JP2019039732A - Current detection sensor and current measuring device - Google Patents

Abstract

To improve mountability in an electric circuit to be measured and a reduction in weight.SOLUTION: Provided is a current detection sensor 2 comprising one annular magnetic core and a magnetic sensor 13 disposed in a gap part GP formed in the annular magnetic core and detecting a magnetic flux induced in the annular magnetic core and outputting a detection signal S1. The annular magnetic core is formed by bending a long magnetic sheet medium 21 having flexibility to a ring shape where a surface 21c at longitudinal one end EN1 and a surface 21d at other end EN2 face each other at equal interval, and the gap part GP is composed of an area sandwiched between the surface 21c at the one end EN1 and the surface 21d at the other end EN2 facing each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a current detection sensor that is mounted in a state of surrounding a measurement target electric circuit and detects a current flowing through the measurement target electric circuit, and a current measurement device including the current detection sensor.

  As an example of this type of current detection sensor, the present applicant has already proposed a current detection sensor device disclosed in Patent Document 1 below. This current detection sensor includes one annular magnetic core and a magnetoelectric conversion element (flux gate element or Hall element) disposed in a gap formed in the annular magnetic core, and the current detection sensor is inserted into the annular magnetic core. The magnetoelectric transducer can output a detection signal having a voltage value proportional to the current value of the current to be measured flowing through the measurement signal line.

JP 2012-83241 A (page 6, FIG. 1)

  By the way, although there is no specific description in the above Patent Document 1, the annular magnetic core is generally formed by molding a powder of a magnetic material such as ferrite into a predetermined shape and firing it. In addition, since the annular magnetic core formed in this way is hard and may be chipped or cracked when an impact is applied, the direction of the magnetic flux generated inside (magnetic path) The thickness of the cross-section along the plane orthogonal to the direction of () is increased to a thickness that does not easily cause chipping or cracking.

  However, the current detection sensor provided with the annular magnetic core should be improved such that it is difficult to attach the current detection sensor to the measurement target electric path due to the thick annular magnetic core, or it becomes heavy. There are challenges.

  The present invention has been made to improve such a problem, and provides a current detection sensor that can be mounted on a measurement target circuit and can be reduced in weight, and a current measurement device including the current detection sensor. The main purpose.

  In order to achieve the above object, the current detection sensor according to claim 1 is disposed in one annular magnetic core and a gap formed in the annular magnetic core and generates a magnetic flux induced in the annular magnetic core. A current detection sensor including a magnetoelectric conversion element that detects and outputs a detection signal, wherein the annular magnetic core includes a flexible long magnetic sheet body, one end along the longitudinal direction, and the other. The surface excluding the end surface and the side surface at the one end portion of the end portion and the surface excluding the end surface and the side surface at the other end portion are formed to be curved in an annular shape facing each other at equal intervals, and the gap portion is opposed to each other It is comprised by the area | region pinched | interposed by the said surface in one end part, and the said surface in the said other end part.

  The current detection sensor according to claim 2 is disposed in one annular magnetic core and a gap formed in the annular magnetic core, and detects a magnetic flux induced in the annular magnetic core and outputs a detection signal. A current detection sensor including a magnetoelectric conversion element for outputting, wherein the annular magnetic core includes a plurality of flexible magnetic sheets arranged in parallel along the longitudinal direction, and the plurality of magnetic A surface excluding an end face and a side surface at one end portion in the longitudinal direction of one magnetic sheet body in any two adjacent magnetic sheet bodies of the sheet bodies, and the other magnetic sheet body in the two magnetic sheet bodies Are formed in an annular shape as a whole by facing the end surface and the surface excluding the side surface at the other end along the longitudinal direction at equal intervals, and the gap portions are opposed to each other. It is composed of a region sandwiched between the surface of the other end and the surface at the ends.

  The current detection sensor according to claim 3 is the current detection sensor according to claim 1 or 2, wherein the magnetoelectric conversion element includes the surface at the one end and the surface at the other end constituting the gap. It is fixed to one side.

  The current detection sensor according to claim 4, wherein the one end portion and the other end portion in the longitudinal direction of the long magnetic sheet body having flexibility and the annularly curved magnetic sheet body are provided at the one end portion. And one end of the other end is detachable, and the surface excluding the end face and the side face at the one end and the surface excluding the end face and the side face at the other end face each other at equal intervals. A holding portion that can be held in the holding portion, and a gap formed by a region sandwiched between the surface of the one end portion and the surface of the other end portion in the holding state in the holding portion, And a magnetoelectric conversion element that detects a magnetic flux induced in the magnetic sheet and outputs a detection signal.

