってフィードバック磁界が発生することにより、ケーブルＣＬを流れる電流によって誘導されたフィードバックコア３０内の磁界が打ち消される。すなわち、フィードバックコイル２０には、フラックスゲートコア１１に加わる外部磁界がゼロになるように負帰還電流が流れるようになる。 The driver 54 includes an error amplifier and a feedback circuit. The feedback coil 20 is connected to the output stage of the driver 54. The error amplifier detects the difference between the output voltage from the low-pass filter 53 and a predetermined reference voltage Vref . The feedback circuit causes a current having a magnitude based on the detected difference to flow through the feedback coil 20. When a feedback magnetic field is generated by the current flowing through the feedback coil 20, the magnetic field in the feedback core 30 induced by the current flowing through the cable CL is canceled out. That is, a negative feedback current flows through the feedback coil 20 so that the external magnetic field applied to the fluxgate core 11 becomes zero.
　フラックスゲート電流センサ１は、フィードバックコイル２０に流れる電流（言い換えると、出力電圧ＶOUT）をシャント抵抗Ｒｓで測定することにより、ケーブルＣＬを流れる電流の大きさを測定する。なお、フィードバックコイル２０に流れる電流は、上記の負帰還によって高速で周期的に変化する。しかし、差分増幅回路５５は、ドライバ５４に対して応答速度が数桁低い。そのため、出力電圧ＶOUTの波形は測定対象の電流波形と一致し、実質的に、ケーブルＣＬに流れる電流の大きさと相関する値となる。 The fluxgate current sensor 1 measures the magnitude of the current flowing through the cable CL by measuring the current flowing through the feedback coil 20 (in other words, the output voltage V OUT ) with the shunt resistor Rs. Note that the current flowing through the feedback coil 20 periodically changes at a high speed by the negative feedback. However, the differential amplifier 55 has a response speed several orders of magnitude lower than that of the driver 54. Therefore, the waveform of the output voltage V OUT coincides with the current waveform to be measured, and is substantially a value correlated with the magnitude of the current flowing through the cable CL.
　本実施形態のフラックスゲート電流センサ１は、地磁気に基づく電流測定誤差を有効に抑えるため、フィードバックコア３０の磁気抵抗が小さくなるように、第１コア部３１と第２コア部３２とを効果的に密着等させている。以下、フラックスゲート電流センサ１の具体的実施例を複数例説明する。 The fluxgate current sensor 1 of the present embodiment effectively connects the first core portion 31 and the second core portion 32 so that the magnetic resistance of the feedback core 30 is reduced in order to effectively suppress current measurement errors based on geomagnetism. It is made to adhere to. Hereinafter, a plurality of specific examples of the fluxgate current sensor 1 will be described.
（実施例１）
　図２は、本実施例１のフラックスゲート電流センサ１の断面図を兼ね、図３は、本実施例１のフィードバックコア３０単体の斜視図を兼ねている。図４（ａ）～図４（ｃ）は、本実施例１のフラックスゲート電流センサ１の組立を説明する図である。 Example 1
2 also serves as a cross-sectional view of the fluxgate current sensor 1 according to the first embodiment, and FIG. 3 also serves as a perspective view of the feedback core 30 according to the first embodiment. 4 (a) to 4 (c) are diagrams illustrating the assembly of the fluxgate current sensor 1 of the first embodiment.
　図２（ａ）、図２（ｂ）及び図３に示されるように、フィードバックコア３０は、中途の括れ位置側から見て、第１コア部３１の第２外脚部３１ｂ、第２コア部３２の第２外脚部３２ｂの順に配置されており、第２外脚部３１ｂの上面３１ｂＵと、第２外脚部３２ｂの下面３２ｂＤとが互いに重ね合わせられている。また、図２（ａ）、図２（ｃ）、及び図３に示されるように、フィードバックコア３０は、中途の括れ位置側から見て、第１コア部３１の第１外脚部３１ｃ、第２コア部３２の第１外脚部３２ｃの順に配置されており、第１外脚部３１ｃの下面３１ｃＤと、第１外脚部３２ｃの上面３２ｃＵとが互いに重ね合わせられている。 As shown in FIG. 2A, FIG. 2B, and FIG. 3, the feedback core 30 has a second outer leg portion 31b of the first core portion 31 and a second core as viewed from the middle constricted position side. The second outer leg portions 32b of the portion 32 are arranged in this order, and the upper surface 31bU of the second outer leg portion 31b and the lower surface 32bD of the second outer leg portion 32b are overlapped with each other. Further, as shown in FIGS. 2A, 2C, and 3, the feedback core 30 has a first outer leg portion 31c of the first core portion 31 as viewed from the middle constricted position side. It arrange | positions in order of the 1st outer leg part 32c of the 2nd core part 32, and the lower surface 31cD of the 1st outer leg part 31c and the upper surface 32cU of the 1st outer leg part 32c mutually overlap.
　図４に示されるフラックスゲート電流センサ１の組立工程に沿って説明すると、第１コア部３１の第２外脚部３１ｂが第２ボビン４２の内側に挿入され通されるとともに、第１コア部３１の第１外脚部３１ｃが第１ボビン４１の内側に挿入され通される（図４（ａ）参照）。第２環部３４内の、フィードバックコア３０によって囲われたスペース内に、プローブ１０が組み付けられると（図４（ｂ）参照）、第２コア部３２の第２外脚部３２ｂが第２ボビン４２内の残りのスペースに挿入され通されるとともに、第２コア部３２の第１外脚部３２ｃが第１ボビン４１内の残りのスペースに挿入され通される（図４（ｃ）参照）。なお、第１ボビン４１、第２ボビン４２はそれぞれ、第１巻線２１、第２巻線２２とフィードバックコア３０との絶縁が担保されるように、第１巻線２１、第２巻線２２とフィードバックコア３０との間の少なくとも一部を囲うように形成されている。本実施例１では、図２（ｂ）、図２（ｃ）に示されるように、第１ボビン４１、第２ボビン４２はともに、長軸方向と直交する断面が略ロの字状となっている。 Describing along the assembly process of the fluxgate current sensor 1 shown in FIG. 4, the second outer leg portion 31 b of the first core portion 31 is inserted into and passed through the second bobbin 42, and the first core portion The 31st 1st outer leg part 31c is inserted inside the 1st bobbin 41, and is penetrated (refer Fig.4 (a)). When the probe 10 is assembled in the space surrounded by the feedback core 30 in the second ring portion 34 (see FIG. 4B), the second outer leg portion 32b of the second core portion 32 is the second bobbin. The first outer leg portion 32c of the second core portion 32 is inserted into and passed through the remaining space in the first bobbin 41 (see FIG. 4C). . The first bobbin 41 and the second bobbin 42 have the first winding 21 and the second winding 22 so that the insulation between the first winding 21 and the second winding 22 and the feedback core 30 is secured. And the feedback core 30 are formed so as to surround at least a part thereof. In the first embodiment, as shown in FIGS. 2B and 2C, both the first bobbin 41 and the second bobbin 42 have a substantially square shape in cross section perpendicular to the major axis direction. ing.
