JP6051459B2 - Current sensor - Google Patents

Description

  The present invention relates to a current sensor that detects a magnetic field generated when a current flows and measures a current flowing in a current path to be measured, and more particularly to a current sensor that can suppress a decrease in accuracy due to the influence of a magnetic field from a neighboring current path. .

  In recent years, in order to control and monitor various devices, current sensors that are attached to various devices and measure currents flowing through the various devices are generally used. As this type of current sensor, a current sensor including a magnetic sensor using a magnetoelectric conversion element such as a magnetoresistive effect element or a Hall element that senses a magnetic field generated from a current to be measured flowing in a current path to be measured is well known. Yes.

  As the above-described current sensor, Patent Document 1 (conventional example) proposes a current measuring device (current sensor) 900 as shown in FIG. FIG. 14 is a diagram illustrating a measurement principle of a current measuring device 900 according to a conventional example, FIG. 14A is an explanatory diagram illustrating a configuration of the current measuring device 900, and FIG. 14B is a diagram illustrating a configuration in which the current measuring device 900 has one conductor. It is explanatory drawing integrated in 904a.

14A includes a Hall element 902a and a Hall element 902b (hereinafter collectively referred to as a pair of magnetic sensors) that detect a magnetic field generated by a current flowing through a conductor 904a (shown in FIG. 14B) that is a current measurement target. And a signal processing integrated circuit 903 that processes the detection output of the pair of magnetic sensors (902a, 902b), and these are mounted on a printed circuit board 901. Then, the magnetic sensitive surface 902p ₁ of the Hall element 902a and the magnetic sensitive surface 902p ₂ of the Hall element 902b (the surface extending in the Z direction shown in FIG. 14A) are the planes of the flat conductor 904a (the surfaces in the XY direction shown in FIG. 14A). A recess 910 provided in the printed circuit board 901 is assembled to one end of the conductor 904a so as to be substantially perpendicular to the conductor 904a. For this reason, the magnetic field 905a caused by the current flowing through the conductor 904a (arrow Xa shown in FIG. 14B) enters substantially perpendicular to the magnetic sensitive surfaces (902p ₁ and 902p ₂ ) of the pair of magnetic sensors, and this magnetic sensitive surface (902p ₁ and 902p ₁ and 902p ₂ ) perpendicular to the normal direction (Y direction shown in FIG. 14A), the magnetic sensing direction JD1 of the Hall element 902a (Y1 direction shown in FIG. 14A) and the magnetic sensitive direction JD2 of the Hall element 902b (shown in FIG. 14A). Y2 direction). Thereby, the magnetic field generated by the current flowing through the conductor 904a can be detected, and the signal processing integrated circuit 903 processes the detection outputs of the pair of magnetic sensors (902a, 902b) to calculate the current value flowing through the conductor 904a. I am doing so.

Further, since the positional relationship is as described above, as shown in FIG. 14B, the magnetic field 905b by the current (arrow Xb shown in FIG. 14B) flowing through the conductor (neighboring current path) 904b adjacent to the conductor 904a is to become substantially parallel to the magnetic sensitive surface (902P ₁ and 902P _2), Hall electromotive force caused thereby is an extremely small.

International Publication No. 2006/090769

However, a pair of magnetic sensors (902a, 902b) when viewed in detail the magnetic field 905b in the vicinity of, not in the parallel magnetic field 905b in the vicinity with respect to necessarily sensitive surface (902P ₁ and 902P _2). 15 is a schematic diagram showing the vicinity of a pair of magnetic sensors (902a, 902b) in a conventional example, and FIG. 15A shows a magnetic field 905b near the pair of magnetic sensors (902a, 902b) shown in FIG. 14B. FIG. 15B is a diagram showing a magnetic field 905a and a magnetic field 905b in the vicinity of the pair of magnetic sensors (902a, 902b) in the configuration of the eighth embodiment of the conventional example, and FIG. 15C is a diagram of the conventional example. It is the figure which showed the magnetic field 905a, the magnetic field 905b, and the magnetic field 905c near a pair of magnetic sensor (902a, 902b) by the structure (The conductor (neighboring current path) 904c is added) of Example 9. FIG. As shown in FIG. 15A, the magnetic field 905b entering the one magnetic sensor (Hall element 902a) is entered obliquely to the sensitive surface 902P _1, the magnetic field 905b enters the other magnetic sensor (Hall element 902b) , it has entered diagonally in the opposite direction with respect to the magnetic sensing surface 902p _2.

  In particular, in the Hall element 902a, the magnetic sensing direction JD1 of the Hall element 902a and the direction of the Y direction component of the magnetic field 905b are in agreement with each other, and in the Hall element 902b, the magnetic sensing direction JD2 of the Hall element 902b and the magnetic field are aligned. The direction of the Y direction component of 905b is in the same state as the Hall element 902a. That is, the influence of the magnetic field 905b by the adjacent conductor 904b is similarly applied to the magnetic sensing directions (JD1, JD2) of the respective magnetic sensors (Hall element 902a and Hall element 902b). For this reason, even if the detection information obtained from the pair of magnetic sensors is differentially processed, there is a problem in that the influence of the magnetic field 905b due to the adjacent conductor (neighboring current path) 904b cannot be eliminated.

Further, in order to solve this problem in which the magnetic field 905b (magnetic field 905c) in the vicinity is not parallel to the magnetic sensitive surfaces (902p ₁ and 902p ₂ ), measures as shown in FIGS. 15B and 15C are taken. Yes. However, the means for changing the angle of each of the pair of magnetic sensors (Hall element 902a and Hall element 902b) corresponding to its own magnetic field 905a and the nearby magnetic field 905b (magnetic field 905c) is laborious and substantial. It was not sustainable.

  The present invention solves the above-described problems, and an object of the present invention is to provide a current sensor that can suppress a decrease in measurement accuracy due to the influence of a magnetic field from a neighboring current path.

