WO2014162687A1 - Magnetic shield body for current sensor, and current sensor device - Google Patents

Magnetic shield body for current sensor, and current sensor device Download PDF

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Publication number
WO2014162687A1
WO2014162687A1 PCT/JP2014/001657 JP2014001657W WO2014162687A1 WO 2014162687 A1 WO2014162687 A1 WO 2014162687A1 JP 2014001657 W JP2014001657 W JP 2014001657W WO 2014162687 A1 WO2014162687 A1 WO 2014162687A1
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Prior art keywords
magnetic shield
plate
portions
surface portion
parallel
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PCT/JP2014/001657
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French (fr)
Japanese (ja)
Inventor
正樹 高島
紀博 車戸
江介 野村
亮輔 酒井
孝昌 金原
Original Assignee
株式会社デンソー
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Application filed by 株式会社デンソー filed Critical 株式会社デンソー
Priority to DE112014001790.6T priority Critical patent/DE112014001790B4/en
Publication of WO2014162687A1 publication Critical patent/WO2014162687A1/en

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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/20Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
    • G01R15/207Constructional details independent of the type of device used

Definitions

  • the present disclosure relates to a magnetic shield body for a current sensor and a current sensor device.
  • Patent Document 1 proposes a configuration of a current sensor device including a magnetic shield body.
  • the magnetic shield body is a component that surrounds the outer side of the annular outer shell portion in which the current detection unit is accommodated and shields a disturbance magnetic field from the outside.
  • Patent Document 1 proposes a magnetic shield body that is assembled to an annular outer shell portion so that two semi-square cylinders, that is, U-shaped magnetic shield members are square cylinders.
  • a current sensor equipped with such a magnetic shield body detects a current flowing so as to penetrate through the annular outer shell portion located in the hollow portion of the magnetic shield body.
  • the rectangular cylindrical magnetic shield body has four surfaces in a direction perpendicular to the direction penetrating the hollow portion of the magnetic shield body. For this reason, the magnetic shield body functions to shield disturbance magnetic fields from four directions perpendicular to these four surfaces.
  • the magnetic shield body has a square cylindrical shape in which two magnetic shield members are combined, and therefore there are two openings in the direction penetrating the hollow portion of the magnetic shield body. For this reason, there exists a problem that a disturbance magnetic field will penetrate
  • the present disclosure has been made in view of the above points, and one object of the present disclosure is to provide a magnetic shield body capable of suppressing intrusion of a disturbance magnetic field from all six directions. is there. Another object of the present disclosure is to provide a current sensor device including the magnetic shield body.
  • This disclosure provides a magnetic shield body for a current sensor that forms a housing space in which a current sensor including a magnetoresistive element for detecting a current to be measured is housed.
  • the magnetic shield body has a first magnetic shield part and a second magnetic shield part.
  • the first magnetic shield part suppresses intrusion of electromagnetic waves and has a first plate part in which two first side face parts facing each other on both sides of the first upper face part are formed seamlessly with the first upper face part. And two second side surface portions that are opposite to each other on both sides of the second upper surface portion and that have a second plate portion that is formed seamlessly with the second upper surface portion.
  • the second magnetic shield portion suppresses intrusion of electromagnetic waves, and has a plurality of third side surfaces in which two third side surface portions facing each other on both sides of the third upper surface portion are formed seamlessly with the third upper surface portion. It has a plate part.
  • the first magnetic shield portion the first upper surface portion and the second upper surface portion are in contact with each other, and the two first side surface portions are arranged non-parallel to the two second side surface portions, respectively.
  • the said 1st board part and the said 2nd board part are laminated
  • the third upper surface portions of the two adjacent third plate portions of the plurality of third plate portions are in contact with each other, and the third plate portions of the plurality of third plate portions are in contact with each other.
  • the plurality of third plate portions are arranged such that the two third side surface portions in one of the two adjacent third plate portions are in contact with the two third side surface portions in the other, respectively. They are sequentially stacked.
  • the third upper surface portion of one of the plurality of third plate portions adjacent to the accommodation space faces one of the first upper surface portion and the second upper surface portion located on the third upper surface portion side.
  • the two third side surface portions of each of the third plate portions are arranged non-parallel to one of the two first side surface portions and the two second side surface portions, and
  • the accommodation space is formed by combining the first magnetic shield portion and the second magnetic shield portion so as to be adjacent to each other.
  • the present disclosure provides a current sensor device including the magnetic shield body and a current sensor housed in the housing space of the magnetic shield body and having a magnetoresistive element for detecting a current to be measured.
  • FIG. 1 is a schematic diagram illustrating a state in which a magnetic shield body according to an embodiment of the present disclosure is installed on a bus bar.
  • FIG. 2 is a diagram for explaining the principle of current measurement of the current sensor.
  • FIG. 3 is a schematic view of a magnetic shield body.
  • FIG. 4 is an exploded view of the magnetic shield body shown in FIG.
  • FIG. 5 is a V cross-sectional view of FIG. 6 is a cross-sectional view taken along the line VI in FIG.
  • FIG. 7A is a diagram showing how eddy current loss is divided when a plurality of thin plates are used, and FIG. 7B shows eddy current loss when a single thin plate is used. It is the figure which showed a mode that it generate
  • the magnetic shield body 1 is arranged around the current sensor 10 for detecting the magnitude of the current to be measured flowing through the bus bar 2.
  • the bus bar 2 is fixed to the holding member 3 as shown in FIG.
  • the holding member 3 has grooves and protrusions for positioning, and is a part for positioning the bus bar 2, the current sensor 10, and the magnetic shield body 1 in a self-aligned manner.
  • the current sensor 10 includes a bias magnet 11 and a magnetoresistive element 12 as shown in FIG.
  • the bias magnet 11 is a magnetic field generating unit that generates a bias magnetic field in a direction perpendicular to a signal magnetic field generated when a current to be measured flows through the bus bar 2. That is, the bias magnet 11 is disposed above the bus bar 2 so that the N pole and the S pole are aligned in the direction in which the current to be measured flows, that is, the longitudinal direction of the bus bar 2. As a result, the bias magnet 11 applies a bias magnetic field to the magnetoresistive element 12.
  • the magnetoresistive element 12 has a sensing part whose resistance value changes when affected by an external magnetic field.
  • the magnetoresistive element 12 is disposed in the vicinity of the bus bar 2, that is, between the bus bar 2 and the bias magnet 11.
  • the current sensor 10 is arranged in a housing space which is a hollow portion of the magnetic shield body 1 so that the current direction of the current to be measured flowing through the bus bar 2, that is, the longitudinal direction of the bus bar 2 and the bias magnetic field are parallel to each other.
  • the current sensor 10 is housed in the magnetic shield body 1 so that the signal magnetic field generated by the current to be measured flowing through the bus bar 2 and the bias magnetic field are perpendicular to each other. Therefore, a synthetic magnetic field composed of a bias magnetic field and a signal magnetic field is applied to the magnetoresistive element 12.
  • a signal magnetic field is generated when the current to be measured flows through the bus bar 2, and the magnetic field angle ⁇ is changed by changing the combined magnetic field composed of the signal magnetic field and the bias magnetic field according to the magnitude of the current to be measured. . Therefore, the magnetoresistive element 12 detects that the resistance value of the sensing unit has changed due to the change in angle.
  • the magnetic shield body 1 shown in FIG. 3 has a housing space 4 for housing a part of the bus bar 2 and the current sensor 10, and serves to shield a magnetic field from the outside.
  • the magnetic shield body 1 includes a first magnetic shield part 20 and a second magnetic shield part 30.
  • the first magnetic shield part 20 is configured by stacking a first plate part 21 and a plurality of second plate parts 22.
  • the number of second plate portions 22 is two.
  • the first plate portion 21 is formed by bending the first flat plate-like member 23 that suppresses intrusion of electromagnetic waves. Specifically, in the first plate portion 21, two first side surface portions (first side wall portions) 25a and 25b that face each other in parallel on both sides of the first upper surface portion (first upper wall portion) 24 are first. The upper surface portion 24 is formed integrally with the seam.
  • Each second plate portion 22 is formed by bending a second flat plate-like member 26 that suppresses intrusion of electromagnetic waves. Specifically, in each second plate portion 22, two second side surface portions (second side wall portions) 28 a and 28 b that face each other in parallel with each other on both sides of the second upper surface portion (second upper wall portion) 27 are the first. 2. It is formed seamlessly integrally with the upper surface portion 27.
  • the second upper surface portions 27 of the two second plate portions 22 are in contact with each other in parallel, and the two second side surface portions 28 a and 28 b in one second plate portion 22 are in the other second plate portion 22.
  • Two second plate portions 22 are stacked in a direction perpendicular to the plane of the bus bar 2 (up and down direction in FIG. 5) so as to be in parallel with the two second side surface portions 28a and 28b.
  • each of the second side surface portions 28 a and 28 b of the second plate portion 22 has two protruding portions extending in a direction in which a part of the end portion opposite to the second upper surface portion 27 is separated from the second upper surface portion 27. 29.
  • the protruding portion 29 extends in a direction in which both end portions of the second side surface portions 28 a and 28 b in the direction perpendicular to the extending direction of the second side surface portions 28 a and 28 b are separated from the second upper surface portion 27. Is provided.
  • the second side surface portions 28a and 28b a part of the end opposite to the second upper surface portion 27 is recessed toward the second upper surface portion 27 to form the recessed portions (openings) 28a1 and 28b1.
  • the part which comprises the said recessed parts 28a1 and 28b1 becomes the protrusion part 29.
  • FIG. It can be said that due to the recesses 28a1 and 28b1 and the protrusion 29, the surfaces of the second side surface portions 28a and 28b are divided surfaces in which a part of the second side surface portions 28a and 28b is divided.
  • the bus bar 2 is inserted into the recessed portions 28a1 and 28b1 of the second side surface portions 28a and 28b.
  • the first plate portion 21 and one second plate portion 22 adjacent to the first plate portion 21 are the first upper surface portion 24 of the first plate portion 21 and the second upper surface portion of the second plate portion 22. 27 are stacked in a direction perpendicular to the plane of the bus bar 2 so as to be in contact with each other in parallel.
  • the two second plate portions 22 are laminated so that the second upper surface portion 27 of one second plate portion 22 and the second upper surface portion 27 of the other second plate portion 22 are in contact with each other in parallel. ing.
  • the 1st board part 21 is located in the outer side
  • one 2nd board part 22 is located inside, ie, the accommodation space 4 side.
  • the two first side surface portions 25 a and 25 b of the first plate portion 21 are sandwiched between the two second side surface portions 28 a and 28 b of each second plate portion 22.
  • the first plate portion is such that the two first side surface portions 25a, 25b of the first plate portion 21 are perpendicular to the two second side surface portions 28a, 28b of the second plate portions 22, respectively. 21 and two second plate portions 22 are laminated.
  • the first magnetic shield part 20 is configured.
  • the second magnetic shield part 30 is configured by laminating a plurality of third plate parts 31.
  • the number of third plate portions 31 is three.
  • Each third plate portion 31 is formed by bending a third flat plate-like member 32 that suppresses intrusion of electromagnetic waves.
  • two third side surface portions (third side wall portions) 34 a and 34 b facing each other in parallel with each other on both sides of the third upper surface portion (third upper wall portion) 33 are the first. 3 It is formed seamlessly with the upper surface portion 33.
  • the third upper surface portions 33 of the two third plate portions 31 adjacent to each other among the three third plate portions 31 are in parallel contact with each other, and each of the two third plate portions adjacent to each other.