　図２（ａ）又は図２（ｂ）に示されるように、第２コア部３２の第２外脚部３２ｂの上面３２ｂＵから屈曲部３１ａ（又は３２ａ）の下面３１ａＤ（又は３２ａＤ）までの幅ｗ１は、第２ボビン４２の、対向する内壁面間の距離ｄ１と略等しい。また、第１コア部３１の第２外脚部３１ｂの上面３１ｂＵから下面３１ａＤ（又は３２ａＤ）までの幅ｗ２と、第２コア部３２の第２外脚部３２ｂの板厚ｔとの和も、距離ｄ１と略等しい。幅ｗ１（及び幅ｗ２と板厚ｔとの和）と距離ｄ１は、例えばはめあい公差（中間ばめ又はしまりばめ）で規定されている。そのため、第２ボビン４２をフィードバックコア３０に取り付けると（図２（ａ）又は図４（ｃ）参照）、第２環部３４、屈曲部３１ａ、及び３２ａの全体が第２ボビン４２の内壁面間に挟み込まれて、適度な締め付け力を受ける。これにより、第２外脚部３１ｂの上面３１ｂＵと、第２外脚部３２ｂの下面３２ｂＤとが互いに密着し、固定状態となる。 As shown in FIG. 2A or 2B, the width from the upper surface 32bU of the second outer leg portion 32b of the second core portion 32 to the lower surface 31aD (or 32aD) of the bent portion 31a (or 32a). w1 is substantially equal to the distance d1 between the opposing inner wall surfaces of the second bobbin 42. The sum of the width w2 from the upper surface 31bU to the lower surface 31aD (or 32aD) of the second outer leg portion 31b of the first core portion 31 and the thickness t of the second outer leg portion 32b of the second core portion 32 is also the sum. Is substantially equal to the distance d1. The width w1 (and the sum of the width w2 and the plate thickness t) and the distance d1 are defined by, for example, a fit tolerance (intermediate fit or interference fit). Therefore, when the second bobbin 42 is attached to the feedback core 30 (see FIG. 2A or FIG. 4C), the entire second ring portion 34, the bent portions 31a, and 32a are the inner wall surface of the second bobbin 42. It is sandwiched between and receives moderate tightening force. As a result, the upper surface 31bU of the second outer leg portion 31b and the lower surface 32bD of the second outer leg portion 32b are in close contact with each other and are in a fixed state.
　また、第１ボビン４１の、対向する内壁面間の距離ｄ２は、第１コア部３１の第１外脚部３１ｃと、第２コア部３２の第１外脚部３２ｃの板厚の合計と略等しい。この板厚の合計と距離ｄ２は、例えばはめあい公差（中間ばめ又はしまりばめ）で規定されている。そのため、第１ボビン４１をフィードバックコア３０に取り付けると（図２（ａ）又は図４（ｃ）参照）、第１外脚部３１ｃ及び３２ｃが第１ボビン４１の内壁面間に挟み込まれて、適度な締め付け力を受ける。これにより、第１外脚部３１ｃの下面３１ｃＤと、第１外脚部３２ｃの上面３２ｃＵとが互いに密着し、固定状態となる。 The distance d2 between the opposing inner wall surfaces of the first bobbin 41 is the sum of the plate thicknesses of the first outer leg part 31c of the first core part 31 and the first outer leg part 32c of the second core part 32. Almost equal. The total thickness and the distance d2 are defined by fit tolerance (intermediate fit or interference fit), for example. Therefore, when the first bobbin 41 is attached to the feedback core 30 (see FIG. 2A or 4C), the first outer leg portions 31c and 32c are sandwiched between the inner wall surfaces of the first bobbin 41, Receive moderate tightening force. As a result, the lower surface 31cD of the first outer leg portion 31c and the upper surface 32cU of the first outer leg portion 32c are in close contact with each other and are in a fixed state.
　本実施例１においては、第２ボビン４２による圧接狭持という簡易な工法により、第１コア部３１の第２外脚部３１ｂの上面３１ｂＵと、第２コア部３２の第２外脚部３２ｂの下面３２ｂＤとが面接触して固定される。上面３１ｂＵと下面３２ｂＤとの密着により、第１コア部３１と第２コア部３２との接触部分における磁気抵抗が小さい値に抑えられる。例えば地磁気の向きがプローブ１０の長軸方向の場合を考える。この場合において、第１コア部３１と第２コア部３２との接触部分に達した地磁気は、フラックスゲートコア１１を経由することなく、磁気抵抗のより小さい接触部分を経由して流れていく。また、地磁気の向きがプローブ１０の長軸方向と直交する場合を考える。例えば図２（ａ）の紙面と直交する向きの場合、地磁気は、フラックスゲートコア１１を経由することなく、磁気抵抗のより小さいフィードバックコア３０内に引き寄せられて流れていく。図２（ａ）の紙面と平行（図面上下方向）な場合、地磁気は、フラックスゲートコア１１を経由することなく、磁気抵抗のより小さいフィードバックコア３０内を略３の字形状に沿って流れていく。このように、フラックスゲートコア１１は、地磁気の影響を実質的に受けない、若しくは非常に受け難くなる。そのため、フラックスゲート電流センサ１は、ケーブルＣＬを流れる電流を精度良く検出することができる。また、フィードバックコア３０は２ピース構成であり、部品点数が少ない。 In the first embodiment, the upper surface 31bU of the second outer leg portion 31b of the first core portion 31 and the second outer leg portion 32b of the second core portion 32 by a simple construction method of nipping and pressing with the second bobbin 42. Is fixed in surface contact with the lower surface 32bD. Due to the close contact between the upper surface 31bU and the lower surface 32bD, the magnetic resistance at the contact portion between the first core portion 31 and the second core portion 32 is suppressed to a small value. For example, consider the case where the direction of geomagnetism is the long axis direction of the probe 10. In this case, the geomagnetism that has reached the contact portion between the first core portion 31 and the second core portion 32 flows through the contact portion having a smaller magnetic resistance without passing through the flux gate core 11. Further, consider the case where the direction of geomagnetism is orthogonal to the long axis direction of the probe 10. For example, in the case of a direction orthogonal to the paper surface of FIG. 2A, the geomagnetism flows without being routed through the fluxgate core 11 and attracted into the feedback core 30 having a lower magnetic resistance. When parallel to the paper surface of FIG. 2 (a) (vertical direction in the drawing), the geomagnetism flows along the substantially 3 shape in the feedback core 30 having a smaller magnetic resistance without passing through the fluxgate core 11. Go. Thus, the fluxgate core 11 is not substantially affected by the geomagnetism or becomes very difficult to receive. Therefore, the fluxgate current sensor 1 can accurately detect the current flowing through the cable CL. Further, the feedback core 30 has a two-piece configuration and has a small number of parts.
　本実施例２～８の各実施例のフラックスゲート電流センサ１は、フィードバックコア以外の構成が本実施例１と共通である。そのため、本実施例２～８においては、各実施例のフィードバックコア単体についてだけ説明する。また、本実施例２以降の各実施例において、本実施例１と同様の構成には同様の名称及び符号を付し、その説明を簡略又は省略する。 The flux gate current sensor 1 of each of Examples 2 to 8 has the same configuration as that of Example 1 except for the feedback core. Therefore, in Examples 2 to 8, only the single feedback core of each example will be described. Moreover, in each Example after this Example 2, the same name and code | symbol are attached | subjected to the structure similar to this Example 1, and the description is simplified or abbreviate | omitted.