In order to solve this problem, a current sensor of the present invention includes a measured current path through which a measured current flows, a neighboring current path having a neighboring parallel section disposed in parallel with the measured current path, A current sensor comprising a first magnetic sensor and a second magnetic sensor for detecting a magnetic field generated when the current to be measured flows in a measurement current path, and a magnetic member for reducing the influence of an external magnetic field. The first magnetic sensor and the second magnetic sensor are disposed across a measured parallel segment section of the measured current path disposed in parallel with the neighboring parallel segment section, and the first magnetic sensor The direction of the current flowing in the measured side parallel section at the position sandwiched between the sensor and the second magnetic sensor is the X1 direction, the direction crossing the measured current path and the neighboring current path is the Y direction, From the second magnetic sensor to the first magnetism When the direction toward the sensor is the Z1 direction, the X1 direction, the Y direction, and the Z1 direction are orthogonal to each other, and a part of the neighboring current path is in the vicinity of the first magnetic sensor and the second magnetic sensor. It is bent to the Z1 direction side, and the magnetic member is provided only on the Z1 direction side from the first magnetic sensor.

  According to this, in the current sensor of the present invention, the neighboring parallel section of the neighboring current path and the measured parallel section of the measured current path are arranged in parallel in the X1 direction, and a part of the neighboring current path is arranged. Since the first magnetic sensor is bent in the Z1 direction side, the direction of the Z direction component of the magnetic flux generated by the current flowing in the neighboring current path at the position of the first magnetic sensor and the second magnetic sensor in the parallel side section to be measured is The position and the position of the second magnetic sensor can be in the same direction. For this reason, since the sensitivity axis directions of the first magnetic sensor 11 and the second magnetic sensor are the Y direction orthogonal to the Z direction, the Y direction component of the magnetic flux received by the first magnetic sensor and the second magnetic sensor can be reduced as much as possible. The Y direction component of the magnetic flux can be made uniform. As a result, differential processing by the first magnetic sensor and the second magnetic sensor can be facilitated. In addition, since the magnetic member is provided on the Z1 direction side of the first magnetic sensor, this influence can be reduced with respect to the first magnetic sensor that is strongly influenced by the magnetic field of the neighboring current path in the bent portion. it can. For this reason, the strength of the magnetic field received by the first magnetic sensor and the second magnetic sensor can be made the same. As a result, the magnetic field from the neighboring current path having the same direction and the same strength can be easily canceled by the differential processing, so that a decrease in measurement accuracy due to the influence of the magnetic field from the neighboring current path can be suppressed. .

The current sensor of the present invention is characterized in that the Y direction component of the magnetic flux received by the first magnetic sensor and the second magnetic sensor is uniform .

  The current sensor of the present invention is characterized in that a part of the measured current path is bent toward the Z1 direction in the vicinity of the first magnetic sensor and the second magnetic sensor.

  According to this, since a part of the current path to be measured is bent in the Z1 direction side, at the position of the first magnetic sensor and the second magnetic sensor in the parallel side section to be measured, the portion of the current path to be measured is bent. The direction of the Y direction component of the magnetic flux generated by the flowing current is the Y direction. For this reason, the direction of magnetic flux can be made the same direction at the position of the first magnetic sensor and the position of the second magnetic sensor, and Y of the magnetic flux in the Y direction that is the sensitivity axis direction of the first magnetic sensor and the second magnetic sensor. Directional components can be made equal. Thereby, the Y-direction component of the magnetic flux can be made uniform, and the differential processing can be made easier at the positions of the first magnetic sensor and the second magnetic sensor. As described above, since the magnetic field from the bent portion of the current path to be measured having the same direction and the same strength is easily canceled by the differential processing, it is possible to further suppress a decrease in measurement accuracy.

  In the current sensor of the present invention, the direction of the Z-direction component of the magnetic flux generated by the current flowing in the neighboring current path at the position of the first magnetic sensor and the second magnetic sensor in the parallel section to be measured is determined by the position of the first magnetic sensor. And in the same direction at the position of the second magnetic sensor. For this reason, since the sensitivity axis directions of the first magnetic sensor 11 and the second magnetic sensor are the Y direction orthogonal to the Z direction, the Y direction component of the magnetic flux received by the first magnetic sensor and the second magnetic sensor can be reduced as much as possible. The Y direction component of the magnetic flux can be made uniform. As a result, differential processing by the first magnetic sensor and the second magnetic sensor can be facilitated. Moreover, this influence can be reduced by the magnetic member with respect to the first magnetic sensor that is strongly influenced by the magnetic field of the neighboring current path of the bent portion. For this reason, the strength of the magnetic field received by the first magnetic sensor and the second magnetic sensor can be made the same. As a result, the magnetic field from the neighboring current path having the same direction and the same strength can be easily canceled by the differential processing, so that a decrease in measurement accuracy due to the influence of the magnetic field from the neighboring current path can be suppressed. .

It is a perspective view explaining the current sensor of a 1st embodiment of the present invention. It is a block diagram explaining the current sensor of 1st Embodiment of this invention, Comprising: It is the front view seen from the Z1 side shown in FIG. It is a block diagram explaining the current sensor of 1st Embodiment of this invention, Comprising: It is the side view seen from the X1 side shown in FIG. It is a figure explaining the current sensor of a 1st embodiment of the present invention, and is a model figure used for simulation. FIG. 5A is a schematic diagram illustrating the current sensor according to the first embodiment of the present invention, and FIG. 5A is a diagram illustrating a simulation result of the model of the first embodiment, and FIG. 5B is a simulation result of the model of the comparative example. FIG. It is a perspective view explaining the current sensor of a 2nd embodiment of the present invention. It is a block diagram explaining the current sensor of 2nd Embodiment of this invention, Comprising: It is the front view seen from the Z1 side shown in FIG. It is a block diagram explaining the current sensor of 2nd Embodiment of this invention, Comprising: It is the side view seen from the X1 side shown in FIG. It is a perspective view explaining the current sensor of a 3rd embodiment of the present invention. It is a block diagram explaining the current sensor of 3rd Embodiment of this invention, Comprising: FIG. 10A is the front view seen from the Z1 side shown in FIG. 9, FIG. 10B was seen from the Z2 side shown in FIG. It is a rear view. It is a block diagram explaining the current sensor of 3rd Embodiment of this invention, Comprising: It is the side view seen from the X1 side shown in FIG. It is a block diagram explaining the modification of the current sensor of this invention, Comprising: FIG. 12A is a front view of the modification 1 which changed the current sensor of 1st Embodiment, FIG. 12B is the electric current of 1st Embodiment. It is a side view of the modification 2 which changed the sensor. FIG. 13A is a configuration diagram illustrating a modified example of the current sensor of the present invention, FIG. 13A is a perspective view of Modified Example 3 in which the second embodiment is modified, and FIG. 13B is a modified example in which the second embodiment is modified. 4 is a perspective view of FIG. FIG. 14A is a diagram illustrating a measurement principle of a current measuring device according to a conventional example, FIG. 14A is an explanatory diagram illustrating a configuration of the current measuring device, and FIG. 14B is an explanatory diagram in which the current measuring device is incorporated into one conductor. is there. 15A is a schematic diagram showing the vicinity of a pair of magnetic sensors in a conventional example, FIG. 15A is an enlarged plan view showing a magnetic field in the vicinity of the pair of magnetic sensors shown in FIG. 14B, and FIG. It is a block diagram of Example 8, FIG. 15C is a block diagram of Example 9 of a prior art example.

