JP2012058199A - Current detection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an electronic component from being broken down by a high voltage applied from a bus bar and to realize reduction in size compatibly in a current detection apparatus for detecting a current flowing to the bus bar.SOLUTION: A current detection apparatus 1 includes a current detection bus bar 30 having a member of a conductor formed by concatenating a through part 31 which passes through a hollow part 11 of a magnetic core 10, and a terminal part 32 connected with connection terminals of a front stage and a rear stage of a current transmission route at both sides of the through part 31, and an insulation coating 33 formed on a surface of a portion including the through part 31 in that member of the conductor. The insulation coating 33 is e.g., a film of insulation paint formed by painting or a film of a resin formed by heat-shrinkable tubing or insert molding.

Description

  The present invention relates to a current detection device that detects a current flowing in a bus bar.

  A vehicle such as a hybrid vehicle or an electric vehicle is often equipped with a current detection device that detects a current flowing through a bus bar connected to a battery. As such a current detection device, a magnetic proportional current detection device or a magnetic balance current detection device may be employed.

  For example, as disclosed in Patent Document 1, a magnetic proportional type or magnetic balance type current detection device includes a magnetic core and a magnetoelectric conversion element (magnetic sensitive element). The magnetic core is a generally ring-shaped magnetic body formed in a series surrounding both sides of a hollow portion where both ends face each other through a gap portion and the bus bar passes therethrough. The hollow portion of the magnetic body is a space (current detection space) through which a current to be detected passes.

  The magnetoelectric conversion element is disposed in the gap portion of the magnetic core, detects a magnetic flux that changes according to the current flowing through the bus bar disposed through the hollow portion, and outputs a detection signal of the magnetic flux as an electric signal. It is an element. As the magnetoelectric conversion element, a Hall element is usually adopted.

  As shown in Patent Document 1, in a conventional current detection device, a magnetic core, a bus bar, and a magnetoelectric conversion element are often held in a fixed positional relationship by an insulating casing. This housing positions a plurality of components constituting the current detection device in a fixed positional relationship.

  By the way, when a high voltage due to static electricity or the like is generated in the bus bar, electronic components including a magnetoelectric conversion element disposed near the bus bar and a component electrically connected to the magnetoelectric conversion element are A voltage may be applied to cause a failure. In the current detection device, the insulating housing functions as an electrical shielding material that partitions the bus bar and the magnetoelectric conversion element and enhances the electrical insulation between the bus bar and the electronic component including the magnetoelectric conversion element. To do. This function prevents the electronic component including the magnetoelectric conversion element from being damaged by the high voltage applied from the bus bar.

JP 2009-128116 A

  However, recently, there is an increasing demand for downsizing of a current detection device mounted on a vehicle. For this reason, it is difficult to secure a space for electrically shielding the bus bar and the magnetoelectric conversion element with an insulating member. That is, the conventional current detection device has a problem that it is difficult to achieve both prevention of failure of the electronic component due to the high voltage applied from the bus bar and downsizing.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a current detection device for detecting a current flowing through a bus bar, which can both prevent a failure of an electronic component due to a high voltage applied from the bus bar and reduce the size.

A current detection device according to the present invention is a current detection device that detects a current flowing through a bus bar, and includes the following components.
(1) The first component is a magnetic core that is formed in a series with both ends facing each other via a gap portion and surrounding the periphery of the hollow portion.
(2) A 2nd component is a magnetoelectric conversion element which is arrange | positioned at the gap part of a magnetic body core, and detects the magnetic flux which changes according to the electric current which passes the hollow part of a magnetic body core.
(3) The third component is formed by connecting a penetrating portion that penetrates the hollow portion of the magnetic core and terminal portions that are connected to the connection ends of the front and rear stages of the current transmission path on both sides of the penetrating portion. And a current detection bus bar having an insulating coating formed on a surface of a portion of the conductor member including a penetrating portion.

