JP2013096850A - Current sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a current sensor having high measurement accuracy even if arrangement position accuracy of a current path to be measured is low.SOLUTION: A current sensor includes: a magnetic core for focusing magnetic flux generated around a current path to be measured; a magnetic sensor for sensing magnetism; and a substrate on which the magnetic sensor is mounted. The magnetic core is composed of a soft magnetic material and includes a first magnetic core that is annular and has a first gap interleaved by one end and the other end and a second magnetic core that is annular and has a second gap interleaved by one end and the other end. The first and second magnetic cores are arranged so that the first and second gaps adjoin each other. The magnetic sensor includes a magnetic resistance element and is arranged between the first and second gaps. The magnetic sensor or at least part of the substrate is interleaved by one end of the first magnetic core and one end of the second magnetic core.

Description

  The present invention relates to a current sensor for detecting a current flowing in a current path to be measured, and more particularly to a current sensor for detecting a current by a magnetic sensor.

  For controlling and monitoring various devices, a current sensor that detects a current flowing through a current path (wire) to be measured is well known. As this type of current sensor, it is known to use a magnetic sensor using a coil or a Hall element that senses a magnetic field generated from a current flowing in a current path to be measured.

  As the above-described conventional technique, Patent Document 1 proposes a current sensor 700 as shown in FIG. A current sensor 700 of Conventional Example 1 shown in FIG. 11 is configured in a substantially rectangular ring shape, and passes through a core body 701 in which a gap 702 is formed in a part of the ring portion and a through hole 706 of the core body 701. It is composed of a Hall IC (Hall element) 705 that detects a magnetic field generated according to the current flowing through the arranged conductor 707. The Hall IC 705 of the current sensor is disposed so as to be sandwiched in the gap 702 of the core body 701 so that the sensitivity axis direction KD7 of the Hall IC 705 coincides with the magnetic field direction MD7.

  However, when a Hall element is used as the magnetosensitive element as in Conventional Example 1, it is difficult to obtain a highly accurate detection value due to the performance of the element. Therefore, it is known that a magnetoresistive element is used in place of the Hall element, and that when a magnetoresistive element is used, a highly accurate detection value can be obtained.

  As a current sensor using a magnetoresistive element, Patent Document 2 proposes a current sensor 800 as shown in FIG. A current sensor 800 of Conventional Example 2 shown in FIG. 12 includes a core 811 as magnetic field focusing means for focusing a magnetic field generated according to a current flowing through the conductor coil 810, and a magnetoresistive element 812 as magnetic field detection means. It is configured. The core 811 is formed in an annular shape, a conductor coil 810 is wound around a part of the core 811, a gap 813 is provided on the opposite side, and the focused magnetic field is strong between the gaps 813. In the magnetoresistive element 812, the sensitivity axis direction KD7 of the Hall IC 705 and the sensitivity axis direction KD8 of the magnetoresistive element 812 are different from the Hall IC 705 of Conventional Example 1 by 90 ° with respect to the thickness direction of the element. In order to match the direction MD8 of the magnetic field generated in the gap 813 with the direction KD8 of the sensitivity axis of the magnetoresistive element 812, the magnetoresistive element 812 cannot be disposed so as to be sandwiched in the narrow gap 813. As shown in FIG. 12, it is arranged in the vicinity of the gap 813. The magnetoresistive element 812 can detect a change in magnetic field caused by a change in current flowing through the conductor coil 810 with high accuracy.

JP 2009-14549 A JP-A-6-130088

  However, when the magnetoresistive element 812 is arranged at the position as in Conventional Example 2, there is a problem that the measurement accuracy is lowered due to the influence of the external magnetic field. Therefore, when measuring the current in the current path to be measured as in Conventional Example 1 using the configuration of the magnetic core and magnetoresistive element as in Conventional Example 2, in order to suppress the influence of the external magnetic field, FIG. A current sensor 900 as shown in FIG. A current sensor 900 of a comparative example shown in FIG. 13 includes an annular magnetic core 901 and a magnetoresistive element 903. The magnetic core 901 is disposed at a position surrounding the current path 910 to be measured, and the gap 901g of the magnetic core 901 is A magnetoresistive element 903 is disposed in the vicinity.

