JP6671985B2 - Current sensor - Google Patents

Description

  The present invention relates to a current sensor that detects a current flowing through a conductor.

  Patent Literature 1 discloses a current sensor in which a through hole is provided in a conductor serving as a current path (bus bar), and two magnetic sensors are provided in the through hole. In this current sensor, since two magnetic sensors are provided close to each other, even if there is a magnetic noise source that causes a spatially biased external magnetic field (magnetic field that is a noise), an external noise generated near the two magnetic sensors may occur. The magnetic fields can be almost equal. Therefore, by calculating the difference between the magnetic field detection results near the two magnetic sensors, the magnetic field component of the external magnetic field can be removed, and the measurement error can be reduced.

JP 2006-184269 A JP-A-9-93771 JP-A-10-73619 JP 2003-28899 A JP 2010-85228 A JP 2010-112767 A JP 2010-117165 A JP 2010-121983 A JP 2014-55790 A JP-A-2005-72124 JP 2015-135267 A JP 2015-137892 A JP 2015-137894 A

  However, in the above-described conventional current sensor, if the two magnetic sensors are too close to each other, there is a problem that the difference between the induced magnetic fields generated in the vicinity of the two magnetic sensors is reduced, and the S / N characteristics are reduced.

  Patent Documents 2 to 13 disclose current sensors having a configuration in which a bus bar is divided by an opening. However, in the current sensors disclosed in Patent Documents 2 to 13, the height (thickness) is smaller than the width of the opening, and the magnetic flux density gradient in the opening is small. Therefore, if the two magnetic sensors are too close to each other, the difference between the induced magnetic fields generated in the vicinity of the two magnetic sensors becomes small, and there is a problem that the S / N characteristics are reduced.

  An object of the present invention is to provide a current sensor that can detect a current flowing through a conductor with high accuracy while suppressing the influence of an external magnetic field.

In order to solve the above-mentioned problems of the related art and achieve the above-described object, the current sensor of the present invention is configured such that current inflow portions and current outflow portions are electrically connected to each other and extend in parallel with each other. the first conductor section and a second conductor portion, the first conductor portion and said first conductor portion and the non-conductive region formed between the second conductor portion and the second for standing A first magnetic sensor and a second magnetic sensor that are provided at different positions with respect to each other and detect an induced magnetic field generated by a current flowing through the first conductor and the second conductor. Sensors and
The a, a non-conductive region width x which is the distance between the width and becomes the second conductor portion and the first conductor portion of the non-conductive region, wherein the direction of the non-conductive region width x The following expression (1) with the height t in the direction perpendicular to both the current direction of the first conductor and the second conductor.
[Equation 1]
R = t / x (1)
The ratio R represented by the following formula (2)
[Equation 2]
1/4 ≦ R ≦ 1 (2)
The filling,
The first magnetic sensor is provided closer to the first conductor than the second magnetic sensor,
The second magnetic sensor is provided closer to the second conductor than the first magnetic sensor,
The first conductor portion and the second conductor portion are plane-symmetric with respect to an imaginary plane along both the height direction and the current flowing direction,
The distance between the first conductor and the first magnetic sensor is equal to the distance between the second conductor and the second magnetic sensor,
The ratio R is defined such that the magnetic flux density gradient at the center in the direction of the non-conductive region width x in the non-conductive region is maximized in the range of the expression (2).

According to this configuration, the first magnetic sensor and the second magnetic sensor are provided with the opposite magnetic fields from the first conductive unit and the second conductive unit, respectively. An external magnetic field having substantially the same size and substantially the same direction is applied to the first magnetic sensor and the second magnetic sensor.
Therefore, the value of the current flowing through the first conductor and the second conductor can be calculated from the difference between the detection results of the first magnetic sensor and the second magnetic sensor.
In addition, according to this configuration, the magnetic flux density gradient in the non-conductor region where the first magnetic sensor and the second magnetic sensor are located can be increased, so that the first magnetic sensor and the second magnetic sensor have the first magnetic sensor. The difference between the induced magnetic fields of the current flowing through the conductive portion and the second conductive portion can be increased, and high measurement accuracy can be obtained.

  Further, according to this configuration, the magnetic flux density gradient in the non-conductor region where the first magnetic sensor and the second magnetic sensor are located can be increased, so that the first magnetic sensor and the second magnetic sensor can be brought closer. As a result, the influence of an external magnetic field generated on both magnetic sensors can be removed with high accuracy, and high measurement accuracy can be realized.

  According to this configuration, in order to maximize the magnetic flux density gradient in the non-conductive region, the first magnetic sensor and the second magnetic sensor can be brought closest to each other, and the influence of an external magnetic field can be removed. The difference between the induced magnetic fields of the currents flowing through the first conductive part and the second conductive part, which occur in the first magnetic sensor and the second magnetic sensor, can be maximized, and high measurement accuracy can be obtained. .

  According to this configuration, the first conductor and the second conductor are plane-symmetric with respect to the virtual plane, and a distance between the first conductor and the first magnetic sensor; The distance between the second conductor and the second magnetic sensor is equal. Therefore, the first magnetic sensor and the second magnetic sensor can be easily positioned, high-precision measurement can be performed with high positioning accuracy, and the manufacturing cost can be reduced.

