JP2013002901A - Current detecting device - Google Patents

Abstract

In a current detection device, it is possible to reduce the size of the device by adopting a small magnetic core, to prevent excessive heat generation of a bus bar, and to prevent the current detection device from being mounted in an incorrect direction.
In a current detection device, a current detection bus bar has a through portion that passes through a hollow portion of a magnetic core and a terminal portion that continues to both sides of the through portion. The thickness D4 of the penetrating part 31 is larger than the thickness D6 of each of the two terminal parts 32, and the width D5 of each of the two terminal parts 32 is larger than the width D1 of the hollow part 11. A protrusion 33 is formed on one of the two terminal portions 32. The lid member 42 constituting the insulating housing 40 is formed with a first bus bar hole 45A through which the first terminal portion 32A having the protrusion 33 can pass. The main body case 41 constituting the insulating housing 40 is formed with a second bus bar hole 45B through which only the second terminal portion 32B having no protrusion 33 can pass.
[Selection] Figure 1

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, Patent Document 1, Patent Document 2, and Patent Document 3 include a magnetic proportional method or a magnetic balance method current detection device, which includes a magnetic core and a magnetoelectric conversion 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.

  In the conventional current detection device, the magnetic core has a structure in which a plurality of thin plate-like members that are substantially ring-shaped and made of a magnetic material are laminated via an adhesive. Hereinafter, the magnetic core having such a structure is referred to as a laminated type magnetic core.

  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.

  In the current detection device, the polarity of the detection signal of the magnetoelectric conversion element is determined according to the direction of the current passing through the hollow portion of the magnetic core. Therefore, the current detection device needs to be arranged so as to have a predetermined normal direction with respect to the direction of the current flowing through the bus bar.

  Moreover, as shown in Patent Document 4, in a current detection device, the magnetic core and the magnetoelectric conversion element are often supported 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. Note that the casing is generally made of an insulating resin member.

JP-A-10-104279 JP 2006-166528 A JP 2009-58451 A JP 2009-128116 A

  By the way, in the conventional electric current detection apparatus, since the flat bus bar is inserted through the hollow portion of the magnetic core, the maximum width (diameter) of the hollow portion of the magnetic core is larger than the width of the bus bar. It needs to be formed in a size. On the other hand, in an electric vehicle, a hybrid vehicle, and the like, a wide bus bar is being adopted in order to prevent excessive heat generation of the bus bar as the current flowing through the bus bar increases.

  Therefore, the conventional current detection device has a problem that, as the bus bar width increases, a large magnetic core proportional to the bus bar width is required, and the installation space for the device increases. In particular, when the magnetic core is in an annular shape, an elliptical shape, or a rectangular shape in which the ratio of the vertical dimension to the horizontal dimension is 1 or 1, the larger the bus bar width, the more wasted space in the hollow part of the magnetic core. Increase. In addition, when a bus bar in which only the portion disposed in the hollow portion of the magnetic core is narrowed is employed, there is a problem that the narrowed portion generates excessive heat.

  In addition, the current detection device needs to be arranged in a normal direction predetermined with respect to the direction of the current flowing through the bus bar. Therefore, it is also important that the current detection device has a structure that prevents the current detection device from being attached in an incorrect orientation to a housing portion in the vehicle such as a power supply box having a bus bar for connecting a device such as a battery or a motor.

  In the current detection device for detecting the current flowing through the bus bar, the present invention can reduce the size of the device by adopting a relatively small magnetic core in relation to the width of the bus bar, and can prevent excessive heat generation of the bus bar. An object of the present invention is to prevent the current detection device from being attached in the wrong direction.