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

[First Embodiment]
FIG. 1 is a perspective view illustrating a current sensor 101 according to the first embodiment of the present invention. FIG. 2 is a configuration diagram illustrating the current sensor 101 according to the first embodiment of the present invention, and is a front view seen from the Z1 side shown in FIG. FIG. 3 is a configuration diagram illustrating the current sensor 101 according to the first embodiment of the present invention, and is a side view seen from the X1 side shown in FIG. Note that only part of the measured current path CB1 and the neighboring current path NB shown in FIGS. 1 to 3 is shown.

  As shown in FIGS. 1 to 3, the current sensor 101 according to the first embodiment of the present invention includes a measured current path CB1 through which a measured current flows and a neighboring current path NB arranged in parallel with the measured current path CB1. A first magnetic sensor 11 and a second magnetic sensor 12 for detecting a magnetic field, and a magnetic member 15 for reducing the influence of an external magnetic field. In addition, the current sensor 101 is provided with a first substrate 19A on which the first magnetic sensor 11 is mounted and a second substrate 19B on which the second magnetic sensor 12 is mounted. Although not shown in the drawing, the housing for accommodating the current path CB1, the first magnetic sensor 11 and the second magnetic sensor 12, the magnetic member 15, the first substrate 19A and the second substrate 19B is provided as necessary. Used.

  The measured current path CB1 is made of a material having good conductivity such as copper (Cu), and as shown in FIGS. 1 and 3, a part of the measured current path CB1 is bent into an L shape. Yes. Further, the measured current path CB1 has a measured-side parallel section CB1p at a position sandwiched between the first magnetic sensor 11 and the second magnetic sensor 12.

  Here, assuming that the direction of the current flowing in the measured side parallel section CB1p is the X1 direction, as shown in FIG. 1, the measured side parallel section CB1p extends in the X direction and is orthogonal to the X direction. A first magnetic sensor 11 and a second magnetic sensor 12 are disposed in the Z direction, and a neighboring current path NB is disposed in the Y direction orthogonal to the X direction and the Z direction. The direction from the second magnetic sensor 12 toward the first magnetic sensor 11 is the Z1 direction. As a result, the bent direction of the measured current path CB1 is the Z1 direction side, and in the first embodiment of the present invention, the measured current path CB1 is bent at a right angle with respect to the measured parallel section CB1p.

  The neighboring current path NB is made of a material having good conductivity such as copper (Cu), and is arranged in parallel with the measured current path CB1 as shown in FIGS. 1 and 2, and further, a part of the neighboring current path NB. Is also bent in an L shape toward the Z1 direction.

  Further, the neighboring current path NB has a neighboring parallel section NBp arranged in parallel with the measured side parallel section CB1p, and the direction of the current flowing through the neighboring parallel section NBp is also the X1 direction. . Further, the direction crossing the measured current path CB1 and the neighboring current path NB is the Y direction. Moreover, in 1st Embodiment of this invention, like the to-be-measured electric current path CB1, it is bent at right angle with respect to the near side parallel section part NBp. In the configuration diagrams of FIGS. 1 and 2, the neighboring current path NB is arranged in parallel on the Y2 side of the measured current path CB1, but the Y1 side may be used instead of the Y2 side, and the Y1 side and Neighboring current paths NB may be arranged in parallel on both sides of Y2. Further, although copper (Cu) is used as the material of the measured current path CB1 and the neighboring current path NB, the material is not limited to this, and any material having good conductivity, such as aluminum (Al), may be used. good.

  The first magnetic sensor 11 and the second magnetic sensor 12 are sensors for detecting a magnetic field generated when a current to be measured flows through the current path CB1 to be measured. For example, a magnetic detection element using a giant magnetoresistance effect (Referred to as GMR (Giant Magneto Resistive) element) is packaged. Further, as described above, the first magnetic sensor 11 and the second magnetic sensor 12 are, as shown in FIGS. 1 and 3, the measured side of the measured current path CB1 arranged in parallel with the neighboring parallel section NBp. Arranged across the parallel section CB1p. Further, in the vicinity of the first magnetic sensor 11 and the second magnetic sensor 12, the first magnetic sensor 11 and the second magnetic sensor 12 are arranged so that a part of the neighboring current path NB is bent to the Z1 direction side. doing.

  In the first magnetic sensor 11 and the second magnetic sensor 12, after the GMR element is fabricated on the silicon substrate, the GMR element is cut out to form a chip, and the chip of the cut out GMR element and the lead for signal extraction are obtained. The terminals (11r, 12r) are electrically connected and packaged with a thermosetting synthetic resin. Since the GMR element has a property that the resistance value of the GMR element changes in accordance with the change of the magnetic field, the first magnetic sensor 11 and the second magnetic sensor 12 are measured from the change of the resistance value. By calculating the current flowing through the current path CB1, the current flowing through the measured current path CB1 can be measured.

  Further, the first magnetic sensor 11 and the second magnetic sensor 12 are soldered to lead terminals (11r, 12r) and a circuit pattern (not shown), and as shown in FIG. It is mounted on the first substrate 19A and the second substrate 19B that are arranged to face each other across the measured side parallel section CB1p. When the first substrate 19A and the second substrate 19B are disposed in the measured current path CB1, as shown in FIG. 2, the sensitivity axis direction KD1 of the first magnetic sensor 11 is the same as that of the measured current path CB1. As shown in FIG. 1, the sensitivity axis direction KD2 of the second magnetic sensor 12 is also arranged in the direction parallel to the width direction (Y2 direction in FIG. 2). It is arranged facing the direction parallel to the direction (Y2 direction in FIG. 1).