  • the three third plate portions 31 are on the plane of the bus bar 2 so that the two third side surface portions 34a, 34b on one side of the 31 are in contact with the two third side surface portions 34a, 34b on the other side in parallel.
  • the layers are sequentially stacked in the vertical direction. In this way, the second magnetic shield part 30 is configured.
  • the flat plate members 23, 26, and 32 are each formed of a thin plate.
  • each flat member 23, 26, 32 for example, an electromagnetic steel sheet (magnetic material) having a thickness of 1 mm or less, more specifically 0.5 mm, is employed.
  • board thickness of each flat member 23, 26, 32 is not limited to 1 mm or less, You may exceed 1 mm as needed.
  • An insulating film is formed on the surface of the electromagnetic steel sheet (that is, each flat member 23, 26, 32 is covered with an insulating film).
  • each said board part 21,22,31 is bend
  • first flat plate member 23 and the second flat plate member 26 are set so that the first plate portion 21 and the two second plate portions 22 are stacked in close contact.
  • dimensions of the respective third flat plate members 32 are set so that the three third flat plate members 32 are stacked in close contact.
  • the third upper surface portion 33 of the second magnetic shield portion 30 is parallel to the first upper surface portion 24 and the second upper surface portion 27 of the first magnetic shield portion 20.
  • the first magnetic shield part 20 and the second magnetic shield part 30 are combined.
  • the third side surface portions 34a and 34b of the second magnetic shield portion 30 are parallel to the first side surface portions 25a and 25b of the first magnetic shield portion 20 and perpendicular to the second side surface portions 28a and 28b.
  • the first magnetic shield part 20 and the second magnetic shield part 30 are combined.
  • the accommodation space 4 is formed between the first magnetic shield part 20 and the second magnetic shield part 30.
  • the first magnetic shield part 20 and the second magnetic shield part 30 are assembled to the holding member 3 so as to form the accommodation space 4.
  • the first magnetic shield part 20 and the second magnetic shield part 30 are fixed to the holding member 3 by screwing the holding member 3 or by molding the magnetic shield body 1 with resin.
  • the protruding portions 29 of the second side surface portions 28a and 28b described above are the first upper surface portion 24 and the second upper surface portion 27 of the second side surface portions 28a and 28b arranged perpendicular to the third side surface portions 34a and 34b. It can be said that a part of the end portion on the opposite side is a portion extending in a direction away from the first upper surface portion 24 and the second upper surface portion 27.
  • each third upper surface portion 33 of the second magnetic shield portion 30 has two protruding portions 35 from which a part of the third upper surface portion 33 protrudes.
  • the protruding portion 35 is provided in a portion corresponding to the recessed portions 28 a 1 and 28 b 1 formed by the protruding portion 29 in the second side surface portions 28 a and 28 b of the first magnetic shield portion 20. With this protruding portion 35, the shielding area of the third upper surface portion 33 can be increased.
  • the first upper surface portion 24 of the first magnetic shield portion 20 shields a disturbance magnetic field from one direction on the first upper surface portion 24 side of the bus bar 2.
  • the first side surface portions 25 a and 25 b of the first magnetic shield portion 20 shield a disturbance magnetic field from two directions perpendicular to the longitudinal direction of the bus bar 2 in a plane parallel to the flat portion of the bus bar 2.
  • the second side surface portions 28 a and 28 b of the second magnetic shield portion 30 shield a disturbance magnetic field from two directions parallel to the longitudinal direction of the bus bar 2 in a plane parallel to the flat portion of the bus bar 2.
  • the third upper surface portion 33 of the second magnetic shield portion 30 shields a disturbance magnetic field from one direction on the third upper surface portion 33 side of the bus bar 2.
  • the third side surface portions 34a and 34b of the second magnetic shield portion 30 are formed from two directions perpendicular to the longitudinal direction of the bus bar 2 on a plane parallel to the flat surface portion of the bus bar 2, similarly to the first side surface portions 25a and 25b.
  • the disturbance magnetic field is shielded. Therefore, the magnetic shield body 1 has a surface or a part of a surface that shields disturbance magnetic fields from all six directions.
  • the current sensor 10 disposed in the accommodation space 4 of the magnetic shield body 1 will be described.
  • the current sensor 10 includes a lead 13, a circuit chip 14, and a resin package 15 in addition to the bias magnet 11 and the magnetoresistive element 12 described above. 5 and 6, the holding member 3 is omitted.
  • the lead 13 has one surface 13a on which the bias magnet 11 is mounted and the other surface 13b on which the magnetoresistive element 12 and the circuit chip 14 are mounted.
  • the circuit chip 14 outputs a signal corresponding to the current to be measured to the outside by performing a preset operation on the signal input from the magnetoresistive element 12. Bonding wires 16 are electrically connected between the magnetoresistive element 12 and the circuit chip 14 and between the circuit chip 14 and the leads 13.
  • the resin package 15 is a sealing member that seals the bias magnet 11, the magnetoresistive element 12, the lead 13, the circuit chip 14, and a part of the lead 13 so that a part of the lead 13 is exposed.
  • the first magnetic shield part 20 and the second magnetic shield part 30 are arranged with respect to each other via the gap 40.
  • the first side surface portions 25a and 25b, the second side surface portions 28a and 28b, and the third side surface portions 34a and 34b are arranged with a gap 40 therebetween.
  • the air gap 40 plays a role of passing the bus bar 2, a role of taking out a signal from the accommodation space 4 of the magnetic shield body 1, and a role of resistance to weaken the disturbance magnetic field by the air located in the air gap 40.
  • the air gap 40 is formed in a self-aligned manner by assembling the first magnetic shield part 20 and the second magnetic shield part 30 to the holding member 3.
  • the magnetoresistive element 12 has a detection surface 12a for detecting a change in a magnetic field generated in the accommodation space 4 when a current to be measured flows through the bus bar 2.
  • the sensing surface for detecting a change in magnetic field is provided on the detection surface 12a.
  • a signal magnetic field generated from the bus bar 2 is generated in the accommodation space 4 and re-emitted in the gap 40 between the first magnetic shield part 20 and the second magnetic shield part 30.
  • the central portion of the accommodation space 4 is least affected by the disturbance magnetic field, so that the detection surface 12 a of the magnetoresistive element 12 is disposed in the central portion of the magnetic shield body 1.
  • the detection surface 12 a of the magnetoresistive element 12 is parallel to the first upper surface portion 24 of the first magnetic shield portion 20. And at a height of h / 2.
  • the center position 12 b of the detection surface 12 a of the magnetoresistive element 12 is the center position of the surface parallel to the first upper surface portion 24 in the accommodation space 4 in the direction perpendicular to the first upper surface portion 24 of the first magnetic shield portion 20.
  • the first magnetic shield part 20 and the second magnetic shield part 30 are combined so as to be aligned with 41. That is, the magnetoresistive element 12 is arranged so that the detection surface 12a is symmetrical at the position h / 2 in the accommodation space 4 of the magnetic shield body 1.
  • the position of the detection surface 12a of the magnetoresistive element 12 in the accommodation space 4 is determined in a self-aligning manner by arranging the current sensor 10 on the holding member 3 and assembling the magnetic shield body 1 on the holding member 3. Designed in advance.
  • the detection surface 12a of the magnetoresistive element 12 can be positioned at a position farthest from the outside of the magnetic shield body. For this reason, it becomes difficult for the magnetoresistive element 12 to receive the influence of the exterior of the magnetic shield body 1, and it can reduce the influence on the detection characteristic of the magnetoresistive element 12.
  • the present embodiment is characterized in that the magnetic shield body 1 shown in FIGS. 3 and 4 is configured.
  • the second side parts 28 a and 28 b of the second plate part 22 are arranged perpendicular to the first side parts 25 a and 25 b of the first plate part 21.
  • the first magnetic shield part 20 can suppress the intrusion of a disturbance magnetic field from five directions including the two directions of the second side face parts 28a and 28b.
  • the third upper surface part 33 of the third plate part 31 has a direction that cannot be shielded by the first magnetic shield part 20, that is, the first upper surface part 24 of the first magnetic shield part 20. Can suppress the intrusion of a disturbance magnetic field from the opposite side.
  • the disturbance magnetic field from the same two directions as the 1st side surface parts 25a and 25b can be shielded by the 3rd side surface parts 34a and 34b. Therefore, in the magnetic shield body 1, it is possible to suppress the intrusion of a disturbance magnetic field from all six directions. In this embodiment, it can be used in a magnetic field of 10 mT practically.
  • the bus bar 2 handles a strong disturbance magnetic field and a high-frequency AC current
  • a strong disturbance magnetic field and a high-frequency AC current for example, when the bus bar 2 passes a current that drives a three-phase AC motor
  • the influence of the disturbance magnetic field generated in the adjacent bus bar 2 by the current sensor 10. Can be considered.
  • the disturbance magnetic field from all six directions can be shielded by the magnetic shield body 1 according to the present embodiment, the shielding effect against the disturbance magnetic field can be exhibited even in a situation where a high-frequency alternating current is handled.
  • the first side surface portions 25a and 25b and the second side surface portions 28a and 28b are arranged vertically, and the first side surface portions 25a and 25b and the third side surface portions 34a and 34b are arranged in parallel. Therefore, the overall shape of the magnetic shield body 1 can be a cubic shape. For this reason, the whole size of the magnetic shield body 1 can be minimized.
  • the second side surface portions 28a and 28b are provided with the protruding portions 29 from which part of the second side surface portions 28a and 28b protrudes, the second side surface portions 28a and 28b
  • the shielding part for shielding a disturbance magnetic field can be increased. Therefore, it is possible to improve the magnetic shield effect against the disturbance magnetic field.
  • the magnetic shield body 1 has a gap 40 between each side surface portion.
  • the air gap 40 cannot be completely eliminated for reasons such as signal extraction, but the air located in the air gap 40 functions as a resistance to weaken the disturbance magnetic field as described above.
  • board thickness of the 1st flat plate member 23, the 2nd flat plate member 26, and the 3rd flat plate member 32 which comprise the 1st magnetic shield part 20 and the 2nd magnetic shield part 30 can be made thin, respectively. There is a merit.
  • the first magnetic shield part 20 and the second magnetic shield part 30 are characterized in that a plurality of thin plates (flat plate members 23, 26, 32) are laminated while being insulated from each other. .
  • a plurality of thin plates flat plate members 23, 26, 32
  • the eddy current loss generated in proportion to the square of the plate thickness of each flat plate member 23, 26, 32 is divided into small plates. Therefore, as shown in FIG. 7B, the heat generation of the first magnetic shield part 20 and the second magnetic shield part 30 is suppressed compared with the use of a single flat plate member 200 having a thickness of three sheets. be able to.
  • the magnetic shield body 1 is composed of a plurality of thin plates, thereby generating heat due to eddy current loss. Can be suppressed. For this reason, it is possible to prevent the characteristics of the current sensor 10 and the magnetoresistive element 12 from being affected by the heat generated by the magnetic shield body 1.
  • the configuration of the magnetic shield body 1 shown in the above embodiment is merely an example, and is not limited to the configuration shown above, and may be other configurations that can realize the present disclosure.
  • the magnetic shield body 1 has a cubic shape, but this is an example of the shape of the magnetic shield body 1. Therefore, each surface does not need to be parallel or perpendicular to each other.
  • first side surfaces 25a and 25b only need to face each other.
  • second side surface portions 28a and 28b and the third side surface portions 34a and 34b As for the first magnetic shield part 20, the first upper surface part 24 and the second upper surface part 27 are in contact with each other, and the two first side surface parts 25a, 25b are in contact with the two second side surface parts 28a, 28b.