The current detection device according to the present invention is a device that detects a current flowing through a bus bar, and includes the following components.
(1) The first component is a magnetic core made of a magnetic material, both ends of which face each other via a gap portion, and are formed in a series 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 connected to the through-hole passing through the hollow portion of the magnetic core and the connection end at the front stage or the rear stage of the current transmission path connected to both sides of the through-hole in the direction passing through the hollow portion. The terminal portion is formed with a conductor formed therein, the thickness of the penetrating portion is formed larger than the thickness of each of the two terminal portions, and the width of each of the two terminal portions is formed larger than the width of the hollow portion. This is a bus bar for current detection in which a protrusion is formed on one of the two terminal portions.
(4) The fourth component is an insulating housing that supports the magnetic core, the magnetoelectric transducer, and the current detection bus bar through a fixed positional relationship while the two terminal portions are exposed to the outside. Is the body. Here, the insulating casing includes a first element casing and a second element casing combined from both sides of the magnetic core. The first element housing is formed with a first through-hole through which the first terminal portion having the protrusion of the two terminal portions can pass. The second element housing is formed with a second through-hole through which the second terminal portion having no protrusion of the two terminal portions can pass but the first terminal portion cannot pass. .

  In the current detection bus bar of the current detection device according to the present invention, the first terminal portion is configured by a flat base portion and a protrusion rising from a part of the base portion, and the second terminal portion is a flat plate shape. It is possible that there is.

  Further, in the current detection device according to the present invention, the current detection bus bar is formed of a long metal member that has a cross-sectional width and thickness larger than the interval between both ends of the magnetic core and penetrates the hollow portion of the magnetic core. It is conceivable that both end portions are members having a structure that is crushed into a shape having a width wider than that of other portions by pressing, and the crushed both end portions constitute two terminal portions.

  Hereinafter, in the current detection device according to the present invention, a direction (current passing direction) in which the current detection bus bar passes through the hollow portion of the magnetic core is referred to as a first direction. Further, in the current detection bus bar, the width direction and the thickness direction of the terminal portion connected before and after the through portion penetrating the hollow portion of the magnetic core are referred to as a second direction and a third direction, respectively.

  In the current detection bus bar provided in the current detection device according to the present invention, the width of the penetrating portion that penetrates the hollow portion of the magnetic core is larger than the width of the terminal portion (maximum width) as compared to the terminal portion that is connected to the front and rear. Is also formed small. That is, the outline shape of the cross-section of the penetrating portion is constricted in the second direction with respect to the terminal portion. As a result, a relatively small magnetic core can be employed in relation to the width of the bus bar, and the overall size of the apparatus including the magnetic core can be avoided. In addition, since both ends of the current detection bus bar are terminal portions, the current detection bus bar in a state of penetrating through the hollow portion of the magnetic core is connected to the pre-stage and post-stage bus bars laid in advance. Is possible.

  In the current detection bus bar, the penetrating portion that penetrates the hollow portion of the magnetic core is formed with a thickness larger than the thickness of the terminal portions on both sides, such as a rod shape such as a round bar or a square bar, or a cylindrical shape. Therefore, the penetrating portion can be formed with a larger cross-sectional area under the constraint that the width and thickness thereof are smaller than the width of the hollow portion of the magnetic core as compared with the conventional flat bus bar. Therefore, even when a relatively small magnetic core is employed, excessive heat generation of the current detection bus bar can be prevented.

  Further, in the current detection device according to the present invention, the magnetic core, the current detection bus bar, and the magnetoelectric conversion element are supported in a predetermined positional relationship by an insulating housing that covers a portion other than the portion to be exposed. Therefore, the operation | work which attaches the electric current detection apparatus which concerns on this invention with respect to the bus bar previously laid becomes easy.

  By the way, the current detection bus bar needs to be connected to the front and rear bus bars in a predetermined normal direction so that the polarity of the detection signal of the magnetoelectric conversion element becomes a desired polarity. However, if the two terminal portions of the current detection bus bar have exactly the same shape, a mistake that the current detection bus bar is connected to the front and rear bus bars in an incorrect direction is likely to occur.