  The current measuring device according to claim 5 is provided with the current detection sensor according to any one of claims 1 to 4 attached to a measurement target electric circuit, and the magnetic flux in the magnetic sheet body when a current flows through the measurement target electric circuit. And a processing unit that measures a current value of the current based on the detection signal when the current is induced.

  According to the current detection sensor according to claim 1, 2 and 4, and the current measurement device according to claim 5 provided with the current detection sensor, the magnetic sheet body (flat magnetic body) is used. Compared to a configuration using a general magnetic core formed by molding and firing a powder of magnetic material such as ferrite into a predetermined shape as a magnetic body corresponding to the body, the volume of the magnetic body is greatly increased Since it can be reduced, significant weight reduction can be achieved. In addition, according to the current detection sensor and the current measuring device, because the configuration uses a flat magnetic sheet body, it can be inserted into a narrow gap that cannot be inserted in the configuration using the general magnetic core described above. Further, it is possible to improve the mounting property to the measurement target electric circuit. In addition, according to the current detection sensor and the current measurement device, the magnetoelectric conversion element is not disposed between the end surface of the one end portion and the end surface of the other end portion along the longitudinal direction of the magnetic sheet body. The magnetic sheet body is bent in an annular shape so that the other end and the other end face each other, and the region sandwiched between the surface at the one end and the surface at the other end facing each other is used as a gap. With the configuration in which the magnetoelectric conversion element is disposed in the part, the width of the magnetic sheet body is defined to be longer than the width of the magnetoelectric conversion element, and the lengths of the one end part and the other end part (the lengths of the opposing parts) Is defined to be longer than the length of the magnetoelectric conversion element so that a high-density magnetic flux leaking into the gap is allowed to pass through the magnetoelectric conversion element in a uniform state while using a magnetic sheet body that is a flat magnetic body. What to do It is possible to ensure the partial detection sensitivity.

  According to the current measuring device according to claim 3 and the current measuring device according to claim 5 provided with the current detection sensor, of the surface at one end and the surface at the other end of the magnetic sheet constituting the gap portion. Since the magnetoelectric conversion element is fixed to one side, it is possible to fix the magnetoelectric conversion element only by fixing this one of the magnetic sheet bodies. Therefore, the fixing work of the magnetoelectric conversion element alone can be omitted.

  According to the current measuring device according to claim 4 and the current measuring device according to claim 5 provided with the current detection sensor, by making one end of the magnetic sheet body detachable, the current measuring device cannot be removed. You can also wear it.

1 is a partially cutaway external view of a current measuring device 1 including a current detection sensor 2. FIG. FIG. 2 is a cross-sectional view taken along line AA showing the internal structure of the magnetic core portion 11 in FIG. 1. It is a perspective view which shows the structure of the electric current detection sensor 2 in which an annular magnetic core is formed with one magnetic core part 11 (that is, one magnetic sheet body 21). FIG. 4 is an enlarged view of a gap GP of an annular magnetic core formed by a magnetic sheet body 21 and the vicinity thereof. FIG. 5 is a plan view of one end EN1 and the other end EN2 of the magnetic sheet body 21 in FIG. 4 as viewed from the arrow B side. It is explanatory drawing which shows the other structure of the electric current detection sensor 2 in which an annular magnetic core is formed with one magnetic core part 11 (namely, one magnetic sheet body 21). FIG. 6 is a perspective view showing a main part of another configuration of the magnetic sheet body 21. 6 is a perspective view showing another configuration of the magnetic sheet body 21. FIG. It is explanatory drawing which shows the structure of the electric current detection sensor 2 with which a cyclic | annular magnetic core is formed with the magnetic sheet body 21 by two (it is two in this example). It is explanatory drawing which shows the other structure of the electric current detection sensor 2 with which a cyclic | annular magnetic core is formed with the magnetic sheet body 21 by two (it is two in this example). FIG. 5 is a perspective view showing another configuration of the magnetic core unit 11. It is CC sectional view taken on the line which shows the internal structure of the other magnetic core part 11 in FIG.

  Hereinafter, embodiments of a current detection sensor and a current measurement device will be described with reference to the accompanying drawings.

  First, the configuration of the current measuring device 1 as a current measuring device will be described with reference to the drawings.

  As shown in FIG. 1, the current measuring device 1 includes a current detection sensor 2 and a measuring device main body 3. A current value I1 of a measurement current I (at least one of a direct current and an alternating current) that flows in the measurement target circuit 51 is mounted by bending the current detection sensor 2 in a ring shape and surrounding the measurement target circuit 51. It is configured to be measurable.

  As shown in FIG. 1, the current detection sensor 2 includes, for example, a magnetic core unit 11, a holding unit 12, a magnetic sensor (magnetoelectric conversion element) 13, a signal cable 14, and a connector 15.