  The first substrate 19A and the second substrate 19B use a generally well-known single-sided printed wiring board, such as copper (Cu) provided on the base substrate on an epoxy resin base substrate containing glass. The metal foil is patterned to form a circuit pattern for configuring a circuit. In addition, although the printed wiring board which consists of an epoxy resin containing glass was used for 19A of 1st substrates and the 2nd board | substrate 19B, it is not limited to this, For example, a ceramic wiring board and a flexible wiring board may be used.

  The magnetic member 15 is made of silicon steel having a high magnetic permeability, and is provided closer to the Z1 direction than the first magnetic sensor 11 as shown in FIGS. And the influence of the external magnetic field from the Z1 side is reduced. In addition, although silicon steel was used as a material of the magnetic member 15, if it is a material which has a magnetic shielding effect, it will not restrict to this.

  Here, a simulation was performed on the influence of the magnetic field generated from the current flowing in the neighboring current path NB. FIG. 4 is a diagram illustrating the current sensor 101 according to the first embodiment of the present invention, and is a diagram of the model MD1 used for the simulation.

  As shown in FIG. 4, the numerical values of the model MD1 used in this simulation are the total length of the measured current path CB1 and the neighboring current path NB (not shown) being 60 (mm) and the total width W1. The thickness T1 of the measured side parallel section CB1p and the adjacent side parallel section NBp was 2 (mm) and was bent at a right angle at a length of 30 (mm). Further, the distance between the measured current path CB1 and the neighboring current path NB was set to 10 (mm). The first magnetic sensor 11 and the second magnetic sensor 12 are disposed at a position facing the center of the width W1 at a distance of 13 mm from the portion bent at a right angle of the measured current path CB1. The distance D1 between the center of the sensor 11 and the second magnetic sensor 12 and the measured current path CB1 is 2 (mm), respectively, and the distance D2 between the center of the first magnetic sensor 11 and the magnetic member 15 is 5 (mm). . The size of the magnetic member 15 was 20 (mm), the same width as the width W1 of the measured current path CB1, the length was 10 (mm), and the thickness T2 was 0.3 (mm). And the magnetic member 15 was arrange | positioned so that the 1st magnetic sensor 11 might become the center of the magnetic member 15. FIG. Although the current sensor 101 shown in FIGS. 1 to 3 is an embodiment of the model MD1, the neighboring current path NB is arranged on the Y1 side in performing the simulation. Further, the model MD1 shown in FIG. 4 is a view seen from the X1 side shown in FIG. 2, and the measured current path CB1 on the back side of the drawing is not shown for easy explanation.

  In addition, a simulation is performed for the comparative example, and the model of the comparative example is the same in the size of the measured current path CB1 and the neighboring current path NB, the arrangement distance of the first magnetic sensor 11 and the second magnetic sensor 12, and the like. The magnetic member 15 is not provided. Further, the measured current path CB1 and the neighboring current path NB are not bent in the Z1 direction side, but are extended in a direction penetrating the paper surface.

  FIG. 5 is a schematic diagram for explaining the current sensor according to the first embodiment of the present invention. FIG. 5A is a diagram showing a simulation result AA of the model MD1 of the first embodiment, and FIG. 5B is a comparison. It is the figure which showed the simulation result CC of the model of an example. FIG. 5 shows the flow of magnetic flux generated by the current flowing through the neighboring current path NB.

  As shown in the simulation result of FIG. 5A, at the positions of the first magnetic sensor 11 and the second magnetic sensor 12, the direction of the Z direction component of the magnetic flux generated by the current flowing through the neighboring current path NB in the measured side parallel section CB1p is determined. The position of the first magnetic sensor 11 and the position of the second magnetic sensor 12 can be set in the same direction. For this reason, since the sensitivity axis directions (KD1, KD2) of the first magnetic sensor 11 and the second magnetic sensor 12 are the Y direction orthogonal to the Z direction, the Y direction of the magnetic flux received by the first magnetic sensor 11 and the second magnetic sensor 12 The component can be made as small as possible, and the Y direction component of the magnetic flux can be made uniform.

  On the other hand, as shown in the simulation result of FIG. 5B, the direction of the Z-direction component of the magnetic flux generated by the current flowing through the neighboring current path NBC in the measured side parallel section CB1C depends on the position of the first magnetic sensor 11C and the second magnetic sensor. It is not facing the same direction at the position of 12C. For this reason, since the Y direction which is the sensitivity axis direction (KD1, KD2) of the first magnetic sensor 11C and the second magnetic sensor 12C is orthogonal to the Z direction, the magnetic flux received by the first magnetic sensor 11C and the second magnetic sensor 12C The Y direction component is large, and the Y direction component of the magnetic flux is different between the first magnetic sensor 11C and the second magnetic sensor 12C. This causes a large error in the differential processing by the first magnetic sensor 11C and the second magnetic sensor 12C.

  In addition, the magnetic member 15 can reduce this influence on the first magnetic sensor 11 that is strongly influenced by the magnetic field of the neighboring current path NB in a bent portion (back side of the drawing) not shown. .

  Further, in the current sensor 101 according to the first embodiment of the present invention, a part of the current path CB1 to be measured is bent toward the Z1 direction, so the first magnetic sensor 11 and the second magnetic sensor in the measured side parallel section CB1p. At the position of the sensor 12, the direction of the magnetic flux generated by the current flowing in the bent portion of the measured current path CB1 is the Y direction. For this reason, the direction of magnetic flux can be made the same direction in the position of the 1st magnetic sensor 11 and the position of the 2nd magnetic sensor 12, and the sensitivity axis direction (KD1, KD2) of the 1st magnetic sensor 11 and the 2nd magnetic sensor 12 ), The Y direction component of the Y direction magnetic flux can be made equal.

  The effects of the current sensor 101 according to the first embodiment of the present invention configured as described above will be described below.

