JP6413267B2 - Current detection structure - Google Patents

Description

  The present invention relates to a current detection structure.

  2. Description of the Related Art Conventionally, when detecting a current flowing through a bus bar, the intensity of a magnetic field generated by a current to be detected is detected by a magnetic detection element. By detecting the strength of the magnetic field by the magnetic detection element, the current flowing through the bus bar can be obtained by calculation based on the strength of the magnetic field.

  As magnetic detection elements, MR (Magneto Resistance) sensors and GMR (Giant Magneto Resistive effect) sensors are known.

  As prior art document information related to the invention of this application, there are Patent Documents 1 and 2.

Japanese Patent No. 5153481 JP 2013-170878 A

  However, in the above-described conventional current detection structure, for example, when detecting a current flowing through each phase of a three-phase motor, the magnetic detection element is affected by a magnetic field generated by a current flowing through a bus bar other than the detection target. There is a problem that it is difficult to accurately detect the current flowing through the detection target bus bar.

  Therefore, an object of the present invention is to solve the above-described problems and provide a current detection structure that can accurately detect a current flowing through a bus bar.

  The present invention has been devised to achieve the above object, and has a current detection structure including a plurality of bus bars and a magnetic detection element for measuring the strength of a magnetic field generated by a current flowing through the plurality of bus bars. The plurality of bus bars are arranged such that surfaces perpendicular to the surface of each bus bar and passing through the center in the width direction are perpendicular to each other, and the magnetic detection element is perpendicular to the surface of each bus bar and has a width This is a current detection structure arranged at a position where planes passing through the center of directions intersect.

  Three bus bars may be provided, and the magnetic detection element may be arranged at a position where a plane perpendicular to the surface of each bus bar and passing through the center in the width direction intersects.

  As the magnetic detection element, a triaxial magnetic detection element having three detection axes perpendicular to each other may be used.

  The three bus bars are composed of two linear bus bars and one crank-shaped bus bar formed in a crank shape in plan view, and the two linear bus bars are parallel to each other in the longitudinal direction. Further, the crank-shaped bus bars are arranged so that the surfaces parallel to the surface are orthogonal to each other, and the longitudinal direction of the connecting portion connecting the ends of the parallel portions at both ends thereof is the length of the two linear bus bars. You may arrange | position so that the surface of the said connection part and one surface of the said 2 linear bus bar may become parallel to a direction.

  The three bus bars include a linear first bus bar, a second bus bar formed in a crank shape in a plan view, and a third bus bar formed in a crank shape in a side view, and the second bus bar The third bus bar is disposed so that the longitudinal directions of the connecting portions connecting the ends of the parallel portions at both ends thereof are parallel to each other, and the surfaces parallel to the surface of the connecting portion are orthogonal to each other, The 1 bus bar is arranged such that the longitudinal direction thereof is orthogonal to the longitudinal direction of the connecting portion of the second bus bar and the third bus bar, and the surface thereof is parallel to the surface of the connecting portion of the third bus bar. May be.

  ADVANTAGE OF THE INVENTION According to this invention, the electric current detection structure which can detect the electric current which flows into a bus bar accurately can be provided.

It is a figure which shows the electric current detection structure which concerns on one Embodiment of this invention, (a) is a perspective view, (b) is the 1B-1B sectional view taken on the line, (c) is the side view. It is a perspective view of the current detection structure concerning one modification of the present invention. It is a perspective view of the current detection structure concerning one modification of the present invention.

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

  1A and 1B are diagrams showing a current detection structure according to the present embodiment, in which FIG. 1A is a perspective view, FIG. 1B is a sectional view taken along line 1B-1B, and FIG.

  As shown in FIGS. 1A to 1C, the current detection structure 1 includes a plurality of bus bars 2 and a magnetic detection element 3 that measures the strength of a magnetic field generated by the current flowing through the plurality of bus bars 2. I have.

  The bus bar 2 is a plate-like conductor and serves as a current path through which a current flows. Here, a case will be described in which three bus bars 2 through which a three-phase alternating current flows are provided and the current of each bus bar 2 is detected using the magnetic detection element 3. The bus bar 2 is, for example, a current path between an automobile inverter and a motor.

  The bus bar 2 is formed in a rectangular shape in sectional view. In addition, although the cross-sectional shape of the bus bar 2 is not limited to this, in this embodiment, it is necessary to form at least line symmetry with respect to the center in the width direction.

  Now, in the current detection structure 1 according to the present embodiment, the three bus bars 2 are arranged such that planes perpendicular to the surface of each bus bar 2 and passing through the center in the width direction are orthogonal to each other.

  In the present embodiment, the three bus bars 2 include two linear bus bars 2 and one crank-shaped bus bar 2 formed in a crank shape in plan view. Here, the two linear bus bars 2 are referred to as a first bus bar 2a and a second bus bar 2b, and the crank-shaped bus bar 2 is referred to as a third bus bar 2c.