  In the current detection device according to the present invention, it is preferable that the cross-sectional shape of the through portion in the current detection bus bar is similar to the contour shape of the hollow portion of the magnetic core.

  Further, in the current detection device according to the present invention, the insulation coating in the current detection bus bar may be any of an insulating paint film formed by painting, a heat shrinkable tube, or a resin film formed by insert molding. Conceivable. It is also conceivable that metal powder covered with an insulating oxide coating is added to the insulating coating.

  In the current detection device according to the present invention, an insulating coating is formed in a through portion that is a portion located in the vicinity of the magnetic core and the magnetoelectric conversion element in the bus bar that is a high-voltage transmission medium. The insulation coating is a very thin film, and it is necessary to provide a gap (play) in consideration of dimensional tolerances with the bus bar as in the case where an insulating member for electrical shielding is separately provided. do not do. Therefore, according to the present invention, it is possible to increase the creepage distance between the bus bar, the magnetic core, and the magnetoelectric conversion element while reducing the spatial distance between them. As a result, the bus bar, the magnetic core, and each of the magnetoelectric conversion elements can be arranged close to a narrow space. Furthermore, even if such an arrangement is made, a sufficient creepage distance is secured, so that high voltage electricity generated in the bus bar propagates directly from the bus bar to the magnetoelectric conversion element, or from the bus bar to the magnetic core. The phenomenon of propagating to surrounding electronic parts such as a magnetoelectric conversion element is less likely to occur via the. The creepage distance is the shortest distance along the insulating coating between the bus bar, the magnetic core, and the magnetoelectric conversion element.

  As described above, according to the present invention, it is possible to prevent a failure of the electronic component due to the high voltage applied from the bus bar. Furthermore, according to the present invention, there is no need to secure a large space for electrically shielding the bus bar, the magnetoelectric conversion element, and the magnetic core with an insulating member such as a resin member. Miniaturization is possible.

  By the way, in order to reduce the size of the current detection device, it is desirable to employ a small magnetic core that forms a small hollow portion. On the other hand, when a thin bus bar that can be passed through a small hollow portion is employed, the electrical resistance increases, causing a problem that the bus bar generates excessive heat due to the current flowing through the bus bar.

  Therefore, in the present invention, it is preferable if the cross-sectional shape of the through portion of the current detection bus bar is similar to the contour shape of the hollow portion of the magnetic core. As a result, even when a small magnetic core that forms a small hollow portion is adopted, the gap between the penetrating portion and the magnetic core is reduced, and the conductor member in the current detection bus bar is disconnected within a limited space. The area can be maximized. In particular, since the insulating coating is thin, the thickness of the conductor member in the penetrating portion can be maximized. As a result, it is possible to achieve both downsizing of the apparatus by employing a small magnetic core and prevention of excessive heat generation of the current detection bus bar.

  In addition, as the insulating coating, various types of coatings may be employed depending on the required insulating performance, that is, the required coating thickness. For example, if the insulating coating is an insulating coating film formed by painting, a very thin insulating coating can be easily formed by spraying the insulating coating. If the insulating coating is a heat-shrinkable tube, it is possible to form a slightly thicker insulating coating having a higher insulating property than the insulating paint film. Further, if the insulating coating is a resin film formed by insert molding, a thicker insulating coating having a higher insulating property than the heat shrinkable tube can be formed. Moreover, if the metal powder covered with the insulating oxide coating is added to the insulating coating, the conductivity of the insulating coating is increased and the heat dissipation performance of the bus bar is improved.

It is a disassembled perspective view of the electric current detection apparatus 1 which concerns on embodiment of this invention. FIG. 3 is a three-side view of a current detection bus bar 30 provided in the current detection device 1. 1 is a plan view of a current detection device 1. FIG. 2 is a side view and a cross-sectional view of a main part of the current detection device 1. FIG. 3 is a perspective view of a current detection bus bar 30A according to an application example that can be employed in the current detection device 1. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiment is an example embodying the present invention, and is not an example of limiting the technical scope of the present invention.