（実施例２）
　図５は、本実施例２のフィードバックコア１３０単体の断面図を示す。図５に示されるように、本実施例２のフィードバックコア１３０は、第１コア部１３１と第２コア部１３２からなる。第２コア部１３２の第２外脚部１３２ｂの先端には、爪部１３２ｅが形成されている。組立時において、第２コア部１３２の第２外脚部１３２ｂの下面１３２ｂＤを第１コア部１３１の第２外脚部１３１ｂの上面１３１ｂＵに重ね合わせるように、第２コア部１３２を第１コア部１３１に対して矢印Ｃ方向に動かすと、爪部１３２ｅが上面１３１ｂＵに当たって、第２外脚部１３２ｂが変形する。この状態で、第２コア部１３２を第１コア部１３１に対して矢印Ｃ方向に更に動かすと、爪部１３２ｅが第２外脚部１３１ｂの根元位置（図５に示される位置）に落ち込む。これにより、第２外脚部１３１ｂの上面１３１ｂＵと、第２外脚部１３２ｂの下面１３２ｂＤとが互いに密着した状態で、第１コア部１３１と第２コア部１３２とが連結し、固定状態となる。 (Example 2)
FIG. 5 is a cross-sectional view of the feedback core 130 alone according to the second embodiment. As shown in FIG. 5, the feedback core 130 according to the second embodiment includes a first core portion 131 and a second core portion 132. A claw portion 132 e is formed at the tip of the second outer leg portion 132 b of the second core portion 132. At the time of assembly, the second core portion 132 is moved to the first core so that the lower surface 132bD of the second outer leg portion 132b of the second core portion 132 is superimposed on the upper surface 131bU of the second outer leg portion 131b of the first core portion 131. When the part 131 is moved in the direction of arrow C, the claw part 132e hits the upper surface 131bU and the second outer leg part 132b is deformed. In this state, when the second core part 132 is further moved in the direction of arrow C with respect to the first core part 131, the claw part 132e falls into the root position (position shown in FIG. 5) of the second outer leg part 131b. Thereby, in a state where the upper surface 131bU of the second outer leg portion 131b and the lower surface 132bD of the second outer leg portion 132b are in close contact with each other, the first core portion 131 and the second core portion 132 are connected and fixed. Become.
　本実施例２においては、爪部１３２ｅによる係合という簡易な工法により、第１コア部１３１の第２外脚部１３１ｂの上面１３１ｂＵと、第２コア部１３２の第２外脚部１３２ｂの下面１３２ｂＤとが面接触した状態で固定される。上面１３１ｂＵと下面１３２ｂＤとの密着により、第１コア部１３１と第２コア部１３２との接触部分における磁気抵抗が小さい値に抑えられるため、フラックスゲートコア１１は、地磁気の影響を実質的に受けない、若しくは非常に受け難くなる。そのため、本実施例２のフラックスゲート電流センサ１は、ケーブルＣＬを流れる電流を精度良く検出することができる。 In the second embodiment, the upper surface 131bU of the second outer leg portion 131b of the first core portion 131 and the lower surface of the second outer leg portion 132b of the second core portion 132 by a simple method of engagement by the claw portion 132e. It is fixed in a state of surface contact with 132bD. Since the magnetic resistance at the contact portion between the first core portion 131 and the second core portion 132 is suppressed to a small value due to the close contact between the upper surface 131bU and the lower surface 132bD, the flux gate core 11 is substantially affected by geomagnetism. No or very difficult to receive. Therefore, the fluxgate current sensor 1 according to the second embodiment can accurately detect the current flowing through the cable CL.
（実施例３）
　図６は、本実施例３のフィードバックコア２３０単体の断面図を示す。図６に示されるように、本実施例３のフィードバックコア２３０は、第１コア部２３１と第２コア部２３２からなる。本実施例３においては、第１コア部２３１の第２外脚部２３１ｂの上面２３１ｂＵと、第２コア部２３２の第２外脚部２３２ｂの下面２３２ｂＤとを面接触させつつ、第２外脚部２３１ｂの先端を第２外脚部２３２ｂの根元付近に形成された孔部（不図示）に挿し込んだうえで、溶接Ｗにより固定している。 (Example 3)
FIG. 6 shows a cross-sectional view of the feedback core 230 alone in the third embodiment. As shown in FIG. 6, the feedback core 230 according to the third embodiment includes a first core portion 231 and a second core portion 232. In the third embodiment, the upper surface 231bU of the second outer leg portion 231b of the first core portion 231 and the lower surface 232bD of the second outer leg portion 232b of the second core portion 232 are brought into surface contact with each other, and the second outer leg The tip of the portion 231b is inserted into a hole (not shown) formed near the base of the second outer leg portion 232b, and then fixed by welding W.
　本実施例３においては、第１コア部２３１の第２外脚部２３１ｂの上面２３１ｂＵと、第２コア部２３２の第２外脚部２３２ｂの下面２３２ｂＤとの密着により、第１コア部２３１と第２コア部２３２との接触部分における磁気抵抗が小さい値に抑えられるため、フラックスゲートコア１１は、地磁気の影響を実質的に受けない、若しくは非常に受け難くなる。そのため、本実施例３のフラックスゲート電流センサ１は、ケーブルＣＬを流れる電流を精度良く検出することができる。なお、本実施例３においては、第２ボビン４２による圧接狭持を併用して、上面１３１ｂＵと下面１３２ｂＤとを密着させると尚よい。 In the third embodiment, due to the close contact between the upper surface 231bU of the second outer leg portion 231b of the first core portion 231 and the lower surface 232bD of the second outer leg portion 232b of the second core portion 232, Since the magnetic resistance at the contact portion with the second core portion 232 is suppressed to a small value, the fluxgate core 11 is not substantially affected by the geomagnetism or very difficult to receive. Therefore, the fluxgate current sensor 1 according to the third embodiment can accurately detect the current flowing through the cable CL. In the third embodiment, it is more preferable that the upper surface 131bU and the lower surface 132bD are brought into close contact with each other by using the pressing contact holding by the second bobbin 42 together.
（実施例４）
　図７は、本実施例４のフィードバックコア３３０単体の断面図を示す。図７に示されるように、本実施例４のフィードバックコア３３０は、第１コア部３３１と第２コア部３３２からなる。本実施例４において、第１コア部３３１と第２コア部３３２は、第１コア部３３１の第２外脚部３３１ｂの下面３３１ｂＤと、第２コア部３３２の第２外脚部３３２ｂの上面３３２ｂＵとの間に塗布された磁性接着剤Ａを介して接触し、固定されている。なお、図７では、磁性接着剤Ａを示す便宜上、下面３３１ｂＤと上面３３２ｂＵとが離れるように図示されているが、磁性接着剤Ａの塗布量は極めて薄いため、これらの面は実質的に密着状態にある。 (Example 4)
FIG. 7 shows a cross-sectional view of the feedback core 330 alone of the fourth embodiment. As shown in FIG. 7, the feedback core 330 according to the fourth embodiment includes a first core portion 331 and a second core portion 332. In the fourth embodiment, the first core portion 331 and the second core portion 332 are the lower surface 331bD of the second outer leg portion 331b of the first core portion 331 and the upper surface of the second outer leg portion 332b of the second core portion 332. It is contacted and fixed via the magnetic adhesive A applied between 332bU. In FIG. 7, for convenience of showing the magnetic adhesive A, the lower surface 331bD and the upper surface 332bU are illustrated so as to be separated from each other. However, since the amount of the magnetic adhesive A applied is extremely thin, these surfaces are substantially in close contact with each other. Is in a state.
　本実施例４においては、第１コア部３３１の第２外脚部３３１ｂの下面３３１ｂＤと、第２コア部３３２の第２外脚部３３２ｂの上面３３２ｂＵとの密着により、第１コア部３３１と第２コア部３３２との接触部分における磁気抵抗が小さい値に抑えられるため、フラックスゲートコア１１は、地磁気の影響を実質的に受けない、若しくは非常に受け難くなる。そのため、本実施例４のフラックスゲート電流センサ１は、ケーブルＣＬを流れる電流を精度良く検出することができる。なお、本実施例４においては、第２ボビン４２による圧接狭持を併用して、下面３３１ｂＤと上面３３２ｂＵとを密着させると尚よい。 In the fourth embodiment, the lower surface 331bD of the second outer leg portion 331b of the first core portion 331 and the upper surface 332bU of the second outer leg portion 332b of the second core portion 332 are brought into close contact with the first core portion 331. Since the magnetic resistance at the contact portion with the second core portion 332 is suppressed to a small value, the fluxgate core 11 is not substantially affected by the geomagnetism or very difficult to receive. Therefore, the fluxgate current sensor 1 according to the fourth embodiment can accurately detect the current flowing through the cable CL. In the fourth embodiment, it is more preferable that the lower surface 331bD and the upper surface 332bU are brought into close contact with each other by using the pressure contact holding by the second bobbin 42 together.