  • the 1st board part 21 and the 2nd board part 22 should just be laminated
  • the third upper surface parts 33 of the two third plate parts 31 adjacent to each other out of the three third plate parts 31 are in contact with each other, and the two adjacent each other.
  • the three third plate portions 31 are sequentially stacked so that the two third side surface portions 34a and 34b on one side of the third plate portion 31 are in contact with the two third side surface portions 34a and 34b on the other side, respectively. It only has to be.
  • the third upper surface portion 33 of one of the three third plate portions 31 adjacent to the accommodation space 4 has the first upper surface portion 24 and the second upper surface portion 27 located on the third upper surface portion 33 side.
  • the two third side surface portions 34a and 34b of each third plate portion 31 are disposed on one of the two first side surface portions 25a and 25b and the two second side surface portions 28a and 28b.
  • the first magnetic shield part 20 and the second magnetic shield part 30 are combined so as to be arranged non-parallel to each other and adjacent to each other, whereby the accommodation space 4 is formed.
  • the third side face parts 34a, 34b and the second side face parts 28a, 28b are arranged non-parallel to each other, and In addition to adjoining, the third side surface portions 34a and 34b and the first side surface portions 25a and 25b may be arranged non-parallel to each other and adjacent to each other.
  • the shape of the protrusions 29 provided on the second side surfaces 28a and 28b and the protrusion 35 provided on the third upper surface 33 is not limited to the shape shown in FIGS. 3 and 4 and can be set as appropriate. That is, if a part of the second side surface parts 28a and 28b and a part of the third upper surface part 33 are projected, a shielding effect against a disturbance magnetic field can be generated in the projected part.
  • the air gap 40 may be set in any way.
  • the gap 40 is provided between the side portions, but this is an example in which the gap 40 is provided.
  • the first side surface portions 25a and 25b may be in contact with the second side surface portions 28a and 28b
  • the third side surface portions 34a and 34b are the first side surface portions 25a and 25b and the second side surface portions 28a and 28b. It may be in contact with either one.
  • the first magnetic shield part 20 and the second magnetic shield part 30 are each composed of three thin plates, but the first magnetic shield part 20 and the second magnetic shield part 30 are thin plates. It is not necessary to have the same number of sheets. Further, the number of the first plate portion 21 and the second plate portion 22 of the first magnetic shield portion 20 and the number of the third plate portion 31 of the second magnetic shield portion 30 according to the strength of the magnetic field received by the magnetoresistive element 12. May be determined.

Abstract

In a first magnetic shield (20), second side surface portions (28a, 28b) of a second plate (22) are disposed so as to be perpendicular to first side surface portions (25a, 25b) of a first plate (21). As a result, the first magnetic shield (20) suppresses the intrusion of disturbance magnetic fields from a total of five directions, that is, one direction from a first-upper-surface-portion (24) side and the four directions of the first side surface portions (25a, 25b) and second side surface portions (28a, 28b). Meanwhile, in a second magnetic shield (30), a third upper surface portion (33) of a third plate (31) suppresses the intrusion of disturbance magnetic fields from the third-upper-surface-portion (33) side. Further, third side surface portions (34a, 34b) shield against disturbance magnetic fields from the same two directions as the first side surface portions (25a, 25b).

Description

電流センサ用の磁気シールド体及び電流センサ装置Magnetic shield for current sensor and current sensor device 関連出願の相互参照Cross-reference of related applications
 本開示は、2013年4月1日に出願された日本国特許出願第2013-75804号に基づくものであり、この開示をもってその内容を本明細書中に開示したものとする。 This disclosure is based on Japanese Patent Application No. 2013-75804 filed on April 1, 2013, and the content thereof is disclosed in this specification.
 本開示は、電流センサ用の磁気シールド体及び電流センサ装置に関する。 The present disclosure relates to a magnetic shield body for a current sensor and a current sensor device.
 従来より、磁気シールド体を備えた電流センサ装置の構成が、例えば特許文献1で提案されている。磁気シールド体は、電流検出部が収納された環状外殻部の外側を囲むと共に、外部からの外乱磁界を遮蔽する部品である。特許文献1では、半四角筒状すなわちコの字型の2個の磁気シールド部材が四角筒状となるように環状外殻部に組み付けられた磁気シールド体が提案されている。 Conventionally, for example, Patent Document 1 proposes a configuration of a current sensor device including a magnetic shield body. The magnetic shield body is a component that surrounds the outer side of the annular outer shell portion in which the current detection unit is accommodated and shields a disturbance magnetic field from the outside. Patent Document 1 proposes a magnetic shield body that is assembled to an annular outer shell portion so that two semi-square cylinders, that is, U-shaped magnetic shield members are square cylinders.
 このような磁気シールド体を備えた電流センサは、磁気シールド体の中空部に位置する環状外殻部を貫通するように流れる電流を検出する。また、四角筒状の磁気シールド体は、当該磁気シールド体の中空部を貫通する方向に対して垂直な方向に4つの面を有している。このため、磁気シールド体は、これら4つの面に垂直な4方向からの外乱磁界を遮蔽するように機能する。 A current sensor equipped with such a magnetic shield body detects a current flowing so as to penetrate through the annular outer shell portion located in the hollow portion of the magnetic shield body. The rectangular cylindrical magnetic shield body has four surfaces in a direction perpendicular to the direction penetrating the hollow portion of the magnetic shield body. For this reason, the magnetic shield body functions to shield disturbance magnetic fields from four directions perpendicular to these four surfaces.
 しかしながら、上記従来の技術では、磁気シールド体は2個の磁気シールド部材が組み合わされた四角筒状となっているので、磁気シールド体の中空部を貫通する方向に2つの開口部が存在する。このため、外乱磁界が磁気シールド体の2つの開口部を介する2方向から磁気シールド体の中空部に浸入してしまうという問題がある。したがって、電流センサが外乱磁界の影響を受ける方向を加味しなければならず、被測定体に対する電流センサの搭載制約が生じてしまう。あるいは、電流センサは外乱磁界が弱い環境での使用に限定されてしまう。 However, in the above-described conventional technology, the magnetic shield body has a square cylindrical shape in which two magnetic shield members are combined, and therefore there are two openings in the direction penetrating the hollow portion of the magnetic shield body. For this reason, there exists a problem that a disturbance magnetic field will penetrate | invade into the hollow part of a magnetic shield body from two directions through two openings of a magnetic shield body. Therefore, the direction in which the current sensor is affected by the disturbance magnetic field must be taken into account, and the mounting of the current sensor on the object to be measured occurs. Alternatively, the current sensor is limited to use in an environment where the disturbance magnetic field is weak.
 ここで、強い外乱磁界を受ける環境において磁気シールド体の磁気シールド効果を確保するために、磁気シールド部材を構成する板材を厚くすることが考えられる。しかし、板材の厚みに伴って板材の抵抗値が下がるので、外乱磁界を受けた磁気シールド体に発生する渦電流損による発熱が大きくなってしまうという問題がある。したがって、渦電流損による発熱が電流センサの電流検出特性に悪影響を与えてしまう。よって、磁気シールド部材を構成する板材を厚くすることは好ましくない。 Here, in order to ensure the magnetic shield effect of the magnetic shield body in an environment where a strong disturbance magnetic field is received, it is conceivable to increase the thickness of the plate material constituting the magnetic shield member. However, since the resistance value of the plate material decreases with the thickness of the plate material, there is a problem that heat generation due to the eddy current loss generated in the magnetic shield body subjected to the disturbance magnetic field increases. Therefore, heat generated by eddy current loss adversely affects the current detection characteristics of the current sensor. Therefore, it is not preferable to thicken the plate material constituting the magnetic shield member.
特開2010-14477号公報JP 2010-14477 A
 本開示は上記の点に鑑みて成されたものであり、本開示の1つの目的は、6方向の全ての方向からの外乱磁界の浸入を抑制することができる磁気シールド体を提供することにある。本開示の別の目的は、前記の磁気シールド体を備えた電流センサ装置を提供することにある。 The present disclosure has been made in view of the above points, and one object of the present disclosure is to provide a magnetic shield body capable of suppressing intrusion of a disturbance magnetic field from all six directions. is there. Another object of the present disclosure is to provide a current sensor device including the magnetic shield body.
 本開示では、測定対象の電流を検出するための磁気抵抗素子を備えた電流センサが収容される収容空間を形成する電流センサ用の磁気シールド体を提供する。前記磁気シールド体は、第1磁気シールド部及び第2磁気シールド部を有する。前記第1磁気シールド部は、電磁波の浸入を抑制するとともに、第1上面部の両側において互いに対向する2つの第1側面部が前記第1上面部と一体に継ぎ目無く形成された第1板部と、電磁波の浸入を抑制するとともに、第2上面部の両側において互いに対向する2つの第2側面部が前記第2上面部と一体に継ぎ目無く形成された第2板部とを有する。前記第2磁気シールド部は、電磁波の浸入を抑制するとともに、第3上面部の両側において互いに対向する2つの第3側面部が前記第3上面部と一体に継ぎ目無く形成された複数の第3板部を有する。前記第1磁気シールド部では、前記第1上面部と前記第2上面部とが互いに接触すると共に、前記2つの第1側面部が前記2つの第2側面部に対しそれぞれ非平行に配置され、かつ、隣り合うように、前記第1板部と前記第2板部とが積層されている。前記第2磁気シールド部では、前記複数の第3板部のうちの互いに隣接する各2枚の前記第3板部の前記第3上面部同士が互いに接触し、前記複数の第3板部のうちの互いに隣接する各2枚の前記第3板部の一方における前記2つの第3側面部が、他方における前記2つの第3側面部にそれぞれ接触するように、前記複数の第3板部が順次積層されている。前記複数の第3板部のうちの前記収容空間に隣接する1枚における前記第3上面部が、前記第3上面部側に位置する前記第1上面部及び前記第2上面部の一方と対向すると共に、前記各第3板部の前記2つの第3側面部が前記2つの第1側面部と、前記2つの第2側面部とのうちの一方に対しそれぞれ非平行に配置され、かつ、隣り合うように、前記第1磁気シールド部と前記第2磁気シールド部とが組み合わされて、前記収容空間が形成される。 This disclosure provides a magnetic shield body for a current sensor that forms a housing space in which a current sensor including a magnetoresistive element for detecting a current to be measured is housed. The magnetic shield body has a first magnetic shield part and a second magnetic shield part. The first magnetic shield part suppresses intrusion of electromagnetic waves and has a first plate part in which two first side face parts facing each other on both sides of the first upper face part are formed seamlessly with the first upper face part. And two second side surface portions that are opposite to each other on both sides of the second upper surface portion and that have a second plate portion that is formed seamlessly with the second upper surface portion. The second magnetic shield portion suppresses intrusion of electromagnetic waves, and has a plurality of third side surfaces in which two third side surface portions facing each other on both sides of the third upper surface portion are formed seamlessly with the third upper surface portion. It has a plate part. In the first magnetic shield portion, the first upper surface portion and the second upper surface portion are in contact with each other, and the two first side surface portions are arranged non-parallel to the two second side surface portions, respectively. And the said 1st board part and the said 2nd board part are laminated | stacked so that it may adjoin. In the second magnetic shield portion, the third upper surface portions of the two adjacent third plate portions of the plurality of third plate portions are in contact with each other, and the third plate portions of the plurality of third plate portions are in contact with each other. The plurality of third plate portions are arranged such that the two third side surface portions in one of the two adjacent third plate portions are in contact with the two third side surface portions in the other, respectively. They are sequentially stacked. The third upper surface portion of one of the plurality of third plate portions adjacent to the accommodation space faces one of the first upper surface portion and the second upper surface portion located on the third upper surface portion side. And the two third side surface portions of each of the third plate portions are arranged non-parallel to one of the two first side surface portions and the two second side surface portions, and The accommodation space is formed by combining the first magnetic shield portion and the second magnetic shield portion so as to be adjacent to each other.