  In the current sensor 101 according to the present invention, a neighboring parallel section NBp of the neighboring current path NB and a measured parallel section CB1p of the measured current path CB1 are arranged in parallel to the X1 direction, and a part of the neighboring current path NB. Is bent in the Z1 direction side, so that at the positions of the first magnetic sensor 11 and the second magnetic sensor 12, the direction of the Z direction component of the magnetic flux generated by the current flowing in the adjacent current path NB in the measured side parallel section CB1p is The first magnetic sensor 11 and the second magnetic sensor 12 can be in the same direction. For this reason, since the sensitivity axis directions (KD1, KD2) of the first magnetic sensor 11 and the second magnetic sensor 12 are the Y direction orthogonal to the Z direction, the Y direction of the magnetic flux received by the first magnetic sensor 11 and the second magnetic sensor 12 The component can be made as small as possible, and the Y direction component of the magnetic flux can be made uniform. As a result, differential processing by the first magnetic sensor 11 and the second magnetic sensor 12 can be facilitated. In addition, since the magnetic member 15 is provided on the Z1 direction side of the first magnetic sensor 11, this influence is exerted on the first magnetic sensor 11 that is strongly influenced by the magnetic field of the neighboring current path NB in the bent portion. Can be reduced. For this reason, the strength of the magnetic field received by the first magnetic sensor 11 and the second magnetic sensor 12 can be made the same. As a result, the magnetic field from the neighboring current path NB of the same direction and the same strength can be easily canceled by the differential processing, so that a decrease in measurement accuracy due to the influence of the magnetic field from the neighboring current path NB is suppressed. Can do.

  In addition, since a part of the measured current path CB1 is bent in the Z1 direction side, the measured current path CB1 is bent at the position of the first magnetic sensor 11 and the second magnetic sensor 12 in the measured side parallel section CB1p. The direction of the Y direction component of the magnetic flux generated by the current flowing through the portion is the Y direction. For this reason, the direction of magnetic flux can be made the same direction in the position of the 1st magnetic sensor 11 and the position of the 2nd magnetic sensor 12, and the sensitivity axis direction (KD1, KD2) of the 1st magnetic sensor 11 and the 2nd magnetic sensor 12 ), The Y direction component of the Y direction magnetic flux can be made equal. Thereby, the Y direction component of the magnetic flux can be made uniform, and the differential processing by the first magnetic sensor 11 and the second magnetic sensor 12 can be more easily performed at the positions of the first magnetic sensor 11 and the second magnetic sensor 12. Can do. As described above, since the magnetic field from the bent portion of the current path CB1 having the same strength in the same direction is easily canceled by the differential processing, it is possible to further suppress a decrease in measurement accuracy.

[Second Embodiment]
FIG. 6 is a perspective view illustrating the current sensor 102 according to the second embodiment of the present invention. FIG. 7 is a configuration diagram illustrating the current sensor 102 according to the second embodiment of the present invention, and is a front view seen from the Z1 side shown in FIG. FIG. 8 is a configuration diagram illustrating the current sensor 102 according to the second embodiment of the present invention, and is a side view seen from the X1 side shown in FIG. The current sensor 102 of the second embodiment is different from the first embodiment in the shape of the current path CB2 to be measured. In addition, about the same structure as 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. Further, the measured current path CB2 and the neighboring current path NB shown in FIGS. 6 to 8 show only a part thereof.

  As shown in FIGS. 6 to 8, the current sensor 102 according to the second embodiment of the present invention includes a measured current path CB2 through which the measured current flows and a neighboring current path NB arranged in parallel with the measured current path CB2. A first magnetic sensor 21 and a second magnetic sensor 22 for detecting a magnetic field, and a magnetic member 25 for reducing the influence of an external magnetic field. In addition, the current sensor 102 is provided with a first substrate 19A on which the first magnetic sensor 11 is mounted and a second substrate 19B on which the second magnetic sensor 12 is mounted. Although not shown, the housing for accommodating the measured current path CB2, the first magnetic sensor 21 and the second magnetic sensor 22, the magnetic member 25, the first substrate 19A and the second substrate 19B is provided as necessary. Used.

  The measured current path CB2 is formed using a material having good conductivity such as copper (Cu) and extending in the X direction as shown in FIGS. Further, the measured current path CB2 has a measured-side parallel section CB2p at a position sandwiched between the first magnetic sensor 21 and the second magnetic sensor 22. And the direction of the electric current which flows into to-be-measured side parallel area part CB2p is the direction which turned to X1 direction from the X2 side.

  The neighboring current path NB is made of a material having good conductivity such as copper (Cu), and is arranged in parallel with the measured current path CB2 as shown in FIGS. 6 to 8, and further, a part of the neighboring current path NB. Is bent in an L shape toward the Z1 direction.

  Further, the neighboring current path NB has a neighboring parallel section NBp arranged in parallel with the measured side parallel section CB2p, and the direction of the current flowing in the neighboring parallel section NBp is also the X1 direction. . Further, the direction crossing the measured current path CB2 and the neighboring current path NB is the Y direction. Moreover, in 2nd Embodiment of this invention, it is bent at right angle with respect to the neighborhood side parallel area part NBp. 6 and 7, the neighboring current path NB is arranged in parallel on the Y2 side of the current path CB2 to be measured. However, the neighboring current path NB is not limited to the Y2 side, and may be on the Y1 side, Neighboring current paths NB may be arranged in parallel on both sides of Y2. Further, although copper (Cu) is used as the material of the current path CB2 and the neighboring current path NB, the material is not limited to this, and any material having good conductivity may be used. For example, aluminum (Al) or the like may be used. good.

  The first magnetic sensor 21 and the second magnetic sensor 22 are sensors that detect a magnetic field generated when a current to be measured flows through the current path CB2 to be measured. MR (Magneto Resistive) element) is packaged.

  As described above, the first magnetic sensor 21 and the second magnetic sensor 22 are, as shown in FIGS. 6 and 8, the measured side of the measured current path CB2 arranged in parallel with the neighboring parallel section NBp. Arranged across the parallel section CB2p. Further, in the vicinity of the first magnetic sensor 21 and the second magnetic sensor 22, the first magnetic sensor 21 and the second magnetic sensor 22 are arranged so that a part of the neighboring current path NB is bent to the Z1 direction side. doing. The first magnetic sensor 21 and the second magnetic sensor 22 are arranged by mounting the first magnetic sensor 21 and the second magnetic sensor 22 on the first substrate 19A and the second substrate 19B, respectively. This can be easily achieved by placing the second substrate 19B in contact with the measured side parallel section CB2p of the measured current path CB2.