  In the case of the current sensor 900 configured as described above, it is desirable that the current path to be measured 910 is disposed at the center of the magnetic core 901 formed in an annular shape. However, the current path 910 to be measured cannot always be accurately placed in the center of the magnetic core 901. If the position of the current path 910 to be measured is slightly shifted, the strength of the magnetic field detected by the magnetoresistive element 903 changes. As a result, the measurement accuracy of the current sensor 900 is reduced. Further, since the measured current path 910 to be measured has various thickness types, it has been difficult to increase the arrangement position accuracy of the measured current path 910 using a simple mechanism. For this reason, in the case of the current sensor 900 that measures the current in the current path 910 as shown in FIG. 13, even if the magnetoresistive element 903 capable of obtaining a highly accurate detection value is used, the current sensor 900 can be highly accurate. It was difficult.

  The present invention solves the above-described problems, and an object of the present invention is to provide a current sensor with high measurement accuracy even when the arrangement position accuracy of the current path to be measured is low.

  In order to solve this problem, the current sensor according to the present invention includes a magnetic core that surrounds a current path to be measured and focuses a magnetic flux generated around the current path to be measured, and a current flows through the current path to be measured. A current sensor including a magnetic sensor for detecting magnetism generated in the magnetic field and a substrate on which the magnetic sensor is mounted, wherein the magnetic core is formed of a soft magnetic material and is annularly sandwiched between one end and the other end. A first magnetic core having a gap of 1 and a second magnetic core having a second gap formed of a soft magnetic material and having a second gap sandwiched between one end and the other end, and the first gap and the The first magnetic core and the second magnetic core are arranged so that a second gap is adjacent to each other, the magnetic sensor includes a magnetoresistive element, and the first gap and the first gap are arranged. By disposing the magnetic sensor between two gaps, the first One end of the magnetic core, at least a portion of the magnetic sensor or the substrate to one end of the second magnetic core is characterized by being pinched.

  According to this configuration, the current sensor according to the present invention includes the first end of the first magnetic core and the second end between the first gap of the first magnetic core and the second gap of the second magnetic core. Since the magnetic sensor is arranged so that at least a part of the magnetic sensor or the substrate is sandwiched between one end of the magnetic core, the magnetic sensor is sandwiched between the two magnetic cores. For this reason, when the current sensor is attached to the current path to be measured, even if a displacement of the current path to be measured with respect to the magnetic core occurs, the influence of the displacement of the current path to be measured can be reduced and adjacent to the current core. It is also possible to reduce the influence of an external magnetic field from other current paths and the like. As a result, the detection value of the magnetoresistive element can be stably obtained, so that the accuracy of the current sensor using the magnetoresistive element that can obtain the highly accurate detection value can be improved.

  In the current sensor of the present invention, it is preferable that a direction in which the first gap and the second gap are continuous is parallel to an axial direction of the current path to be measured.

  According to this configuration, in the current sensor of the present invention, the direction in which the first gap and the second gap are continuous is parallel to the axial direction of the current path to be measured. The magnetic core can be arranged so as to overlap. As a result, the size of the current sensor in the radial direction can be reduced.

  In the current sensor of the present invention, it is preferable that the first magnetic core and the second magnetic core have the same shape.

  According to this configuration, since the first magnetic core and the second magnetic core have the same shape in the current sensor of the present invention, the first magnetic core and the second magnetic core are manufactured in different shapes. Compared to the case, the manufacturing cost of the current sensor can be reduced. In addition, the first magnetic core and the second magnetic core can be arranged in an overlapping manner, and the size of the current sensor in the radial direction can be reduced.

  In the current sensor of the present invention, the outer shape of the second magnetic core is smaller than the inner shape of the first magnetic core, and the second magnetic core is disposed in the inner shape of the first magnetic core. The direction in which the first gap and the second gap are continuous is preferably perpendicular to the axial direction of the current path to be measured.