 さらに、本開示では、前記磁気シールド体と、前記磁気シールド体の前記収容空間に収容され、測定対象の電流を検出するための磁気抵抗素子を有する電流センサとを備える電流センサ装置を提供する。 Furthermore, the present disclosure provides a current sensor device including the magnetic shield body and a current sensor housed in the housing space of the magnetic shield body and having a magnetoresistive element for detecting a current to be measured.
図1は、本開示の一実施形態に係る磁気シールド体がバスバーに設置された状態を示す模式図である。FIG. 1 is a schematic diagram illustrating a state in which a magnetic shield body according to an embodiment of the present disclosure is installed on a bus bar. 図2は、電流センサの電流測定原理を説明するための図である。FIG. 2 is a diagram for explaining the principle of current measurement of the current sensor. 図3は、磁気シールド体の模式図である。FIG. 3 is a schematic view of a magnetic shield body. 図4は、図3に示された磁気シールド体の分解図である。FIG. 4 is an exploded view of the magnetic shield body shown in FIG. 図5は、図1のV断面図である。FIG. 5 is a V cross-sectional view of FIG. 図6は、図1のVI断面図である。6 is a cross-sectional view taken along the line VI in FIG. 図7(a)は、複数の薄板を用いた場合に渦電流損が分割される様子を示した図であり、図7(b)は、1枚の薄板を用いた場合に渦電流損が発生する様子を示した図である。FIG. 7A is a diagram showing how eddy current loss is divided when a plurality of thin plates are used, and FIG. 7B shows eddy current loss when a single thin plate is used. It is the figure which showed a mode that it generate | occur | produces.
 以下、本開示の実施形態について図に基づいて説明する。図1及び図2に示されるように、本実施形態の電流センサ装置100では、磁気シールド体1は、バスバー2に流れる被測定電流の大きさを検出するための電流センサ10の周囲に配置される。 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. As shown in FIGS. 1 and 2, in the current sensor device 100 of the present embodiment, the magnetic shield body 1 is arranged around the current sensor 10 for detecting the magnitude of the current to be measured flowing through the bus bar 2. The
 バスバー2は、図1に示されるように、保持部材3に固定されている。保持部材3は位置決めのための溝や突起等を有し、バスバー2、電流センサ10、及び磁気シールド体1がはめ込まれることでそれぞれを自己整合的に位置決めするための部品である。 The bus bar 2 is fixed to the holding member 3 as shown in FIG. The holding member 3 has grooves and protrusions for positioning, and is a part for positioning the bus bar 2, the current sensor 10, and the magnetic shield body 1 in a self-aligned manner.
 電流センサ10は、図2に示されるように、バイアス磁石11と磁気抵抗素子12とを備えている。このうちバイアス磁石11は、バスバー2に測定対象の被測定電流が流れることによって生じる信号磁界に対して垂直方向にバイアス磁界を発生させる磁界発生手段である。すなわち、バイアス磁石11は、被測定電流が流れる方向すなわちバスバー2の長手方向にN極とS極とが並ぶようにバスバー2の上方に配置されている。これにより、バイアス磁石11はバイアス磁界を磁気抵抗素子12に印加する。 The current sensor 10 includes a bias magnet 11 and a magnetoresistive element 12 as shown in FIG. Among them, the bias magnet 11 is a magnetic field generating unit that generates a bias magnetic field in a direction perpendicular to a signal magnetic field generated when a current to be measured flows through the bus bar 2. That is, the bias magnet 11 is disposed above the bus bar 2 so that the N pole and the S pole are aligned in the direction in which the current to be measured flows, that is, the longitudinal direction of the bus bar 2. As a result, the bias magnet 11 applies a bias magnetic field to the magnetoresistive element 12.
 磁気抵抗素子12は、外部の磁場の影響を受けたときに抵抗値が変化するセンシング部を有している。例えば、磁気抵抗素子12はバスバー2の近接位置すなわちバスバー2とバイアス磁石11との間に配置される。 The magnetoresistive element 12 has a sensing part whose resistance value changes when affected by an external magnetic field. For example, the magnetoresistive element 12 is disposed in the vicinity of the bus bar 2, that is, between the bus bar 2 and the bias magnet 11.
 また、電流センサ10は、バスバー2に流れる被測定電流の電流方向すなわちバスバー2の長手方向とバイアス磁界とが平行になるように、磁気シールド体1の中空部である収容空間に配置される。言い換えると、電流センサ10は、バスバー2に流れる被測定電流によって生成される信号磁界とバイアス磁界とが垂直になるように、磁気シールド体1に収納される。したがって、磁気抵抗素子12には、バイアス磁界及び信号磁界で構成される合成磁界が印加されるようになっている。 Further, the current sensor 10 is arranged in a housing space which is a hollow portion of the magnetic shield body 1 so that the current direction of the current to be measured flowing through the bus bar 2, that is, the longitudinal direction of the bus bar 2 and the bias magnetic field are parallel to each other. In other words, the current sensor 10 is housed in the magnetic shield body 1 so that the signal magnetic field generated by the current to be measured flowing through the bus bar 2 and the bias magnetic field are perpendicular to each other. Therefore, a synthetic magnetic field composed of a bias magnetic field and a signal magnetic field is applied to the magnetoresistive element 12.
 そして、バスバー2に被測定電流が流れることで信号磁界が発生し、信号磁界及びバイアス磁界で構成される合成磁界が被測定電流の大きさに応じて変化することにより磁気ベクトル角度θが変化する。したがって、磁気抵抗素子12はその角度変化によりセンシング部の抵抗値が変化したことを検出する。 Then, a signal magnetic field is generated when the current to be measured flows through the bus bar 2, and the magnetic field angle θ is changed by changing the combined magnetic field composed of the signal magnetic field and the bias magnetic field according to the magnitude of the current to be measured. . Therefore, the magnetoresistive element 12 detects that the resistance value of the sensing unit has changed due to the change in angle.
 図3に示された磁気シールド体1は、バスバー2の一部と電流センサ10を収容する収容空間4を有すると共に、外部からの磁界を遮蔽する役割を果たすものである。磁気シールド体1は、第1磁気シールド部20と第2磁気シールド部30とを備えている。 The magnetic shield body 1 shown in FIG. 3 has a housing space 4 for housing a part of the bus bar 2 and the current sensor 10, and serves to shield a magnetic field from the outside. The magnetic shield body 1 includes a first magnetic shield part 20 and a second magnetic shield part 30.
 第1磁気シールド部20は、図4に示されるように、第1板部21と複数の第2板部22とが重ねられて構成されている。本実施形態では、第2板部22の数は2枚である。 As shown in FIG. 4, the first magnetic shield part 20 is configured by stacking a first plate part 21 and a plurality of second plate parts 22. In the present embodiment, the number of second plate portions 22 is two.
 第1板部21は、電磁波の浸入を抑制する第1平板状部材23が折り曲げられたことによって形成されている。具体的には、第1板部21では、第1上面部(第1上壁部)24の両側に互いに平行に対向する2つの第1側面部(第1側壁部)25a、25bが第1上面部24と一体に継ぎ目無く形成されている。また、各第2板部22は、電磁波の浸入を抑制する第2平板状部材26が折り曲げられたことによって形成されている。具体的には、各第2板部22では、第2上面部(第2上壁部)27の両側に互いに平行に対向する2つの第2側面部(第2側壁部)28a、28bが第2上面部27と一体に継ぎ目無く形成されている。2枚の第2板部22の第2上面部27同士が互いに平行に接触すると共に、一方の第2板部22における2つの第2側面部28a、28bが、他方の第2板部22における2つの第2側面部28a、28bに対しそれぞれ平行に接触するように、2枚の第2板部22がバスバー2の平面に垂直な方向(図5の上下方向)に積層されている。 The first plate portion 21 is formed by bending the first flat plate-like member 23 that suppresses intrusion of electromagnetic waves. Specifically, in the first plate portion 21, two first side surface portions (first side wall portions) 25a and 25b that face each other in parallel on both sides of the first upper surface portion (first upper wall portion) 24 are first. The upper surface portion 24 is formed integrally with the seam. Each second plate portion 22 is formed by bending a second flat plate-like member 26 that suppresses intrusion of electromagnetic waves. Specifically, in each second plate portion 22, two second side surface portions (second side wall portions) 28 a and 28 b that face each other in parallel with each other on both sides of the second upper surface portion (second upper wall portion) 27 are the first. 2. It is formed seamlessly integrally with the upper surface portion 27. The second upper surface portions 27 of the two second plate portions 22 are in contact with each other in parallel, and the two second side surface portions 28 a and 28 b in one second plate portion 22 are in the other second plate portion 22. Two second plate portions 22 are stacked in a direction perpendicular to the plane of the bus bar 2 (up and down direction in FIG. 5) so as to be in parallel with the two second side surface portions 28a and 28b.
 ここで、第2板部22の各第2側面部28a、28bは、第2上面部27とは反対側の端部の一部が第2上面部27から離れる方向に伸びた2つの突出部29を有している。本実施形態では、突出部29は、第2側面部28a、28bのうち当該第2側面部28a、28bの延設方向に垂直な方向の両端部がそれぞれ第2上面部27から離れる方向に伸びたことにより設けられている。言い換えると、第2側面部28a、28bのうち第2上面部27とは反対側の端部の一部が第2上面部27側に凹んで凹み部(開口部)28a1、28b1を形成し、当該凹み部28a1、28b1を構成する部分が突出部29となる。この凹み部28a1、28b1及び突出部29により、第2側面部28a、28bの表面は第2側面部28a、28bの一部が分割された分割面になっていると言える。バスバー2は、第2側面部28a、28bの凹み部28a1、28b1に挿通される。 Here, each of the second side surface portions 28 a and 28 b of the second plate portion 22 has two protruding portions extending in a direction in which a part of the end portion opposite to the second upper surface portion 27 is separated from the second upper surface portion 27. 29. In the present embodiment, the protruding portion 29 extends in a direction in which both end portions of the second side surface portions 28 a and 28 b in the direction perpendicular to the extending direction of the second side surface portions 28 a and 28 b are separated from the second upper surface portion 27. Is provided. In other words, of the second side surface portions 28a and 28b, a part of the end opposite to the second upper surface portion 27 is recessed toward the second upper surface portion 27 to form the recessed portions (openings) 28a1 and 28b1. The part which comprises the said recessed parts 28a1 and 28b1 becomes the protrusion part 29. FIG. It can be said that due to the recesses 28a1 and 28b1 and the protrusion 29, the surfaces of the second side surface portions 28a and 28b are divided surfaces in which a part of the second side surface portions 28a and 28b is divided. The bus bar 2 is inserted into the recessed portions 28a1 and 28b1 of the second side surface portions 28a and 28b.
 そして、第1板部21と、該第1板部21に隣接する一方の第2板部22とは、第1板部21の第1上面部24と第2板部22の第2上面部27とが互いに平行に接触するように、バスバー2の平面に垂直な方向に積層されている。また、2枚の第2板部22は、一方の第2板部22の第2上面部27と他方の第2板部22の第2上面部27とが互いに平行に接触するように積層されている。これにより、第1板部21が外側に位置し、一方の第2板部22が内側すなわち収容空間4側に位置する。 The first plate portion 21 and one second plate portion 22 adjacent to the first plate portion 21 are the first upper surface portion 24 of the first plate portion 21 and the second upper surface portion of the second plate portion 22. 27 are stacked in a direction perpendicular to the plane of the bus bar 2 so as to be in contact with each other in parallel. The two second plate portions 22 are laminated so that the second upper surface portion 27 of one second plate portion 22 and the second upper surface portion 27 of the other second plate portion 22 are in contact with each other in parallel. ing. Thereby, the 1st board part 21 is located in the outer side, and one 2nd board part 22 is located inside, ie, the accommodation space 4 side.
