JP2013015365A - Current detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a current detector that employs a magnetic core in which an interval between both ends is small as much as possible, can fix a magnetoelectric transducer in gap parts of the magnetic core, and can easily mount the magnetoelectric transducer on an electronic substrate.SOLUTION: A current detector 1 comprises an insulation housing 40 for supporting a magnetic core 10 and an electronic substrate 50 mounted with surface mounting type of hall elements 20 in a fixed positional relation while covering the magnetic core 10 and the electronic substrate 50. The electronic substrate 50 is formed with a notch 502 into which element bodies 21 of the hall elements 20 are inserted, and contact pins 22 of the hall elements 20 are fixed to the electronic substrate 50 at both sides of the notch 502. The insulation housing 40 supports the magnetic core 10 and the electronic substrate 50 in a state where the hall elements 20 are placed in gap parts 12 of the magnetic core 10.

Description

  The present invention relates to a current detection device that detects a current flowing in a power transmission path such as 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.

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

  As shown in Patent Document 1, in a current detection device, a magnetic core 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. Note that the casing is generally made of an insulating resin member.

  In the conventional current detection device, a support portion for positioning the magnetic core and the magnetoelectric conversion element is formed in the casing. For example, in the current detection device disclosed in Patent Document 1, the support portion of the magnetic core is a hollow portion of the casing that has a shape along each of the outer peripheral surface and the inner peripheral surface of the magnetic core.

  In the current detection device disclosed in Patent Document 1, the element mounting portion that surrounds the periphery of the magnetoelectric conversion element in the gap portion of the magnetic core is the support portion of the magnetoelectric conversion element. Usually, the magnetoelectric conversion element is mounted on an electronic substrate together with a signal amplifier circuit and the like. The element mounting portion also serves as a rotation stopping portion that limits the rotation of the magnetic core.

JP 2009-128116 A

  By the way, it is desirable that the distance between both ends of the magnetic core in the current detection device is as small as possible in order to increase the current detection sensitivity. In particular, as the magnetic core is smaller, the distance between the ends of the magnetic core greatly affects the current detection sensitivity.

  However, as shown in Patent Document 1, when a part of the casing surrounds and supports the magnetoelectric conversion element, both ends of the magnetic core have a gap between the magnetoelectric conversion element and the support portion surrounding the magnetoelectric conversion element. It must be formed with a relatively large interval so that it can be inserted into the part.

  That is, in the conventional current detection device, since the support portion of the magnetoelectric conversion element needs to be disposed in the gap portion of the magnetic core, it is possible to increase the current detection sensitivity by reducing the distance between both ends of the magnetic core. It has the problem of being difficult.

  Further, in the current detection device disclosed in Patent Document 1, after the main body portion of the magnetoelectric conversion element is fixed to the element mounting portion of the housing, the lead wire extending from the main body portion of the magnetoelectric conversion element is attached to the electronic substrate. Need to be connected. Thus, the operation of mounting the magnetoelectric conversion element integrated with the housing on the electronic substrate is more complicated than the operation of mounting the single unit of the magnetoelectric conversion element on the electronic substrate.

  According to the present invention, in the current detection device, the magnetic core can be fixed in the gap portion of the magnetic core while adopting the magnetic core having the smallest distance between both ends, and the magnetoelectric transducer can be easily mounted on the electronic substrate. The purpose is to be able to.

The current detection device according to the present invention 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) The second component is a surface mount type magnetoelectric transducer that is disposed in the gap portion of the magnetic core and detects a magnetic flux that changes according to the current passing through the hollow portion of the magnetic core.
(3) The third component is formed with a cut portion into which the main body portion of the magnetoelectric conversion element is inserted, and the connection pins protruding from the main body portion of the magnetoelectric conversion element are fixed to both sides of the cut portion. It is an electronic board.
(4) The fourth component is a support member that supports the magnetic core and the electronic substrate in a state in which the magnetoelectric conversion element is positioned in the gap portion of the magnetic core.

  Further, it is conceivable that the current detection device according to the present invention further has the following configuration. That is, it is conceivable that the main body portions of the two magnetoelectric conversion elements are positioned so as to overlap each other in the thickness direction of the electronic substrate within the cut portion of the electronic substrate. In this case, the connection pin of one magnetoelectric conversion element is fixed to both sides of the cut portion on one surface of the electronic substrate, and the connection pin of the other magnetoelectric conversion element is fixed to both sides of the cut portion on the other surface of the electronic substrate. ing.