  As the magnetic member 25, a plate-shaped member obtained by dispersing a flat magnetic powder in a synthetic resin such as ABS (acrylonitrile butadiene styrene) or PP (polypropylene) and molded by injection molding or the like is shown in FIGS. As shown, the first magnetic sensor 21 is provided on the Z1 direction side. And the influence of the external magnetic field from the Z1 side is reduced. In addition, although the thing which disperse | distributed flat magnetic powder to the synthetic resin was used as a material of the magnetic member 25, if it is a material which has a magnetic shielding effect, it will not restrict to this.

  The current sensor 102 configured as described above is similar to the simulation result AA shown in FIG. 5A of the current sensor 101 according to the first embodiment, at the positions of the first magnetic sensor 21 and the second magnetic sensor 22. The direction of the Z-direction component of the magnetic flux generated by the current flowing in the neighboring current path NB in the parallel section CB2p can be set to the same direction at the position of the first magnetic sensor 21 and the position of the second magnetic sensor 22. For this reason, since the sensitivity axis directions (KD1, KD2) of the first magnetic sensor 21 and the second magnetic sensor 22 are the Y direction orthogonal to the Z direction, the Y direction of the magnetic flux received by the first magnetic sensor 21 and the second magnetic sensor 22 The component can be made as small as possible, and the Y direction component of the magnetic flux can be made uniform.

  In addition, the magnetic member 25 can reduce this influence on the first magnetic sensor 21 that is strongly influenced by the magnetic field of the neighboring current path NB in the bent portion (the back side of the drawing) (not shown). .

  The effects of the current sensor 102 according to the second embodiment of the present invention configured as described above will be described below.

  In the current sensor 102 of the present invention, the neighboring parallel section NBp of the neighboring current path NB and the measured side parallel section CB2p of the measured current path CB2 are arranged in parallel to the X1 direction, and a part of the neighboring current path NB. Is bent in the Z1 direction side, so that the direction of the Z direction component of the magnetic flux generated by the current flowing in the adjacent current path NB in the measured side parallel section CB2p at the position of the first magnetic sensor 21 and the second magnetic sensor 22 is The first magnetic sensor 21 and the second magnetic sensor 22 can be in the same direction. For this reason, since the sensitivity axis directions (KD1, KD2) of the first magnetic sensor 21 and the second magnetic sensor 22 are the Y direction orthogonal to the Z direction, the Y direction of the magnetic flux received by the first magnetic sensor 21 and the second magnetic sensor 22 The component can be made as small as possible, and the Y direction component of the magnetic flux can be made uniform. As a result, differential processing by the first magnetic sensor 21 and the second magnetic sensor 22 can be facilitated. In addition, since the magnetic member 25 is provided on the Z1 direction side of the first magnetic sensor 21, this influence is exerted on the first magnetic sensor 21 that is strongly influenced by the magnetic field of the neighboring current path NB in the bent portion. Can be reduced. For this reason, the strength of the magnetic field received by the first magnetic sensor 21 and the second magnetic sensor 22 can be made the same. As a result, the magnetic field from the neighboring current path NB of the same direction and the same strength can be easily canceled by the differential processing, so that a decrease in measurement accuracy due to the influence of the magnetic field from the neighboring current path NB is suppressed. Can do.

[Third Embodiment]
FIG. 9 is a perspective view illustrating the current sensor 103 according to the third embodiment of the present invention. FIG. 10 is a configuration diagram illustrating the current sensor 103 according to the third embodiment of the present invention, in which FIG. 10A is a front view seen from the Z1 side shown in FIG. 9, and FIG. 10B is shown in FIG. It is the rear view seen from the Z2 side. FIG. 11 is a configuration diagram illustrating the current sensor 103 according to the third embodiment of the present invention, and is a side view seen from the X1 side shown in FIG. Further, the current sensor 103 of the third embodiment differs from the first embodiment in the shape of the current path CB3 to be measured and the configuration of the magnetic member 35. In addition, about the same structure as 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. Further, only part of the measured current path CB3 and the neighboring current path NB shown in FIGS. 9 to 11 are shown.

  As shown in FIGS. 9 to 11, the current sensor 103 according to the third embodiment of the present invention includes a measured current path CB3 through which a measured current flows, and a neighboring current path NB arranged in parallel with the measured current path CB3. And a first magnetic sensor 31 and a second magnetic sensor 32 for detecting a magnetic field, and a magnetic member 35 for reducing the influence of an external magnetic field. In addition, the current sensor 103 is provided with a first substrate 19A on which the first magnetic sensor 31 is mounted and a second substrate 19B on which the second magnetic sensor 32 is mounted. Although not shown, the housing for accommodating the current path CB3 to be measured, the first magnetic sensor 31 and the second magnetic sensor 32, the magnetic member 35, the first substrate 19A and the second substrate 19B is provided as necessary. Used.

  The measured current path CB3 is formed using a material having good conductivity such as copper (Cu) and extending in the X direction as shown in FIGS. Further, the measured current path CB3 has a measured-side parallel section CB3p at a position sandwiched between the first magnetic sensor 31 and the second magnetic sensor 32.

  Here, assuming that the direction of the current flowing in the measured side parallel section CB3p is the X1 direction, as shown in FIG. 9, the measured side parallel section CB3p extends in the X direction and is orthogonal to the X direction. The first magnetic sensor 31 and the second magnetic sensor 32 are arranged in the Z direction. In addition, the neighboring current path NB is disposed in the Y direction orthogonal to the X direction and the Z direction, respectively. The direction from the second magnetic sensor 32 toward the first magnetic sensor 31 is the Z1 direction.

  The neighboring current path NB is made of a material having good conductivity such as copper (Cu), and is arranged in parallel with the measured current path CB3 as shown in FIGS. 9 to 11, and further, a part of the neighboring current path NB. Is bent in an L shape toward the Z1 direction.