 第1板部21の2つの第1側面部25a、25bは、各第2板部22の2つの第2側面部28a、28bに挟まれている。具体的には、第1板部21の2つの第1側面部25a、25bが各第2板部22の2つの第2側面部28a、28bに対しそれぞれ垂直になるように、第1板部21と2枚の第2板部22とが積層されている。このようにして第1磁気シールド部20が構成されている。 The two first side surface portions 25 a and 25 b of the first plate portion 21 are sandwiched between the two second side surface portions 28 a and 28 b of each second plate portion 22. Specifically, the first plate portion is such that the two first side surface portions 25a, 25b of the first plate portion 21 are perpendicular to the two second side surface portions 28a, 28b of the second plate portions 22, respectively. 21 and two second plate portions 22 are laminated. Thus, the first magnetic shield part 20 is configured.
 一方、第2磁気シールド部30は、複数の第3板部31が積層されて構成されている。本実施形態では、第3板部31の数は3枚である。各第3板部31は、電磁波の浸入を抑制する第3平板状部材32が折り曲げられたことによって形成されている。具体的には、各第3板部31では、第3上面部(第3上壁部)33の両側に互いに平行に対向する2つの第3側面部(第3側壁部)34a、34bが第3上面部33と一体に継ぎ目無く形成されている。そして、3枚の第3板部31のうちの互いに隣接する各2枚の第3板部31の第3上面部33同士が互いに平行に接触し、互いに隣接する各2枚の第3板部31の一方における2つの第3側面部34a、34bが、他方における2つの第3側面部34a、34bに対しそれぞれ平行に接触するように、3枚の第3板部31がバスバー2の平面に垂直な方向に順次積層されている。このようにして第2磁気シールド部30が構成されている。 On the other hand, the second magnetic shield part 30 is configured by laminating a plurality of third plate parts 31. In the present embodiment, the number of third plate portions 31 is three. Each third plate portion 31 is formed by bending a third flat plate-like member 32 that suppresses intrusion of electromagnetic waves. Specifically, in each third plate portion 31, two third side surface portions (third side wall portions) 34 a and 34 b facing each other in parallel with each other on both sides of the third upper surface portion (third upper wall portion) 33 are the first. 3 It is formed seamlessly with the upper surface portion 33. The third upper surface portions 33 of the two third plate portions 31 adjacent to each other among the three third plate portions 31 are in parallel contact with each other, and each of the two third plate portions adjacent to each other. The three third plate portions 31 are on the plane of the bus bar 2 so that the two third side surface portions 34a, 34b on one side of the 31 are in contact with the two third side surface portions 34a, 34b on the other side in parallel. The layers are sequentially stacked in the vertical direction. In this way, the second magnetic shield part 30 is configured.
 上記の各平板状部材23、26、32は、それぞれ薄板で構成されている。各平板状部材23、26、32として、例えば1mm以下、より具体的には0.5mmの板厚の電磁鋼板(磁性材料)が採用される。なお、各平板状部材23、26、32の板厚は、1mm以下に限定されるものではなく、必要に応じて1mmを超えてもよい。電磁鋼板の表面には絶縁膜が形成されている(即ち、各平板状部材23、26、32は、絶縁膜で被覆されている)。また、上記の各板部21、22、31は、所定の形状に加工された薄板がプレス加工されることにより図3に示される形状に折り曲げられる。これにより、上述のように概略的には「コの字」の形状になっている。なお、第1板部21と2枚の第2板部22とが密着状態で積層されるように第1平板状部材23と第2平板状部材26の寸法が設定されている。同様に、3枚の第3平板状部材32が密着状態で積層されるようにそれぞれの第3平板状部材32の寸法が設定されている。 The flat plate members 23, 26, and 32 are each formed of a thin plate. As each flat member 23, 26, 32, for example, an electromagnetic steel sheet (magnetic material) having a thickness of 1 mm or less, more specifically 0.5 mm, is employed. In addition, the plate | board thickness of each flat member 23, 26, 32 is not limited to 1 mm or less, You may exceed 1 mm as needed. An insulating film is formed on the surface of the electromagnetic steel sheet (that is, each flat member 23, 26, 32 is covered with an insulating film). Moreover, each said board part 21,22,31 is bend | folded by the shape shown by FIG. 3 by pressing the thin plate processed into the predetermined shape. As a result, the shape is generally “U” as described above. The dimensions of the first flat plate member 23 and the second flat plate member 26 are set so that the first plate portion 21 and the two second plate portions 22 are stacked in close contact. Similarly, the dimensions of the respective third flat plate members 32 are set so that the three third flat plate members 32 are stacked in close contact.
 そして、図3に示されるように、第2磁気シールド部30の第3上面部33が第1磁気シールド部20の第1上面部24及び第2上面部27と互いに平行になるように、第1磁気シールド部20及び第2磁気シールド部30が組み合わされる。また、第2磁気シールド部30の第3側面部34a、34bが、第1磁気シールド部20の第1側面部25a、25bと平行になり、第2側面部28a、28bと垂直になるように、第1磁気シールド部20と第2磁気シールド部30とが組み合わされる。これにより、第1磁気シールド部20と第2磁気シールド部30との間に収容空間4が形成される。第1磁気シールド部20及び第2磁気シールド部30は、収容空間4を形成するように保持部材3に組み付けられる。 Then, as shown in FIG. 3, the third upper surface portion 33 of the second magnetic shield portion 30 is parallel to the first upper surface portion 24 and the second upper surface portion 27 of the first magnetic shield portion 20. The first magnetic shield part 20 and the second magnetic shield part 30 are combined. Further, the third side surface portions 34a and 34b of the second magnetic shield portion 30 are parallel to the first side surface portions 25a and 25b of the first magnetic shield portion 20 and perpendicular to the second side surface portions 28a and 28b. The first magnetic shield part 20 and the second magnetic shield part 30 are combined. Thereby, the accommodation space 4 is formed between the first magnetic shield part 20 and the second magnetic shield part 30. The first magnetic shield part 20 and the second magnetic shield part 30 are assembled to the holding member 3 so as to form the accommodation space 4.
 なお、第1磁気シールド部20及び第2磁気シールド部30は、保持部材3に対してネジ締めされたり、磁気シールド体1が樹脂でモールドされたりすることで保持部材3に固定される。 The first magnetic shield part 20 and the second magnetic shield part 30 are fixed to the holding member 3 by screwing the holding member 3 or by molding the magnetic shield body 1 with resin.
 また、上述の第2側面部28a、28bの突出部29は、第3側面部34a、34bに垂直に配置された第2側面部28a、28bのうち第1上面部24及び第2上面部27とは反対側の端部の一部が第1上面部24及び第2上面部27から離れる方向に伸びた部分であると言える。 Further, the protruding portions 29 of the second side surface portions 28a and 28b described above are the first upper surface portion 24 and the second upper surface portion 27 of the second side surface portions 28a and 28b arranged perpendicular to the third side surface portions 34a and 34b. It can be said that a part of the end portion on the opposite side is a portion extending in a direction away from the first upper surface portion 24 and the second upper surface portion 27.
 さらに、第2磁気シールド部30の各第3上面部33は、当該第3上面部33の一部が突出した2つの突出部35を有している。この突出部35は、第1磁気シールド部20の第2側面部28a、28bのうち突出部29によって構成された凹み部28a1、28b1に対応する部分に設けられている。この突出部35により、第3上面部33の遮蔽面積を増加させることができる。 Furthermore, each third upper surface portion 33 of the second magnetic shield portion 30 has two protruding portions 35 from which a part of the third upper surface portion 33 protrudes. The protruding portion 35 is provided in a portion corresponding to the recessed portions 28 a 1 and 28 b 1 formed by the protruding portion 29 in the second side surface portions 28 a and 28 b of the first magnetic shield portion 20. With this protruding portion 35, the shielding area of the third upper surface portion 33 can be increased.
 上記のような磁気シールド体1の構成によると、第1磁気シールド部20の第1上面部24はバスバー2のうちの第1上面部24側の1方向からの外乱磁界を遮蔽する。また、第1磁気シールド部20の第1側面部25a、25bは、バスバー2の平面部に平行な平面においてバスバー2の長手方向に垂直な2方向からの外乱磁界を遮蔽する。さらに、第2磁気シールド部30の第2側面部28a、28bは、バスバー2の平面部に平行な平面においてバスバー2の長手方向に平行な2方向からの外乱磁界を遮蔽する。 According to the configuration of the magnetic shield body 1 as described above, the first upper surface portion 24 of the first magnetic shield portion 20 shields a disturbance magnetic field from one direction on the first upper surface portion 24 side of the bus bar 2. Further, the first side surface portions 25 a and 25 b of the first magnetic shield portion 20 shield a disturbance magnetic field from two directions perpendicular to the longitudinal direction of the bus bar 2 in a plane parallel to the flat portion of the bus bar 2. Further, the second side surface portions 28 a and 28 b of the second magnetic shield portion 30 shield a disturbance magnetic field from two directions parallel to the longitudinal direction of the bus bar 2 in a plane parallel to the flat portion of the bus bar 2.
 一方、第2磁気シールド部30の第3上面部33はバスバー2のうちの第3上面部33側の1方向からの外乱磁界を遮蔽する。また、第2磁気シールド部30の第3側面部34a、34bは、第1側面部25a、25bと同様に、バスバー2の平面部に平行な平面においてバスバー2の長手方向に垂直な2方向からの外乱磁界を遮蔽する。したがって、磁気シールド体1は6方向の全ての方向からの外乱磁界を遮蔽する面または面の一部を有している。 On the other hand, the third upper surface portion 33 of the second magnetic shield portion 30 shields a disturbance magnetic field from one direction on the third upper surface portion 33 side of the bus bar 2. Further, the third side surface portions 34a and 34b of the second magnetic shield portion 30 are formed from two directions perpendicular to the longitudinal direction of the bus bar 2 on a plane parallel to the flat surface portion of the bus bar 2, similarly to the first side surface portions 25a and 25b. The disturbance magnetic field is shielded. Therefore, the magnetic shield body 1 has a surface or a part of a surface that shields disturbance magnetic fields from all six directions.
 次に、磁気シールド体1の収容空間4に配置される電流センサ10について説明する。図5及び図6の各断面図に示されるように、電流センサ10は、上述のバイアス磁石11及び磁気抵抗素子12の他に、リード13、回路チップ14、及び樹脂パッケージ15を備えている。なお、図5及び図6では、保持部材3を省略している。 Next, the current sensor 10 disposed in the accommodation space 4 of the magnetic shield body 1 will be described. 5 and 6, the current sensor 10 includes a lead 13, a circuit chip 14, and a resin package 15 in addition to the bias magnet 11 and the magnetoresistive element 12 described above. 5 and 6, the holding member 3 is omitted.