  In the present invention, the support member positions the magnetoelectric conversion element in the gap portion of the magnetic core by supporting the electronic substrate on which the surface mount type magnetoelectric conversion element is mounted. Therefore, it is not necessary to dispose the support portion for the magnetoelectric conversion element in the gap portion of the magnetic core. Further, a notch is formed in a region between the portions of the electronic substrate where the connection pins on both sides of the magnetoelectric conversion element are fixed, and the main body of the magnetoelectric conversion element is located in the notch. That is, the magnetoelectric conversion element is mounted on the electronic substrate in an inverted state.

  Therefore, by adopting an electronic substrate having a thickness less than or equal to the thickness of the magnetoelectric conversion element, it is possible to employ a magnetic core whose distance between both ends is about the same as the thickness of the magnetoelectric conversion element. That is, it is possible to increase the current detection sensitivity by using a magnetic core having a small distance between both ends. Further, if the cut portion is formed in the electronic substrate, the electronic substrate can be prevented from disturbing the magnetic flux passing through the gap portion of the magnetic core.

  In addition, according to the present invention, it is possible to mount the magnetoelectric conversion element alone on the electronic substrate before the magnetoelectric conversion element is fixed to the gap portion of the magnetic core. Therefore, unlike the case where the magnetoelectric conversion element integrated with the support member is mounted on the electronic substrate, the magnetoelectric conversion element can be easily mounted on the electronic substrate.

  By the way, a current detection device mounted on a vehicle such as an electric vehicle or a hybrid vehicle is required to have high reliability. In general, a magnetic core that is a lump of metal has high durability against environmental changes, but a magnetoelectric conversion element that is an electronic component may fail due to environmental changes such as temperature changes, water intrusion, and generation of static electricity. .

  Therefore, in order to increase the reliability of the on-vehicle current detection device, it is conceivable to arrange two magnetoelectric conversion elements in the gap portion of the magnetic core, that is, to make the magnetoelectric conversion elements double. As a result, when the difference between the detection signals of the two magnetoelectric transducers exceeds the allowable range, it is possible to warn that an abnormality has occurred in the current detection device and to avoid erroneous control based on the abnormal current detection value. it can.

  The current detection device according to the present invention can cope with the duplication of the magnetoelectric conversion element. In the present invention, when the magnetoelectric conversion element is doubled, the connection pin of one magnetoelectric conversion element is fixed to both sides of the cut portion on one surface of the electronic substrate, and the connection pin of the other magnetoelectric conversion element is the other of the electronic substrate What is necessary is just to adhere to the both sides of the notch part in the surface. In this case, it is possible to employ a magnetic core in which the distance between both ends is approximately the same as the total thickness of the two magnetoelectric conversion elements.

1 is an exploded side view of a current detection device 1 according to a first embodiment of the present invention. 1 is a side view of a current detection device 1. FIG. It is a perspective view of the magnetic body core with which the electric current detection apparatus 1 is provided. 4 is a plan view of a gap portion of a magnetic core in the current detection device 1. FIG. It is a front view inside the main body case of the insulation housing | casing with which the electric current detection apparatus 1 is provided. It is a top view of the magnetic body core with which the electric current detection apparatus 1 is provided, and the bus bar for electric current detection. It is sectional drawing seen from the electric current passage direction of the electric current detection apparatus 1. FIG. It is a side view of the magnetic body core and the electronic substrate which were positioned. It is a front view of the magnetic body core and the electronic substrate which were positioned. It is a top view of the part of the gap part of the magnetic body core in current detector 1A concerning a 2nd embodiment of the present invention. It is a top view of the part of the gap part of the magnetic body core in the electric current detection apparatus concerning the 1st reference example. It is a top view of the part of the gap part of the magnetic body core in the electric current detection apparatus concerning the 2nd reference example.

  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 Embodiment>
Hereinafter, the configuration of the current detection device 1 according to the first 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.

  As shown in FIG. 3, the outer edge surfaces of both end portions of the magnetic core 10 in the present embodiment are flat surfaces 13 along one plane. Further, the inner edge surface of the magnetic core 10 and the outer edge surface other than both end portions are circumferential surfaces along concentric arcs. That is, the shape of the magnetic core 10 is such that a small region of the outer edge portion at both ends is missing from the 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.