  In the current detection device according to the present invention, only one of the two terminal portions of the current detection bus bar has a protrusion. Therefore, when the current detection device is attached to a housing in a vehicle such as a power supply box having a bus bar for connecting a device such as a battery or a motor, the protrusion becomes a mark in the attachment direction, and the current detection bus bar is mistaken. The mistake of connecting to the front and rear bus bars in the direction is unlikely to occur. In addition, the protrusion of the terminal portion also plays a role of restricting the rotation of the current detection bus bar by being caught on the front or rear bus bar or a pedestal supporting the bus bar. Therefore, when the terminal portion of the current detection bus bar is screwed to the terminal portion of the front or rear bus bar, the current detection bus bar is prevented from rotating by the rotation of the screw, and the screw fixing work Increases nature.

  In addition, if the current detection bus bar is assembled in the insulating casing in the wrong direction at the stage of assembling the current detection device, an error in the polarity of the detection signal eventually occurs. However, in the present invention, only one of the two element casings constituting the insulating casing has a through-hole through which the terminal portion provided with the protrusion on the current detection bus bar can be passed. Therefore, in the assembly stage of the current detection device, there is no mistake that the current detection bus bar is assembled to the insulating casing in the wrong direction.

  If the current detection bus bar is a member having a structure in which the end of the metal member that can penetrate the hollow portion of the magnetic core is crushed into a flat shape having a width wider than that of the other portion, the width of the hollow portion A flat terminal portion having a wider width can be easily formed. Therefore, it is possible to easily produce a current detection bus bar in which the width and thickness of the through portion are larger than the distance between both ends of the magnetic core (the height of the gap portion). In addition, as a metal member whose cross-sectional shape is not flat, a rod-shaped metal member or a cylindrical metal member can be considered.

It is a disassembled perspective view of the electric current detection apparatus 1 which concerns on embodiment of this invention. It is a three-plane figure of the bus bar for current detection with which current detection device 1 is provided. It is a perspective view which shows typically the manufacturing process of the bus bar for electric current detection. 1 is a plan view of a current detection device 1. FIG. It is a perspective view which shows typically a mode that the electric current detection apparatus 1 is connected with the bus bar laid beforehand. It is a top view which shows a mode that a magnetic body core is mounted | worn with the penetration part of the bus bar for electric current detection.

  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.

  First, the configuration of the current detection device 1 according to the embodiment of the present invention will be described with reference to FIGS. 2A is a plan view, FIG. 2B is a side view, and FIG. 2C is a front view. The current detection device 1 is a device that detects a current flowing in a bus bar that electrically connects a battery and a device such as a motor in 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 member (magnetic body) made of a magnetic material such as permalloy, ferrite, or silicon steel. The magnetic core 10 is a member formed by sintering powder made of a magnetic material, for example. Such a magnetic core 10 was solidified and molded by compressing a solid powder assembly made of a magnetic material in a mold and further heating it at a temperature lower than the melting point of the magnetic material. It is a member.

  Further, the magnetic core 10 has a shape in which both ends face each other via a gap portion 12 of about several millimeters and are formed in a series around the periphery of the hollow portion 11. In other words, the magnetic core 10 has a narrow gap portion 12 but is formed in a generally annular shape. The magnetic core 10 in this embodiment is formed in an annular shape surrounding the circular hollow portion 11.

<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.

<Electronic board>
The electronic board 50 is a board on which a circuit connected to the terminal 21 of the Hall element 20 and a connector 51 for connecting the circuit and other external circuits are mounted. Accordingly, the connector 51 is electrically connected to the hall element 20. The circuit mounted on the electronic substrate 50 is, for example, a circuit that amplifies a magnetic flux detection signal output from the Hall element 20. The hall element 20 is connected to an external circuit through an electronic substrate 50 including a connector 51.

<Bus bar for current detection>
The current detection bus bar 30 is a conductor made of a metal such as copper or aluminum, 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 the other bus bars (battery side bus bar and device side bus bar) of the front stage and the rear stage where both ends thereof are laid in advance. The current detection bus bar 30 and the other bus bars at the front stage and the rear stage connected thereto form a current transmission path from the battery to the electrical equipment. The end portions of the other bus bars are an example of connection ends of conductors at the front and rear stages of the current detection bus bar 30 in the current transmission path.