 リード13は、バイアス磁石11が実装された一面13aと、磁気抵抗素子12及び回路チップ14が実装された他面13bを有している。また、回路チップ14は、磁気抵抗素子12から入力した信号に対して予め設定された演算を行うことにより被測定電流に対応した信号を外部に出力する。磁気抵抗素子12と回路チップ14との間、及び回路チップ14とリード13との間はボンディングワイヤ16で電気的に接続されている。樹脂パッケージ15は、リード13の一部が露出するように、バイアス磁石11、磁気抵抗素子12、リード13、回路チップ14、及びリード13の一部を封止した封止部材である。 The lead 13 has one surface 13a on which the bias magnet 11 is mounted and the other surface 13b on which the magnetoresistive element 12 and the circuit chip 14 are mounted. The circuit chip 14 outputs a signal corresponding to the current to be measured to the outside by performing a preset operation on the signal input from the magnetoresistive element 12. Bonding wires 16 are electrically connected between the magnetoresistive element 12 and the circuit chip 14 and between the circuit chip 14 and the leads 13. The resin package 15 is a sealing member that seals the bias magnet 11, the magnetoresistive element 12, the lead 13, the circuit chip 14, and a part of the lead 13 so that a part of the lead 13 is exposed.
 ここで、上記の電流センサ10が磁気シールド体1の収容空間4に収容されるに際し、第1磁気シールド部20及び第2磁気シールド部30は空隙40を介して互いに配置されている。本実施形態では、第1側面部25a、25b、第2側面部28a、28b、及び第3側面部34a、34bが互いに空隙40を介して配置されている。この空隙40は、バスバー2を通す役割と、磁気シールド体1の収容空間4から信号を取り出す役割と、空隙40に位置する空気によって外乱磁界を弱める抵抗としての役割を果たす。なお、空隙40は、第1磁気シールド部20及び第2磁気シールド部30が保持部材3に組み付けられることで自己整合的に形成される。 Here, when the current sensor 10 is accommodated in the accommodating space 4 of the magnetic shield body 1, the first magnetic shield part 20 and the second magnetic shield part 30 are arranged with respect to each other via the gap 40. In the present embodiment, the first side surface portions 25a and 25b, the second side surface portions 28a and 28b, and the third side surface portions 34a and 34b are arranged with a gap 40 therebetween. The air gap 40 plays a role of passing the bus bar 2, a role of taking out a signal from the accommodation space 4 of the magnetic shield body 1, and a role of resistance to weaken the disturbance magnetic field by the air located in the air gap 40. The air gap 40 is formed in a self-aligned manner by assembling the first magnetic shield part 20 and the second magnetic shield part 30 to the holding member 3.
 また、磁気抵抗素子12は、バスバー2に被測定電流が流れることによって収容空間4に発生する磁界の変化を検出するための検出面12aを有している。この検出面12aに磁界の変化を検出するための上述のセンシング部が設けられている。 Further, the magnetoresistive element 12 has a detection surface 12a for detecting a change in a magnetic field generated in the accommodation space 4 when a current to be measured flows through the bus bar 2. The sensing surface for detecting a change in magnetic field is provided on the detection surface 12a.
 そして、図6に示されるように、バスバー2から発生する信号磁界が収容空間4で発生し、第1磁気シールド部20及び第2磁気シールド部30の空隙40で再放出される。このとき、磁気抵抗素子12の検出面12aへの影響を抑制する必要がある。そこで、磁気シールド体1では収容空間4の中央部分が最も外乱磁界の影響を受けにくくなるので、磁気抵抗素子12の検出面12aは磁気シールド体1の中央部分に配置される。 Then, as shown in FIG. 6, a signal magnetic field generated from the bus bar 2 is generated in the accommodation space 4 and re-emitted in the gap 40 between the first magnetic shield part 20 and the second magnetic shield part 30. At this time, it is necessary to suppress the influence of the magnetoresistive element 12 on the detection surface 12a. Therefore, in the magnetic shield body 1, the central portion of the accommodation space 4 is least affected by the disturbance magnetic field, so that the detection surface 12 a of the magnetoresistive element 12 is disposed in the central portion of the magnetic shield body 1.
 具体的には、第1上面部24に垂直な方向における収容空間4の高さをhと定義すると、磁気抵抗素子12の検出面12aは第1磁気シールド部20の第1上面部24と平行になると共にh/2の高さに配置されている。さらに、磁気抵抗素子12の検出面12aの中心位置12bは、第1磁気シールド部20の第1上面部24に垂直な方向において収容空間4のうち第1上面部24と平行な面の中心位置41と一致するように配置されるように、第1磁気シールド部20及び第2磁気シールド部30が組み合わされる。すなわち、磁気シールド体1の収容空間4においてh/2の位置で検出面12aがシンメトリカルになるように磁気抵抗素子12が配置されている。 Specifically, if the height of the accommodation space 4 in the direction perpendicular to the first upper surface portion 24 is defined as h, the detection surface 12 a of the magnetoresistive element 12 is parallel to the first upper surface portion 24 of the first magnetic shield portion 20. And at a height of h / 2. Further, the center position 12 b of the detection surface 12 a of the magnetoresistive element 12 is the center position of the surface parallel to the first upper surface portion 24 in the accommodation space 4 in the direction perpendicular to the first upper surface portion 24 of the first magnetic shield portion 20. The first magnetic shield part 20 and the second magnetic shield part 30 are combined so as to be aligned with 41. That is, the magnetoresistive element 12 is arranged so that the detection surface 12a is symmetrical at the position h / 2 in the accommodation space 4 of the magnetic shield body 1.
 このような収容空間4における磁気抵抗素子12の検出面12aの位置は、電流センサ10が保持部材3に配置されると共に磁気シールド体1が保持部材3に組み付けられることで自己整合的に決まるように予め設計されている。このように磁気抵抗素子12の検出面12aの位置を規定することにより、磁気抵抗素子12の検出面12aを磁気シールド体の外部から最も遠い場所に位置させることができる。このため、磁気抵抗素子12が磁気シールド体1の外部の影響を受けにくくなり、磁気抵抗素子12の検出特性への影響を低減することができる。 The position of the detection surface 12a of the magnetoresistive element 12 in the accommodation space 4 is determined in a self-aligning manner by arranging the current sensor 10 on the holding member 3 and assembling the magnetic shield body 1 on the holding member 3. Designed in advance. By defining the position of the detection surface 12a of the magnetoresistive element 12 in this way, the detection surface 12a of the magnetoresistive element 12 can be positioned at a position farthest from the outside of the magnetic shield body. For this reason, it becomes difficult for the magnetoresistive element 12 to receive the influence of the exterior of the magnetic shield body 1, and it can reduce the influence on the detection characteristic of the magnetoresistive element 12.
 一方、図5に示されるように、バスバー2の長手方向においてはバスバー2の信号磁界を考慮しないで済む。このため、外部から磁気シールド体1の収容空間4に浸入する外乱磁界の抑制に重きをおいて、外乱磁界が磁気抵抗素子12に直接印加されないように、磁気抵抗素子12から離れた位置に空隙40が設けられている。 On the other hand, as shown in FIG. 5, it is not necessary to consider the signal magnetic field of the bus bar 2 in the longitudinal direction of the bus bar 2. Therefore, emphasis is placed on the suppression of the disturbance magnetic field that enters the housing space 4 of the magnetic shield body 1 from the outside, so that the disturbance magnetic field is not directly applied to the magnetoresistive element 12. 40 is provided.
 次に、本実施形態に係る磁気シールド体1の効果について説明する。本実施形態では、図3及び図4に示された磁気シールド体1が構成されていることが特徴となっている。特に、第1磁気シールド部20では、第2板部22の第2側面部28a、28bが第1板部21の第1側面部25a、25bに対して垂直に配置されている。このため、第1磁気シールド部20によって第2側面部28a、28bの2方向を含めた5方向からの外乱磁界の浸入を抑制することができる。 Next, effects of the magnetic shield body 1 according to this embodiment will be described. The present embodiment is characterized in that the magnetic shield body 1 shown in FIGS. 3 and 4 is configured. In particular, in the first magnetic shield part 20, the second side parts 28 a and 28 b of the second plate part 22 are arranged perpendicular to the first side parts 25 a and 25 b of the first plate part 21. For this reason, the first magnetic shield part 20 can suppress the intrusion of a disturbance magnetic field from five directions including the two directions of the second side face parts 28a and 28b.
 また、第2磁気シールド部30では、第3板部31の第3上面部33によって、第1磁気シールド部20では遮蔽することができない方向すなわち第1磁気シールド部20の第1上面部24とは反対側からの外乱磁界の浸入を抑制することができる。もちろん、第3側面部34a、34bによって第1側面部25a、25bと同じ2方向からの外乱磁界を遮蔽することができる。したがって、磁気シールド体1において、6方向の全ての方向からの外乱磁界の浸入を抑制することができる。本実施形態では、実用上、10mTの磁界中での使用が可能となる。 In the second magnetic shield part 30, the third upper surface part 33 of the third plate part 31 has a direction that cannot be shielded by the first magnetic shield part 20, that is, the first upper surface part 24 of the first magnetic shield part 20. Can suppress the intrusion of a disturbance magnetic field from the opposite side. Of course, the disturbance magnetic field from the same two directions as the 1st side surface parts 25a and 25b can be shielded by the 3rd side surface parts 34a and 34b. Therefore, in the magnetic shield body 1, it is possible to suppress the intrusion of a disturbance magnetic field from all six directions. In this embodiment, it can be used in a magnetic field of 10 mT practically.
 特に、バスバー2が強い外乱磁界及び高周波交流電流を扱う場合、例えばバスバー2が3相交流モータを駆動する電流を流すものである場合、電流センサ10が隣のバスバー2で発生した外乱磁界の影響を受けることが考えられる。しかしながら、本実施形態に係る磁気シールド体1によって6方向の全てからの外乱磁界を遮蔽できるので、高周波交流電流を扱う状況においても外乱磁界に対するシールド効果を発揮することができる。 In particular, when the bus bar 2 handles a strong disturbance magnetic field and a high-frequency AC current, for example, when the bus bar 2 passes a current that drives a three-phase AC motor, the influence of the disturbance magnetic field generated in the adjacent bus bar 2 by the current sensor 10. Can be considered. However, since the disturbance magnetic field from all six directions can be shielded by the magnetic shield body 1 according to the present embodiment, the shielding effect against the disturbance magnetic field can be exhibited even in a situation where a high-frequency alternating current is handled.
 また、本実施形態では、第1側面部25a、25bと第2側面部28a、28bとを垂直に配置し、第1側面部25a、25bと第3側面部34a、34bとを平行に配置しているので、磁気シールド体1の全体形状を立方体形状にすることができる。このため、磁気シールド体1の全体の大きさを最小にすることができる。 In the present embodiment, the first side surface portions 25a and 25b and the second side surface portions 28a and 28b are arranged vertically, and the first side surface portions 25a and 25b and the third side surface portions 34a and 34b are arranged in parallel. Therefore, the overall shape of the magnetic shield body 1 can be a cubic shape. For this reason, the whole size of the magnetic shield body 1 can be minimized.
 ここで、本実施形態では、第2側面部28a、28bには当該第2側面部28a、28bの一部が突出した突出部29が設けられているので、当該第2側面部28a、28bにおいて外乱磁界を遮蔽するための遮蔽部分を増やすことができる。したがって、外乱磁界に対する磁気シールド効果を向上させることができる。 Here, in the present embodiment, since the second side surface portions 28a and 28b are provided with the protruding portions 29 from which part of the second side surface portions 28a and 28b protrudes, the second side surface portions 28a and 28b The shielding part for shielding a disturbance magnetic field can be increased. Therefore, it is possible to improve the magnetic shield effect against the disturbance magnetic field.