Preferably, in the current sensor of the present invention, R satisfies the following expression (3).
[Equation 3]
0. 4 ≦ R ≦ 0.6 (3)

Preferably, in the current sensor of the present invention, a cross section of the first conductor portion and the second conductor portion orthogonal to the current direction is rectangular.
According to this configuration, if the cross sections of the first conductor portion and the second conductor portion on the current input side and the current outflow side are rectangular, a relatively simple shape can be obtained. Can be easy.

Current sensor preferably present invention, in cross-section a rectangular plate shape, has a conductor opening that extends to the current direction is formed, the opening is perpendicular to the current direction in the conductor The first conductor portion is formed in the center of the opening width direction with respect to the opening portion, and one of the opening width directions with respect to the opening portion is the first conductor portion, and the other in the opening width direction with respect to the opening portion is the a second conductor portion, wherein the opening is in the non-conductive region.
According to this configuration, the first conductor portion and the second conductor portion can be relatively easily formed by relatively simple processing of forming an opening in the plate-shaped conductor having a rectangular cross section.

Preferably, the current sensor of the present invention calculates a current flowing through the first conductor and the second conductor from a difference between detection results of the first magnetic sensor and the second magnetic sensor. Further comprising a part.
According to this configuration, the influence of the external magnetic field can be removed by calculating the difference between the detection results of the first magnetic sensor and the second magnetic sensor.

Preferably, in the current sensor of the present invention, the first conductor portion and the second conductor portion are separate bodies, and the current inflow portions and the current outflow portions are electrically connected directly or indirectly. And a surface that forms the long side of the first conductor portion and extends along the flow direction and a surface that forms the long side of the second conductor portion and extends along the flow direction face each other. I have.
According to this configuration, the height of the non-conductive region can be increased by simple processing by simply increasing the long sides of the rectangular cross section of the first conductor and the second conductor. That is, when forming a non-conductive region by hollowing out one conductor, processing is difficult if the hollowing is deep, but the present invention does not require hollowing out and can be made simple and inexpensive.

Preferably, the first conductor portion and the second conductor portion of the current sensor of the present invention have a flat plate shape.
According to this configuration, since the first conductor and the second conductor are flat, the height of the non-conductive region can be increased by simple processing.

Preferably, in the current sensor according to the present invention, the first conductor is flat, and the second conductor is bent to form the non-conductor region between the first conductor and the first conductor. Having a part.
According to this configuration, the distance between the first conductor and the second conductor in the non-conductive region can be increased by providing the second conductor with a bent portion. .

  Preferably, in the current sensor according to the present invention, the first conductor and the second conductor are electrically directly joined at both ends of the non-conductive region in the flow direction.

  Preferably, the second conductor portion of the current sensor according to the present invention includes a first flat plate portion in contact with the first conductor portion, a second flat plate portion in contact with the first conductor portion, A third flat plate portion positioned parallel to and separated from the first conductor portion, a fourth flat plate portion interposed between the first flat plate portion and one end of the third flat plate portion, A second flat plate portion and a fifth flat plate portion interposed between the other end of the third flat plate portion, the first flat plate portion, the fourth flat plate portion, and the third flat plate portion. And the fourth flat plate portion, the second flat plate portion and the fifth flat plate portion, and the third flat plate portion and the fifth flat plate portion form the bent portion.

According to this configuration, by providing both the first conductor portion and the second conductor portion with the bent portion, the distance between the first conductor portion and the second conductor portion can be simplified. With a simple configuration, the length can be increased.
According to this configuration, since the current inflow portion and the current outflow portion are directly connected to each other by the first conductor portion and the second conductor portion, the first conductor portion and the second conductor portion are connected to each other. There is no need to separately provide a conductive part for connecting the parts, and the configuration can be simplified and inexpensive.
According to this configuration, in the non-conductive region, the spread pattern of the intensity of the induced magnetic field generated from both the first conductor portion and the second conductor portion becomes the same, so that the vicinity of the center of the non-conductive region Magnetic flux density gradient approaches a straight line, and it is easy to design to increase measurement accuracy.

Preferably, in the current sensor of the present invention, the first conductor and the second conductor are plane-symmetric with respect to a virtual plane along both the long side direction and the flow direction. In the cross-sectional direction, the distance between the first conductor and the first magnetic sensor is equal to the distance between the second conductor and the second magnetic sensor.
According to this configuration, the first magnetic sensor and the second magnetic sensor can be easily positioned, high-precision measurement can be performed with high positioning accuracy, and the manufacturing cost can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the influence of an external magnetic field can be offset and the current sensor which can detect the electric current which flows through a conductor with high precision can be provided.