  As shown in FIG. 1, the current detection bus bar 30 is made of a member in which both end portions of a rod-shaped conductor that penetrates the hollow portion 11 of the magnetic core 10 are processed. In the current detection bus bar 30, the processed both end portions are two 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 is generally formed of two rod-shaped through portions 31 occupying a certain range in the central portion, and two sides formed on both sides of the through portion 31 in the direction penetrating the hollow portion 11. It is a member made of a conductor having a terminal portion 32.

  The penetration part 31 is a part which penetrates the hollow part 11 of the magnetic body core 10 along the electric current passage direction, and the cross-sectional shape is not a flat shape. 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. In the following description, the current passing direction (X-axis direction) is referred to as a first direction.

  The through-hole 31 in the current detection bus bar 30 is formed in a rod shape such as a columnar shape or an elliptical column shape, and the cross-sectional shape thereof is non-flat. On the other hand, the two terminal portions 32 are both formed in a flat shape. More specifically, the first terminal portion 32 </ b> A that is one of the two terminal portions 32 is configured by a flat plate-like base portion and a protrusion 33 that rises from a part of the base portion. The second terminal portion 32B, which is the other of the two terminal portions 32, has a flat plate shape without a protrusion.

  In each figure, the width direction and the thickness direction of the terminal portion 32 are described as a Y-axis direction and a Z-axis direction, respectively. In the following description, the width direction (Y-axis direction) and the thickness direction (Z-axis direction) of the terminal portion 32 are referred to as a second direction and a third direction, respectively.

  FIG. 3 is a perspective view schematically showing a manufacturing process of the current detection bus bar 30. The current detection bus bar 30 has a structure in which both end portions of a rod-shaped metal member 30X are processed. The rod-shaped metal member 30 </ b> X has a width and thickness that are larger than the gap height D <b> 2 that is the distance between both ends of the magnetic core 10. Since the metal member 30X shown in FIG. 3 is cylindrical, the width and thickness of the metal member 30X are the diameter of the metal member 30X.

  More specifically, the current detection bus bar 30 has other parts in a certain range at both ends of the rod-shaped metal member 30X that penetrates the hollow portion 11 of the magnetic core 10 by pressing using the press machine 60 or the like. It is a member having a structure crushed into a flat shape having a width wider than that of the portion.

  That is, in the process of manufacturing the current detection device 1, the process of manufacturing the current detection bus bar 30 includes a flat shape having one end of the bar-shaped metal member 30X wider than the other part by the press machine 60 or the like. And a second pressing step of crushing the other end portion of the rod-shaped metal member 30X into a flat shape having a width wider than that of the other portion by the press machine 60 or the like.

  And the part of the both ends crushed by flat shape comprises the two flat terminal parts 32 in the bus bar 30 for electric current detection, and the rod-shaped part between them comprises the penetration part 31 of the bus bar 30 for electric current detection To do.

  However, the first press step and the second press step are slightly different in the shape of the press contact portion of the press machine 60 used in each step. In the pressing step for forming the first terminal portion 32A having the protrusion 33, as shown in FIG. 3, the protrusion 61 is formed on one of the pair of press contact portions in the press 60, and the protrusion is on the other. A recess 62 is formed opposite to 61.

  By the pressing process using the press machine 60 as shown in FIG. 3, the first terminal portion 32 </ b> A composed of the flat plate-like base portion and the protrusion 33 rising from a part of the base portion is formed. On the other hand, in the pressing step of forming the second terminal portion 32B that does not have the protrusion 33, a press machine including a pair of flat pressure contact portions without the protrusion portion 61 and the recess portion 62 is used.