  Hereinafter, the configuration of the current detection device 1 according to the embodiment of the present invention will be described with reference to FIGS. The current detection device 1 is a device that detects a current flowing through a bus bar that electrically connects a battery and a device such as a motor in a vehicle such as an electric vehicle or a hybrid vehicle. As shown in FIG. 1, the current detection device 1 includes a magnetic core 10, a Hall element 20, a current detection bus bar 30, an insulating housing 40, and an electronic substrate 50.

<Magnetic core>
The magnetic core 10 is a magnetic body made of ferrite, silicon steel, or the like, and has both ends opposed to each other via a gap portion 12 of about several millimeters and a series of shapes surrounding the hollow portion 11. ing. That is, the magnetic core 10 is formed in an annular shape together with the narrow gap portion 12. The magnetic core 10 in this embodiment is formed in an annular shape that surrounds the circular hollow portion 11 together with the gap portion 12.

<Hall element (magnetoelectric conversion element)>
The Hall element 20 is disposed in the gap portion 12 of the magnetic core 10, detects a magnetic flux that changes according to a current passing through the hollow portion 11 of the magnetic core 10, and outputs a magnetic flux detection signal as an electric signal. It is an example of a conversion element. In the Hall element 20, a magnetic flux detection unit 21 disposed in the gap portion 12 of the magnetic core 10 and a connection terminal 22 extending from the magnetic flux detection unit 21 are formed.

  The magnetic flux detection unit 21 of the Hall element 20 has a predetermined detection center point positioned at the center point of the gap portion 12 of the magnetic core 10, and the front and back surfaces of the magnetic flux detection portion 21 are formed in the gap portion 12. It arrange | positions so as to be orthogonal to.

<Electronic board>
The electronic board 50 is a printed circuit board on which the Hall element 20 is mounted at the connection terminal 22 portion. In addition to the Hall element 20, a circuit that performs a process such as amplification on a magnetic flux detection signal output from the Hall element 20 and a connector 51 are mounted on the electronic substrate 50.

  The connector 51 is a component to which a mating connector provided on an electric wire (not shown) is connected. Further, the electronic substrate 50 is provided with a circuit that electrically connects the Hall element 20 connection terminals 22 and the terminals of the connector 51. For example, the electronic board 50 amplifies the circuit that supplies power input from the outside via the electric wire and the connector 51 to the connection terminal of the Hall element 20, and the detection signal of the Hall element 20, and outputs the amplified signal. A circuit for outputting to the terminal of the connector 51 is provided. Thereby, the current detection device 1 can output a current detection signal to an external circuit such as an electronic control unit through the electric wire with a connector connected to the connector 51.

<Bus bar for current detection>
The current detection bus bar 30 is a member whose base material is a conductor member made of metal such as copper, and is a part of the bus bar that electrically connects the battery and the electrical equipment. That is, a current to be detected flows through the current detection bus bar 30. The current detection bus bar 30 is a member independent of the battery-side bus bar connected in advance to the battery and the device-side bus bar connected in advance to the electrical equipment. The current detection bus bar 30 is connected to other bus bars (battery-side bus bar and device-side bus bar) laid at both ends thereof in advance.

  In FIG. 2, which is a three-view diagram of the current detection bus bar 30, FIG. 2 (a) is a plan view, FIG. 2 (b) is a side view, and FIG. 2 (c) is a front view. In FIG. 2, the magnetic core 10 combined with the current detection bus bar 30 is indicated by a virtual line (two-dot chain line).

  As shown in FIGS. 1 and 2, the current detection bus bar 30 has an insulating coating on a part of a base material processed at both end portions of a rod-shaped conductor that penetrates the hollow portion 11 of the magnetic core 10. It consists of the member to which 33 was given. In the current detection bus bar 30, the processed both end portions are terminal portions 32 connected to the connection ends of the front and rear stages of the current transmission path. That is, the current detection bus bar 30 generally includes a conductor base material having a rod-like through portion 31 that occupies a certain range in the central portion, and terminal portions 32 formed at both end portions thereof.