  In the present embodiment, the Hall element 20 is a surface mount type IC including an element main body 21 and a plurality of connection pins 22 projecting to both sides of the bottom surface of the element main body 21. That is, the Hall element 20 in this embodiment is not a lead wire type IC. The plurality of connection pins 22 include a power input pin and a detection signal output pin. The plurality of connection pins 22 are fixed to the wiring pattern of the electronic substrate 50 with solder.

  In the Hall element 20, a predetermined detection center point in the element body 21 is positioned at the center point of the gap 12 of the magnetic core 10, and the front and back surfaces of the element body 21 are formed in the gap 12. It arrange | positions so that it may orthogonally cross with respect to the direction of the magnetic flux made. In the ideal arrangement state, the detection center point of the Hall element 20 is located on a line connecting the centers of the projection planes at the opposite ends of the magnetic core 10.

<Electronic board>
The electronic substrate 50 is a printed circuit board on which the Hall element 20 is mounted at the connection pin 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 for electrically connecting the connection pins 22 of the Hall element 20 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 pin 22 of the Hall element 20, and the detection signal of the Hall element 20, and the amplified signal Is output to the terminal of the connector 51. 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.

  In addition, a pair of chipped portions 501 into which a part of the insulating housing 40 is inserted is formed at the left and right side edge portions of the electronic substrate 50. The electronic substrate 50 is supported by a part of the insulating housing 40 inserted into the pair of chipped portions 501 and is held at a predetermined position inside the insulating housing 40.

  In addition, as shown in FIGS. 1, 4, 7, 8, and 9, the portion of the electronic substrate 50 to which the connection pins 22 that protrude from the element main body 21 of the Hall element 20 on both sides are fixed. A notch 502 is formed between them. The element main body 21 of the Hall element 20 is inserted into the notch 502 of the electronic substrate 50, and the connection pins 22 protruding from the element main body 21 to both sides are fixed to the both sides of the notch in the electronic substrate 50. Has been.

  That is, the Hall element 20 is mounted on the electronic substrate 50 across the cut portion 502 in an inverted state. Therefore, as shown in FIG. 4, the element main body 21 of the Hall element 20 is held in a state of hardly protruding from the front and back surfaces of the electronic substrate 50. Furthermore, both the front and back surfaces of the element body 21 of the Hall element 20 are exposed without being blocked by the electronic substrate 50.

<Bus bar for current detection>
The current detection bus bar 30 is a conductive member 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 other bus bars (battery-side bus bar and device-side bus bar) laid at both ends thereof in advance.

  As shown in FIGS. 1 and 6, the current detection bus bar 30 is made of a member in which both ends of a rod-like conductor that penetrates the hollow portion 11 of the magnetic core 10 are pressed. In the current detection bus bar 30, both end portions formed into a flat plate shape by pressing 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 is a member made of a conductor having a rod-like through portion 31 that occupies a certain range in the central portion and flat 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.

  In the current detection bus bar 30, the terminal portion 32 has a flat plate shape, and the penetrating portion 31 is formed in a rod shape such as a columnar shape or an 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 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 machine or the like. In the present embodiment, the metal member that is the source of the current detection bus bar 30 has a cylindrical shape, and therefore the through portion 31 of the current detection bus bar 30 has a cylindrical shape.

  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. Further, the through portion 31 is formed to have a thickness larger than that of the flat terminal portion 32.

  The current detection bus bar 30 is integrally combined with the magnetic core 10 and the electronic substrate 50 in a state where the current detection bus bar 30 penetrates the hollow portion 11 of the magnetic core 10, and then the front and rear stages of the terminal portion 32. Connected to other bus bars. 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.

<Insulated housing>
The insulating casing 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 and the connector 51 are mounted in a fixed positional relationship. The insulating housing 40 includes two members: a main body case 41 and a lid member 42 attached to the main body case 41. 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. Further, the main body case 41 and the lid member 42 are formed with bus bar holes 45 that are through holes into which both terminal portions 32 of the current detecting bus bar 30 are inserted from the inside to the outside.

  In addition, the lid member 42 has the magnetic body core 10, the hall element 20, and the electronic substrate 50 including the connector 51 with respect to the main body case 41 that holds the magnetic body core 10, the hall element 20, and the current detection bus bar 30. It is attached so as to close the opening of the main body case 41 while sandwiching. 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 bus bar 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.