  As an example, the magnetic core portion 11 includes a magnetic sheet body 21 and an insulating coating 22 as shown in FIGS. The magnetic sheet body 21 is a flat and long outer shape magnetic body having a uniform thickness, for example, a flat planar magnetic sheet having a rectangular shape in plan view, or a flat magnetic sheet, respectively. It is made of a laminate of a plurality of magnetic sheets that are flexible and have the same plan view shape (for example, a rectangular shape) and are flattened and laminated together. In this case, the laminate is configured as a long and flat magnetic body having flexibility as a whole and having a rectangular shape in plan view. Further, as an example, this magnetic sheet is produced by molding soft magnetic powder into a sheet having a uniform thickness using a binding material such as a resin material.

  The insulating coating 22 is made of a nonmagnetic resin material having insulating properties and flexibility, and as shown in the cross-sectional view of the magnetic core portion 11 shown in FIG. 2, the entire outer surface (a pair of side surfaces) of the magnetic sheet body 21. 21a, 21b, a pair of surfaces 21c, 21d, and a pair of end surfaces 21e, 21f (see FIGS. 3 and 4)). The insulating coating 22 is formed in one layer in this example, but may be formed in multiple layers such as two layers. Further, the insulating coating 22 may be formed with a uniform thickness over the entire outer surface of the magnetic sheet body 21, but a gap GP for disposing the magnetic sensor 13 is provided between each other as described later. The thickness on the pair of surfaces 21c and 21d of the magnetic sheet 21 to be formed is preferably at least uniform.

  Since the magnetic core 11 having the above-described configuration is formed in a long and flat rectangular shape as described above, the magnetic core 21 is long and flat even when the insulating coating 22 is applied. It is formed in a rectangular shape. As a result, the magnetic core portion 11 is significantly lighter compared to a configuration using a general magnetic core formed by molding and firing a powder of magnetic material such as ferrite into a predetermined shape. It is illustrated.

  The holding unit 12 is made of a rigid resin material (which may be a non-magnetic material or a magnetic material, but a magnetic material is preferable in order to reduce the influence of an unnecessary external magnetic field on the magnetic sensor 13 described later). As an example, as shown in FIG. 1, the inside is formed in a hollow box shape. Also, the holding unit 12 has two holding mechanisms (not shown) disposed therein, and one of the one end portion 11a and the other end portion 11b along the longitudinal direction of the magnetic core portion 11 inserted therein. The end portion (one end portion 11a as an example in this example) is held detachably by one of the two holding mechanisms, and the magnetic core portion 11 is bent (curved so as not to twist). ), As shown in FIG. 1, in the direction opposite to the insertion direction of the one end (the direction from right to left in FIG. 1) (in the direction from left to right in FIG. 1) The other end portion (the other end portion 11b as an example in this example) of the inserted one end portion 11a and the other end portion 11b is configured to be detachably held by the other holding mechanism of the two holding mechanisms. ing.

  The magnetic core portion 11 that is curved in this way and has the one end portion 11a and the other end portion 11b held by the holding portion 12 has the one end portion 11a and the other end portion 11b as shown by the solid line in FIG. By being arranged close to each other in the holding portion 12, the whole is formed in an annular shape. In this state, as shown in FIGS. 1 and 3, the magnetic sheet body 21 constituting the magnetic core portion 11 is also curved and has one end EN <b> 1 (the end located in the one end 11 a) along the longitudinal direction. ) And the other end portion EN2 (the end portion located in the other end portion 11b) are arranged close to each other, thereby forming an annular shape as a whole (that is, formed on the annular magnetic core). .

  In addition, as shown in FIG. 1, the holding portion 12 is in a state in which one end portion 11 a and the other end portion 11 b of the magnetic core portion 11 face each other at equal intervals (for example, as shown in FIG. The one end portion 11a and the other end portion 11b are configured to be held by each holding mechanism. With this configuration, the one end EN1 and the other end EN2 of the magnetic sheet body 21 are also opposed to each other at equal intervals as shown in FIGS. 1, 3 and 4 (for example, as shown in each drawing, So that they face each other in parallel). Specifically, in a state where the magnetic sheet body 21 is curved and formed in an annular shape as shown in FIGS. 1 and 3, as shown in FIGS. 1, 3, and 4, the one end EN1 and the other end EN2 are The surface excluding the end surface 21e and the side surfaces 21a and 21b in the end portion EN1 (in this example, the surface 21c of the surfaces 21c and 21d) and the surface excluding the end surface 21f and the side surfaces 21a and 21b in the other end portion EN2 (in this example) The surfaces 21d of the surfaces 21c and 21d are held in a state of being opposed to each other at equal intervals (in this example, in a parallel state).