  The penetration part 31 is a part that penetrates the hollow part 11 of the magnetic core 10 along the current passing direction. The current passing direction is the thickness direction of the magnetic core 10, the axial direction of the cylinder when the annular magnetic core 10 is regarded as a cylinder, and further on the surface formed by the annular magnetic core 10. It is also an orthogonal direction. In each figure, the current passing direction is indicated as the X-axis direction.

  The terminal part 32 in this embodiment is flat form. Moreover, the penetration part 31 in the bus bar 30 for electric current detection is formed in rod shapes, such as column shape or elliptical column shape, for example. In each figure, the width direction and the thickness direction of the flat terminal portion 32 are described as a Y-axis direction and a Z-axis direction, respectively.

  The base material of the current detection bus bar 30 is a member having a structure in which a portion in a certain range at both ends of a rod-shaped metal member is crushed into a flat plate shape by pressing using a press or the like. At this time, at least one of both ends of the rod-shaped metal member is pressed into a flat plate shape after the rod-shaped metal member is inserted into the hollow portion 11 of the magnetic core 10.

  The metal member that is the basis of the current detection bus bar 30 shown in FIGS. 1 and 2 is a cylindrical member, and the through-hole 31 of the current detection bus bar 30 manufactured by processing both ends of the cylindrical metal member is It is cylindrical. In addition, it is also conceivable that the metal member that is the source of the current detection bus bar 30 has an elliptical bar shape with an elliptical cross section or a square bar shape with a rectangular cross section. Moreover, it is also conceivable that the bar-shaped metal member as a base has a bar shape whose cross section is a quadrangle or other polygons. However, it is desirable that the cross-sectional shape of the through portion 31 of the current detection bus bar 30 is similar to the contour shape of the hollow portion 11 of the magnetic core 10.

  In the current detection bus bar 30, the width of the flat terminal portion 32 is formed to be larger than the diameter (maximum width) of the hollow portion 11 of the magnetic core 10. Therefore, the magnetic core 10 cannot be mounted on the through-hole 31 of the current detection bus bar 30 manufactured in advance. Accordingly, after a set of the magnetic core 10 and the current detection bus bar 30 penetrating through the hollow portion 11 of the magnetic core 10 is made, the current detection bus bar 30 is connected to the other bus bars in the front and rear stages. Connected. Therefore, the flat terminal portion 32 is formed with a through hole 32z for screwing, whereby the flat terminal portion 32 is connected to the other bus bars at the front and rear stages by screws.

<Insulation coating>
An insulating coating 33 is applied to the surface of the current detection bus bar 30 excluding the terminal portion 32, that is, the surface of the through portion 31 and the portion between the through portion 31 and both the terminal portions 32. In FIG. 1, FIG. 2 and FIG. 4, the portion of the insulation coating 33 is marked with cross-line hatching. The insulating coating 33 is formed over at least the entire peripheral surface of the through-hole 31 in the current detection bus bar 30.

  If the insulating property of the electrically insulating material constituting the insulating coating 33 is the same, the more the magnetic core 10 is formed from the through-hole 31 in the current detection bus bar 30 over a wider range on both sides thereof. In addition, the creepage distance between the Hall element 20 and the Hall element 20 increases, and the insulation performance increases. Likewise, the insulation performance of the insulating coating 33 increases as the film thickness increases. However, at least the terminal portion 32 of the current detection bus bar 30 needs to be in a state in which the insulating coating 33 is not formed for electrical connection with the front and rear connection ends.

  As the insulation coating 33 in the current detection bus bar 30, various types of coating can be employed depending on the required insulation performance, that is, the required coating thickness. For example, if the insulating coating 33 is a film of an insulating coating formed by painting, the very thin insulating coating 33 of 50 micrometers or less can be easily formed by spraying the insulating coating.