  Further, in both the first press process and the second press process, by using a press machine having a pair of flat pressure contact portions without the protrusions 61 and the recesses 62, the protrusions 33 are not provided. It is conceivable that two terminal portions 32 are formed. In this case, the protrusion 33 is formed only on one terminal portion 32 by a molding process using a press machine 60 as shown in FIG.

  The metal member 30X shown in FIG. 3 is a cylindrical member, and the through portion 31 of the current detection bus bar 30 manufactured by processing both ends of the metal member 30X is cylindrical. In addition, it is also conceivable that the rod-shaped metal member 30X has an elliptical bar shape with an elliptical cross section or a square bar shape with a rectangular cross section. Further, the rod-shaped metal member 30X may have a rod shape whose cross section is a polygon other than a quadrangle.

  The cross-sectional shape of the metal member 30 </ b> X, that is, the cross-sectional shape of the penetrating portion 31 is desirably a shape similar to the contour shape of the hollow portion 11 of the magnetic core 10. For example, when N is an integer of 3 or more, when the contour shape of the hollow portion 11 of the magnetic core 10 is a regular N square, it is preferable that the shape of the metal member 30X is a regular N prism. Moreover, when the outline shape of the hollow part 11 of the magnetic body core 10 is circular, if the shape of the metal member 30X is a cylinder, it is suitable. Moreover, when the outline shape of the hollow part 11 of the magnetic body core 10 is an ellipse whose ratio of the major axis to the minor axis is R, the shape of the metal member 30X is the ratio of the major axis to the minor axis in the cross section. It is suitable if is an elliptic cylinder with R.

  In the current detection bus bar 30, the width D5 of each of the two terminal portions 32 is formed to be larger than the diameter D1 (width) of the hollow portion 11. Further, the thickness D4 (diameter) of the penetrating portion 31 is formed larger than the thickness D6 of the flat terminal portion 32. That is, the ratio of the vertical dimension and the horizontal dimension of the cross-sectional outline of the penetrating part 31 is closer to 1 than the ratio of the vertical dimension and the horizontal dimension of the flat terminal part 32. In addition, when the penetration part 31 is cylindrical, the thickness D4 and the width D3 of the penetration part 31 are the same. Moreover, that the ratio is close to 1 includes that the ratio is 1.

  Further, the magnetic core 10 and the current detection bus bar 30 are combined in a procedure as shown in FIG. 6, for example. FIG. 6 is a plan view showing a state in which the magnetic core 10 is attached to the through portion 31 of the current detection bus bar 30.

  When the magnetic core 10 and the current detection bus bar 30 are combined, first, the terminal portion 32 of the current detection bus bar 30 is spaced from the hollow portion 11 of the magnetic core 10 as indicated by an arrow line A1 in FIG. It is inserted into the space over the section 12.

  Next, the magnetic core 10 moves so that a part of the penetration part 31 of the current detection bus bar 30 enters a part of the hollow part 11 of the magnetic core 10 as indicated by an arrow A2 in FIG. Is done. As a result, a portion of the current detection bus bar 30 extending from a part of the through portion 31 to a portion of the terminal portion 32 is inserted into a space extending from the hollow portion 11 to the gap portion 12 of the magnetic core 10.

  Finally, as indicated by the arrow A3 in FIG. 6, the magnetic material core 10 is disconnected from the gap portion 12 of the magnetic core 10 so that the terminal portion 32 of the current detection bus bar 30 passes through the through portion of the current detection bus bar 30. 31 is moved so as to penetrate the hollow portion 11 of the magnetic core 10. As described above, the current detection bus bar 30 is combined with the magnetic core 10 in a state in which the penetrating portion 31 penetrates the hollow portion 11 of the magnetic core 10.

  Note that at least one of both ends of the rod-shaped metal member 30X may be pressed into a flat shape after the rod-shaped metal member 30X is inserted into the hollow portion 11 of the magnetic core 10.