  The linear first bus bar 2a and the second bus bar 2b are arranged so that their longitudinal directions are parallel to each other and their surfaces parallel to the surface are orthogonal to each other. More specifically, the first bus bar 2a is arranged on the XZ plane so that its longitudinal direction is along the X-axis direction and its width direction is along the Z-axis direction. The second bus bar 2b is disposed on the XY plane so that its longitudinal direction is along the X-axis direction and its width direction is along the Y-axis direction. The first bus bar 2a and the second bus bar 2b are disposed at positions where they do not overlap when viewed from the direction perpendicular to the surface (when viewed from the Y-axis direction and the Z-axis direction).

  The third bus bar 2c is formed in a crank shape when viewed from the front surface side or the back surface side, and ends of parallel portions (referred to as parallel portions 4) at both ends thereof are connected to each other by the connection portion 5. Connected and configured. The connecting portion 5 is formed so that the longitudinal direction thereof is orthogonal to the longitudinal direction of the parallel portion 4, and is formed integrally with both parallel portions 4 so as to extend in the width direction from the end of the parallel portion 4. ing. The connecting portion 5 and the parallel portion 4 have the same cross-sectional shape.

  In the third bus bar 2c, the longitudinal direction of the connecting portion 5 is orthogonal to the longitudinal directions of the first bus bar 2a and the second bus bar 2b, and the surface of the connecting portion 5 and one of the two linear bus bars 2a, 2b (here Then, it arrange | positions so that the surface of the 1st bus bar 2a) may become parallel. That is, the third bus bar 2c is arranged on the XZ plane so that the longitudinal direction of the parallel portion 4 is along the X-axis direction and the longitudinal direction of the connection portion 5 is along the Z-axis direction. In the present embodiment, the third bus bar 2c is arranged so that the second bus bar 2b is sandwiched between the first bus bar 1a in a side view (when viewed from the Z-axis direction).

  The reason why the third bus bar 2c is crank-shaped is to make the direction of current input / output coincide with the first bus bar 2a and the second bus bar 2b. If there is no need to match the input / output directions of the current, the third bus bar 2c can of course be formed in a straight line by omitting the portion corresponding to the parallel portion 4, as shown in FIG. It is.

  The magnetic detection element 3 is disposed at a position where a plane perpendicular to the surface of each bus bar 2 and passing through the center in the width direction intersects. In the present embodiment, a triaxial magnetic detection element having three detection axes perpendicular to each other is used as the magnetic detection element 3. The magnetic detection element 3 is arranged so that each detection axis is in the X-axis direction, the Y-axis direction, and the Z-axis direction. As the magnetic detection element 3, for example, a three-dimensional Hall IC can be used.

  As shown in FIGS. 1B and 1C, on a plane perpendicular to the surface of the bus bar 2 and passing through the center in the width direction, the magnetic field generated by the current flowing through the bus bar 2 is the width direction of the bus bar 2. It becomes only the component of the direction along.

  In the present embodiment, the magnetic field (Ba in the figure) generated by the current flowing through the first bus bar 2a has only a component in the Z-axis direction, and the magnetic field (Bb in the figure) generated by the current flowing through the second bus bar 2b is in the Y-axis direction. The magnetic field (Bc in the figure) generated by the current flowing through the third bus bar 2c (connector 5) is only the component in the X-axis direction, and the magnetic fields (Ba-Bc in the figure) generated by the bus bars 2a-2c are mutually connected. Orthogonal.

  Therefore, the magnetic detection element 3 is arranged at a position where a plane perpendicular to the surface of each of the bus bars 2a to 2c and passing through the center in the width direction intersects, and the magnetic field strengths in the Z axis direction, the Y axis direction, and the X axis direction are respectively set. By measuring, the current flowing through each of the bus bars 2a to 2c can be accurately obtained based on the measured magnetic field strength.

  In the present embodiment, the current of each phase of the three-phase alternating current is passed through the bus bars 2a to 2c, and the magnitudes of the currents flowing through the bus bars 2a to 2c are substantially the same. Therefore, the position at which the magnetic detection element 3 is arranged (position where the plane perpendicular to the surface of each bus bar 2a to 2c and passing through the center in the width direction) is equidistant from each bus bar 2a to 2c. The arrangement of the bus bars 2a to 2c is adjusted so that the intensity of the magnetic field generated in each bus bar 2a to 2c and detected by the magnetic detection element 3 is approximately the same.