 また、磁気シールド体1は、各側面部の間等に空隙40を有している。信号取り出し等の理由により空隙40を完全に無くすことはできないが、上述のように空隙40に位置する空気が外乱磁界を弱める抵抗として機能する。このため、第1磁気シールド部20及び第2磁気シールド部30を構成する第1平板状部材23、第2平板状部材26、及び第3平板状部材32の板厚をそれぞれ薄くすることができるというメリットがある。 Also, the magnetic shield body 1 has a gap 40 between each side surface portion. The air gap 40 cannot be completely eliminated for reasons such as signal extraction, but the air located in the air gap 40 functions as a resistance to weaken the disturbance magnetic field as described above. For this reason, the plate | board thickness of the 1st flat plate member 23, the 2nd flat plate member 26, and the 3rd flat plate member 32 which comprise the 1st magnetic shield part 20 and the 2nd magnetic shield part 30 can be made thin, respectively. There is a merit.
 さらに、本実施形態では、第1磁気シールド部20及び第2磁気シールド部30は複数の薄板(平板状部材23、26、32)が互いに絶縁されて積層されていることが特徴となっている。これにより、図7(a)に示されるように、各平板状部材23、26、32の板厚の二乗に比例して発生する渦電流損が薄板毎に小さく分割される。したがって、図7(b)に示されるように、3枚分の板厚を有する1枚の平板状部材200を用いるよりも第1磁気シールド部20及び第2磁気シールド部30の発熱を抑制することができる。 Further, in the present embodiment, the first magnetic shield part 20 and the second magnetic shield part 30 are characterized in that a plurality of thin plates ( flat plate members 23, 26, 32) are laminated while being insulated from each other. . Thereby, as shown in FIG. 7A, the eddy current loss generated in proportion to the square of the plate thickness of each flat plate member 23, 26, 32 is divided into small plates. Therefore, as shown in FIG. 7B, the heat generation of the first magnetic shield part 20 and the second magnetic shield part 30 is suppressed compared with the use of a single flat plate member 200 having a thickness of three sheets. be able to.
 上述のように、バスバー2が高周波交流電流を扱う場合には隣のバスバー2からの外乱磁界の影響が大きいが、磁気シールド体1が複数の薄板で構成されることで渦電流損による発熱を抑制することができる。このため、磁気シールド体1の発熱によって電流センサ10や磁気抵抗素子12の特性変動に影響を及ぼさないようにすることができる。 As described above, when the bus bar 2 handles high-frequency alternating current, the influence of the disturbance magnetic field from the adjacent bus bar 2 is large. However, the magnetic shield body 1 is composed of a plurality of thin plates, thereby generating heat due to eddy current loss. Can be suppressed. For this reason, it is possible to prevent the characteristics of the current sensor 10 and the magnetoresistive element 12 from being affected by the heat generated by the magnetic shield body 1.
 (他の実施形態)
 上記実施形態で示された磁気シールド体1の構成は一例であり、上記で示した構成に限定されることなく、本開示を実現できる他の構成とすることもできる。例えば、上記の実施形態では、磁気シールド体1は立方体をなしていたが、これは磁気シールド体1の形状の一例である。したがって、各面が互いに平行であったり、垂直になっていなくても良い。
(Other embodiments)
The configuration of the magnetic shield body 1 shown in the above embodiment is merely an example, and is not limited to the configuration shown above, and may be other configurations that can realize the present disclosure. For example, in the above embodiment, the magnetic shield body 1 has a cubic shape, but this is an example of the shape of the magnetic shield body 1. Therefore, each surface does not need to be parallel or perpendicular to each other.
 具体的には、第1側面部25a、25bは互いに対向していれば良い。第2側面部28a、28b及び第3側面部34a、34bについても同様である。また、第1磁気シールド部20については、第1上面部24と第2上面部27とが互いに接触すると共に、2つの第1側面部25a、25bが2つの第2側面部28a、28bに対しそれぞれ非平行に配置され、かつ、隣り合うように、第1板部21と第2板部22とが積層されていれば良い。第2磁気シールド部30については、3枚の第3板部31のうちの互いに隣接する各2枚の第3板部31の第3上面部33同士が互いに接触し、互いに隣接する各2枚の第3板部31の一方における2つの第3側面部34a、34bが、他方における2つの第3側面部34a、34bにそれぞれ接触するように、3枚の第3板部31が順次積層されていれば良い。この場合、3枚の第3板部31のうちの収容空間4に隣接する1枚における第3上面部33が、第3上面部33側に位置する第1上面部24及び第2上面部27の一方と対向すると共に、各第3板部31の2つの第3側面部34a、34bが2つの第1側面部25a、25bと、2つの第2側面部28a、28bとのうちの一方に対しそれぞれ非平行に配置され、かつ、隣り合うように、第1磁気シールド部20と第2磁気シールド部30とが組み合わされて、収容空間4が形成されることになる。 Specifically, the first side surfaces 25a and 25b only need to face each other. The same applies to the second side surface portions 28a and 28b and the third side surface portions 34a and 34b. As for the first magnetic shield part 20, the first upper surface part 24 and the second upper surface part 27 are in contact with each other, and the two first side surface parts 25a, 25b are in contact with the two second side surface parts 28a, 28b. The 1st board part 21 and the 2nd board part 22 should just be laminated | stacked so that it may each arrange | position in non-parallel and may adjoin. Regarding the second magnetic shield part 30, the third upper surface parts 33 of the two third plate parts 31 adjacent to each other out of the three third plate parts 31 are in contact with each other, and the two adjacent each other. The three third plate portions 31 are sequentially stacked so that the two third side surface portions 34a and 34b on one side of the third plate portion 31 are in contact with the two third side surface portions 34a and 34b on the other side, respectively. It only has to be. In this case, the third upper surface portion 33 of one of the three third plate portions 31 adjacent to the accommodation space 4 has the first upper surface portion 24 and the second upper surface portion 27 located on the third upper surface portion 33 side. The two third side surface portions 34a and 34b of each third plate portion 31 are disposed on one of the two first side surface portions 25a and 25b and the two second side surface portions 28a and 28b. On the other hand, the first magnetic shield part 20 and the second magnetic shield part 30 are combined so as to be arranged non-parallel to each other and adjacent to each other, whereby the accommodation space 4 is formed.
 ここで、第1磁気シールド部20と第2磁気シールド部30とを組み合わせる際には、第3側面部34a、34bと、第2側面部28a、28bとを互いに非平行に配置し、かつ、隣り合わせるだけでなく、第3側面部34a、34bと、第1側面部25a、25bとを互いに非平行に配置し、かつ、隣り合わせても良い。 Here, when combining the first magnetic shield part 20 and the second magnetic shield part 30, the third side face parts 34a, 34b and the second side face parts 28a, 28b are arranged non-parallel to each other, and In addition to adjoining, the third side surface portions 34a and 34b and the first side surface portions 25a and 25b may be arranged non-parallel to each other and adjacent to each other.
 また、第2側面部28a、28bに設けられた突出部29や第3上面部33に設けられた突出部35の形状は、図3及び図4に示された形状に限られず適宜設定できる。すなわち、第2側面部28a、28bの一部や第3上面部33の一部を突出させれば、当該突出させた部分に外乱磁界に対する遮蔽効果を生じさせることができる。 Moreover, the shape of the protrusions 29 provided on the second side surfaces 28a and 28b and the protrusion 35 provided on the third upper surface 33 is not limited to the shape shown in FIGS. 3 and 4 and can be set as appropriate. That is, if a part of the second side surface parts 28a and 28b and a part of the third upper surface part 33 are projected, a shielding effect against a disturbance magnetic field can be generated in the projected part.
 空隙40については、どのように設定されても構わない。上記の実施形態では、各側面部の間に空隙40が設けられていたが、これは空隙40を設けた一例である。例えば第1側面部25a、25bと第2側面部28a、28bは接触していても良いし、第3側面部34a、34bは第1側面部25a、25b及び第2側面部28a、28bのうちいずれか一方と接触していても良い。 The air gap 40 may be set in any way. In the above embodiment, the gap 40 is provided between the side portions, but this is an example in which the gap 40 is provided. For example, the first side surface portions 25a and 25b may be in contact with the second side surface portions 28a and 28b, and the third side surface portions 34a and 34b are the first side surface portions 25a and 25b and the second side surface portions 28a and 28b. It may be in contact with either one.
 さらに、上記の実施形態では、第1磁気シールド部20及び第2磁気シールド部30はそれぞれ3枚の薄板でそれぞれ構成されていたが、第1磁気シールド部20及び第2磁気シールド部30で薄板の枚数を同じにする必要はない。また、磁気抵抗素子12が受ける磁界の強さに応じて第1磁気シールド部20の第1板部21及び第2板部22の枚数及び第2磁気シールド部30の第3板部31の枚数を決定しても良い。
 
Furthermore, in the above embodiment, the first magnetic shield part 20 and the second magnetic shield part 30 are each composed of three thin plates, but the first magnetic shield part 20 and the second magnetic shield part 30 are thin plates. It is not necessary to have the same number of sheets. Further, the number of the first plate portion 21 and the second plate portion 22 of the first magnetic shield portion 20 and the number of the third plate portion 31 of the second magnetic shield portion 30 according to the strength of the magnetic field received by the magnetoresistive element 12. May be determined.

Claims (11)

  1.  測定対象の電流を検出するための磁気抵抗素子(12)を備えた電流センサが収容される収容空間(4)を形成する電流センサ用の磁気シールド体であって、
     電磁波の浸入を抑制するとともに、第1上面部(24)の両側において互いに対向する2つの第1側面部(25a、25b)が前記第1上面部(24)と一体に継ぎ目無く形成された第1板部(21)と、電磁波の浸入を抑制するとともに、第2上面部(27)の両側において互いに対向する2つの第2側面部(28a、28b)が前記第2上面部(27)と一体に継ぎ目無く形成された第2板部(22)と、を有する第1磁気シールド部(20)と、
     電磁波の浸入を抑制するとともに、第3上面部(33)の両側において互いに対向する2つの第3側面部(34a、34b)が前記第3上面部(33)と一体に継ぎ目無く形成された複数の第3板部(31)を有する第2磁気シールド部(30)と、
    を備え、
     前記第1磁気シールド部(20)では、前記第1上面部(24)と前記第2上面部(27)とが互いに接触すると共に、前記2つの第1側面部(25a、25b)が前記2つの第2側面部(28a、28b)に対しそれぞれ非平行に配置され、かつ、隣り合うように、前記第1板部(21)と前記第2板部(22)とが積層されており、
     前記第2磁気シールド部(30)では、前記複数の第3板部(31)のうちの互いに隣接する各2枚の前記第3板部(31)の前記第3上面部(33)同士が互いに接触し、前記複数の第3板部(31)のうちの互いに隣接する各2枚の前記第3板部(31)の一方における前記2つの第3側面部(34a、34b)が、他方における前記2つの第3側面部(34a、34b)にそれぞれ接触するように、前記複数の第3板部(31)が順次積層されており、
     前記複数の第3板部(31)のうちの前記収容空間(4)に隣接する1枚における前記第3上面部(33)が、前記第3上面部(33)側に位置する前記第1上面部(24)及び前記第2上面部(27)の一方と対向すると共に、前記各第3板部(31)の前記2つの第3側面部(34a、34b)が前記2つの第1側面部(25a、25b)と、前記2つの第2側面部(28a、28b)とのうちの一方に対しそれぞれ非平行に配置され、かつ、隣り合うように、前記第1磁気シールド部(20)と前記第2磁気シールド部(30)とが組み合わされて、前記収容空間(4)が形成される磁気シールド体。
    A magnetic shield for a current sensor that forms a housing space (4) in which a current sensor including a magnetoresistive element (12) for detecting a current to be measured is housed,
    The first side surface portions (25a, 25b) opposing to each other on both sides of the first upper surface portion (24) are seamlessly formed integrally with the first upper surface portion (24) while suppressing the intrusion of electromagnetic waves. One plate portion (21) and two second side surface portions (28a, 28b) opposing to each other on both sides of the second upper surface portion (27) while suppressing intrusion of electromagnetic waves are formed with the second upper surface portion (27). A first magnetic shield part (20) having a second plate part (22) formed integrally and seamlessly;
    A plurality of third side surface portions (34a, 34b) that are opposite to each other on both sides of the third upper surface portion (33) and are seamlessly formed integrally with the third upper surface portion (33) while suppressing intrusion of electromagnetic waves. A second magnetic shield part (30) having a third plate part (31) of
    With
    In the first magnetic shield part (20), the first upper surface part (24) and the second upper surface part (27) are in contact with each other, and the two first side surface parts (25a, 25b) are in the second state. The first plate portion (21) and the second plate portion (22) are laminated so as to be arranged non-parallel to each of the second side surface portions (28a, 28b) and adjacent to each other,
    In the second magnetic shield part (30), the third upper surface parts (33) of the two third plate parts (31) adjacent to each other among the plurality of third plate parts (31) are mutually connected. The two third side surface portions (34a, 34b) in one of the two third plate portions (31) adjacent to each other among the plurality of third plate portions (31) are in contact with each other. The plurality of third plate portions (31) are sequentially stacked so as to come into contact with the two third side surface portions (34a, 34b), respectively,
    The first upper surface portion (33) of one of the plurality of third plate portions (31) adjacent to the accommodation space (4) is located on the third upper surface portion (33) side. The two third side surfaces (34a, 34b) of each of the third plate portions (31) are opposed to one of the upper surface portion (24) and the second upper surface portion (27), and the two first side surfaces. Part (25a, 25b) and the first magnetic shield part (20) so as to be arranged non-parallel to one of the two second side face parts (28a, 28b) and adjacent to each other. And the second magnetic shield part (30) are combined to form the accommodation space (4).