  In addition, in the state where the measurement current I is flowing in the measurement target electric circuit 51 to which the current detection sensor 2 is mounted as shown in FIG. 1, a magnetic field is generated around the measurement target electric circuit 51. A magnetic flux is induced in the magnetic sheet body 21 at a density corresponding to the strength of the magnetic field. In this case, in the space between the one end portion EN1 and the other end portion EN2 of the magnetic sheet body 21 held in opposition to each other as described above, the magnetic sheet body is shown by a line with an arrow in FIG. Although the magnetic flux in 21 leaks in various directions, the region sandwiched between the surface 21c of one end EN1 and the surface 21d of the other end EN2 facing each other at equal intervals (region surrounded by a broken line in FIG. 4) Magnetic flux leaks at a higher density than other areas. That is, as shown in FIGS. 1 and 3, in the magnetic sheet body 21 formed in an annular shape and configured as an annular magnetic core, the region sandwiched between the surface 21c of the one end EN1 and the surface 21d of the other end EN2 is It functions as a gap (gap) GP in the annular magnetic core.

  For this reason, in the current detection sensor 2, the magnetic sensor 13 is disposed in the gap GP which forms the magnetic circuit for the magnetic flux together with the magnetic sheet body 21. In this case, as shown in FIG. 5, in order to prevent the magnetic sensor 13 from protruding from the gap GP in a state where the one end EN1 and the other end EN2 of the magnetic sheet body 21 facing each other are viewed in plan (magnetic) In order to allow the entire sensor 13 to be included in the gap GP, that is, to allow a high-density magnetic flux leaking into the gap GP to pass through the magnetic sensor 13 in a uniform state), the magnetic sheet 21 is The width L2 is defined to be longer than the width of the magnetic sensor 13, and the length (length of the facing portion) L3 of the one end EN1 and the other end EN2 facing each other is defined to be longer than the length of the magnetic sensor 13. ing.

  Further, the magnetic sensor 13 is driven by a drive circuit (not shown) disposed in the holding unit 12 together with the magnetic sensor 13 to detect the magnetic flux passing through the gap GP, and according to the magnetic flux density. A detection signal S1 (voltage signal) having a voltage value and polarity according to the direction of the magnetic flux is output. This detection signal S1 is amplified by, for example, an amplifier (not shown) provided in the holding unit 12, and is externally (measured with the current detection sensor 2 connected) from the connector 15 via the signal cable 14 as the detection signal S2. Is output to the apparatus body 3).

  Further, in this type of current detection sensor, if the position of the measurement target electric path 51 in the magnetic core portion 11 curved in an annular shape is too close to the gap GP (location where the magnetic sensor 13 is disposed), the magnetic sensor 13 In some cases, the detection signal S1 that accurately indicates the current value I1 of the measurement current I cannot be output due to the influence of the measurement target electric circuit 51. For this reason, in the current detection sensor 2 of this example, the gap GP (the magnetic sensor 13 disposed in the gap GP) from the outer surface of the holding portion 12 positioned inside the annularly curved magnetic core portion 11. The distance L1 is defined as a length that is not easily affected by the electric circuit 51 to be measured.

  The measuring apparatus main body 3 includes a case 31, a connector 32 that is disposed on the outer surface of the case 31 and is connected to the connector 15 of the current detection sensor 2, a processing unit 33 and an output unit 34 built in the case 31. In the measurement apparatus main body 3, the processing unit 33 inputs the detection signal S2 output from the current detection sensor 2 attached to the measurement target electric circuit 51 via the connector 32, and based on the voltage value of the detection signal S2. The current value I1 of the measurement current I flowing through the measurement target electric circuit 51 is calculated, the polarity of the measurement current I is specified based on the polarity of the detection signal S2, and the information indicating the current value I1 is indicated together with the information indicating the specified polarity. It outputs to the output part 34 as electric current information.

  For example, the output unit 34 includes a display device such as an LCD, and displays the current value I1 and its polarity on the screen based on the current information output from the processing unit 33. The output unit 34 may be configured by various interface circuits instead of the display device. For example, the output unit 34 may store the above current information in a removable medium as a media interface circuit, or may be externally connected via a network as a network interface circuit. It is also possible to adopt a configuration in which the current information is transmitted to the device.

  Next, the detection operation of the current detection sensor 2 will be described together with the measurement operation of the measurement current I of the measurement target electric circuit 51 by the current measurement device 1.