  According to this configuration, in the current sensor of the present invention, the outer shape of the second magnetic core is smaller than the inner shape of the first magnetic core, and the second magnetic core is disposed within the inner shape of the first magnetic core. Therefore, the first magnetic core and the second magnetic core can be arranged side by side. As a result, the size of the current sensor in the thickness direction can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, even if the influence of an external magnetic field is reduced and the arrangement position accuracy of a to-be-measured current path is low, a current sensor with high measurement accuracy can be provided.

It is a perspective view explaining the current sensor of a 1st embodiment of the present invention. 2A and 2B are diagrams illustrating the current sensor according to the first embodiment of the present invention, in which FIG. 2A is a front view seen from the Y2 side shown in FIG. 1 and FIG. 2B is shown in FIG. It is the top view seen from the Z1 side. FIGS. 3A and 3B are diagrams illustrating the current sensor according to the first embodiment of the present invention, in which FIG. 3A is an enlarged view of a portion P illustrated in FIG. 2A and FIG. It is an enlarged view of Q part shown in b). It is a perspective view explaining the current sensor of a 2nd embodiment of the present invention. It is a figure explaining the current sensor of 2nd Embodiment of this invention, Comprising: Fig.5 (a) is the front view seen from the Y2 side shown in FIG. 4, FIG.5 (b) shows in FIG. It is the top view seen from the Z1 side. 6A and 6B are diagrams for explaining a current sensor according to a second embodiment of the present invention, in which FIG. 6A is an enlarged view of an R portion shown in FIG. 5A, and FIG. It is an enlarged view of S part shown in b). It is a figure explaining the modification of the current sensor of 1st Embodiment of this invention, Comprising: Fig.7 (a) is a front view of the modification 1 compared with Fig.2 (a), FIG.7 (b) These are top views of the modification 2 compared with FIG.2 (b). It is a figure explaining the modification of the current sensor of 1st Embodiment of this invention, Comprising: It is a front view of the modification 3 compared with Fig.3 (a). It is a figure explaining the modification of the current sensor of 2nd Embodiment of this invention, Comprising: Fig.9 (a) is a front view of the modification 4 compared with Fig.5 (a), FIG.9 (b) These are the front views of the modification 5 compared with Fig.6 (a). It is a figure explaining the modification of the current sensor of 2nd Embodiment of this invention, Comprising: Fig.10 (a) is a top view of the modification 6 compared with FIG.5 (b), FIG.10 (b). These are top views of the modification 7 compared with FIG.5 (b). It is a perspective view explaining the core main body and Hall IC of the current sensor in Conventional Example 1. It is a whole perspective view explaining the current sensor in Conventional Example 2. It is a figure explaining the current sensor in a comparative example, Comprising: It is the top view seen from the axial direction of the to-be-measured current path.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a perspective view illustrating a current sensor 101 according to the first embodiment of the present invention. 2A and 2B are diagrams for explaining the current sensor 101 according to the first embodiment of the present invention. FIG. 2A is a front view as viewed from the Y2 side shown in FIG. 1, and FIG. FIG. 2 is a plan view seen from the Z1 side shown in FIG. FIG. 3 is a diagram for explaining the current sensor 101 according to the first embodiment of the present invention. FIG. 3A is an enlarged view of a portion P shown in FIG. 2A, and FIG. These are the enlarged views of Q part shown in Drawing 2 (b).

  As shown in FIGS. 1 and 2, the current sensor 101 according to the first embodiment of the present invention detects the magnetic core 1 that focuses the magnetic flux and the magnetism that is generated when a current flows through the current path CB to be measured. And a magnetic sensor 3.

  The magnetic core 1 is made of a soft magnetic material such as permalloy (Fe—Ni alloy), and has a first magnetic core 11 and a second magnetic core 21 as shown in FIGS. 1 and 2. ing. Then, the first magnetic core 11 and the second magnetic core 21 are arranged so as to surround the measured current path CB, and the magnetic flux generated around the measured current path CB is focused. Although permalloy (Fe—Ni alloy) is used for the magnetic core 1, any soft magnetic material may be used, such as Sendust (Fe—Si—Al alloy), a non-ferrous amorphous magnetic alloy, etc. But it ’s okay.