  After the 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, each of the two terminal portions 32 is formed with a through-hole 32Z for screwing, whereby the terminal portion 32 is connected to the other bus bars in the front and rear stages by screws. FIG. 5 schematically shows that the two terminal portions 32 in the current detection device 1 are connected by screws 8 to the other bus bars 9 in the front stage and the rear stage that are laid in advance in a storage box 6 such as a power supply box. It is a perspective view shown in FIG.

  In FIG. 5, the illustration of the insulating housing 40 is omitted for convenience. As shown in FIG. 5, the connection end connected to the terminal portion 32 in the other bus bar 9 has a structure as a terminal block in the housing box 6 such as a power supply box, and has a hole 9 </ b> A for screwing. Is formed.

  The protrusion 33 provided on the first terminal portion 32A supports the front-stage or rear-stage bus bar 9 or the two in the state where the two terminal sections 32 are in contact with the front-stage and rear-stage bus bars 9 provided in the storage box 6. The pedestal 7 is caught, and the rotation of the current detection bus bar 30 is restricted.

  The position of the protrusion 33 in the current detection bus bar 30 is determined according to the relationship with the front or rear bus bar 9 or the pedestal 7 supporting the bus bar 9 or other factors. Therefore, the position of the protrusion 33 in the current detection bus bar 30 may be either the position near the through portion 31 or the position near the end in the first terminal portion 32A. Similarly, the position of the protrusion 33 may be either a position near the center or a position near the end in the width direction of the first terminal portion 32A.

<Insulated housing>
The insulating housing 40 is made of an insulator and is a member that holds the magnetic core 10, the Hall element 20, the current detection bus bar 30, and the electronic substrate 50, and is a main body case 41 and a lid member 42 that is attached to the main body case 41. Including. Each of the main body case 41 and the lid member 42 is an integrally formed member made of an insulating resin such as polyamide (PA), polypropylene (PP), polybutylene terephthalate (PBT), 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 state where they are not in contact with each other.

  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 bars 30 are held in a state where they do not contact each other. Further, the second holding portion 44 fits into the gap between the magnetic core 10 and the Hall element 20 disposed in the gap portion 12, thereby bringing the magnetic core 10 and the Hall element 20 into contact with each other. Hold in a state that does not.

  The main body case 41 and the lid member 42 are formed with bus bar holes 45 that are slit-like through holes through which the terminal portions 32 at both ends of the current detection bus bar 30 penetrate from the inside to the outside. When the second terminal portion 32B of the current detection bus bar 30 penetrating the hollow portion 11 of the magnetic core 10 is passed through the second bus bar hole 45B of the main body case 41, the first holding portion of the main body case 41 43 and the second holding unit 44 hold 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 first terminal portion 32A of the current detection bus bar 30 is passed from the inside to the outside with respect to the first bus bar hole 45A of the lid member.

  Further, since the electronic board 50 is sandwiched between the main body case 41 and the lid member 42, the connector 51 mounted on the electronic board 50 is held in a state of being fitted into the chipped portion 46 formed in the main body case 41. Is done.

  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.

  FIG. 4 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. As shown in FIG. 4, the main body case 41 and the lid member 42 (insulating housing 40) are combined from both sides of the magnetic core 10. The main body case 41 and the lid member 42 are combined with each other, so that the portion where the through hole 32Z is formed in each of the two terminal portions 32 of the current detection bus bar 30 and the connector 51 of the electronic board 50 are externally connected. The magnetic core 10, the through-hole 31 of the current detection bus bar 30, and the Hall element 20 are covered and supported in a fixed positional relationship.

  The first bus bar hole 45 </ b> A formed in the lid member 42 constituting the insulating housing 40 is formed in a shape through which the first terminal portion 32 </ b> A having the protrusion 33 can pass. More specifically, the first bus bar hole 45A includes a slit hole through which the plate-like base portion of the first terminal portion 32A passes, and a protrusion formed by cutting from the slit hole in a direction intersecting the longitudinal direction. This is a through-hole configured to be continuous with the passage hole 451.