  If the insulating coating 33 is a heat-shrinkable tube, a slightly thicker insulating coating 33 of about 0.3 mm to 0.5 mm can be formed. Of course, the heat-shrinkable tube forming the insulating coating 33 is a heat-shrinkable tube that is in close contact with the surface of the base material (conductor) of the current detection bus bar 30 after being shrunk by heating. Thereby, it becomes possible to form the insulating coating 33 having a higher insulating property than the film of the insulating paint. Furthermore, the insulating coating 33 made of a heat-shrinkable tube is less likely to be scratched than the insulating paint and has high wear resistance. The heat-shrinkable tube is a tube made of an insulating heat-shrinkable material such as polyolefin, double polyolefin, fluoroplastic cainer, or fluoroplastic Teflon (Teflon is a registered trademark of DuPont).

  Further, if the insulating coating 33 is a resin film formed by insert molding, the insulating coating 33 of about 0.7 millimeters or more can be formed. Thereby, it becomes possible to form the insulating coating 33 having a higher insulating property than the heat-shrinkable tube. Furthermore, the insulating coating 33 made of a resin film formed by insert molding is less likely to be scratched than the heat shrinkable tube and has high wear resistance. In this case, the resin is an insulating resin such as polyamide (PA), polypropylene (PP), or ABS resin.

<Insulated housing>
The insulating housing 40 is an insulating member that holds the magnetic core 10, the current detection bus bar 30, and the electronic substrate 50 on which the Hall element 20 is mounted in a fixed positional relationship. And a lid member 42 attached to the lid. Each of the main body case 41 and the lid member 42 is an integrally molded member made of an insulating resin such as polyamide (PA), polypropylene (PP), or ABS resin.

  The body case 41 is formed in a box shape having an opening, and the lid member 42 closes the opening of the body case 41 by being attached to the body case 41. The main body case 41 is formed with a first holding portion 43 and a second holding portion 44 that protrude on the inner surface thereof. The main body case 41 includes the first holding portion 43 and the second holding portion 44, the magnetic core 10, the current detection bus bar 30 penetrating the hollow portion 11, and the Hall element 20 disposed in the gap portion 12. Are held in a fixed positional relationship.

  More specifically, the first holding portion 43 is fitted into the gap between the magnetic core 10 and the through portion 31 of the current detection bus bar 30 that penetrates the hollow portion 11, thereby detecting the current detection of the magnetic core 10. The bus bar 30 is held. Further, the second holding portion 44 holds the magnetic core 10 and the Hall element 20 by fitting into the gap between the magnetic core 10 and the Hall element 20 disposed in the gap portion 12. In addition, a third holding portion 49 formed to protrude from the inner side surface of the side wall of the main body case 41 fits into the chipped portion 52 formed in the electronic substrate 50, and holds the electronic substrate 50 at a predetermined position.

  The main body case 41 and the lid member 42 are formed with slit holes 45 into which both terminal portions 32 of the current detection bus bar 30 are inserted from the inside to the outside. In the state where one terminal portion 32 of the current detection bus bar 30 penetrating through the hollow portion 11 of the magnetic core 10 is passed through the slit hole 45 of the main body case 41, the first holding portion 43 and the second holding portion 43 of the main body case 41. The holding unit 44 holds the magnetic core 10, the Hall element 20, and the current detection bus bar 30.

  The lid member 42 is attached to the main body case 41 holding the magnetic core 10, the Hall element 20 and the current detection bus bar 30 so as to close the opening of the main body case 41 while sandwiching the electronic substrate 50. At that time, the other terminal portion 32 of the current detection bus bar 30 is passed from the inside to the outside with respect to the slit hole 45 of the lid member 42, and the electronic substrate 50 is sandwiched between the main body case 41 and the lid member 42. Held.

  FIG. 3 is a plan view of the current detection device 1 in a state where the main body case 41 and the lid member 42 are combined. FIG. 4 is a cross-sectional view of the magnetic core 10 and the electronic board 50 held by the insulating housing 40 and a side view of the current detection bus bar 30.