  As shown in FIGS. 1 and 2, the first magnetic core 11 is formed in a substantially rectangular annular shape, and has a first gap 11 g sandwiched between one end and the other end in a part of the annular shape. Similarly, the second magnetic core 21 is formed in a substantially rectangular annular shape, and has a second gap 21g sandwiched between one end and the other end in a part of the annular shape. In the current sensor 101 according to the first embodiment of the present invention, the first magnetic core 11 and the second magnetic core 21 have the same shape. As a result, the manufacturing cost of the current sensor 101 can be reduced as compared with the case where the first magnetic core 11 and the second magnetic core 21 are manufactured in different shapes.

  Also, as shown in FIGS. 1 to 3, the first magnetic core 11 and the second magnetic core 21 are arranged so that the first gap 11g and the second gap 21g are adjacent to each other. Furthermore, the current sensor 101 according to the first embodiment of the present invention is attached to the measured current path CB, and the measured current path CB is at the center of the magnetic core 1 (the first magnetic core 11 and the second magnetic core 21). When arranged, the direction TD1 in which the first gap 11g and the second gap 21g are continuous with the axial direction JD of the measured current path CB is configured to be parallel. As a result, the first magnetic core 11 and the second magnetic core 21 can be arranged so as to overlap each other, so that the size of the current sensor 101 in the radial direction can be reduced. Note that the current sensor 101 according to the first embodiment of the present invention is attached to the measured current path CB by a housing and an attachment mechanism that house the current sensor 101, although not shown.

The magnetic sensor 3 is a current sensor for detecting magnetism generated when a current flows through the current path CB to be measured. For example, a magnetoresistive element (GMR (Giant Magneto Resistive) element using a giant magnetoresistive effect) is used. Is used). In the GMR element, for example, the antiferromagnetic layer is an α-Fe ₂ O ₃ layer, the pinned layer is a NiFe layer, the intermediate layer is a Cu layer, and the free layer is a NiFe layer. In the magnetic sensor 3, a GMR element is produced on a silicon substrate, and the cut out GMR chip is packaged with a thermosetting synthetic resin.

  As shown in FIGS. 1 to 3, the magnetic sensor 3 is mounted on a substrate 9 such as a printed circuit board (PCB), and between the first gap 11g and the second gap 21g. It is placed between. That is, in the magnetic sensor 3, as shown in FIG. 3A, both ends 11s of the first gap 11g (in other words, one end and the other end of the first magnetic core 11) and the magnetic sensor 3 face each other. Both ends 21s of the second gap 21g (in other words, one end and the other end of the second magnetic core 21) and the magnetic sensor 3 are disposed so as to face each other with the substrate 9 therebetween. Since the magnetoresistive elements arranged in this way have a sensitivity axis (magnetism sensing axis) direction KD1 in a direction parallel to the substrate 9, the sensitivity axis (magnetism sensing axis) direction. KD1 and the direction TD1 in which the first gap 11g and the second gap 21g are continuous are perpendicular to each other. Further, when the magnetic flux generated by the current flowing through the measured current path CB is focused by the magnetic core 1, the magnetic field direction MD1 of the first gap 11g and the second gap 21g, and the sensitivity axis direction KD1 Are parallel.

  The current sensor 101 according to the first embodiment of the present invention configured as described above is provided between the first gap 11g of the first magnetic core 11 and the second gap 21g of the second magnetic core 21. Since the magnetic sensor 3 is arranged so that the magnetic sensor 3 is adjacent to both ends 11s of the first gap 11g and both ends 21s of the second gap 21g, the magnetic sensor 3 has two magnetic cores 1 (first magnetic It is sandwiched between the core 11 and the second magnetic core 21). For this reason, when the current sensor 101 is attached to the current path CB to be measured, even if a displacement of the current path CB to be measured with respect to the magnetic core 1 occurs, the influence of the displacement of the current path CB to be measured is reduced. In addition, the influence of an external magnetic field from other adjacent current paths can be reduced. As a result, since the detection value of the magnetoresistive element can be stably obtained, the accuracy of the current sensor 101 using the magnetoresistive element that can obtain a highly accurate detection value can be improved. Therefore, even if the influence of the external magnetic field is reduced and the arrangement position accuracy of the current path CB to be measured is low, the current sensor 101 with high measurement accuracy can be provided.