  On the other hand, the second bus bar hole 45B formed in the main body case 41 constituting the insulating housing 40 can pass through the second terminal portion 32B having no protrusion 33, but the first bus bar having a protrusion 33 is provided. The terminal portion 32A is formed in a shape that cannot pass through. More specifically, the second bus bar hole 45B is a slit hole through which the plate-like second terminal portion 32B passes, and is a through hole in which the projection passage hole 451 is not formed.

<Effect>
In the current detection bus bar 30 of the current detection device 1 described above, the through portion 31 is formed so that the maximum width D3 of the cross-sectional contour is smaller than the width D5 (maximum width) of the terminal portion. That is, the outline shape of the cross section of the through portion 31 is constricted in the second direction with respect to the terminal portion 32. As a result, in the current detection device 1, the relatively small magnetic core 10 can be employed in relation to the widths of the other bus bars in the front and rear stages, and the entire apparatus including the magnetic core 10 can be downsized. Moreover, since both ends of the current detection bus bar 30 are the terminal portions 32, the current detection bus bar 30 in a state of penetrating through the hollow portion 11 of the magnetic core 10 with respect to the pre-laying and the pre-stage bus bars 9. Can be connected later.

  Further, in the current detection bus bar 30, the penetrating part 31 penetrating the hollow part 11 of the magnetic core 10 is formed with a thickness larger than the thickness of the terminal parts on both sides, such as a round bar or a square bar. Therefore, the penetrating portion 31 is larger than the conventional flat bus bar, with the width D3 and the thickness D4 being smaller than the diameter D1 (width) of the hollow portion 11 of the magnetic body core 10. It can be formed in area. Therefore, even when a relatively small magnetic core 10 is employed, excessive heat generation of the current detection bus bar 30 can be prevented.

  Moreover, if the cross-sectional shape of the penetration part 31 of the current detection bus bar 30 is similar to the outline shape of the hollow part 11 of the magnetic core 10, the gap between the penetration part 31 and the magnetic core 10 is further reduced. be able to. As a result, the apparatus can be reduced in size by adopting a smaller magnetic core 10.

  In the current detection device 1, the magnetic core 10, the current detection bus bar 30, and the Hall element 20 are supported in a fixed positional relationship by an insulating housing 40 that covers the portion other than the portion to be exposed. Therefore, the work of attaching the current detection device 1 to the bus bar 9 laid in advance is facilitated.

  Further, in the current detection device 1, since only one of the two terminal portions 32 of the current detection bus bar 30 has the protrusion 33, the protrusion 33 serves as a mark in the mounting direction, and the current detection bus bar 30 is mistaken. The mistake of connecting to the front and rear bus bars 9 in the direction is unlikely to occur. Moreover, the protrusion 33 of the first terminal portion 32A also plays a role of restricting the rotation of the current detection bus bar 30 by being hooked on the front or rear bus bar 9 or the pedestal 7 supporting the bus bar 9 or the like. Therefore, when the terminal portion 32 of the current detection bus bar 30 is screwed to the terminal portion of the front-stage or rear-stage bus bar 9, the current detection bus bar 30 is prevented from rotating due to the rotation of the screw. The workability of screwing increases.

  Further, if the current detection bus bar 30 is assembled in the wrong direction in the insulating casing 40 in the assembly stage of the current detection device 1, an error in the polarity of the detection signal eventually occurs. However, in the current detection device 1, only one lid member 42 of the two element casings constituting the insulating casing 40 has the first terminal portion 32 </ b> A provided with the protrusion 33 in the current detection bus bar 30. It has the 1st bus-bar hole 45A which can let it pass. Therefore, in the assembly stage of the current detection device 1, there is no mistake that the current detection bus bar 30 is assembled to the insulating housing 40 in the wrong direction.