  In the current measuring device 1, prior to the measuring operation of the measuring current I, first, as shown by a broken line in FIG. 1, while curving the magnetic core portion 11 in a state where the other end portion 11b is not attached to the holding portion 12 It is arranged around the measurement target electrical circuit 51 so as to surround the measurement target electrical circuit 51 (bending), and then the other end portion 11b of the magnetic core unit 11 is inserted into the holding unit 12 as shown by a solid line in FIG. Is attached to the holding portion 12. Accordingly, the current detection sensor 2 is attached to the measurement target electric circuit 51 in a state where the magnetic core unit 11 surrounds the measurement target electric circuit 51. Moreover, the magnetic sheet body 21 which comprises the magnetic core part 11 is comprised as one cyclic | annular magnetic core, as shown to FIG.

  In this case, since the magnetic core portion 11 is formed in a flat rectangular shape, for example, even when the measurement target electric circuit 51 is disposed in close proximity to other electric circuits and there is only a narrow gap around it, it is narrow. The magnetic core portion 11 can be attached to the measurement target electric path 51 through the gap. Further, the other end portion 11b of the magnetic core portion 11 inserted into the holding portion 12 faces the one end portion 11a of the magnetic core portion 11 at equal intervals across the magnetic sensor 13, as shown in FIG. Be placed. Thereby, the area | region pinched | interposed by 21d in the surface 21c in the one end part 11a and the other end part 11b of the magnetic core part 11 is comprised as the space | gap part GP, and the state which the magnetic sensor 13 is located in this space | gap part GP Become.

  In this state, when the measurement current I flows through the measurement target circuit 51, a magnetic field having a strength corresponding to the current value I1 of the measurement current I is generated around the measurement target circuit 51, and the magnetic core unit 11 is configured accordingly. A magnetic flux is induced in the magnetic sheet body 21 with a density corresponding to the strength of the magnetic field. The magnetic sensor 13 disposed in the gap GP in the holding unit 12 detects the magnetic flux and outputs a detection signal S1 having a voltage value corresponding to the magnetic flux density and a polarity corresponding to the direction of the magnetic flux. . An amplifier (not shown) disposed in the holding unit 12 amplifies the detection signal S1 and outputs the detection signal S1 to the connector 15 via the signal cable 14.

  In the measurement apparatus main body 3, the processing unit 33 inputs the detection signal S2 output from the current detection sensor 2 via the connector 32, and the measurement current I flowing in the measurement target electric circuit 51 based on the voltage value of the detection signal S2. Current value I1 is calculated, the polarity of the measurement current I is specified based on the polarity of the detection signal S2, and information indicating the current value I1 is output to the output unit 34 as current information together with information indicating the specified polarity. . The output unit 34 displays the current value I1 and its polarity on the screen based on the current information output from the processing unit 33. Thereby, the measurement of the measurement current I is completed.

  As described above, in the current detection sensor 2, the magnetic sheet 21 constituting the magnetic core unit 11 is formed by using the end surface 21e and the side surfaces 21a and 21b at the one end EN1 of the one end EN1 and the other end EN2 along the longitudinal direction. The surface excluding the surface (the surface 21c of the surfaces 21c and 21d) and the surface excluding the end surface 21f and the side surfaces 21a and 21b (the surface 21d of the surfaces 21c and 21d) at the other end EN2 face each other at equal intervals. The gap GP in which the annular magnetic core is formed by being bent in an annular shape and the magnetic sensor 13 is disposed is configured by a region sandwiched between the surface 21c at one end EN1 and the surface 21d at the other end EN2 facing each other. Has been.

  Therefore, according to the current detection sensor 2 and the current measurement device 1 including the current detection sensor 2, the magnetic sheet body 21 (flat magnetic body) is used. Compared to a configuration using a general magnetic core formed by molding and firing a powder of magnetic material such as ferrite into a predetermined shape as a body, the volume of the magnetic body can be greatly reduced Therefore, significant weight reduction can be achieved. In addition, according to the current detection sensor 2 and the current measurement device 1, since the configuration uses the flat magnetic sheet body 21, even in a narrow gap that cannot be inserted in the configuration using the general magnetic core described above. Since it can insert, it can improve also about the mounting property to the measuring object electric circuit 51. FIG.

  In addition, according to the current detection sensor 2 and the current measurement device 1, the magnetic sensor 13 is disposed between the end surface 21e of the one end EN1 and the end surface 21f of the other end EN2 along the longitudinal direction of the magnetic sheet body 21. The magnetic sheet 21 is curved in an annular shape so that the one end EN1 and the other end EN2 are opposed to each other, and the surface 21c at the one end EN1 and the surface 21d at the other end EN2 that are actually opposed to each other are provided. By adopting a configuration in which the sandwiched region is the gap portion GP and the magnetic sensor 13 is disposed in the gap portion GP, the width L2 of the magnetic sheet body 21 is made larger than the width of the magnetic sensor 13 as shown in FIG. By defining the length of the one end EN1 and the other end EN2 (the length of the opposing portion) L3 longer than the length of the magnetic sensor 13, the flat magnetic body is defined. While using sex sheet 21 and directed to pass through the magnetic sensor 13 the magnetic flux of the high density leaking air gap GP in a uniform state, that it is possible to secure sufficient detection sensitivity.