  Further, since the direction TD1 in which the first gap 11g and the second gap 21g are continuous is parallel to the axial direction JD of the measured current path CB, the both ends 11s of the first gap 11g and the second gap 21g The direction KD1 of the sensitivity axis of the magnetic sensor 3 arranged at a position adjacent to both ends 21s and the direction MD1 of the magnetic field generated by the current flowing through the measured current path CB are parallel to each other. For this reason, compared with the case where it is not parallel, the magnetism which the magnetic sensor 3 detects becomes stronger. As a result, the accuracy of the current sensor 101 using the magnetoresistive element capable of obtaining a highly accurate detection value can be further improved.

  Further, the first magnetic core 11 and the second magnetic core 21 have the same shape, and the first magnetic core 11 and the second magnetic core 21 are connected to each other by the first gap 11g and the second gap 21g. Since they are arranged adjacent to each other, the magnetic field between the first gap 11g of the first magnetic core 11 and the second gap 21g of the second magnetic core 21 is uniform. As a result, the magnetic sensor 3 disposed at a position adjacent to the first gap 11g and the second gap 21g stably detects the magnetism, so that a magnetoresistive element capable of obtaining a highly accurate detection value is used. The accuracy of the current sensor 101 can be further improved.

  As described above, the current sensor 101 of the present invention has the magnetic sensor 3 placed between the first gap 11g of the first magnetic core 11 and the second gap 21g of the second magnetic core 21. Since the magnetic sensor 3 is disposed adjacent to both ends 11s of 11g and both ends 21s of the second gap 21g, the magnetic sensor 3 includes two magnetic cores 1 (first magnetic core 11 and second magnetic core 21). ). For this reason, when the current sensor 101 is attached to the current path CB to be measured, even if a displacement of the current path CB to be measured with respect to the magnetic core 1 occurs, the influence of the displacement of the current path CB to be measured is reduced. In addition, the influence of an external magnetic field from other adjacent current paths can be reduced. As a result, since the detection value of the magnetoresistive element can be stably obtained, the accuracy of the current sensor 101 using the magnetoresistive element that can obtain a highly accurate detection value can be improved.

  Further, since the direction TD1 in which the first gap 11g and the second gap 21g are continuous is parallel to the axial direction JD of the measured current path CB, the first magnetic core 11 and the second magnetic core 21 are overlapped. Can be arranged together. As a result, the radial size of the current sensor 101 can be reduced.

  In addition, since the first magnetic core 11 and the second magnetic core 21 have the same shape, compared to the case where the first magnetic core 11 and the second magnetic core 21 are manufactured in different shapes, the current The manufacturing cost of the sensor 101 can be reduced. Moreover, the first magnetic core 11 and the second magnetic core 21 can be arranged so as to overlap each other, and the size of the current sensor 101 in the radial direction can be reduced.

[Second Embodiment]
FIG. 4 is a perspective view illustrating the current sensor 102 according to the second embodiment of the present invention. FIG. 5 is a diagram illustrating the current sensor 102 according to the second embodiment of the present invention. FIG. 5 (a) is a front view seen from the Y2 side shown in FIG. 4, and FIG. FIG. 5 is a plan view seen from the Z1 side shown in FIG. FIG. 6 is a diagram for explaining the current sensor 102 according to the second embodiment of the present invention. FIG. 6A is an enlarged view of a portion R shown in FIG. 5A, and FIG. FIG. 6 is an enlarged view of a portion S shown in FIG.