FIG. 1 is a perspective view illustrating the configuration of the current sensor according to the first embodiment of the present invention. FIG. 2 is a sectional view taken along a sectional line AA shown in FIG. FIG. 3 is a diagram for explaining distribution of a magnetic field generated by a current flowing through the conductive unit in FIG. FIG. 4 is a diagram for explaining the ratio of the length of each part in FIG. FIG. 5 is a diagram for explaining the magnetic flux density distribution in the non-conductive region of the current sensor shown in FIG. FIG. 6 is a diagram showing the relationship between the height t of the non-conductive region and the magnetic flux density gradient when the width x of the non-conductive region of the current sensor shown in FIG. 1 is 5 mm. FIG. 7 is a diagram showing the relationship between the ratio R of the non-conductive region and the magnetic flux density gradient of the current sensor shown in FIG. FIG. 8 is a diagram for explaining the influence of an external magnetic field from an adjacent conductor of the current sensor shown in FIG. FIG. 9 is a diagram for explaining the relationship between the distance between the first magnetic sensor and the second magnetic sensor shown in FIG. 1 and the difference calculated by the processing unit. FIG. 10 is a diagram for explaining the current sensor according to the second embodiment of the present invention. FIG. 11 is a flowchart for explaining a manufacturing process of the current sensor shown in FIG. FIG. 12 is a diagram for explaining a current sensor according to the third embodiment of the present invention. FIG. 13 is a view for explaining a current sensor according to the fourth embodiment of the present invention.

Hereinafter, a current sensor according to an embodiment of the present invention will be described.
FIG. 1 is a perspective view for explaining a configuration of a current sensor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along a cross-sectional line AA shown in FIG. 1, and FIG. FIG. 4 is a diagram for explaining the distribution of the magnetic field generated by the above, and FIG. 4 is a diagram for explaining the ratio of the length of each part in FIG.

  As shown in FIG. 1, the current sensor 1 includes a conductor 11, a first magnetic sensor 15, a second magnetic sensor 17, and a processing unit 21 each having a first conductor 11b and a second conductor 11c. Have.

As shown in FIGS. 1 and 2, the current sensor 1 is a plate having a rectangular cross section, and has a non-conductive region 13 which is an opening (through hole) at a predetermined position in a Y1 direction which is a flow direction (current direction). Is formed on the conductor 11.
The first conductor portion 11b is located on the X1 direction side of the non-conductive region 13, and the second conductor portion 11c is located on the X2 direction side.
The cross section orthogonal to the flow direction of the first conductor 11b and the second conductor 11c is rectangular, and has, for example, the same size.

The current inflow portion 11b1 of the first conductor portion 11b and the current inflow portion 11c1 of the second conductor portion 11c are electrically connected by a third conductive portion 11a. Also, the first conductor portion 11b and the fourth conductor portion 11d, in which the current outflow portion 11b2 of the first conductor portion 11b and the current outflow portion 11c2 of the second conductor portion 11c are electrically connected by the fourth conductive portion 11d. As shown in FIGS. 1 and 2, currents Ib and Ic, which are １ ／ of the current I flowing through the third conductive portion 11a and the fourth conductive portion 11d, flow through each of the two conductor portions 11c. .

  The non-conductive region 13 is located between the first conductor 11b and the second conductor 11c in the X1-X2 direction, and has a rectangular parallelepiped shape penetrating between the Z1 side and the Z2 side of the conductor 11. You are.

In the non-conductive region 13, a first magnetic sensor 15 and a second magnetic sensor 17 are provided at positions where distances between the first conductor 11b and the second conductor 11c are different from each other. I have.
Specifically, the first magnetic sensor 15 is provided on the first conductor 11b side with respect to the second conductor 11c. The second magnetic sensor 17 is provided closer to the second conductor 11c than to the first conductor 11b. The first conductor 11b and the second conductor 11c are plane-symmetric with respect to the imaginary plane 31 along both the direction of the long side and the direction of flow of these rectangular cross sections, and the cross-sectional direction (X- In the Z-plane direction), the distance between the first conductor 11b and the first magnetic sensor 15 is equal to the distance between the second conductor 11c and the second magnetic sensor 17.
The first magnetic sensor 15 and the second magnetic sensor 17 are fixed on a substrate (not shown) or the like.

The first magnetic sensor 15 and the second magnetic sensor 17 have the same magnetic detection characteristics.
As shown in FIG. 3, the first magnetic sensor 15 and the second magnetic sensor 17 include a first induction magnetic field Bb and a second induction magnetic field Bb generated by a current flowing through the first conductor 11b and the second conductor 11c. The induction magnetic field Bc is detected.

  Each of the first magnetic sensor 15 and the second magnetic sensor 17 includes, for example, a magnetoresistive element (GMR element, TMR element, or the like), and exhibits strong sensitivity to a magnetic field having a specific sensitivity axis. For example, the sensitivity axis S1 of the first magnetic sensor 15 and the sensitivity axis S2 of the second magnetic sensor 17 both point in the direction of Z2.

In the present embodiment, as shown in FIG. 4, the distance in the X1-X2 direction between the first conductor portion 11b and the second conductor portion 11c, which is the width of the non-conductive region 13, is defined as the non-conductive region width x. I do.
Further, the height of the non-conductive region 13 in the Z1-Z2 direction is represented by t.