  As shown in FIG. 2, 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 Hall element 20, and the electronic substrate 50 are sandwiched and held in a fixed positional relationship.

  5 is a front view of the inside of the main body case 41, and FIG. 7 is a cross-sectional view taken along the line CC in the side view shown in FIG.

  As shown in FIGS. 5 and 7, at the edge of the bus bar hole 45 on the inner surface of the main body case 41, a core support portion 43 that supports the magnetic core 10 extends along the current passage direction (X-axis direction). The protrusion is formed. The core support portion 43 is divided into two semi-cylindrical portions with a slit-like gap therebetween so that the flat terminal portion 32 of the current detection bus bar 30 can pass therethrough.

  An inner side surface, which is a surface facing the through portion 31 of the current detecting bus bar 30 in the core support portion 43, is formed in a shape along the outer peripheral surface of the through portion 31 of the current detecting bus bar 30. Further, the outer side surface that is the surface facing the magnetic core 10 in the core support portion 43 is formed in a shape along the inner peripheral surface of the magnetic core 10 that forms the hollow portion 11.

  The core support portion 43 is inserted into a gap between the inner edge of the magnetic core 10 and the through-hole 31 of the current detection bus bar 30 in the hollow portion 11 of the magnetic core 10, and the circumference of the inner edge of the magnetic core 10 is The magnetic core 10 is supported in contact with the surface. The position in the insulating housing 40 of the magnetic core 10 in the direction of the plane (YZ plane) orthogonal to the current passage direction (X-axis direction) is held by the core support portion 43.

  Furthermore, the core support part 43 supports the current detection bus bar 30 by being sandwiched between the inner edge of the magnetic core 10 and the through part 31 of the current detection bus bar 30. The position of the current detecting bus bar 30 in the direction of the plane (YZ plane) orthogonal to the current passing direction (X-axis direction) is held by the core support portion 43.

  Further, the magnetic core 10 and the through-hole 31 of the current detection bus bar 30 are held between the main body case 41 and the lid member 42, so that the position in the current passing direction (X-axis direction) is maintained.

  In the present embodiment, the surface of the inner edge of the magnetic core 10 is a circumferential surface along an arc, so that the magnetic core 10 can rotate when it is only supported at the inner edge by the core support portion 43.

  Therefore, as shown in FIGS. 5 and 7, a rotation stopper 44 that restricts the rotation of the magnetic core 10 is formed upright on the inner surface of the main body case 41. The anti-rotation portion 44 is formed in two parts corresponding to each of both end portions of the magnetic core 10, and they are in contact with the flat surface 13 of each end portion of the magnetic core 10. Limit the rotation of

  In order to hold the magnetic core 10 supported by the core support 43 in the correct orientation without error, the rotation stopper 44 needs to contact the flat surface 13 at two positions with a relatively long interval. That is, the length Lf of the formation region of the flat surface 13 needs to be relatively long. This is because, when the length Lf of the formation region of the flat surface 13 is short, variation in the orientation of the magnetic core 10 increases due to a slight dimensional tolerance of the rotation stopper 44.

  The magnetic core 10 desirably has a uniform cross-sectional area as much as possible in order to obtain good characteristics without waste. In particular, as the magnetic core 10 is smaller, the uniformity of the cross-sectional area of the magnetic core 10 greatly affects the characteristics of the magnetic core 10.

  In the present embodiment, the flat surfaces 13 are formed at both end portions of the outer edge of the magnetic core 10 and are separated into two portions via the gap portion 12. In this case, the gap portion 12 of the magnetic core 10 is not particularly different from the gap portion of the annular magnetic core. Therefore, even when the length Lf of the formation region of the two flat surfaces 13 is sufficiently secured, the shape of the magnetic core 10 is a relatively small shape with respect to the annular shape. Therefore, the ratio of the non-uniform cross-sectional area in the magnetic core 10 is small, and adverse effects on the characteristics of the magnetic core 10 due to the formation of the flat surface 13 can be suppressed.

  In addition, a pair of substrate support portions 49 protrude from the inner surface of the main body case 41 and the inner surface of the lid member 42. The pair of substrate support portions 49 are fitted into a pair of chipped portions 501 formed on the electronic substrate 50, and support the electronic substrate 50 at a predetermined position. The positions of the electronic substrate 50 and the Hall element 20 mounted thereon in the direction of the plane (XZ plane) orthogonal to the width direction (Y-axis direction) are held by a pair of substrate support portions 49.