（実施例５）
　図８は、本実施例５のフィードバックコア４３０単体の断面図を示す。図８に示されるように、本実施例５のフィードバックコア４３０は、第１コア部４３１と第２コア部４３２からなる。第２コア部４３２の第２外脚部の先端は、クリップ状に形成されている。クリップ形状は、クリップ上部４３２ｆとクリップ下部４３２ｇからなる。本実施例５においては、クリップ上部４３２ｆとクリップ下部４３２ｇとが弾性変形しつつ、第１コア部４３１の第２外脚部４３１ｂの先端を狭持する。これにより、第２外脚部４３１ｂの下面４３１ｂＤと、クリップ下部４３２ｇとが互いに密着し、固定状態となる。 (Example 5)
FIG. 8 shows a cross-sectional view of the feedback core 430 alone of the fifth embodiment. As shown in FIG. 8, the feedback core 430 according to the fifth embodiment includes a first core portion 431 and a second core portion 432. The tip of the second outer leg portion of the second core portion 432 is formed in a clip shape. The clip shape includes a clip upper part 432f and a clip lower part 432g. In the fifth embodiment, the clip upper portion 432f and the clip lower portion 432g are elastically deformed, and the tip of the second outer leg portion 431b of the first core portion 431 is pinched. Thereby, the lower surface 431bD of the second outer leg portion 431b and the clip lower portion 432g are brought into close contact with each other, and are fixed.
　本実施例５においては、第２コア部４３２の先端で第１コア部４３１の先端を狭持するという簡易な工法により、第１コア部４３１の第２外脚部４３１ｂの下面４３１ｂＤと、クリップ下部４３２ｇとが面接触した状態で固定される。これにより、第１コア部４３１と第２コア部４３２との接触部分における磁気抵抗が小さい値に抑えられるため、フラックスゲートコア１１は、地磁気の影響を実質的に受けない、若しくは非常に受け難くなる。そのため、本実施例５のフラックスゲート電流センサ１は、ケーブルＣＬを流れる電流を精度良く検出することができる。 In the fifth embodiment, the lower surface 431bD of the second outer leg portion 431b of the first core portion 431 and the clip are formed by a simple method of holding the tip of the first core portion 431 with the tip of the second core portion 432. The lower portion 432g is fixed in surface contact. Thereby, since the magnetic resistance in the contact part of the 1st core part 431 and the 2nd core part 432 is restrained to a small value, the fluxgate core 11 does not receive the influence of geomagnetism substantially, or is very hard to receive. Become. Therefore, the fluxgate current sensor 1 of the fifth embodiment can accurately detect the current flowing through the cable CL.
（実施例６）
　図９は、本実施例６のフィードバックコア５３０単体の断面図を示す。図９に示されるように、本実施例６のフィードバックコア５３０は、第１コア部５３１と第２コア部５３２からなる。第１コア部５３１の第２外脚部５３１ｂの上面５３１ｂＵには凸部５３１ｈが形成されており、第２コア部５３２の第２外脚部５３２ｂの下面５３２ｂＤには凹部５３２ｈが形成されている。組立時において、下面５３２ｂＤを上面５３１ｂＵに重ね合わせた状態で、第２コア部５３２を第１コア部５３１に対して矢印Ｃ方向に動かすと、第２外脚部５３２ｂの先端が凸部５３１ｈに乗り上げて変形し、図９に示される位置に達すると、凸部５３１ｈと凹部５３２ｈが嵌合する。これにより、上面５３１ｂＵと下面５３２ｂＤとが互いに密着した状態で、第１コア部５３１と第２コア部５３２とが連結し、固定状態となる。 (Example 6)
FIG. 9 is a cross-sectional view of the feedback core 530 according to the sixth embodiment. As shown in FIG. 9, the feedback core 530 according to the sixth embodiment includes a first core portion 531 and a second core portion 532. A convex portion 531h is formed on the upper surface 531bU of the second outer leg portion 531b of the first core portion 531, and a concave portion 532h is formed on the lower surface 532bD of the second outer leg portion 532b of the second core portion 532. . When the second core portion 532 is moved in the arrow C direction with respect to the first core portion 531 with the lower surface 532bD overlapped with the upper surface 531bU during assembly, the tip of the second outer leg portion 532b becomes the convex portion 531h. When it gets on and deforms and reaches the position shown in FIG. 9, the convex portion 531h and the concave portion 532h are fitted. As a result, the first core portion 531 and the second core portion 532 are connected to each other in a fixed state in a state where the upper surface 531bU and the lower surface 532bD are in close contact with each other.
　本実施例６においては、凸部５３１ｈと凹部５３２ｈとの嵌合という簡易な工法により、第１コア部５３１の第２外脚部５３１ｂの上面５３１ｂＵと、第２コア部５３２の第２外脚部５３２ｂの下面５３２ｂＤとが面接触した状態で固定される。上面５３１ｂＵと下面５３２ｂＤとの密着により、第１コア部５３１と第２コア部５３２との接触部分における磁気抵抗が小さい値に抑えられるため、フラックスゲートコア１１は、地磁気の影響を実質的に受けない、若しくは非常に受け難くなる。そのため、本実施例６のフラックスゲート電流センサ１は、ケーブルＣＬを流れる電流を精度良く検出することができる。なお、凸部５３１ｈと凹部５３２ｈのセットは、少なくとも一つあれば、本発明の目的は好適に達成される。 In the sixth embodiment, the upper surface 531bU of the second outer leg portion 531b of the first core portion 531 and the second outer leg of the second core portion 532 are simply formed by fitting the convex portion 531h and the concave portion 532h. The lower surface 532bD of the part 532b is fixed in a state of surface contact. Since the magnetic resistance at the contact portion between the first core portion 531 and the second core portion 532 is suppressed to a small value due to the close contact between the upper surface 531bU and the lower surface 532bD, the flux gate core 11 is substantially affected by geomagnetism. No or very difficult to receive. Therefore, the fluxgate current sensor 1 of the sixth embodiment can accurately detect the current flowing through the cable CL. Note that the object of the present invention is suitably achieved if there is at least one set of the convex portion 531h and the concave portion 532h.
（実施例７）
　図１０は、本実施例７のフィードバックコア６３０単体の断面図を示す。図１０に示されるように、本実施例７のフィードバックコア６３０は、第１コア部６３１と第２コア部６３２からなる。第２コア部６３２の第２外脚部は、第２外脚部６３２ｆと第２外脚部６３２ｇからなる二叉形状に形成されている。第２外脚部６３２ｆと第２外脚部６３２ｇとの隙間と、第１コア部６３１の第２外脚部６３１ｂの板厚は、例えばはめあい公差（中間ばめ又はしまりばめ）で規定されている。そのため、組立時において、第２コア部６３２を第１コア部６３１に対して矢印Ｃ方向に動かすと、第２外脚部６３１ｂが第２外脚部６３２ｆと第２外脚部６３２ｇとの間に挿し込まれて、適度な締め付け力を受ける。これにより、第２外脚部６３１ｂの上面６３１ｂＵと第２外脚部６３２ｆとが互いに密着するとともに、第２外脚部６３１ｂの下面６３１ｂＤと第２外脚部６３２ｇとが互いに密着した状態で、第１コア部６３１と第２コア部６３２とが連結し、固定状態となる。 (Example 7)
FIG. 10 is a sectional view of the feedback core 630 alone according to the seventh embodiment. As shown in FIG. 10, the feedback core 630 of the seventh embodiment includes a first core portion 631 and a second core portion 632. The second outer leg portion of the second core portion 632 is formed in a bifurcated shape including a second outer leg portion 632f and a second outer leg portion 632g. The gap between the second outer leg portion 632f and the second outer leg portion 632g and the plate thickness of the second outer leg portion 631b of the first core portion 631 are defined by, for example, a fit tolerance (intermediate fit or interference fit). ing. Therefore, when the second core portion 632 is moved in the arrow C direction with respect to the first core portion 631 during assembly, the second outer leg portion 631b is located between the second outer leg portion 632f and the second outer leg portion 632g. Inserted into and receives an appropriate tightening force. Accordingly, the upper surface 631bU of the second outer leg portion 631b and the second outer leg portion 632f are in close contact with each other, and the lower surface 631bD of the second outer leg portion 631b and the second outer leg portion 632g are in close contact with each other. The first core part 631 and the second core part 632 are connected to be in a fixed state.