FIG. 5 is a diagram for explaining the magnetic flux density distribution in the non-conductive region 13 of the current sensor 1 shown in FIG.
FIG. 5 shows a result of a simulation in which t = 2.2 mm, x = 5 mm, the width of the first conductor 11b and the second conductor 11c is 1.8 mm, and a current I of 40 A flows. In this case, the magnetic flux density gradient near the center of the non-conductive region 13 is about 1.0 mT / mm, and the difference in the detection magnetic field between the first magnetic sensor 15 and the second magnetic sensor 17 needs to be about 1 mT. If so, the distance between the first magnetic sensor 15 and the second magnetic sensor 17 in the X1-X2 direction needs to be 1.0 mm.

FIG. 6 is a diagram showing the relationship between the height t of the non-conductive region 13 and the magnetic flux density gradient when the non-conductive region width x of the current sensor 1 shown in FIG. 1 is 5 mm.
The simulation in FIG. 6 was performed under the same conditions as in FIG.

FIG. 7 is a diagram showing the relationship between the ratio R of the non-conductive region 13 of the current sensor 1 shown in FIG. 1 and the magnetic flux density gradient.
The simulation of FIG. 7 was performed when x = 6 mm and a current I of 80 A was passed.

  As shown in FIGS. 4 to 7, in the current sensor 1, the ratio R between the non-conductive region width x and the height t of the non-conductive region 13 represented by the following equation (1) is equal to X 1 in the non-conductive region 13. It is defined to be within a predetermined range from the maximum value of the magnetic flux density gradient in the −X2 direction.

[Equation 1]
R = t / x (1)

  The ratio R preferably satisfies the condition of the following equation (2).

[Equation 2]
1/4 ≦ R ≦ 1 (2)

  The ratio R is more preferably defined to be near the maximum value of the magnetic flux density gradient in the non-conductive region 13, and satisfies the condition of the following equation (3), for example.

[Equation 3]
0. 4 ≦ R ≦ 0.6 (3)

The processing unit 21 receives the magnetic field detection results of the first magnetic sensor 15 and the second magnetic sensor 17 and calculates the value of the current flowing through the conductor 11 based on the results.
Specifically, the processing unit 21 calculates the value of the current flowing through the conductor 11 from the difference between the first magnetic detection result of the first magnetic sensor 15 and the second magnetic detection result of the second magnetic sensor 17. calculate.

Hereinafter, the operation of the current sensor 1 will be described.
The current I from the third conductive portion 11a of the conductor 11 is shunted by I / 2 to the first conductor portion 11b and the second conductor portion 11c. Specifically, a current Ib of I / 2 flows from the current inflow portion 11b1 of the first conductor portion 11b to the current outflow portion 11b2. A current Ic of I / 2 flows from the current inflow portion 11c1 of the second conductor portion 11c to the current outflow portion 11c2.

As shown in FIG. 3, the current Ib flowing through the first conductor portion 11b generates a first induction magnetic field Bb in the direction of the right-handed screw with respect to the current direction. Due to the current Ic flowing through the second conductor 11c, a second induction magnetic field Bc is generated in the right-handed screw direction with respect to the current direction.
Here, both the current Ib and the current Ic are I / 2 as described above. Therefore, in the non-conductive area 13, the first induction magnetic field Bb and the second induction magnetic field Bc have opposite directions and the same magnitude.

  Specifically, as shown in FIG. 3, a first induction magnetic field Bb in the Z1 direction is generated by the first conductor 11b at the position of the first magnetic sensor 15 in the non-conductive region 13. On the other hand, a second induced magnetic field Bc in the Z2 direction is generated at the position of the second magnetic sensor 17 by the second conductor 11c. The magnitudes of both magnetic fields are substantially the same.

In the present embodiment, the width x of the non-conductive region is set to “5 mm”, and the height t is set to “2.2 mm”.
In this case, as shown in FIGS. 5 and 6, the magnetic flux density gradient in the non-conductive region 13 in the non-conductive region width x direction is near the maximum.
Therefore, even if the distance between the first magnetic sensor 15 and the second magnetic sensor 17 in the X1-X2 direction is short, such as “0.6 to 3.0 mm”, in the non-conductive region 13, The difference in the induced magnetic field between the first magnetic sensor 15 and the second magnetic sensor 17 can be increased.

Here, the first magnetic field detection result of the first induction magnetic field Bb of the first conductor portion 11b is set to Vb, and the second magnetic field detection result of the second induction magnetic field Bc of the second conductor portion 11c is set to Vc. I do.
The processing unit 21 calculates the difference between the first magnetic field detection result Vb and the second magnetic field detection result Vc as shown in the following equation (4).

[Equation 4]
V = Vb−Vc (4)

  The processing unit 21 calculates a current value flowing through the conductor 11 based on V obtained by calculating the above equation (4).

The operation of the current sensor 1 for suppressing the influence of an external magnetic field will be described.
FIG. 8 is a diagram for explaining the effect of an external magnetic field from an adjacent conductor of the current sensor 1. FIG. 9 is a diagram for explaining the relationship between the distance between the first magnetic sensor 15 and the second magnetic sensor 17 and the difference calculated by the processing unit 21.
FIG. 9 shows the distance (horizontal axis) between the center of the first magnetic sensor 15 and the second magnetic sensor 17 and the center of the adjacent conductor 83 and the influence on the calculated current value due to the disturbance magnetic field from the adjacent conductor 83 (vertical axis). FIG. 3 is a diagram showing the relationship between the first magnetic sensor 15 and the second magnetic sensor 17 for a plurality of distances.