  The magnetic core 10, the electronic substrate 50, and the Hall element 20 shown in FIGS. 7 to 9 are positioned by the core support portion 43 and the substrate support portion 49 of the insulating housing 40. Note that the magnetic core 10, the electronic substrate 50, and the Hall element 20 shown in FIG. 1 are in a state before being positioned by the insulating housing 40.

  As shown in FIGS. 7 to 9, the substrate support portion 49 supports the electronic substrate 50 in a state where the Hall element 20 is positioned in the gap portion 12 of the magnetic core 10.

  In addition, the electronic substrate 50 is held between a part of the main body case 41 and a part of the lid member 42 at the connector 51 portion, so that the position in the current passing direction (X-axis direction) is maintained. Thereby, the position of the Hall element 20 mounted on the electronic substrate 50 in the current passing direction (X-axis direction) is also held at a fixed position.

  The insulating housing 40 in which the pair of substrate support portions 49 are formed is a support member that supports the magnetic core 10 and the electronic substrate 50 in a state where the Hall element 20 is positioned in the gap portion 12 of the magnetic core 10. It is an example.

  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.

<Effect>
In the current detection device 1, the insulating housing 40 supports the electronic substrate 50 on which the surface-mount type Hall element 20 is mounted, so that the element body 21 of the Hall element 20 is placed in the gap 12 of the magnetic core 10. Position. Therefore, it is not necessary to arrange the support portion for the Hall element 20 in the gap portion 12 of the magnetic core 10. Further, a notch 502 is formed in a region between the portions of the electronic substrate 50 where the connection pins 22 on both sides of the Hall element 20 are fixed, and the element body 21 of the Hall element 20 is located in the notch 502. ing. That is, the Hall element 20 is mounted on the electronic substrate 50 in an inverted state.

  Therefore, as shown in FIG. 4, by adopting an electronic substrate 50 having a thickness less than or equal to the thickness of the Hall element 20, a magnetic core having a distance Lg between both ends equal to the thickness of the Hall element 20. 10 can be adopted.

  FIG. 11 is a plan view of the gap 12 portion of the magnetic core 10X in the current detection device according to the first reference example. The first reference example is an example in which the surface-mount type Hall element 20 is mounted on the electronic substrate 50 in a normal direction that is not in an inverted state in a state of straddling the cut portion 502 in the electronic substrate 50. .

  In the first reference example shown in FIG. 11, it is necessary to employ the magnetic core 10 </ b> X in which the distance Lgx between both ends is equal to or greater than the sum of the thickness of the Hall element 20 and the thickness of the electronic substrate 50. That is, the distance Lg between both ends of the magnetic core 10 in the current detection device 1 is smaller by the thickness of the electronic substrate 50 than the distance Lgx between both ends of the magnetic core 10X in the first reference example.

  Therefore, in the current detection device 1, the magnetic core 10 having a small distance Lg between both ends can be employed to increase the current detection sensitivity. In addition, since the cut portion 502 is formed in the electronic substrate 50, it is possible to prevent the electronic substrate 50 from disturbing the magnetic flux passing through the gap portion 12 of the magnetic core 10.

  In addition, in the manufacturing process of the current detection device 1, the Hall element 20 alone can be mounted on the electronic substrate 50 before the Hall element 20 is fixed to the gap portion 12 of the magnetic core 10. Therefore, unlike the case where the Hall element 20 integrated with the main body case 41 is mounted on the electronic substrate 50, the Hall element 20 can be easily mounted on the electronic substrate 50.

Second Embodiment
Next, a current detection device 1A according to a second embodiment of the present invention will be described with reference to FIG. 1 A of electric current detection apparatuses have the structure to which the Hall element 20 was added compared with the electric current detection apparatus 1 shown by FIG. 10, the same components as those shown in FIGS. 1 to 9 are given the same reference numerals. Hereinafter, only the difference of the current detection device 1A from the current detection device 1 will be described.