  In addition, since the magnetic field generated at the bent portion of the crank-shaped third bus bar 2c (the boundary portion between the parallel portion 4 and the connecting portion 5) may cause an error, the distance from the bent portion to the magnetic detection element 3 is also considered. Should be as large as possible. It is most desirable to arrange the magnetic detection element 3 in the vicinity of the central portion in the longitudinal direction of the connecting portion 5 so as to be as far as possible from the bent portions at both ends of the connecting portion 5.

  Although not shown, in the current detection structure 1, a support member made of resin is provided so as to cover the magnetic detection element 3 and the surrounding bus bar 2. At this time, a support member is formed by insert molding with the crank-shaped third bus bar 2c inserted, and then the first bus bar 2a and the second bus bar 2b are inserted into the holes formed in the support member and supported. What is necessary is just to comprise so that the board | substrate which mounted the magnetic detection element 3 in the member may be mounted.

  As described above, in the current detection structure 1 according to the present embodiment, a plurality of (in this case, three) bus bars 2 are arranged such that planes perpendicular to the surface of each bus bar 2 and passing through the center in the width direction are orthogonal to each other. The magnetic detection element 3 is arranged at a position where a plane perpendicular to the surface of each bus bar 2 and passing through the center in the width direction intersects.

  With this configuration, the magnetic fields generated by the currents flowing through the bus bars 2 are orthogonal to each other at the position where the magnetic detection element 3 is disposed. Therefore, by detecting each of the orthogonal magnetic fields, it is possible to accurately detect the current flowing through each bus bar 2 without receiving the interference of the magnetic fields generated in the other bus bars 2.

  In addition, in the current detection structure 1, the magnetic detection element 3 is inevitably disposed in a space surrounded by a plurality (three in this case) of the bus bars 2, and therefore a portion (detection portion) where the magnetic detection element 3 is disposed. ) Can be miniaturized.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

  For example, like the current detection structure 31 shown in FIG. 3, the second bus bar 2b in the current detection structure 1 of FIG. 1 may be formed in a crank shape in a side view (when viewed from the width direction).

  In the current detection structure 31 of FIG. 3, the second bus bar 2 b and the third bus bar 2 c are parallel to each other in the longitudinal direction of the connection portion 5 that connects the ends of the parallel portions 4 at both ends, and the connection portion 5. The first bus bar 2a has a longitudinal direction perpendicular to the longitudinal direction of the connecting portion 5 of the second bus bar 2b and the third bus bar 2c, and the first bus bar 2a is parallel to the surface of the first bus bar 2a. It arrange | positions so that the surface of the connection part of 3 bus bars 2c may become parallel.

  With this configuration, the positional relationship between the current input side and the output side bus bars 2 (the positional relationship when viewing the magnetic detection element 3 side from the outside along the X-axis direction in the drawing) is the same. It becomes possible. As a result, it is possible to share a connection member such as a connector, which contributes to cost reduction.

  In the above-described embodiment, a three-axis element having three detection axes perpendicular to each other is used as the magnetic detection element 3. However, the present invention is not limited to this. For example, three uniaxial magnetic detection elements 3 are used in combination. Alternatively, the biaxial magnetic detection element 3 and the uniaxial magnetic detection element 3 may be combined. That is, two or more magnetic detection elements 3 may be used in combination (for example, stacked).

  Moreover, although the case where the three bus bars 2 were used was demonstrated in the said embodiment, it is not restricted to this, Two bus bars 2 may be sufficient. In this case, the magnetic detection element has a positional relationship similar to that of the first bus bar 2a and the second bus bar 2b in FIG. 1, and is perpendicular to the surfaces of the two bus bars 2a and 2b and intersects with the plane passing through the center in the width direction. 3 may be arranged.

DESCRIPTION OF SYMBOLS 1 Current detection structure 2 Bus bar 3 Magnetic detection element 4 Parallel part 5 Connection part

Claims (2)

A current detection structure comprising three bus bars and a magnetic detection element for measuring the strength of a magnetic field generated by a current flowing through the three bus bars,
The three bus bars are composed of a linear first bus bar, a second bus bar formed in a crank shape in a plan view, and a third bus bar formed in a crank shape in a side view ,
In the second bus bar and the third bus bar, the longitudinal directions of the connecting portions connecting the ends of the parallel portions at both ends thereof are parallel to each other, and the surfaces parallel to the surfaces of the connecting portions are orthogonal to each other. Arranged,
The first bus bar has a longitudinal direction orthogonal to a longitudinal direction of the connection portion of the second bus bar and the third bus bar, and a surface thereof and a surface of the connection portion of the third bus bar are parallel to each other. Placed in
The magnetic detection element is disposed at a position where a plane perpendicular to the surface of each bus bar and passing through the center in the width direction intersects ,
The current detection structure, wherein the three bus bars are arranged in the same positional relationship between the current input side and the output side . The current detection structure according to claim 1, wherein a triaxial magnetic detection element having three detection axes perpendicular to each other is used as the magnetic detection element.

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