  In the above example, as shown in FIG. 1, a configuration in which one end portion 11a and the other end portion 11b of the magnetic core portion 11 are inserted into the holding portion 12 from opposite directions is employed. In addition, as shown in FIG. 6, it is possible to adopt a configuration in which the holders 12 are inserted from the same direction. Also in this configuration, the one end portion 11a and the other end portion 11b are held in parallel with each other by the two holding mechanisms provided in the holding portion 12, so that the one end portion 11a and the other end portion 11b Since the one end EN1 and the other end EN2 of the magnetic sheet body 21 disposed in the same state are also in parallel with each other, they are sandwiched between the surface 21c at the one end EN1 and the surface 21c at the other end EN2 facing each other. This region can be the gap GP. Therefore, in the current detection sensor 2 having the configuration shown in FIG. 6 and the current measurement device 1 having the current detection sensor 2, the same effects as those of the current detection sensor 2 and the current measurement device 1 having the configuration shown in FIG. Can be played. The configurations other than the above-described configuration resulting from the different insertion directions of the one end EN1 and the other end EN2 into the holding unit 12 are the same as the current detection sensor 2 and the current measurement device 1 shown in FIG. Therefore, the description is omitted.

  The fixing structure of the magnetic sensor 13 in the holding part 12 is not directly fixed to either the one end part 11 a or the other end part 11 b of the magnetic core part 11, and is a fixing base disposed in the holding part 12. It is also possible to adopt a structure that is fixed to (not shown) or the like, and one that is detachably held by the holding mechanism of the one end portion 11a and the other end portion 11b in the magnetic core portion 11 (one end in the above example). Portion 11a) is directly fixed to the surface (the surface facing the other detachably held by the holding mechanism) (that is, one of the one end EN1 and the other end EN2 of the magnetic sheet 21 (in this example, It is also possible to employ a configuration in which the one end EN1) on the one end 11a side is directly fixed. In this direct fixing configuration, a wiring pattern (not shown) for supplying a drive signal from the drive circuit to the magnetic sensor 13 and transmitting the detection signal S1 output from the magnetic sensor 13 is formed. The flexible substrate 41 can be attached to the magnetic core portion 11 as shown in FIGS. 7 and 8 and the magnetic sensor 13 can be disposed (fixed) on the flexible substrate 41. According to this configuration, one of the one end portion 11a and the other end portion 11b of the magnetic core portion 11 (one end portion 11a in the above example) is held by the holding mechanism, that is, one end portion of the magnetic sheet body 21. Since one of the EN1 and the other end portion EN2 (one end portion EN1 in the above example) is held by the holding mechanism, the magnetic sensor 13 can also be fixed to the holding portion 12. Therefore, the magnetic sensor 13 alone Fixing work (attachment work) to the holding part 12 can be omitted.

  Moreover, about the magnitude | size of the flexible substrate 41 in the structure which uses this flexible substrate 41, as shown in FIG. 7, it hold | maintains so that attachment or detachment is not possible by the holding mechanism in the one end part 11a and the other end part 11b in the magnetic core part 11. It is possible to have a size that exists only at one end (the one end portion 11a in the above example), or, as shown in FIG. 8, by the holding mechanism of the one end portion 11a and the other end portion 11b in the magnetic core portion 11. It is also possible to have a size that extends from one side that is detachably held (one end portion 11a in the above example) to the other side that is detachably held by the holding mechanism (the other end portion 11b in the above example). When the configurations shown in FIGS. 7 and 8 are compared, the current detection sensor 2 having the configuration shown in FIG. 7 has an effect that the cost of the current detection sensor 2 can be reduced by the size of the flexible substrate 41. On the other hand, the current detection sensor 2 having the configuration shown in FIG. 8 has an effect that the flexible substrate 41 can improve the strength while ensuring the flexibility of the magnetic core portion 11 although the cost is slightly increased. Is done.