　本実施例７においては、上記の二面での密着により、第１コア部６３１と第２コア部６３２との接触部分における磁気抵抗が小さい値に抑えられるため、フラックスゲートコア１１は、地磁気の影響を実質的に受けない、若しくは非常に受け難くなる。そのため、本実施例７のフラックスゲート電流センサ１は、ケーブルＣＬを流れる電流を精度良く検出することができる。なお、本実施例７においては、第２ボビン４２による圧接狭持を併用して、上記の二面を密着させると尚よい。 In the seventh embodiment, since the magnetic resistance at the contact portion between the first core portion 631 and the second core portion 632 is suppressed to a small value due to the close contact on the two surfaces, the flux gate core 11 It is virtually unaffected or very difficult to be affected. Therefore, the fluxgate current sensor 1 according to the seventh embodiment can accurately detect the current flowing through the cable CL. In the seventh embodiment, it is more preferable that the two surfaces are brought into close contact with each other by using the press-contacting / holding by the second bobbin 42 together.
（実施例８）
　図１１は、本実施例８のフィードバックコア７３０単体の断面図を示す。図１１に示されるように、本実施例８のフィードバックコア７３０は、第１コア部７３１と第２コア部７３２からなる。第２コア部７３２の第２外脚部７３２ｂには、略半球状のエンボス部７３２ｉが形成されている。第２外脚部７３２ｂの根元の屈曲部Ｄは、やや鋭角に屈曲されている。そのため、エンボス部７３２ｉは、第１コア部７３１の第２外脚部７３１ｂの上面７３１ｂＵに、適度な付勢力で接触する。これにより、上面７３１ｂＵとエンボス部７３２ｉとが互いに密着した状態で、第１コア部７３１と第２コア部７３２とが連結し、固定状態となる。なお、エンボス部７３２ｉの頂点付近は、上面７３１ｂＵとの接触面積を増加させるため、平面状に形成されてもよい。 (Example 8)
FIG. 11 is a sectional view of the feedback core 730 according to the eighth embodiment. As shown in FIG. 11, the feedback core 730 according to the eighth embodiment includes a first core portion 731 and a second core portion 732. A substantially hemispherical embossed portion 732 i is formed on the second outer leg portion 732 b of the second core portion 732. The bent portion D at the base of the second outer leg portion 732b is bent at a slightly acute angle. Therefore, the embossed portion 732i contacts the upper surface 731bU of the second outer leg portion 731b of the first core portion 731 with an appropriate urging force. As a result, the first core portion 731 and the second core portion 732 are connected and in a fixed state in a state where the upper surface 731bU and the embossed portion 732i are in close contact with each other. Note that the vicinity of the apex of the embossed portion 732i may be formed in a planar shape in order to increase the contact area with the upper surface 731bU.
　本実施例８においては、第１コア部７３１の第２外脚部７３１ｂの上面７３１ｂＵと、エンボス部７３２ｉとの密着により、第１コア部７３１と第２コア部７３２との接触部分における磁気抵抗が小さい値に抑えられるため、フラックスゲートコア１１は、地磁気の影響を実質的に受けない、若しくは非常に受け難くなる。そのため、本実施例８のフラックスゲート電流センサ１は、ケーブルＣＬを流れる電流を精度良く検出することができる。なお、本実施例８においては、第２ボビン４２による圧接狭持を併用して、上面７３１ｂＵとエンボス部７３２ｉとを密着させると尚よい。また、エンボス部７３２ｉは、少なくとも一つあれば、本発明の目的は好適に達成される。 In the eighth embodiment, the magnetic resistance at the contact portion between the first core portion 731 and the second core portion 732 due to the close contact between the upper surface 731bU of the second outer leg portion 731b of the first core portion 731 and the embossed portion 732i. Therefore, the flux gate core 11 is not substantially affected by the geomagnetism or very difficult to receive. Therefore, the fluxgate current sensor 1 according to the eighth embodiment can accurately detect the current flowing through the cable CL. In the eighth embodiment, it is more preferable that the upper surface 731bU and the embossed portion 732i are brought into close contact with each other by using the press-contact clamping by the second bobbin 42 together. Further, if there is at least one embossed portion 732i, the object of the present invention is preferably achieved.
（実施例９）
　図１２（ａ）～図１２（ｃ）は、図２（ａ）～図２（ｃ）と同様の図であり、本実施例９のフラックスゲート電流センサ１の断面図を示す。図１２に示されるように、本実施例９のフラックスゲート電流センサ１は、プローブ１０、フィードバックコイル２０、及びフィードバックコア８３０を備えている。図１３は、本実施例９のフィードバックコア８３０単体の斜視図を示す。図１２又は図１３に示されるように、フィードバックコア８３０は、第１コア部８３１、第２コア部８３２、及び軟磁性介挿部材８３５を組み合わせることにより、ループを形成している。本実施例９のフラックスゲート電流センサ１は、地磁気に基づく電流測定誤差を有効に抑えるため、第１コア部８３１と第２コア部８３２との接触部分の磁気抵抗が小さくなるように構成されている。 Example 9
FIGS. 12A to 12C are views similar to FIGS. 2A to 2C, and show cross-sectional views of the fluxgate current sensor 1 of the ninth embodiment. As shown in FIG. 12, the fluxgate current sensor 1 of the ninth embodiment includes a probe 10, a feedback coil 20, and a feedback core 830. FIG. 13 is a perspective view of the feedback core 830 alone of the ninth embodiment. As shown in FIG. 12 or FIG. 13, the feedback core 830 forms a loop by combining the first core portion 831, the second core portion 832, and the soft magnetic insertion member 835. The fluxgate current sensor 1 according to the ninth embodiment is configured such that the magnetic resistance of the contact portion between the first core portion 831 and the second core portion 832 is reduced in order to effectively suppress a current measurement error based on geomagnetism. Yes.
　図１２（ａ）、図１２（ｂ）及び図１３に示されるように、フィードバックコア８３０は、中途の括れ位置側から見て、第１コア部８３１の第２外脚部８３１ｂ、軟磁性介挿部材８３５、第２コア部８３２の第２外脚部８３２ｂの順に配置されており、第２外脚部８３１ｂの上面８３１ｂＵと、第２外脚部８３２ｂの下面８３２ｂＤとが軟磁性介挿部材８３５を介して互いに重ね合わせられている。軟磁性介挿部材８３５は、第１コア部８３１及び第２コア部８３２よりも透磁率の高い軟磁性材であり、例えばニッケル合金を主とした磁性体をフォイル状にしたパーマロイテープである。軟磁性介挿部材８３５は、柔軟性を有するとともに、一面が接着性を有する接着面となっている。 As shown in FIGS. 12A, 12B, and 13, the feedback core 830 includes a second outer leg portion 831b of the first core portion 831 and a soft magnetic medium, as viewed from the constricted position side. The insertion member 835 and the second outer leg portion 832b of the second core portion 832 are arranged in this order, and the upper surface 831bU of the second outer leg portion 831b and the lower surface 832bD of the second outer leg portion 832b are soft magnetic insertion members. Overlaid on each other via 835. The soft magnetic insertion member 835 is a soft magnetic material having a higher magnetic permeability than the first core portion 831 and the second core portion 832 and is, for example, a permalloy tape made of a magnetic material mainly made of a nickel alloy in a foil shape. The soft magnetic insertion member 835 has flexibility and one surface is an adhesive surface having adhesiveness.