  Further, the neighboring current path NB has a neighboring side parallel section NBp arranged in parallel with the measured side parallel section CB3p, and the direction of the current flowing through the neighboring parallel section NBp is also the X1 direction. . Further, the direction crossing the measured current path CB3 and the neighboring current path NB is the Y direction. Moreover, in 3rd Embodiment of this invention, it is bent at right angle with respect to the neighborhood side parallel area part NBp. In the configuration diagrams of FIGS. 9 and 10, the neighboring current path NB is arranged in parallel on the Y2 side of the current path CB3 to be measured, but the Y1 side may be used instead of the Y2 side, and the Y1 side and Neighboring current paths NB may be arranged in parallel on both sides of Y2. In addition, although copper (Cu) is used as the material of the current path CB3 and the neighboring current path NB, the material is not limited to this, and any material having good conductivity may be used, such as aluminum (Al). good.

  The first magnetic sensor 31 and the second magnetic sensor 32 are sensors that detect a magnetic field generated when a current to be measured flows through the current path CB3 to be measured. AMR (Anisotropic Magneto Resistive) element) is packaged.

  As described above, the first magnetic sensor 31 and the second magnetic sensor 32 are, as shown in FIGS. 9 to 11, the measured side of the measured current path CB3 arranged in parallel with the neighboring parallel section NBp. Arranged across the parallel section CB3p. Further, in the vicinity of the first magnetic sensor 31 and the second magnetic sensor 32, the first magnetic sensor 31 and the second magnetic sensor 32 are arranged so that a part of the neighboring current path NB is bent to the Z1 direction side. doing. The first magnetic sensor 31 and the second magnetic sensor 32 are disposed by mounting the first magnetic sensor 31 and the second magnetic sensor 32 on the first substrate 19A and the second substrate 19B, respectively. This can be easily achieved by placing the second substrate 19B in contact with the measured side parallel section CB3p of the measured current path CB3.

  As shown in FIGS. 9 to 11, the magnetic member 35 includes a first magnetic member 35 </ b> A and a second magnetic member 35 </ b> B, and the first magnetic member 35 </ b> A is in the Z <b> 1 direction more than the first magnetic sensor 31. The second magnetic member 35B is provided on the Z2 direction side opposite to the Z1 direction side with respect to the second magnetic sensor 32. The first magnetic member 35A reduces the influence of the external magnetic field from the Z1 side, and the second magnetic member 35B reduces the influence of the external magnetic field from the Z2 side.

  Further, the second magnetic member 35B is configured to be smaller than the first magnetic member 35A. Thereby, the influence of the external magnetic field from the Z1 side is further reduced.

  The magnetic member 35 is manufactured by applying the ink in which the flat magnetic powder is dispersed to one surface of the insulating base 35k, and drying and curing the magnetic shield layer 35r. Although the magnetic shield layer 35r is used as the material of the magnetic member 35, the material is not limited to this as long as the material has a magnetic shield effect.

  The current sensor 103 configured as described above is the same as the simulation result AA shown in FIG. 5A of the current sensor 101 of the first embodiment, at the positions of the first magnetic sensor 31 and the second magnetic sensor 32. The direction of the Z-direction component of the magnetic flux generated by the current flowing through the neighboring current path NB in the parallel section CB3p can be set to the same direction at the position of the first magnetic sensor 31 and the position of the second magnetic sensor 32. For this reason, since the sensitivity axis directions (KD1, KD2) of the first magnetic sensor 31 and the second magnetic sensor 32 are the Y direction orthogonal to the Z direction, the Y direction of the magnetic flux received by the first magnetic sensor 31 and the second magnetic sensor 32 The component can be made as small as possible, and the Y direction component of the magnetic flux can be made uniform.

  In addition, the first magnetic member 35A reduces this influence on the first magnetic sensor 31 that is strongly affected by the magnetic field of the neighboring current path NB in a bent portion (the back side of the drawing) that is not illustrated. Can do.

  The effects of the current sensor 103 according to the third embodiment of the present invention configured as described above will be described below.

  In the current sensor 103 of the present invention, the neighboring parallel section NBp of the neighboring current path NB and the measured side parallel section CB3p of the measured current path CB3 are arranged in parallel in the X1 direction, and a part of the neighboring current path NB. Is bent in the Z1 direction side, so that at the positions of the first magnetic sensor 31 and the second magnetic sensor 32, the direction of the Z direction component of the magnetic flux generated by the current flowing in the adjacent current path NB in the measured side parallel section CB3p is The first magnetic sensor 31 and the second magnetic sensor 32 can be in the same direction. For this reason, since the sensitivity axis directions (KD1, KD2) of the first magnetic sensor 31 and the second magnetic sensor 32 are the Y direction orthogonal to the Z direction, the Y direction of the magnetic flux received by the first magnetic sensor 31 and the second magnetic sensor 32 The component can be made as small as possible, and the Y direction component of the magnetic flux can be made uniform. As a result, differential processing by the first magnetic sensor 31 and the second magnetic sensor 32 can be facilitated. In addition, the first magnetic member 35A is provided on the Z1 direction side of the first magnetic sensor 31, and the second magnetic member 35B provided on the Z2 direction side of the second magnetic sensor 32 is smaller than the first magnetic member 35A. This effect can be reduced with respect to the first magnetic sensor 31 that is strongly influenced by the magnetic field of the adjacent current path NB in the portion that is provided, and the influence of the external magnetic field from the Z1 side that is received by the first magnetic sensor 31 The influence of the external magnetic field from the Z2 side received by the second magnetic sensor 32 can be reduced in a well-balanced manner. For this reason, the strength of the magnetic field received by the first magnetic sensor 31 and the second magnetic sensor 32 can be made the same. As a result, the magnetic field from the neighboring current path NB of the same direction and the same strength can be easily canceled by the differential processing, so that a decrease in measurement accuracy due to the influence of the magnetic field from the neighboring current path NB is suppressed. Can do. Furthermore, since the first magnetic member 35A and the second magnetic member 35B are provided for the first magnetic sensor 31 and the second magnetic sensor 32, respectively, the first magnetic sensor 31 and the second magnetic sensor 32 are magnetically shielded. The influence from the external magnetic field from other than the neighboring current path NB 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. 12 is a configuration diagram illustrating a modification of the current sensor of the present invention, and FIG. 12A is a front view of a current sensor C111 of Modification 1 in which the current sensor 101 of the first embodiment is changed. 12B is a side view of a current sensor C121 of Modification 2 in which the current sensor 101 of the first embodiment is changed. For ease of explanation, the magnetic member C15 and the first substrate 19C shown in FIG. 12B are indicated by broken lines. FIG. 13 is a configuration diagram illustrating a modification of the current sensor according to the present invention, and FIG. 13A is a perspective view of a current sensor C132 of Modification 3 in which the current sensor 102 of the second embodiment is changed. 13B is a perspective view of a current sensor C142 of Modification 4 in which the current sensor 102 of the second embodiment is changed.