  2.  前記第1板部(21)の前記2つの第1側面部(25a、25b)は、互いに平行であり、
     前記第2板部(22)の前記2つの第2側面部(28a、28b)は、互いに平行であり、
     前記各第3板部(31)の前記2つの第3側面部(34a、34b)は、互いに平行であり、
     前記第1磁気シールド部(20)では、前記第1上面部(24)と前記第2上面部(27)とが互いに平行に接触すると共に、前記2つの第1側面部(25a、25b)と前記2つの第2側面部(28a、28b)とが互いに垂直になるように、前記第1板部(21)と前記第2板部(22)とが積層されており、
     前記第2磁気シールド部(30)では、前記複数の第3板部(31)のうちの互いに隣接する各2枚の前記第3板部(31)の前記第3上面部(33)同士が互いに平行に接触し、前記複数の第3板部(31)のうちの互いに隣接する各2枚の前記第3板部(31)の前記一方における前記2つの第3側面部(34a、34b)が、前記他方における前記2つの第3側面部(34a、34b)に対しそれぞれ平行に接触するように、前記複数の第3板部(31)が順次積層されており、
     前記複数の第3板部(31)のうちの前記収容空間(4)に隣接する前記1枚における前記第3上面部(33)が、前記第3上面部(33)側に位置する前記第1上面部(24)及び前記第2上面部(27)の前記一方と互いに平行になると共に、前記各第3板部(31)の前記2つの第3側面部(34a、34b)が前記2つの第1側面部(25a、25b)と、前記2つの第2側面部(28a、28b)とのうちの前記一方に対し垂直になるように、前記第1磁気シールド部(20)と前記第2磁気シールド部(30)とが組み合わされ、前記収容空間(4)が形成される請求項1に記載の磁気シールド体。
    The two first side surface portions (25a, 25b) of the first plate portion (21) are parallel to each other,
    The two second side surface portions (28a, 28b) of the second plate portion (22) are parallel to each other;
    The two third side surface portions (34a, 34b) of each third plate portion (31) are parallel to each other,
    In the first magnetic shield part (20), the first upper surface part (24) and the second upper surface part (27) are in parallel contact with each other, and the two first side surface parts (25a, 25b) The first plate portion (21) and the second plate portion (22) are laminated so that the two second side surface portions (28a, 28b) are perpendicular to each other,
    In the second magnetic shield part (30), the third upper surface parts (33) of the two third plate parts (31) adjacent to each other among the plurality of third plate parts (31) are mutually connected. The two third side surface portions (34a, 34b) in the one of the two third plate portions (31) adjacent to each other among the plurality of third plate portions (31) in contact with each other in parallel. However, the plurality of third plate portions (31) are sequentially laminated so as to be in parallel contact with the two third side surface portions (34a, 34b) on the other side,
    Of the plurality of third plate portions (31), the third upper surface portion (33) in the one sheet adjacent to the accommodation space (4) is located on the third upper surface portion (33) side. The first upper surface portion (24) and the second upper surface portion (27) are parallel to the one of the first upper surface portion (27) and the two third side surface portions (34a, 34b) of each third plate portion (31) are The first magnetic shield part (20) and the first magnetic shield part (20) so as to be perpendicular to the one of the two first side face parts (25a, 25b) and the two second side face parts (28a, 28b). The magnetic shield body according to claim 1, wherein the housing space (4) is formed by combining with two magnetic shield portions (30).
  3.  前記第1板部(21)、前記第2板部(22)及び前記複数の第3板部(31)のそれぞれの板厚が1mm以下である請求項1または2に記載の磁気シールド体。 The magnetic shield body according to claim 1 or 2, wherein each of the first plate portion (21), the second plate portion (22), and the plurality of third plate portions (31) has a thickness of 1 mm or less.
  4.  前記第1板部(21)の前記各第1側面部(25a、25b)及び前記第2板部(22)の前記各第2側面部(28a、28b)の一方は、前記複数の第3板部(31)の前記第3上面部(33)に隣接するとともに、前記第1上面部(24)及び前記第2上面部(27)とは反対側の端部から前記第1上面部(24)及び前記第2上面部(27)から離れる方向に伸びている少なくとも1つの突出部(29)を有している請求項1ないし3のいずれか1つに記載の磁気シールド体。 One of the first side surface portions (25a, 25b) of the first plate portion (21) and the second side surface portions (28a, 28b) of the second plate portion (22) is the plurality of third surfaces. The plate portion (31) is adjacent to the third upper surface portion (33) and from the end opposite to the first upper surface portion (24) and the second upper surface portion (27), the first upper surface portion ( 24. The magnetic shield body according to claim 1, further comprising at least one protrusion (29) extending in a direction away from the second upper surface portion (24) and the second upper surface portion (27).
  5.  前記第1磁気シールド部(20)及び前記第2磁気シールド部(30)は、空隙(40)を介して互いに配置されている請求項1ないし4のいずれか1つに記載の磁気シールド体。 The magnetic shield body according to any one of claims 1 to 4, wherein the first magnetic shield part (20) and the second magnetic shield part (30) are arranged with respect to each other via a gap (40).
  6.  前記各第1側面部(25a、25b)及び前記各第2側面部(28a、28b)の一方と、前記各第3板部(31)の前記2つの第3側面部(34a、34b)のうちの対応する1つとは、前記空隙(40)によって互いに分離されている請求項5に記載の磁気シールド体。 One of each of the first side surfaces (25a, 25b) and each of the second side surfaces (28a, 28b), and the two third side surfaces (34a, 34b) of each of the third plate portions (31). The magnetic shield body according to claim 5, wherein the corresponding one is separated from each other by the gap (40).
  7.  前記第1磁気シールド部(20)では、前記第1板部(21)は、1つまたは複数の第1板部(21)の1つとして設けられ、前記第2板部(22)は、1つまたは複数の第2板部(22)の1つとして設けられ、
     前記磁気抵抗素子(12)が受ける磁界の強さに応じて前記1つまたは複数の第1板部(21)の数と、前記1つまたは複数の第2板部(22)の数とが設定され、
     前記磁気抵抗素子(12)が受ける前記磁界の強さに応じて前記複数の第3板部(31)の数が設定されている請求項1ないし6のいずれか1つに記載の磁気シールド体。
    In the first magnetic shield part (20), the first plate part (21) is provided as one of one or more first plate parts (21), and the second plate part (22) is Provided as one of the one or more second plate portions (22),
    The number of the one or more first plate portions (21) and the number of the one or more second plate portions (22) according to the strength of the magnetic field received by the magnetoresistive element (12). Set,
    The magnetic shield body according to any one of claims 1 to 6, wherein the number of the plurality of third plate portions (31) is set according to the strength of the magnetic field received by the magnetoresistive element (12). .
  8.  前記第1板部(21)、前記第2板部(22)及び前記複数の第3板部(31)は、それぞれ磁性材料から形成され、かつ、絶縁膜で被覆されている請求項1ないし7のいずれか1つに記載の磁気シールド体。 The first plate portion (21), the second plate portion (22), and the plurality of third plate portions (31) are each formed of a magnetic material and covered with an insulating film. The magnetic shield body according to any one of 7.
  9.  請求項1ないし8のいずれか1つに記載の磁気シールド体(1)と、
     前記磁気シールド体(1)の前記収容空間(4)に収容され、測定対象の電流を検出するための磁気抵抗素子(12)を有する電流センサ(10)と
    を備える電流センサ装置。
    Magnetic shield body (1) according to any one of claims 1 to 8,
    A current sensor device comprising: a current sensor (10) that is housed in the housing space (4) of the magnetic shield body (1) and includes a magnetoresistive element (12) for detecting a current to be measured.
  10.  前記磁気抵抗素子(12)は、前記測定対象の電流が流れた際に前記収容空間(4)に発生する磁界の変化を検出するための検出面(12a)を有し、
     前記検出面(12a)は前記第1上面部(24)と平行であり、
     前記第1上面部(24)に垂直な方向における前記収容空間(4)の高さをhとすると、前記検出面(12a)は前記収容空間(4)におけるh/2の高さに配置され、
     前記検出面(12a)の中心位置(12b)が前記第1上面部(24)に垂直な方向において前記収容空間(4)のうち前記第1上面部(24)と平行な面の中心位置(41)と一致するように配置されている請求項9に記載の電流センサ装置。
    The magnetoresistive element (12) has a detection surface (12a) for detecting a change in a magnetic field generated in the accommodation space (4) when the current to be measured flows.
    The detection surface (12a) is parallel to the first upper surface portion (24),
    When the height of the accommodation space (4) in the direction perpendicular to the first upper surface portion (24) is h, the detection surface (12a) is arranged at a height of h / 2 in the accommodation space (4). ,
    The central position (12b) of the detection surface (12a) is parallel to the first upper surface portion (24) in the accommodation space (4) in the direction perpendicular to the first upper surface portion (24). 41. The current sensor device according to claim 9, which is arranged so as to coincide with 41).
  11.  前記第1板部(21)の前記各第1側面部(25a、25b)及び前記第2板部(22)の前記各第2側面部(28a、28b)の一方には、バスバー(2)を挿通する開口部(28a1、28b1)が形成され、
     前記磁気抵抗素子(12)は前記バスバー(2)に流れる前記測定対象の電流を検出する請求項9または10に記載の電流センサ装置。
    One of the first side surface portions (25a, 25b) of the first plate portion (21) and the second side surface portions (28a, 28b) of the second plate portion (22) has a bus bar (2). Openings (28a1, 28b1) are formed,
    The current sensor device according to claim 9 or 10, wherein the magnetoresistive element (12) detects the current to be measured flowing through the bus bar (2).
PCT/JP2014/001657 2013-04-01 2014-03-21 Magnetic shield body for current sensor, and current sensor device WO2014162687A1 (en)

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