  As shown in FIGS. 4 and 5, the current sensor 102 according to the second embodiment of the present invention detects the magnetic core 5 that focuses the magnetic flux and the magnetism that is generated when a current flows through the measured current path CB. And a magnetic sensor 3.

  As shown in FIGS. 4 and 5, the magnetic core 5 includes a first magnetic core 15 and a second magnetic core 25, and the first magnetic core 5 surrounds the current path CB to be measured. The magnetic core 15 and the second magnetic core 25 are arranged to focus the magnetic flux generated around the current path CB to be measured. The magnetic core 5 is a powdered soft magnetic material, such as permalloy (Fe—Ni alloy) powder. The permalloy (Fe—Ni alloy) powder is kneaded into a synthetic resin, and a molding die is used. It is formed by injection molding. In addition, although the permalloy (Fe-Ni alloy) material was used for the magnetic core 5, what is necessary is just a soft magnetic material, Sendust (Fe-Si-Al alloy) which is another iron-type material, and a non-ferrous-type amorphous magnetic alloy. Etc.

  As shown in FIGS. 4 and 5, the first magnetic core 15 is formed in a substantially rectangular annular shape, and has a first gap 15g in a part of the annular shape. Similarly, the second magnetic core 25 is formed in a substantially rectangular ring shape and has a second gap 25g. In the current sensor 102 according to the second embodiment of the present invention, the outer shape of the second magnetic core 25 is formed smaller than the inner shape of the first magnetic core 15, and the second inner shape of the first magnetic core is within the second shape. The magnetic core 25 is arranged. As a result, the first magnetic core 15 and the second magnetic core 25 can be arranged side by side, so the size of the current sensor 102 in the thickness direction can be reduced.

  4 to 6, the current sensor 102 according to the second embodiment of the present invention includes a first magnetic core 15 and a second magnetic core 25, and a first gap 15g and a second magnetic core 25. It arrange | positions so that the clearance gap 25g may adjoin. Furthermore, the current sensor 102 of the second embodiment of the present invention is attached to the measured current path CB, and the measured current path CB is at the center of the magnetic core 5 (the first magnetic core 15 and the second magnetic core 25). When arranged, the direction TD2 in which the first gap 15g and the second gap 25g are connected to each other and the axial direction JD of the measured current path CB are perpendicular to each other. Note that the current sensor 102 according to the second embodiment of the present invention is attached to the measured current path CB by a housing and an attachment mechanism that house the current sensor 102, although not shown.

  As shown in FIGS. 4 to 6, the magnetic sensor 3 is mounted on a substrate 9 such as a printed circuit board (PCB) and is sandwiched between a first gap 15g and a second gap 25g. Is arranged. That is, in the magnetic sensor 3, as shown in FIG. 6B, both ends 15s of the first gap 15g (in other words, one end and the other end of the first magnetic core 15) and the magnetic sensor 3 face each other. Both ends 25s of the second gap 25g (in other words, one end and the other end of the second magnetic core 25) and the magnetic sensor 3 are arranged to face each other with the substrate 9 interposed therebetween. Since the magnetoresistive element arranged in this way has a direction KD2 of the sensitivity axis (magnetism sensing axis) in a direction parallel to the substrate 9, the direction of the sensitivity axis (magnetism sensing axis) KD2 and the direction TD2 in which the first gap 15g and the second gap 25g are continuous are perpendicular to each other. Further, when the magnetic flux generated by the current flowing through the measured current path CB is focused by the magnetic core 5, the magnetic field direction MD2 of the first gap 15g and the second gap 25g, and the sensitivity axis direction KD2 Are parallel.