<Modification 1>
In the first embodiment, the first magnetic sensor 11 and the second magnetic sensor 12 are not disposed in the neighboring current path NB, and the first magnetic sensor 11 and the second magnetic sensor 12 are disposed only in the measured current path CB1. Two magnetic sensors 12 are provided. However, as shown in FIG. 12A, the magnetic sensors (M11, M12, M13, M14, M15) may be arranged in adjacent current paths (B11, B12, B13, B14, B15), respectively. Although not shown, the magnetic sensors (M21, M22, M22, M13, M14, M15) are also positioned at positions that oppose each other across the current path (B11, B12, B13, B14, B15). , M23, M24, M25).

  Thus, the current path B11 is regarded as the current path to be measured, the magnetic sensor M11 is regarded as the first magnetic sensor, the magnetic sensor M21 is regarded as the second magnetic sensor, and the current path B12 is regarded as the neighboring current path. The current path B12 is regarded as a current path to be measured, the magnetic sensor M12 is regarded as a first magnetic sensor, the magnetic sensor M22 is regarded as a second magnetic sensor, and the current path B11 and the current path B13 are regarded as neighboring current paths. The current path B13 is regarded as a current path to be measured, the magnetic sensor M13 is regarded as a first magnetic sensor, the magnetic sensor M23 is regarded as a second magnetic sensor, and the current path B12 and the current path B14 are regarded as neighboring current paths. Hereinafter, the current path B14 and the current path B15 are regarded in the same manner.

<Modification 2>
The configuration of the current sensor 101 of the first embodiment may be a current sensor C121 in which a second magnetic shield C15B is further provided on the Z2 side of the second magnetic sensor 12.

<Modification 3>
In the second embodiment, a set of the measured current path CB2 and the neighboring current path NB are configured. However, the present invention is not limited thereto, and as shown in FIG. 13A, a plurality of measured current paths (CB2 ₁ , CB2 ₁ ). And a plurality of neighboring current paths (NB ₁ , NB ₂ , NB ₃ ) may be combined.

<Modification 4>
In the second embodiment, a set of the first magnetic sensor 21 and the second magnetic sensor 22 is arranged in one set of the current path CB2a and the neighboring current path NBa. However, the present invention is not limited to this. As shown in FIG. 13B, one of the current paths CB2a to be measured may be bent, and a first magnetic sensor (not shown) and a second magnetic sensor 22a may be disposed in the neighboring current path NBa in the vicinity thereof. . In that case, the current path CB2a in that portion is regarded as a neighboring current path, and the neighboring current path NBa in that portion is regarded as a current path to be measured.

  This combination is not limited to one set, and as shown in FIG. 13B, a plurality of current paths to be measured (CB2a, CB2b), a plurality of neighboring current paths (NBa, NBb, NBc), and a plurality of first magnetic sensors ( A structure in which the second magnetic sensor (22a, 22b, 22c) is combined may be used.

<Modification 5>
In the above embodiment, the first substrate 19A and the second substrate 19B are arranged in contact with the current path to be measured (CB1, CB2, CB3), but may be arranged separately. Moreover, you may arrange | position so that a 1st magnetic sensor (11, 21, 31) and a 2nd magnetic sensor (12, 22, 32) may oppose to a to-be-measured electric current path (CB1, CB2, CB3).

<Modification 6>
In the said embodiment, a 1st magnetic sensor (11, 21, 31) and a 2nd magnetic sensor (12, 22, 32) are packaged with a thermosetting synthetic resin, and a magnetic sensor package (14, 24, 34). Although mounted on the first substrate 19A and the second substrate 19B, the GMR element, the MR element, and the AMR element may be mounted on the first substrate 19A and the second substrate 19B as they are, that is, so-called bare chip mounting.

<Modification 7>
In the above-described embodiment, the neighboring current path NB or the measured current path CB1 is bent at a right angle, but is not limited to a right angle.

  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.

11, 21, 31 First magnetic sensor 12, 22, 32, 22a, 22b, 22c Second magnetic sensor 15, 25, 35, C15 Magnetic member 35A First magnetic member 35B, C15B Second magnetic member CB1, CB2, CB3 _{, CB2 1, CB2 1, CB2a} , CB2b measured current path CB1p, CB2p, CB3p measured side parallel section portion _{NB, NB 1, NB 2,} NB 3, NBa, NBb, NBc close current paths NBp close side parallel section portion 101, 102, 103, C111, C121, C132, C142 Current sensor

Claims (3)

A measured current path through which the measured current flows; and
A neighboring current path having a neighboring parallel section disposed in parallel with the measured current path;
A first magnetic sensor and a second magnetic sensor for detecting a magnetic field generated when the measured current flows through the measured current path;
A current sensor comprising a magnetic member for reducing the influence of an external magnetic field,
The first magnetic sensor and the second magnetic sensor are disposed across a measured-side parallel section of the measured current path disposed in parallel with the neighboring-side parallel section,
The direction of the current flowing through the measured side parallel section at the position sandwiched between the first magnetic sensor and the second magnetic sensor is the X1 direction,
A direction crossing the measured current path and the neighboring current path is a Y direction,
When the direction from the second magnetic sensor toward the first magnetic sensor is the Z1 direction,
The X1 direction, the Y direction, and the Z1 direction are orthogonal to each other,
In the vicinity of the first magnetic sensor and the second magnetic sensor, a part of the neighboring current path is bent toward the Z1 direction side,
The current sensor, wherein the magnetic member is provided only on the Z1 direction side of the first magnetic sensor. 2. The current sensor according to claim 1, wherein Y-direction components of magnetic flux received by the first magnetic sensor and the second magnetic sensor are equal.   3. The current sensor according to claim 1, wherein a part of the current path to be measured is bent toward the Z <b> 1 direction in the vicinity of the first magnetic sensor and the second magnetic sensor.

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