  Further, in the above example, the current detection sensor 2 is configured so that the magnetic core portion 11 is in an annular state (a state in which the one end portion 11a and the other end portion 11b are held by the holding portion 12) to a non-annular state (only the one end portion 11a). In the holding portion 12) and conversely from the non-annular state to the annular state (the configuration in which the other end portion 11 b is detachable) is adopted, to the measurement target electric circuit 51 that cannot be removed. Although mounting is also possible, it is not limited to this configuration. For example, although not illustrated, the magnetic core portion 11 is disposed in an annular case in an annular state (a state where the one end portion 11a and the other end portion 11b face each other), and the one end portion 11a in the annular case and the like. A configuration in which the magnetic sensor 13 is disposed in the gap GP between the end portions 11b can also be employed. Also in this configuration, since the magnetic sheet body 21 (flat magnetic body) is used, a magnetic material powder such as ferrite is molded into a predetermined shape and fired as a magnetic body corresponding to the magnetic sheet body 21. Compared with a configuration using a general magnetic core formed by the above, the volume of the magnetic body can be greatly reduced, and thus a significant weight reduction can be achieved. In addition, about the structure same as the electric current detection sensor 2 shown in FIG. 1, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  In the above example, the current detection sensor 2 is configured by one magnetic core unit 11, but is not limited to this configuration. For example, a plurality of (two or three or more) magnetic core portions 11 are juxtaposed along the longitudinal direction, and any one of any two adjacent magnetic core portions 11 among the plurality of magnetic core portions 11 is selected. As for the two magnetic core parts 11, the surface excluding the end face and the side surface of the one end part 11 a along the longitudinal direction of the one magnetic core part 11 and the length of the other magnetic core part 11 in the two magnetic core parts 11. It is also possible to adopt a configuration in which the end surface and the surface other than the side surface in the other end portion 11b along the direction are opposed to each other at equal intervals so as to form an annular shape as a whole.

  In this configuration, the magnetic sheet bodies 21 constituting each magnetic core portion 11 are also arranged in parallel along the longitudinal direction, and one of the two adjacent magnetic sheet bodies 21 among the plurality of magnetic sheet bodies 21 is arranged. The surface excluding the end face and the side face at one end EN1 along the longitudinal direction of the magnetic sheet body 21 and the end face and the side face at the other end EN2 along the longitudinal direction of the other magnetic sheet body 21 of the two magnetic sheet bodies 21 The other surfaces are also opposed to each other at equal intervals. For this reason, since the gap GP is formed in a region sandwiched between the surface at the one end EN1 and the surface at the other end EN2 facing each other, a magnetic field is formed inside each gap GP. A sensor 13 is provided.

As an example, configuration using two magnetic core portion 11 (that is, two magnetic sheets 21 (hereinafter, denoted one magnetic sheet 21 _1, shall be referred to as a magnetic sheet 21 ₂ and the other) This will be specifically described with reference to a configuration using In this case, as a configuration in which the two magnetic sheet bodies 21 ₁ and 21 ₂ are arranged side by side, as shown in FIG. 9, the two magnetic sheet bodies 21 ₁ and 21 ₂ are adjacent to each other in an annularly curved state. One end EN1 and the other end EN2 of each of the magnetic sheet bodies 21 ₁ and 21 ₂ are positioned in a state where one end EN1 of one magnetic sheet body 21 is located outside the other end EN2 of the other magnetic sheet body 21. may be configured to parallel so as to face, and as shown in FIG. 10, in the two states magnetic sheet 21 _1, 21 ₂ is curved in an annular, two adjacent of the magnetic sheet 21 _1, 21 one magnetic sheet 21 in the _two end portions EN1 and the other end portion EN2 of (magnetic sheet 21 ₁ in the drawing) are both other magnetic sheet 21 (the magnetic sheet 21 ₂ in the drawing) A configuration in which the one end EN1 and the other end EN2 face each other in a state of being located outside the one end EN1 and the other end EN2 may be employed.

9 and 10, the configuration shown in FIGS. 7 and 8 described above, that is, the end along the longitudinal direction of the magnetic core portion 11 (that is, the end along the longitudinal direction of the magnetic sheet 21). When the configuration for fixing the magnetic sensor 13 is employed, the configuration may be such that the magnetic sensor 13 is fixed to the one end EN1 side of each magnetic sheet body 21 ₁ , 21 ₂ , or each magnetic sheet body 21 ₁ , 21 ₂ may be configured such that the magnetic sensor 13 is fixed to the other end portion EN2 side. Moreover, the magnetic sheet ₂₁ 1, 21 ₂ of one of the magnetic sheet 21 one end EN1 end and the other part EN2 side of the magnetic sensor 13 is fixed respectively, the magnetic sheet ₂₁ 1, 21 ₂ A configuration in which the magnetic sensor 13 is not fixed to the one end EN1 side and the other end EN2 side of the other magnetic sheet body 21 may be employed.