　図１４（ａ）～図１４（ｃ）は、本実施例９のフラックスゲート電流センサ１の組立を説明する図である。図１４に示されるフラックスゲート電流センサ１の組立工程に沿って説明すると、第１コア部８３１の第２外脚部８３１ｂの上面８３１ｂＵに軟磁性介挿部材８３５が接着固定されたうえで、第２外脚部８３１ｂが第２ボビン４２の内側に挿入され通されるとともに、第１コア部８３１の第１外脚部８３１ｃが第１ボビン４１の内側に挿入され通される（図１４（ａ）参照）。第２環部８３４内の、フィードバックコア８３０によって囲われたスペース内に、プローブ１０が組み付けられると（図１４（ｂ）参照）、第２コア部８３２の第２外脚部８３２ｂが第２ボビン４２内の残りのスペースに挿入され通されるとともに、第２コア部８３２の第１外脚部８３２ｃが第１ボビン４１内の残りのスペースに挿入され通される（図１４（ｃ）参照）。このとき、軟磁性介挿部材８３５は、第１コア部８３１の第２外脚部８３１ｂの上面８３１ｂＵと、第２コア部８３２の第２外脚部８３２ｂの下面８３２ｂＤの各面に面接触した状態で介挿される。なお、軟磁性介挿部材８３５は、下面８３２ｂＤと面接触する側の面も接着面となっていてもよい。 14 (a) to 14 (c) are diagrams illustrating the assembly of the fluxgate current sensor 1 of the ninth embodiment. Referring to the assembly process of the fluxgate current sensor 1 shown in FIG. 14, the soft magnetic insertion member 835 is bonded and fixed to the upper surface 831bU of the second outer leg portion 831b of the first core portion 831. The second outer leg portion 831b is inserted and passed through the inside of the second bobbin 42, and the first outer leg portion 831c of the first core portion 831 is inserted and passed through the inside of the first bobbin 41 (FIG. 14A). )reference). When the probe 10 is assembled in the space surrounded by the feedback core 830 in the second ring portion 834 (see FIG. 14B), the second outer leg portion 832b of the second core portion 832 is the second bobbin. The first outer leg portion 832c of the second core portion 832 is inserted into and passed through the remaining space in the first bobbin 41 (see FIG. 14C). . At this time, the soft magnetic insertion member 835 is in surface contact with each surface of the upper surface 831bU of the second outer leg portion 831b of the first core portion 831 and the lower surface 832bD of the second outer leg portion 832b of the second core portion 832. Inserted in the state. Note that the soft magnetic insertion member 835 may have an adhesive surface on the side in surface contact with the lower surface 832bD.
　図１２（ａ）又は図１２（ｂ）に示されるように、第２コア部８３２の第２外脚部８３２ｂの上面８３２ｂＵから屈曲部８３１ａ（又は８３２ａ）の下面８３１ａＤ（又は８３２ａＤ）までの幅ｗ１は、第２ボビン４２の、対向する内壁面間の距離ｄ１と略等しい。また、第１コア部８３１の第２外脚部８３１ｂの上面８３１ｂＵから下面８３１ａＤ（又は８３２ａＤ）までの幅ｗ２と、第２コア部８３２の第２外脚部８３２ｂの板厚ｔ１と、軟磁性介挿部材８３５の層厚ｔ２との和も、距離ｄ１と略等しい。幅ｗ１（及び幅ｗ２と板厚ｔ１と層厚ｔ２との和）と距離ｄ１は、例えばはめあい公差（中間ばめ又はしまりばめ）で規定されている。そのため、第２ボビン４２をフィードバックコア８３０に取り付けると（図１２（ａ）又は図１４（ｃ）参照）、第２環部８３４、屈曲部８３１ａ、及び８３２ａの全体が第２ボビン４２の内壁面間に挟み込まれて、適度な締め付け力を受ける。これにより、第２外脚部８３１ｂの上面８３１ｂＵと、第２外脚部８３２ｂの下面８３２ｂＤとが軟磁性介挿部材８３５を介挿した状態で互いに密着し、固定状態となる。 As shown in FIG. 12A or 12B, the width from the upper surface 832bU of the second outer leg portion 832b of the second core portion 832 to the lower surface 831aD (or 832aD) of the bent portion 831a (or 832a). w1 is substantially equal to the distance d1 between the opposing inner wall surfaces of the second bobbin 42. Further, the width w2 from the upper surface 831bU to the lower surface 831aD (or 832aD) of the second outer leg portion 831b of the first core portion 831, the plate thickness t1 of the second outer leg portion 832b of the second core portion 832, and soft magnetism The sum with the layer thickness t2 of the insertion member 835 is also substantially equal to the distance d1. The width w1 (and the sum of the width w2, the plate thickness t1, and the layer thickness t2) and the distance d1 are defined by fit tolerance (intermediate fit or interference fit), for example. Therefore, when the second bobbin 42 is attached to the feedback core 830 (see FIG. 12A or 14C), the entire second ring portion 834, the bent portions 831a, and 832a are the inner wall surface of the second bobbin 42. It is sandwiched between and receives moderate tightening force. As a result, the upper surface 831bU of the second outer leg portion 831b and the lower surface 832bD of the second outer leg portion 832b are in close contact with each other with the soft magnetic insertion member 835 interposed therebetween, thereby achieving a fixed state.
　本実施例９においては、第１コア部８３１の第２外脚部８３１ｂの上面８３１ｂＵと、第２コア部８３２の第２外脚部８３２ｂの下面８３２ｂＤとの隙間を埋めるように、第１コア部８３１及び第２コア部８３２よりも透磁率の高い軟磁性介挿部材８３５が接着され介挿されている。そのため、第１コア部８３１と第２コア部８３２との（軟磁性介挿部材８３５を介した）接触部分における磁気抵抗が小さい値に抑えられる。従って、フラックスゲートコア１１は、地磁気の影響を実質的に受けない、若しくは非常に受け難くなる。そのため、本実施例９のフラックスゲート電流センサ１は、ケーブルＣＬを流れる電流を精度良く検出することができる。 In the ninth embodiment, the first core is formed so as to fill a gap between the upper surface 831bU of the second outer leg portion 831b of the first core portion 831 and the lower surface 832bD of the second outer leg portion 832b of the second core portion 832. A soft magnetic insertion member 835 having a higher magnetic permeability than the portion 831 and the second core portion 832 is bonded and inserted. Therefore, the magnetic resistance at the contact portion (via the soft magnetic insertion member 835) between the first core portion 831 and the second core portion 832 is suppressed to a small value. Therefore, the fluxgate core 11 is not substantially affected by the geomagnetism or becomes very difficult to receive. Therefore, the fluxgate current sensor 1 of the ninth embodiment can accurately detect the current flowing through the cable CL.