As shown in FIG. 8, when a disturbance magnetic field Bn from an adjacent conductor exists, a magnetic field generated in the first magnetic sensor 15 is a first combined magnetic field (Bb + Bnb) of the first induction magnetic field Bb and the external magnetic field Bn. become.
Further, the magnetic field generated in the second magnetic sensor 17 is a second combined magnetic field (Bc + Bnc) of the second magnetic field Bc and the external magnetic field Bn.
Here, since the first magnetic sensor 15 and the second magnetic sensor 17 are close to each other, the magnitudes of the external magnetic fields Bnb and Bnc become substantially the same.

The first magnetic field detection result of the first composite magnetic field (Bb + Bnb) of the first magnetic sensor 15 is (Vb + Vnb), and the second magnetic field detection result of the second composite magnetic field (Bc + Bnc) of the second magnetic sensor 17 is Is (Vc + Vnc).
The processing unit 21 calculates a difference between the first magnetic field detection result (Vb + Vnb) and the second magnetic field detection result (Vc + Vnc) as shown in the following equation (5). At this time, (Vnb-Vnc), which is a component of the external magnetic fields Bnb and Bnc, is very small and can be ignored.

[Equation 5]
V = (Vb + Vnb)-(Vc + Vnc)
= (Vb-Vc) + (Vnb-Vnc) (5)

As shown in FIG. 9, when the distance between the first magnetic sensor 15 and the second magnetic sensor 17 is short, the influence (vertical axis) of the disturbance magnetic field from the adjacent conductor 83 on the calculated current value can be reduced.
If the influence of the disturbance magnetic field from the adjacent conductor 83 on the calculated current value is the same, the shorter the distance between the first magnetic sensor 15 and the second magnetic sensor 17 is, The distance (horizontal axis) between the center of the second magnetic sensor 17 and the center of the adjacent conductor can be shortened.

The influence of the disturbance magnetic field from the adjacent conductor 83 on the calculated current value is allowed up to 1 × 10 ⁻⁵ T (1% of a signal magnetic field of 1 mT), and the first magnetic sensor 15 and the second magnetic sensor 17 Is 1.0 mm, the distance between the center of the first magnetic sensor 15 and the second magnetic sensor 17 and the center of the adjacent conductor 83 needs to be about 27 mm or more.
In order to suppress the influence of the disturbance magnetic field from the adjacent conductor 83 on the calculated current value, it is necessary to shorten the distance between the first magnetic sensor 15 and the second magnetic sensor 17 for performing the differential processing.

As described above, in the current sensor 1, the first magnetic sensor 15 and the second magnetic sensor 17 are provided with the induced magnetic fields in the opposite directions from the first conductor 11b and the second conductor 11c, respectively. The first magnetic sensor 15 and the second magnetic sensor 17 are provided with an external magnetic field having substantially the same size and substantially the same direction.
Therefore, by calculating the difference between the detection results of the first magnetic sensor 15 and the second magnetic sensor 17, the influence of the external magnetic field can be suppressed, and the value of the current flowing through the conductor 11 can be calculated with high accuracy.

  According to the current sensor 1, the ratio R between the width x and the height t of the non-conductive region is defined as shown in the above-described equations (1) to (3), so that the magnetic flux density in the non-conductive region 13 is The gradient can be increased. Therefore, the difference between the induced magnetic fields of the current flowing through the first conductor 11b and the second conductor 11c generated in the first magnetic sensor 15 and the second magnetic sensor 17 can be increased, and high measurement accuracy can be obtained. be able to.

  That is, when the ratio is defined as described above when the constant R is defined according to the maximum current of the conductor 11, the magnetic flux density gradient in the non-conductive region 13 is determined by defining the ratio R as described above. Can be set near the maximum. The shape of the non-conductive region 13 has a large height t, and is significantly different from the idea of the shape of the current path disclosed in Patent Documents 2 to 13.

  Further, according to the current sensor 1, the magnetic flux density gradient in the non-conductive region 13 where the first magnetic sensor 15 and the second magnetic sensor 17 are located can be increased, so that the first magnetic sensor 15 and the second magnetic sensor The sensor 17 can be brought close to the sensor 17 and the influence of an external magnetic field generated on both magnetic sensors can be removed with high accuracy, so that high measurement accuracy can be realized.

  According to the current sensor 1, the first conductor 11b, the second conductor 11c, the third conductor 11a, and the fourth conductor 11d have rectangular cross-sections, which is relatively simple. It can be made into a shape, and the manufacturing process can be simplified by simple processing.

<Second embodiment>
FIG. 10 is a diagram for explaining a current sensor 201 of the present embodiment according to the second embodiment of the present invention.
The current sensor 201 has a first conductor 211b, a second conductor 211c, a third conductor 211a, and a fourth conductor 211d as separate bodies.
Each of the first conductor portion 211b and the second conductor portion 211c has a flat plate shape, and a cross section orthogonal to the flow direction (Y1-Y2 direction) is rectangular. Here, the short side of the rectangle is parallel to the X1-X2 direction, and the long side is parallel to the Z1-Z2 direction.
That is, the first conductor part 211b and the second conductor part 211c form long sides, and the surfaces along the flow direction (Y1-Y2 direction) face each other.