  As shown in FIG. 3, the main body case 41 and the lid member 42 (insulating housing 40) are magnetic in a state where the terminal portion 32 of the current detection bus bar 30 and the connector 51 of the electronic board 50 are exposed to the outside. The body core 10, the penetration part 31 of the current detection bus bar 30 and the Hall element 20 are covered and held.

  Furthermore, the main body case 41 and the lid member 42 are provided with lock mechanisms 47 and 48 that hold them in a combined state. The lock mechanisms 47 and 48 shown in FIG. 1 include a claw portion 47 formed to project from the side surface of the main body case 41 and an annular frame portion 48 formed on the side of the lid member 42. When the claw portion 47 of the main body case 41 is fitted into the hole formed by the frame portion 48 of the lid member 42, the main body case 41 and the lid member 42 are held in a state where they are combined. In the current detection device 1, the conductor disposed closest to the current detection bus bar 30 is the magnetic core 10.

  As shown in FIG. 4, in the current detection bus bar 30, the insulating coating 33 is formed in a range extending from the penetrating portion 31 close to the magnetic core 10 to the portion close to the electronic substrate 50. As a result, a sufficient creepage distance is ensured between the current detection bus bar 30 and each of the electronic components mounted on the magnetic core 10 and the electronic substrate 50.

  In the current detection device 1 described above, the insulating coating 33 is formed in the through-hole 31 that is a portion located in the vicinity of the magnetic core 10 and the Hall element 20 in the current detection bus bar 30 that is a high-voltage transmission medium. Is formed. The insulating coating 33 is a very thin film and has a gap (play) in consideration of a dimensional tolerance with the current detection bus bar 30 as in the case where an insulating member for electrical shielding is separately provided. It is not necessary to provide.

  Therefore, in the current detection device 1, the creepage distance between them can be increased while the spatial distance between the current detection bus bar 30, the magnetic core 10 and the Hall element 20 is reduced. As a result, it is possible to dispose the current detection bus bar 30, the magnetic core 10 and the Hall element 20 close to a narrow space. Furthermore, even if such an arrangement is made, a sufficient creepage distance is ensured, so that high-voltage electricity generated in the current detection bus bar 30 directly propagates to the Hall element 20 or the magnetic core. The phenomenon of propagating to peripheral electronic components such as the Hall element 20 through the pin 10 is unlikely to occur.

  As described above, if the current detection device 1 is employed, it is possible to prevent a failure of the electronic component due to the high voltage applied from the current detection bus bar 30. Further, in the current detection device 1, it is necessary to secure a large space for electrically shielding the current detection bus bar 30 from the hall element 20 and the magnetic core 10 with an insulating member such as a resin member. Therefore, the apparatus can be miniaturized.

  Further, in the current detection device 1, it is preferable if the cross-sectional shape of the through portion 31 of the current detection bus bar 30 is similar to the contour shape of the hollow portion 11 of the magnetic core 10. Thereby, even when the small magnetic core 10 which forms the small hollow part 11 is employ | adopted, the clearance gap between the penetration part 31 and the magnetic core 10 is made small, and in the bus bar 30 for electric current detection in the limited space. The cross-sectional area of the substrate can be maximized. In particular, since the insulating coating 33 is thin, the thickness of the base material in the through portion 31 can be maximized. As a result, it is possible to achieve both downsizing of the apparatus by adopting the small magnetic core 10 and prevention of excessive heat generation of the current detection bus bar 30.

<Others>
Next, a current detection bus bar 30A according to an application example that can be employed in the current detection device 1 will be described with reference to a perspective view shown in FIG. The current detection bus bar 30A is different from the current detection bus bar 30 shown in FIGS. 1 and 2 in that an insulating flange portion 34 is formed. Hereinafter, only the difference between the current detection bus bar 30A and the current detection bus bar 30 will be described.

  Similarly to the current detection bus bar 30, the current detection bus bar 30 </ b> A is a member in which an insulating coating 33 is formed in a region including the through portion 31 in a base material made of a metal conductor. Further, the current detection bus bar 30 </ b> A is provided with a flange portion 34 made of an insulating member connected to the insulating coating 33.