  Moreover, in the structure which forms the flexible substrate 41 in the magnitude | size ranging from the one end part 11a in the magnetic core part 11 to the other end part 11b as shown in above-mentioned FIG. 8, the structure of the flexible substrate 41 shown in FIG. It can also be adopted. In this flexible substrate 41, the magnetic sheet 21 having a substantially uniform thickness is placed between the long film bodies 42 and 42 made of resin constituting the flexible substrate 41 from the one end portion 42 a to the other end portion 42 b. The magnetic sheet body 21 and the film bodies 42 and 42 are integrally formed.

  In this flexible substrate 41, the magnetic sheet body 21 is integrated (including the magnetic sheet body 21), so that the flexible substrate 41 itself constitutes the magnetic core portion 11. Further, in the flexible substrate 41, the surface 21c of the magnetic sheet body 21 is in close contact with one of the film bodies 42 and 42, and the surface 21d of the magnetic sheet body 21 is the other of the film bodies 42 and 42. And adheres to the entire surface. Further, in the flexible substrate 41, a portion of the magnetic sheet 21 sandwiched between the one end portions 42a of the film bodies 42 and 42 constitutes one end portion EN1, and the one end portion EN1 and one end of each of the film bodies 42 and 42 are provided. One end portion 11a of the magnetic core portion 11 is constituted by the portion 42a. Further, in the flexible substrate 41, the portion sandwiched between the other end portions 42b of the film bodies 42, 42 in the magnetic sheet body 21 constitutes the other end portion EN2, and the other end portion EN2 and the film bodies 42, 42 are included. The other end part 11b of the magnetic core part 11 is comprised by each other end part 42b. The flexible substrate 41 shown in FIGS. 11 and 12 is manufactured in advance or purchased and used, so that in the manufacturing process of the current detection sensor 2, the magnetic sheet body 21 and the flexible substrate 41 are bonded and integrated. Can be omitted. In addition, about the structure same as the structure shown to FIGS. 1-3, the same code | symbol was attached | subjected and the overlapping description was abbreviate | omitted.

DESCRIPTION OF SYMBOLS 1 Current measuring apparatus 2 Current detection sensor 13 Magnetic sensor 21 Magnetic sheet body (annular magnetic core)
21c Surface excluding end and side surfaces at one end of magnetic sheet 21d Surface excluding end and side at other end of magnetic sheet EN1 One end of magnetic sheet EN2 Other end of magnetic sheet GP Gap S1 Detection signal

Claims (5)

A current provided with one annular magnetic core and a magnetoelectric conversion element that is disposed in a gap formed in the annular magnetic core and detects a magnetic flux induced in the annular magnetic core and outputs a detection signal A detection sensor,
The annular magnetic core is composed of a long magnetic sheet body having flexibility, a surface excluding end surfaces and side surfaces at one end portion and one end portion along the longitudinal direction, and end surfaces and side surfaces at the other end portion. The surface excluding is formed in an annular shape facing each other at equal intervals,
The gap is a current detection sensor configured by a region sandwiched between the surface at the one end and the surface at the other end facing each other. A current provided with one annular magnetic core and a magnetoelectric conversion element that is disposed in a gap formed in the annular magnetic core and detects a magnetic flux induced in the annular magnetic core and outputs a detection signal A detection sensor,
The annular magnetic core includes a plurality of flexible long magnetic sheet bodies arranged in parallel along the longitudinal direction, and one of any two adjacent magnetic sheet bodies among the plurality of magnetic sheet bodies. The surface of the magnetic sheet body excluding the end surface and the side surface at one end along the longitudinal direction and the end surface and the side surface at the other end of the two magnetic sheet bodies along the longitudinal direction are excluded. It is formed in a ring shape as a whole by facing the surface at equal intervals,
The gap is a current detection sensor configured by a region sandwiched between the surface at the one end and the surface at the other end facing each other.   The current detection sensor according to claim 1, wherein the magnetoelectric conversion element is fixed to one of the surface at the one end portion and the surface at the other end portion constituting the gap portion. A long magnetic sheet body having flexibility;
One end portion and the other end portion in the longitudinal direction of the magnetic sheet body curved in an annular shape are detachable from one end portion of the one end portion and the other end portion, and an end surface at the one end portion And a holding portion that can be held in an opposing state in which the surface excluding the side surface and the surface other than the end surface and the side surface in the other end face each other at equal intervals,
Magnetic flux induced in the magnetic sheet disposed in a gap formed by a region sandwiched between the surface of the one end and the surface of the other end in the opposed state in the holding unit. A current detection sensor comprising a magnetoelectric conversion element that detects a current and outputs a detection signal. The current detection sensor according to any one of claims 1 to 4, which is attached to a measurement target electric circuit;
A current measuring device comprising: a processing unit that measures a current value of the current based on the detection signal when the magnetic flux is induced in the magnetic sheet due to a current flowing through the measurement target electric circuit.

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