　また、本実施例９においては、上面８３１ｂＵ、下面８３２ｂＤの各面と、軟磁性介挿部材８３５との密着性をより一層高めるため、第２ボビン４２によって、第２外脚部８３１ｂ、軟磁性介挿部材８３５、及び第２外脚部８３２ｂの三部材を圧接狭持している。これにより、第１コア部８３１と第２コア部８３２との接触部分における磁気抵抗がより一層小さい値に抑えられている。 Further, in the ninth embodiment, the second outer leg portion 831b and the soft magnetic material are formed by the second bobbin 42 in order to further improve the adhesion between the respective surfaces of the upper surface 831bU and the lower surface 832bD and the soft magnetic insertion member 835. The three members of the insertion member 835 and the second outer leg portion 832b are pressed and sandwiched. Thereby, the magnetic resistance in the contact part of the 1st core part 831 and the 2nd core part 832 is suppressed to the still smaller value.
（実施例１０）
　本実施例１０のフラックスゲート電流センサ１は、フィードバックコア以外の構成が本実施例９と共通である。そのため、本実施例１０は、フィードバックコア単体についてだけ説明する。 (Example 10)
The configuration of the flux gate current sensor 1 of the tenth embodiment is the same as that of the ninth embodiment except for the feedback core. Therefore, in the tenth embodiment, only the feedback core alone will be described.
　図１５は、本実施例１０のフィードバックコア９３０単体の断面図を示す。図１５に示されるように、本実施例１０のフィードバックコア９３０は、第１コア部９３１、第２コア部９３２、及び軟磁性介挿部材９３５からなる。軟磁性介挿部材９３５は、第１コア部９３１及び第２コア部９３２よりも透磁率の高い軟磁性材であり、例えば柔軟性を有するアモルファス薄帯である。図１５に示されるように、軟磁性介挿部材９３５は、一方の端部付近が第１コア部９３１の第２外脚部９３１ｂの先端と、第２コア部９３２の側脚部９３２ｓとの間に挟み込まれるとともに、残りの部分が、第２外脚部９３１ｂの上面９３１ｂＵと、第２外脚部９３２ｂの下面９３２ｂＤとの間に、第２ボビン４２による圧接を介して狭持されている。軟磁性介挿部材９３５は、第１コア部９３１と第２コア部９３２との間に、全体として略Ｌ字状に屈曲した状態で介挿されている。 FIG. 15 is a cross-sectional view of the feedback core 930 according to the tenth embodiment. As shown in FIG. 15, the feedback core 930 of the tenth embodiment includes a first core portion 931, a second core portion 932, and a soft magnetic insertion member 935. The soft magnetic insertion member 935 is a soft magnetic material having a higher magnetic permeability than the first core portion 931 and the second core portion 932, and is, for example, an amorphous ribbon having flexibility. As shown in FIG. 15, the soft magnetic insertion member 935 has one end near the tip of the second outer leg portion 931 b of the first core portion 931 and the side leg portion 932 s of the second core portion 932. The remaining portion is sandwiched between the upper surface 931bU of the second outer leg portion 931b and the lower surface 932bD of the second outer leg portion 932b via the pressure contact by the second bobbin 42. . The soft magnetic insertion member 935 is inserted between the first core portion 931 and the second core portion 932 while being bent in a substantially L shape as a whole.
　本実施例１０においては、第１コア部９３１の第２外脚部９３１ｂの上面９３１ｂＵと、第２コア部９３２の第２外脚部９３２ｂの下面９３２ｂＤとの隙間に加えて、第２外脚部９３１ｂの先端と、第２コア部９３２の側脚部９３２ｓとの隙間も埋めるように、第１コア部９３１及び第２コア部９３２よりも透磁率の高い軟磁性介挿部材９３５が介挿されている。そのため、第１コア部９３１と第２コア部９３２との接触部分における磁気抵抗がより一層抑えられ、フラックスゲートコア１１は、地磁気の影響を実質的に受けない、若しくは非常に受け難くなる。従って、本実施例１０のフラックスゲート電流センサ１は、ケーブルＣＬを流れる電流を精度良く検出することができる。 In the tenth embodiment, in addition to the gap between the upper surface 931bU of the second outer leg portion 931b of the first core portion 931 and the lower surface 932bD of the second outer leg portion 932b of the second core portion 932, the second outer leg A soft magnetic insertion member 935 having a higher magnetic permeability than the first core portion 931 and the second core portion 932 is interposed so as to fill a gap between the tip of the portion 931b and the side leg portion 932s of the second core portion 932. Has been. Therefore, the magnetic resistance at the contact portion between the first core portion 931 and the second core portion 932 is further suppressed, and the fluxgate core 11 is not substantially affected by the geomagnetism or is very difficult to receive. Therefore, the fluxgate current sensor 1 of the tenth embodiment can accurately detect the current flowing through the cable CL.
　以上が本発明の例示的な実施形態の説明である。本発明の実施の形態は、上記に説明したものに限定されず、特許請求の範囲の記載により表現された技術的思想の範囲内で任意に変更することができる。例えば、各実施例に示した密着手段（第２ボビン４２による圧接狭持、爪部１３２ｅによる係合、溶接Ｗによる溶接、磁性接着剤Ａによる接着、クリップ形状による狭持、凸部５３１ｈと凹部５３２ｈとの嵌合、二叉形状による狭持、エンボス部７３２ｉによる付勢）を適宜組み合わせて、第１コア部と第２コア部とを連結固定してもよい。また、本実施例１～８の各実施例のフラックスゲート電流センサ１において、軟磁性介挿部材８３５や９３５が備えられていてもよい。また、軟磁性介挿部材８３５や９３５の介挿位置、材質等は、本実施例９や１０にて例示したものに限定されない。
  The above is the description of the exemplary embodiments of the present invention. The embodiments of the present invention are not limited to those described above, and can be arbitrarily changed within the scope of the technical idea expressed by the claims. For example, the contact means shown in each embodiment (pressure clamping by the second bobbin 42, engagement by the claw 132e, welding by the welding W, adhesion by the magnetic adhesive A, clamping by the clip shape, the convex portion 531h and the concave portion The first core portion and the second core portion may be connected and fixed by appropriately combining the engagement with 532h, the holding by the bifurcated shape, and the urging by the embossed portion 732i. Further, in the fluxgate current sensor 1 of each of the first to eighth embodiments, the soft magnetic insertion member 835 or 935 may be provided. Further, the insertion positions and materials of the soft magnetic insertion members 835 and 935 are not limited to those exemplified in the ninth and tenth embodiments.

Claims (12)

  1. 　略コの字形状に曲折された２つの板形状を一体に連ねた、略３の字状のコアを一対有し、
    　前記一対のコアは、
    　　互いの第１外脚部同士の少なくとも一部が接触するとともに、互いの第２外脚部同士の少なくとも一部が該第２外脚部の板厚方向に重ね合わせられた状態で接触しつつ、前記２つの略コの字形状の互いの連結部分の間に所定のギャップが保たれて、中途が括れた環状ループが形成されるように、対向配置され、
    　　前記環状ループは、前記ギャップ部分を境に、前記第１外脚部側に、測定対象の電線が挿入され通されるスペースを規定する第１環部を有し、前記第２外脚部側に、該電線に流れる電流により誘導される磁界を検出するための磁気プローブを配置するスペースを規定する第２環部を有することを特徴とする、フラックスゲート電流センサ用ループコア。     It has a pair of substantially 3-shaped cores, which are formed by continuously connecting two plate shapes bent into a substantially U-shape,
    The pair of cores is
    While at least a part of each other's first outer legs contact each other and at least a part of each other's second outer legs contact in a state where they are overlapped in the thickness direction of the second outer legs. A predetermined gap is maintained between the two substantially U-shaped connecting portions so as to form an annular loop with a halfway,
    The annular loop has, on the first outer leg side with the gap portion as a boundary, a first ring part that defines a space through which a measurement target electric wire is inserted and passed, and the second outer leg side A loop core for a fluxgate current sensor, further comprising a second ring portion that defines a space for arranging a magnetic probe for detecting a magnetic field induced by a current flowing through the electric wire.