  The current sensor 102 according to the second embodiment of the present invention configured as described above is provided between the first gap 15g of the first magnetic core 15 and the second gap 25g of the second magnetic core 25. Since the magnetic sensor 3 is disposed so that the magnetic sensor 3 is adjacent to both ends 15s of the first gap 15g and both ends 25s of the second gap 25g, the magnetic sensor 3 includes two magnetic cores 5 (first magnetic It is sandwiched between the core 15 and the second magnetic core 25). For this reason, when the current sensor 102 is attached to the current path CB to be measured, even if the positional displacement of the current path CB to be measured with respect to the magnetic core 5 occurs, there is a gap between the magnetic sensor 3 and the current path CB to be measured. By the second magnetic core 25 that is arranged, it is possible to reduce the influence of the arrangement position deviation of the current path CB to be measured. Further, the first magnetic core 15 disposed outside the magnetic sensor 3 can reduce the influence of an external magnetic field from other adjacent current paths and the like. As a result, since the detection value of the magnetoresistive element can be obtained stably, the accuracy of the current sensor 102 using the magnetoresistive element that can obtain a highly accurate detection value can be improved. Therefore, even if the influence of the external magnetic field is reduced and the arrangement position accuracy of the current path CB to be measured is low, the current sensor 102 with high measurement accuracy can be provided.

  As described above, the current sensor 102 of the present invention is configured such that the magnetic sensor 3 is disposed between the first gap 15g of the first magnetic core 15 and the second gap 25g of the second magnetic core 25. Since the magnetic sensor 3 is disposed adjacent to both ends 15s of 15g and both ends 25s of the second gap 25g, the magnetic sensor 3 includes two magnetic cores 5 (first magnetic core 15 and second magnetic core 25). ). For this reason, when the current sensor 102 is attached to the current path CB to be measured, even if the positional displacement of the current path CB to be measured with respect to the magnetic core 5 occurs, there is a gap between the magnetic sensor 3 and the current path CB to be measured. By the second magnetic core 25 that is arranged, it is possible to reduce the influence of the arrangement position deviation of the current path CB to be measured. Further, the first magnetic core 15 disposed outside the magnetic sensor 3 can reduce the influence of an external magnetic field from other adjacent current paths and the like. As a result, since the detection value of the magnetoresistive element can be obtained stably, the accuracy of the current sensor 102 using the magnetoresistive element that can obtain a highly accurate detection value can be improved.

  In addition, since the outer shape of the second magnetic core 25 is smaller than the inner shape of the first magnetic core 15 and the second magnetic core 25 is disposed within the inner shape of the first magnetic core 15, the first magnetic core 15 and the second magnetic core 25 can be arranged side by side. Thereby, the size of the current sensor 102 in the thickness direction can be reduced.

  In addition, this invention is not limited to the said embodiment, For example, it can deform | transform and implement as follows, These embodiments also belong to the technical scope of this invention.

  FIG. 7 is a diagram for explaining a modification of the current sensor 101 according to the first embodiment of the present invention. FIG. 7A is a front view of the modification 1 compared with FIG. FIG.7 (b) is a top view of the modification 2 compared with FIG.2 (b). FIG. 8 is a diagram for explaining a modification of the current sensor 101 according to the first embodiment of the present invention, and is a front view of the modification 3 compared with FIG. FIG. 9 is a diagram for explaining a modification of the current sensor 102 according to the second embodiment of the present invention. FIG. 9A is a front view of the modification 4 compared with FIG. FIG.9 (b) is a front view of the modification 5 compared with Fig.6 (a). FIG. 10 is a diagram for explaining a modification of the current sensor 102 according to the second embodiment of the present invention. FIG. 10 (a) is a plan view of the modification 6 compared with FIG. 5 (b). FIG.10 (b) is a top view of the modification 7 compared with FIG.5 (b).

<Modification 1>
In the first embodiment, the magnetic sensor 3 is configured to be sandwiched between both ends 11s of the first gap 11g and both ends 21s of the second gap 21g. However, as shown in FIG. The magnetic sensor C13 includes one end of the first magnetic core C11 (any one of the two ends C11s of the first gap C11g) and one end of the second magnetic core C21 (any one of the two ends C21s of the second gap C21g). In addition, at least a part may be sandwiched.

<Modification 2>
In the first embodiment, the first magnetic core 11 and the second magnetic core 21 have the same shape and are preferably configured. However, as shown in FIG. The second magnetic core C22 may have a different shape.