  Two Hall elements 20 are mounted on an electronic substrate 50A provided in the current detection device 1A. As shown in FIG. 10, the element main bodies 21 of the two Hall elements 20 are positioned so as to overlap with each other in the thickness direction (Y-axis direction) of the electronic substrate 50 in the cut portion 502 of the electronic substrate 50A. The connection pin 22 of one Hall element 20 is fixed to both sides of the cut portion 502 on one surface of the electronic substrate 50A, and the connection pin 22 of the other Hall element 20 is cut on the other surface of the electronic substrate 50A. It is fixed to both sides of the part 502.

  In the current detection device 1 </ b> A, it is possible to employ the magnetic core 10 in which the distance Lg between both ends is approximately the same as the total thickness of the two Hall elements 20.

  FIG. 12 is a plan view of the gap 12 portion of the magnetic core 10X in the current detection device according to the second reference example. In the second reference example, two surface-mount type Hall elements 20 are mounted on the electronic substrate 50 in a normal orientation that is not reversed, with the notch 502 straddling the front and back surfaces of the electronic substrate 50. This is an example of the case.

  In the second reference example shown in FIG. 12, it is necessary to employ the magnetic core 10 </ b> X in which the distance Lgx between both ends is equal to or greater than the sum of the thicknesses of the two Hall elements 20 and the electronic substrate 50. That is, the distance Lg between both ends of the magnetic core 10 in the current detection device 1A is smaller than the distance Lg between both ends of the magnetic core 10X in the second reference example by about the thickness of the electronic substrate 50.

  Therefore, by adopting the current detection device 1A, it is possible to cope with the duplication of the Hall element 20, and the same effect as the current detection device 1 can be obtained.

<Others>
In the current detection device 1, three or more protrusions that are plastically deformed by pressure sandwiched between the magnetic core 10 and the through-hole 31 of the current detection bus bar 30 are formed on the inner or outer surface of the core support 43. It is desirable that Each of these protrusions is formed, for example, extending along the current passing direction (X-axis direction), that is, along the direction in which the current detection bus bar 30 penetrates the bus bar hole 45.

  When the core support portion 43 formed with such a protrusion is inserted between the magnetic core 10 and the current detection bus bar 30 in the hollow portion 11 of the magnetic core 10, the protrusion is crushed and the core support The portion 43 is in close contact with the inner peripheral surface of the magnetic core 10 and the surface of the through portion 31 of the current detection bus bar 30. Therefore, backlash does not occur between the core support portion 43, the magnetic core 10, and the current detection bus bar 30, and wear of the core support portion 43 due to vibration hardly occurs.

  In addition, since the resin-made protrusions exist on the inner side surface of the core support portion 43, the dimensional tolerances of the current detection bus bar 30, the core support portion 43, and the magnetic core 10 are different from the degree of plastic deformation of the protrusion portions. Is absorbed by. Therefore, it is possible to avoid a situation in which the core support portion 43 cannot be inserted into the gap between the magnetic core 10 and the current detection bus bar 30 due to dimensional tolerance.

DESCRIPTION OF SYMBOLS 1,1A Current detection apparatus 10 Magnetic body core 11 Hollow part of magnetic body core 12 Gap part of magnetic body core 13 Flat surface of magnetic body core 20 Hall element 21 Element main body part 22 Connection pin 30 Current detection bus bar 31 Through part 32 Terminal part 32z Through hole 40 Insulating housing 41 Main body case 42 Cover member 43 Core support part 44 Anti-rotation part 45 Bus bar hole 46 Connection part 47 Claw part (lock mechanism)
48 Frame (locking mechanism)
49 Substrate support part 50, 50A Electronic board 51 Connector 501 Notch part of electronic board 502 Notch part of electronic board

Claims (2)

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 surface mount type magnetoelectric transducer 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 notch portion into which the main body portion of the magnetoelectric conversion element is inserted is formed, and an electronic substrate to which connection pins extending from the main body portion of the magnetoelectric conversion element on both sides of the notch portion are fixed, and
A current detection device comprising: a support member that supports the magnetic core and the electronic substrate in a state where the magnetoelectric conversion element is positioned in the gap portion of the magnetic core.   The main body of each of the two magnetoelectric transducers is positioned so as to overlap in the thickness direction of the electronic substrate within the cut portion of the electronic substrate, and the connection pin of one of the magnetoelectric transducers is one of the electronic substrates 2. The current detection device according to claim 1, wherein the current detection device is fixed to both sides of the cut portion in a surface, and the connection pin of the other magnetoelectric conversion element is fixed to both sides of the cut portion in the other surface of the electronic substrate. .

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