  2. 　前記第２外脚部同士の少なくとも一部を前記板厚方向に重ね合わせた状態で密着させる密着手段
    を有することを特徴とする、請求項１に記載のフラックスゲート電流センサ用ループコア。     2. The loop core for a fluxgate current sensor according to claim 1, further comprising a close contact unit that closely contacts at least a part of the second outer legs in a state of being overlapped in the plate thickness direction.
  3. 　前記密着手段は、
    　　一方の前記第２外脚部の先端に形成され、前記対向配置時に、他方の該第２外脚部に係合することにより、該第２外脚部同士を固定する爪部、
    　　前記対向配置された状態のコア同士の少なくとも一部を溶接した溶接部、
    　　前記対向配置された一対の前記第２外脚部の間に塗布された接着部、
    　　一方の前記第２外脚部の先端に形成され、前記対向配置時に、他方の該第２外脚部を狭持することにより、該第２外脚部同士を固定する狭持部、
    　　前記対向配置時に嵌合する、前記第２外脚部の一方に形成された凸部と、該第２外脚部の他方に形成された凹部からなる嵌合部、
    　　一方の前記第２外脚部に形成されており、前記対向配置時に、他方の該第２外脚部に付勢されて当て付くエンボス部、
    　の少なくとも一つを含むことを特徴とする、請求項２に記載のフラックスゲート電流センサ用ループコア。     The contact means is
    A claw portion that is formed at the tip of one of the second outer legs, and engages the second outer legs of the other at the time of the opposing arrangement, thereby fixing the second outer legs.
    A welded portion that welds at least a part of the cores arranged in opposition to each other;
    An adhesive applied between the pair of second outer legs disposed opposite to each other;
    A sandwiching portion that is formed at the tip of one of the second outer leg portions and fixes the second outer leg portions by sandwiching the other second outer leg portion during the opposing arrangement,
    A fitting portion formed by a convex portion formed on one side of the second outer leg portion and a concave portion formed on the other side of the second outer leg portion, which are fitted at the time of the opposing arrangement,
    An embossed portion that is formed on one of the second outer legs, and is urged against and hits the other second outer leg at the time of the opposing arrangement;
    The loop core for a fluxgate current sensor according to claim 2, comprising at least one of the following.
  4. 　前記一対のコアよりも透磁率の高い軟磁性介挿部材
    を有し、
    　前記一対のコアの互いの第２外脚部同士は、少なくとも一部が前記軟磁性介挿部材を介して接触していることを特徴とする、請求項１から請求項３の何れか一項に記載のフラックスゲート電流センサ用ループコア。     A soft magnetic insertion member having a higher magnetic permeability than the pair of cores;
    The second outer leg portions of the pair of cores are at least partially in contact with each other via the soft magnetic insertion member. Loop core for fluxgate current sensor described in 1.
  5. 　前記軟磁性介挿部材は、前記一対の第２外脚部の間に介挿されたときに変形する軟性材であることを特徴とする、請求項４に記載のフラックスゲート電流センサ用ループコア。 The flux core current sensor loop core according to claim 4, wherein the soft magnetic insertion member is a soft material that is deformed when inserted between the pair of second outer legs.
  6. 　前記軟磁性介挿部材は接着性を有しており、前記第２外脚部同士を接着固定することを特徴とする、請求項４又は請求項５に記載のフラックスゲート電流センサ用ループコア。 The loop core for a fluxgate current sensor according to claim 4 or 5, wherein the soft magnetic insertion member has adhesiveness, and the second outer legs are bonded and fixed to each other.
  7. 　前記第２外脚部同士の少なくとも一部は、該第２外脚部の板厚方向に、前記軟磁性介挿部材を間に介挿したうえで重ね合わせられていることを特徴とする、請求項４から請求項６の何れか一項に記載のフラックスゲート電流センサ用ループコア。 At least a part of the second outer legs are overlapped in the thickness direction of the second outer legs with the soft magnetic insertion member interposed therebetween, The loop core for flux gate current sensors according to any one of claims 4 to 6.
  8. 　前記第１外脚部同士の少なくとも一部は、該第１外脚部の板厚方向に重ね合わせられた状態で接触していることを特徴とする、請求項１から請求項７の何れか一項に記載のフラックスゲート電流センサ用ループコア。 The at least one part of said 1st outer leg parts is contacting in the state piled up in the plate | board thickness direction of this 1st outer leg part, The any one of Claims 1-7 characterized by the above-mentioned. The loop core for flux gate current sensors according to one item.
  9. 　請求項１から請求項８の何れか一項に記載のフラックスゲート電流センサ用ループコアと、
    　前記第２環部によって囲われるスペースに配置される磁気プローブと、
    　前記フラックスゲート電流センサ用ループコアに絶縁体を介して巻回されたコイルと、
    を有することを特徴とする、フラックスゲート電流センサ。     A loop core for a fluxgate current sensor according to any one of claims 1 to 8,
    A magnetic probe disposed in a space surrounded by the second ring portion;
    A coil wound around an insulator on the loop core for the fluxgate current sensor;
    A fluxgate current sensor comprising:
  10. 　前記絶縁体は、前記第１外脚部の板厚方向に重ね合わせられた一対の該第１外脚部の側面の少なくとも一部を囲う第１のボビンであり、
    　前記第１外脚部同士は、前記第１のボビンによる圧接狭持により、互いに接触し固定されていることを特徴とする、請求項８を引用する請求項９に記載のフラックスゲート電流センサ。     The insulator is a first bobbin that surrounds at least a part of a side surface of the pair of first outer legs overlapped in the thickness direction of the first outer legs.
    10. The fluxgate current sensor according to claim 9, wherein the first outer legs are in contact with each other and fixed by press-clamping by the first bobbin. 10.
  11. 　前記絶縁体は、前記第２外脚部の板厚方向に重ね合わせられた一対の該第２外脚部の側面の少なくとも一部を囲う第２のボビンであり、
    　前記第２外脚部同士は、前記第２のボビンによる圧接狭持により、互いに接触し固定されていることを特徴とする、請求項９又は請求項１０に記載のフラックスゲート電流センサ。     The insulator is a second bobbin that surrounds at least a part of the side surfaces of the pair of second outer legs overlapped in the plate thickness direction of the second outer legs,
    11. The fluxgate current sensor according to claim 9, wherein the second outer legs are in contact with each other and fixed by press-contact clamping by the second bobbin. 11.
  12. 　前記第２外脚部同士は、前記第２のボビンによる圧接狭持により、前記軟磁性介挿部材を介挿した状態で互いが固定されていることを特徴とする、請求項４を引用する請求項１１に記載のフラックスゲート電流センサ。
          The second outer leg portions are fixed to each other in a state where the soft magnetic insertion member is inserted by pressure contact holding by the second bobbin. The fluxgate current sensor according to claim 11.
PCT/JP2012/064458 2011-09-15 2012-06-05 Loop core for flux gate current sensor and flux gate current sensor WO2013038759A1 (en)

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CN104124041B (en) * 2013-04-28 2019-01-25 甲神电机株式会社 Magnetive cord and the magnetic balance type current sensor for having the magnetive cord
CN109655651A (en) * 2017-10-10 2019-04-19 株式会社田村制作所 Current detector
EP3477311A1 (en) * 2017-10-10 2019-05-01 Tamura Corporation Current sensor
US10976354B2 (en) 2017-10-10 2021-04-13 Tamura Corporation Current sensor

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