<Modification 3>
In the first embodiment, the magnetic sensor 3 is configured to be sandwiched between both ends 11s of the first gap 11g and both ends 21s of the second gap 21g. However, as shown in FIG. When C33 has a width smaller than the first gap 11g or the second gap 21g, at least a part of the substrate C39 is connected to both ends 11s of the first gap 11g (in other words, one end of the first magnetic core 11). The other end) and both ends 21s of the second gap 21g (in other words, one end and the other end of the second magnetic core 21) are opposed to each other.

<Modification 4>
In the second embodiment, the magnetic sensor 3 is preferably configured so as to be within the thickness of the first magnetic core 15 and the second magnetic core 25. However, as shown in FIG. 3 may be configured to be larger than the thickness of the first magnetic core C15 and the second magnetic core C25.

<Modification 5>
In the second embodiment, the magnetic sensor 3 is configured to be sandwiched between both ends 15s of the first gap 15g and both ends 25s of the second gap 25g, but as shown in FIG. When the magnetic sensor C53 has a width smaller than the first gap 15g or the second gap 25g, at least a part of the substrate C59 has both ends 15s of the first gap 15g (in other words, one end of the first magnetic core 15). And the other end) and both ends 25s of the second gap 25g (in other words, one end and the other end of the second magnetic core 25).

<Modification 6>
In the second embodiment, the first magnetic core 15 and the second magnetic core 25 are formed in a substantially rectangular ring shape. However, as shown in FIG. The second magnetic core C45 may be formed in a substantially circular ring shape.

<Modification 7>
In the second embodiment, the magnetic sensor 3 is arranged so as to face the first gap 15g, and is arranged so as to face the second gap 25g and the substrate 9, with the arrangement shown in FIG. As shown, the magnetic sensor 3 may be arranged so as to face the second gap 25g, and to face the first gap 15g with the substrate 9 interposed therebetween.

<Modification 8>
In the above embodiment, the GMR element using the giant magnetoresistive effect is suitably used as the magnetoresistive element in the above embodiment. However, as long as the magnetoresistive element has a sensitivity axis direction that can detect the same direction of magnetism. It may be an MR (Magneto Resistive) element, an AMR (Anisotropic Magneto Resistive) element, or a TMR (Tunnel Magneto Resistive) element.

  The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the scope of the object of the present invention.

1, 5 Magnetic core 11, 15, C11, C15, C35 1st magnetic core 11g, 15g, C11g 1st clearance 21, 25, C21, C22, C25, C45 2nd magnetic core 21g, 25g, C21g 1st 2 s 11 s, 15 s, 21 s, 25 s, C 11 s, C 21 s Both ends 3, C 13, C 33, C 53 Magnetic sensor 9, C 39, C 59

Claims (4)

A magnetic core that surrounds a current path to be measured and focuses a magnetic flux generated around the current path to be measured; a magnetic sensor that detects magnetism generated when a current flows through the current path to be measured; and A current sensor comprising a substrate to be mounted;
The magnetic core is composed of a soft magnetic material and has a first magnetic core having a first gap sandwiched between one end and the other end, and a second magnetic core composed of a soft magnetic material and sandwiched between the one end and the other end. A second magnetic core having a gap of
The first magnetic core and the second magnetic core are arranged so that the first gap and the second gap are adjacent to each other;
The magnetic sensor has a magnetoresistive element,
By disposing the magnetic sensor between the first gap and the second gap, the magnetic sensor or the substrate is disposed at one end of the first magnetic core and one end of the second magnetic core. A current sensor characterized in that at least a part of is sandwiched.   The current sensor according to claim 1, wherein a direction in which the first gap and the second gap are continuous is parallel to an axial direction of the current path to be measured.   The current sensor according to claim 2, wherein the first magnetic core and the second magnetic core have the same shape. The outer shape of the second magnetic core is smaller than the inner shape of the first magnetic core, and the second magnetic core is disposed within the inner shape of the first magnetic core;
The current sensor according to claim 1, wherein a direction in which the first gap and the second gap are continuous is perpendicular to an axial direction of the current path to be measured.

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