The current inflow portion 211b1 of the first conductor portion 211b and the current inflow portion 211c1 of the second conductor portion 211c are electrically connected by a third conductive portion 211a. Also, the first conductor portion 211b and the first conductor portion 211b2 in which the current outflow portion 211b2 of the first conductor portion 211b and the current outflow portion 211c2 of the second conductor portion 211c are electrically connected by the fourth conductive portion 211d. The cross-sectional area of the second conductor portion 211c is the same, and a current Ib and a current Ic, which are の of the current I flowing through the third conductive portion 211a, flow through each.

The current sensor 201 has a non-conductive region 213 surrounded by a first conductor 211b, a second conductor 211c, a third conductor 211a, and a fourth conductor 211d.
In the non-conductive region 213, the first magnetic sensor 15 and the second magnetic sensor are located at positions where the distances in the XX direction between the first conductor 11b and the second conductor 11c are different from each other. 17 are provided.

Specifically, the first magnetic sensor 15 is provided on the first conductor 211b side with respect to the second conductor 211c. The second magnetic sensor 17 is provided on the second conductor 211c side with respect to the first conductor 211b. The first conductor portion 211b and the second conductor portion 211c are formed on the imaginary plane 31 along both the long side direction (Z1-Z2 direction) and the flow direction (Y1-Y2 direction) of these rectangular cross sections. The distance between the first conductor 211b and the first magnetic sensor 15 and the distance between the second conductor 211c and the second magnetic sensor in the cross-sectional direction (XZ plane direction). 17 are equal to each other.
The first magnetic sensor 15 and the second magnetic sensor 17 detect an induced magnetic field generated by a current flowing through the first conductor 211b and the second conductor 211c.

As in the first embodiment, the distance between the first conductor portion 211b and the second conductor portion 211c that is the width of the non-conductive region 213 is defined as the non-conductive region width x. Further, the height of the non-conductive region 213 in the Z1-Z2 direction is represented by t.
Also in the current sensor 201, as in the first embodiment, the ratio R of the non-conductive region width x and the height t of the non-conductive region 213 is equal to the magnetic flux density gradient in the X1-X2 direction in the non-conductive region 213. Is defined to be within a predetermined range from the maximum value of.
Preferably, the ratio R is defined so as to satisfy the expressions (1) to (3) of the first embodiment.

Hereinafter, a manufacturing process of the current sensor 201 will be described.
FIG. 11 is a flowchart for explaining a manufacturing process of the current sensor 201 shown in FIG.
Step ST1:
A first conductor portion 211b and a second conductor portion 211c having a rectangular flat cross section are prepared.
Also, a third conductor portion 211a and a fourth conductor portion 211d having a rectangular flat cross section are prepared.

Step ST2:
The short side and the long side of the rectangular cross section of the first conductor section 211b are in parallel with the short side and the long side of the rectangular cross section of the second conductor section 211c, respectively. Specifically, the first conductor portion 211b and the second conductor portion 211c are set to face each other.

Step ST3:
The end portion of the third conductor portion 211a is sandwiched between the current inflow portion 211b1 of the first conductor portion 211b and the current inflow portion 211c1 of the second conductor portion 211c.
The end of the fourth conductor 211d is sandwiched between the current outflow 211b2 of the first conductor 211b and the current outflow 211c2 of the second conductor 211c.
As a result, the current inflow portion 211b1 of the first conductor portion 211b and the current inflow portion 211c1 of the second conductor portion 211c are electrically connected. Further, the current outflow portion 211b2 of the first conductor portion 211b is electrically connected to the current outflow portion 211c2 of the second conductor portion 211c.

  At this time, the width x and the height of the non-conductive region 213 of the non-conductive region 213 surrounded by the first conductor portion 211b, the second conductor portion 211c, the third conductor portion 211a, and the fourth conductor portion 211d are represented by t. Is defined so as to satisfy the above equations (1) to (3). This is because the height t (long side) of the first conductor portion 211b and the first conductor portion 211b and the width of the third conductor portion 211a and the fourth conductor portion 211d in the X1-X2 direction are appropriately selected. No special processing is required.

Step ST4:
The first conductor portion 11b and the second conductor portion in the non-conductive region 213 surrounded by the first conductor portion 211b, the second conductor portion 211c, the third conductor portion 211a, and the fourth conductor portion 211d. The first magnetic sensor 15 and the second magnetic sensor 17 are provided at positions different from each other in the X-X2 direction with respect to the first magnetic sensor 11c.

  As described above, according to the current sensor 201 and the method of manufacturing the same, it is possible to simply increase the long side of the rectangular cross section of the first conductor and the second conductor, and to perform non-conductive by simple processing. The height of the area can be lengthened. That is, in the case of forming a non-conductive region by hollowing out one conductor, processing is difficult if the hollowing is deep, but the current sensor 201 does not require such hollowing, and can be made simple and inexpensive. .