  The current detection bus bar 30 is a member having a structure in which the end of the metal member 30X penetrating the hollow portion 11 of the magnetic core 10 is crushed into a flat shape having a width wider than that of other portions. Therefore, after inserting the metal member 30X whose cross-sectional shape is not flat into the hollow portion 11 of the magnetic core 10, the flat terminal portion 32 having a width wider than the diameter D1 (width) of the hollow portion 11 can be formed. Therefore, the current detection bus bar 30 in which the width D3 and the thickness D4 of the penetrating part 31 are larger than the distance between both ends of the magnetic core 10 (the height D2 of the gap part) can be easily manufactured. In addition, as the metal member 30X whose cross-sectional shape is not flat, a rod-shaped metal member or a cylindrical metal member can be considered.

  In order to increase the current detection sensitivity, it is desirable to reduce the gap height D2 and to reduce the gap between the Hall element 20 disposed in the gap portion 12 and both ends of the magnetic core 10.

<Others>
In the current detection device 1, the two terminal portions 32 in the current detection bus bar 30 may be formed in a flat shape along non-parallel surfaces. For example, it is conceivable that one of the two terminal portions 32 is formed along the XY plane and the other is formed along the XZ plane.

  The magnetic core 10 may be formed in a shape other than an annular shape, for example, a polygonal annular shape such as a rectangular annular shape.

DESCRIPTION OF SYMBOLS 1 Current detection apparatus 6 Storage box 7 Base 8 Screw 9 Other bus bar 9A Hole 10 Magnetic body core 11 Hollow part of magnetic body core 12 Gap part of magnetic body core 20 Hall element 21 Terminal 30 Current detection bus bar 30X Metal member 31 Through Part 32 Terminal part 32A First terminal part 32B Second terminal part 32Z Through hole 33 Projection 40 Insulating housing 41 Main body case 42 Cover member 43 First holding part 44 Second holding part 45 Bus bar hole 45A First bus bar hole 45B Second bus bar hole 46 Notch 47 Claw (lock mechanism)
48 Frame (locking mechanism)
50 Electronic Board 51 Connector 60 Press Machine 61 Protrusion 62 Recess 451 Protrusion Passing Hole

Claims (3)

A current detection device for detecting a current flowing in a bus bar,
A magnetic core made of a magnetic material, both ends of which are opposed to each other through a gap portion, and surrounds the periphery of the hollow portion;
A magnetoelectric conversion element that is disposed in the gap portion of the magnetic core and detects a magnetic flux that changes according to a current passing through the hollow portion of the magnetic core;
A penetrating portion penetrating through the hollow portion of the magnetic core, and two terminal portions connected to a connecting end at a preceding stage or a succeeding stage of a current transmission path connected to both sides in a direction penetrating the hollow portion with respect to the penetrating portion; The through portion is formed with a thickness larger than the thickness of each of the two terminal portions, and the width of each of the two terminal portions is larger than the width of the hollow portion. A current detection bus bar having a protrusion formed on one of the terminal portions;
An insulating housing that supports the magnetic core, the magnetoelectric conversion element, and the through portion of the current detection bus bar in a fixed positional relationship with the two terminal portions exposed to the outside. ,
The insulating casing includes a first element casing and a second element casing that are combined from both sides of the magnetic core, and the first element casing includes the two of the terminal portions. A first through-hole through which a first terminal portion having a protrusion can pass is formed, and the second element housing has a second terminal portion that does not have the protrusion of the two terminal portions. Is formed, a second through hole is formed through which the first terminal portion cannot pass.   2. The current detection bus bar according to claim 1, wherein the first terminal portion is configured by a flat plate-like base portion and the protrusions erected from a part of the base portion, and the second terminal portion is flat plate shape. The current detection device described.   The current detection bus bar is formed such that the width and thickness of the cross section are larger than the distance between both ends of the magnetic core, and both end portions of the metal member that can pass through the hollow portion of the magnetic core are formed by pressing. 3. The current detection device according to claim 1, wherein the current detection device is a member having a structure that is crushed into a flat shape having a wider width, and the crushed end portions constitute the two terminal portions.

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