  The flange portion 34 is a non-conductive member such as a resin molded member. The flange portion 34 stands up from the insulating coating 33 at positions on both sides of the through portion 31 in the current detection bus bar 30A, and is formed in a plate shape that partitions the through portion 31 side and the terminal portion 32 side.

  The flange portion 34 is formed by insert molding together with the insulating coating 33, for example. Alternatively, it is conceivable that the resin flange portion 34 is attached later to the portion of the current detection bus bar 30A where the insulating coating 33 is formed. In this case, it is conceivable that the flange portion 34 is composed of two members combined from both sides of the portion where the insulation coating 33 is formed in the current detection bus bar 30A.

  Due to the presence of the flange portion 34, the creeping distance between the magnetic core 10, the Hall element 20 and the electronic substrate 50 on which the Hall element 20 is mounted and the terminal portion 32 on which the insulating coating 33 is not formed is further increased. Become. As a result, a phenomenon in which high-voltage electricity generated in the current detection bus bar 30 directly propagates to the Hall element 20 or propagates to peripheral electronic components such as the Hall element 20 via the magnetic core 10. However, it is less likely to occur and is preferable. And since the flange part 34 functions also as a radiation fin, the effect which the thermal radiation performance of a bus bar improves is also acquired.

  It is also conceivable that metal powder covered with an insulating oxide coating is added to the insulating coating 33 of the current detection bus bar 30. Hereinafter, a metal powder covered with an insulating oxide coating is referred to as an insulating metal powder. By adopting the insulating coating 33 to which the insulating metal powder is added, the conductivity of the insulating coating 33 is increased, and the heat dissipation performance of the bus bar is improved. For example, aluminum oxide powder may be used as the insulating metal powder.

  For example, the insulating coating 33 is a film formed by applying a paint to which an insulating metal powder is added, a resin film to which an insulating metal powder is added, or an insulating metal For example, it may be a film of a heat shrinkable tube to which powder is adhered. It is also conceivable that the flange portion 34 to which the insulating metal powder is added is employed.

DESCRIPTION OF SYMBOLS 1 Current detection apparatus 10 Magnetic body core 11 Hollow part of magnetic body core 12 Gap part of magnetic body core 20 Hall element 21 Magnetic flux detection part 22 Connection terminal 30 Current detection bus bar 31 Through part 32 Terminal part 32z Through hole 33 Insulation coating 34 Flange portion 40 Insulating housing 41 Main body case 42 Lid member 43 First holding portion 44 Second holding portion 45 Slit hole 47 Claw portion (lock mechanism)
48 Frame (locking mechanism)
49 Third holding part 50 Electronic board 51 Connector 52 Chip part of electronic board

Claims (4)

A current detection device for detecting a current flowing in a bus bar,
A magnetic core formed by a series of both ends facing each other through a gap portion and surrounding the periphery of the hollow portion;
A magnetoelectric transducer that is disposed in the gap portion and detects a magnetic flux that changes in accordance with a current passing through the hollow portion;
A conductor member formed by connecting a penetrating portion penetrating the hollow portion of the magnetic core and terminal portions connected to connection ends of the front and rear stages of the current transmission path on both sides of the penetrating portion; and A current detection bus bar having an insulation coating formed on a surface of a portion of the conductor member including the penetrating portion.   2. The current detection device according to claim 1, wherein a cross-sectional shape of the through portion in the current detection bus bar is similar to a contour shape of the hollow portion of the magnetic core.   The said insulation coating in the said bus bar for electric current detection is either the film | membrane of the insulating paint formed by the coating, the heat shrinkable tube, or the film | membrane of the resin formed by insert molding of Claim 1 or Claim 2 Current detection device.   The current detection device according to claim 3, wherein a metal powder covered with an insulating oxide coating is added to the insulating coating in the current detection bus bar.

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