  Further, according to the current sensor 201, the ratio R of the width x and the height t of the non-conductive region of the non-conductive region 213 is defined so as to satisfy the above equations (1) to (3). The functions and effects of the current sensor 1 described in the embodiment can be obtained in the same manner.

<Third embodiment>
FIG. 12 is a diagram for explaining a current sensor 301 according to the third embodiment of the present invention.
Current sensor 301 has first conductor portion 311b and second conductor portion 311c as separate bodies.
A non-conductive region 313 is formed between the first conductor 311b and the second conductor 311c.
The first conductor portion 311b and the second conductor portion 311c are electrically directly joined at both ends of the non-conductive region 313 in the Y1-Y2 direction.
The second conductor 311c has a flat plate shape.

The first conductor portion 311b is parallel to the first conductor portion 351 in contact with the second conductor portion 311c, the second conductor portion 352 in contact with the second conductor portion 311c, and the second conductor portion 311c. , A fourth flat plate portion 354 interposed between one end of the first flat plate portion 351 and one end of the third flat plate portion 353, and a second flat plate portion 352. And a fifth flat plate portion 355 interposed between the third flat plate portion 353 and the other end.
The first flat plate portion 351 and the fourth flat plate portion 354, the third flat plate portion 353 and the fourth flat plate portion 354, the second flat plate portion 352 and the fifth flat plate portion 355, and the third flat plate portion 353 and the The five flat portions 355 form a bent portion.

  The cross-sectional areas of the first conductor portion 311b and the second conductor portion 311c are the same, and a current Ib and a current Ic that are １ ／ of the entire current I flow through each.

The current sensor 301 has a non-conductive region 313 surrounded by the second conductor 311c, the third plate 353, the fourth plate 354, and the fifth plate 355 of the first conductor 311b.
In the non-conductive region 313, the first magnetic sensor is located at a position where the distance in the XX direction between the third plate portion 353 and the second conductor portion 311c of the first conductor portion 311b is different from each other. 15 and a second magnetic sensor 17 are provided.

Specifically, the first magnetic sensor 15 is provided on the third flat plate portion 353 side with respect to the second conductor portion 311c. The second magnetic sensor 17 is provided closer to the second conductor 311c than the third flat plate 353. In the cross-sectional direction (XZ plane direction), the distance between the third flat plate portion 353 and the first magnetic sensor 15 and the distance between the second conductor portion 311c and the second magnetic sensor 17 Are equal.
The first magnetic sensor 15 and the second magnetic sensor 17 detect an induced magnetic field generated by a current flowing through the first conductor 311b and the second conductor 311c.

As in the first embodiment, the distance between the third flat plate portion 353 of the first conductor portion 311b and the second conductor portion 311c, which is the width of the non-conductive region 313, is defined as the non-conductive region width x. Further, the height of the non-conductive region 313 in the Z1-Z2 direction is represented by t.
In the current sensor 301 as well, as in the first embodiment, the ratio R between the non-conductive region width x and the height t of the non-conductive region 313 is equal to the magnetic flux density gradient in the X1-X2 direction in the non-conductive region 213. Is defined to be within a predetermined range from the maximum value of.
Preferably, the ratio R is defined so as to satisfy the expressions (1) to (3) of the first embodiment.

According to the current sensor 301, the same operation and effect as those of the current sensor 201 of the above-described second embodiment can be obtained.
In addition, according to the current sensor 301, the first conductor 311b and the second conductor 311c are used to directly connect the current inflow portion and the current outflow portion, respectively, to the first conductor portion 311b and the second conductor portion. There is no need to separately provide a conductive portion for connecting to 311c, and the configuration can be made simple and inexpensive.

<Fourth embodiment>
FIG. 13 is a diagram for explaining a current sensor 401 of the present embodiment according to the fourth embodiment of the present invention.
The current sensor 401 has a first conductor 311c and a second conductor 411c as separate bodies.
A non-conductive region 413 is formed between the first conductor 311c and the second conductor 411c.

The first conductor 311b and the second conductor 411c are plane-symmetric with respect to a virtual plane 431 parallel to the YZ plane.
The first conductor 311b is the same as the first conductor 311b described in the third embodiment.

The cross-sectional areas of the first conductor portion 311b and the second conductor portion 411c are the same, and a current Ib and a current Ic that are １ ／ of the entire current I flow through each.
The current sensor 401 has a non-conductive region 413 surrounded by a first conductor 311b and a second conductor 411c.

In the non-conductive region 413, the first magnetic sensor 15 and the second magnetic sensor 17 are provided at positions symmetrical with respect to the virtual plane 431.
The first magnetic sensor 15 and the second magnetic sensor 17 detect an induced magnetic field generated by a current flowing through the first conductor 311b and the second conductor 411c.

Similarly to the first embodiment, the distance between the third flat plate portion 353 of the first conductor portion 311b and the second conductor portion 411c, which is the width of the non-conductive region 413, is defined as the non-conductive region width x. Further, the height of the non-conductive region 413 in the Z1-Z2 direction is represented by t.
Also, in the current sensor 401, as in the first embodiment, the ratio R of the non-conductive region width x and the height t of the non-conductive region 413 is equal to the magnetic flux density gradient in the X1-X2 direction in the non-conductive region 213. Is defined to be within a predetermined range from the maximum value of.
Preferably, the ratio R is defined so as to satisfy the expressions (1) to (3) of the first embodiment.

According to the current sensor 401, the same operation and effect as those of the current sensor 201 of the above-described second embodiment can be obtained.
Further, according to the current sensor 401, the first conductor 311b and the second conductor 311c directly connect the current inflow portion and the current outflow portion, respectively, so that the first conductor 311b and the second conductor 311b are directly connected to each other. There is no need to separately provide a conductive portion for connecting to the portion 411c, and the configuration can be simplified and inexpensive.

  Further, according to the current sensor 401, the first conductor 311 b and the second conductor 411 c are plane-symmetric with respect to the virtual plane 431, and the first magnetic sensor 15 and the second magnetic sensor 17 Are plane symmetric, positioning becomes easy. And high-precision measurement can be performed with high positioning accuracy, and manufacturing cost can be suppressed.

The invention is not limited to the embodiments described above.
That is, those skilled in the art may make various changes, combinations, sub-combinations, and alternatives for the components of the above-described embodiments within the technical scope of the present invention or an equivalent scope thereof.

In the above-described embodiment, the case where the non-conductive regions 13, 231, 313, and 413 are hollow is illustrated, but a part or the whole thereof may be filled with a non-conductive material such as a synthetic resin.
In the embodiment described above, the first conductors 11b, 211b. Although the case where the cross-sectional areas of 311b and the second conductor portions 11c, 211c, 311c, and 411c are the same is illustrated, the cross-sectional areas may be different.

  In the above-described embodiment, both the sensitivity axis S1 of the first magnetic sensor 15 and the sensitivity axis S2 of the second magnetic sensor 17 are oriented in the direction of Z2, but may be oriented in the direction of Z1. Further, the direction of the sensitivity axis S1 of the first magnetic sensor 15 and the direction of the sensitivity axis S2 of the second magnetic sensor 17 may be reversed. In this case, the processing unit 21 adds the first magnetic detection result of the first magnetic sensor 15 and the second magnetic detection result of the second magnetic sensor 17 to calculate a current value flowing through the conductor 11. Is calculated.

  Further, in the above-described embodiment, the case where the first magnetic sensor 15 and the second magnetic sensor 17 are provided in the non-conductive regions 13, 231, 313, and 413 has been exemplified. A magnetic sensor may be provided.

  Further, in the above-described embodiment, the magnetoresistive element is illustrated as an example of the magnetic sensor of the present invention, but a Hall element may be used.

  The present invention is applicable to a current sensor that detects a current value of a conductor.

1, 201, 301, 401 ... current sensors 13, 231, 313, 413 ... non-conductive areas 11b, 211b. 311b first conductor portions 11c, 211c, 311c, 411c second conductor portion 15 first magnetic sensor 17 second magnetic sensor 21 processing units 31, 431 virtual surface

Claims (4)

A first conductor portion and a second conductor portion which are electrically connected to each other, and which extend in parallel with each other;
Provided at different distances to the mutual position between said first conductor portion and the first conductor section and the second conductor portion in the formed non-conductive region between the second conductive portion A first magnetic sensor and a second magnetic sensor for detecting an induced magnetic field generated by a current flowing through the first conductor and the second conductor;
Has,
A non-conductive region width x which is a distance between said first conductor portion serving as the width of the non-conductive region and the second conductor portion,
The following equation (1) represents a height t in a direction orthogonal to both the direction of the non-conductive region width x and the current direction of the first conductor and the second conductor.
[Equation 1]
R = t / x (1)
The ratio R represented by the following formula (2)
[Equation 2]
1/4 ≦ R ≦ 1 (2)
Meet the,
The first magnetic sensor is provided closer to the first conductor than the second magnetic sensor,
The second magnetic sensor is provided closer to the second conductor than the first magnetic sensor,
The first conductor portion and the second conductor portion are plane-symmetric with respect to an imaginary plane along both the height direction and the current flowing direction,
The distance between the first conductor and the first magnetic sensor is equal to the distance between the second conductor and the second magnetic sensor,
In the current sensor, the ratio R is defined such that the magnetic flux density gradient at the center in the direction of the non-conductive region width x in the non-conductive region is maximized in the range of the expression (2) . The current sensor according to claim 1 , wherein a cross section of the first conductor portion and the second conductor portion orthogonal to the current direction is rectangular. In cross-section a rectangular plate shape, has a conductor opening that extends to the current direction is formed,
The opening is formed at the center of the conductor in an opening width direction orthogonal to the current direction,
One of the directions of the opening width with respect to the opening is the first conductor,
The other of the direction of the opening width with respect to the opening is the second conductor portion,
Current sensor according to claim 1 or claim 2 wherein the opening is in the non-conductive region. 4. The processing unit further comprising: a processing unit that calculates a current value flowing through the first conductor and the second conductor from a difference between detection results of the first magnetic sensor and the second magnetic sensor. 5. The current sensor according to any one of the above.

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