JP6296103B2 - Current sensor - Google Patents

Description

  The present invention relates to a current sensor configured to detect the magnitude of the current based on the magnitude of magnetic flux generated in a core.

  Conventionally, a core for a current sensor formed by bending a magnetic plate is proposed in Patent Document 1, for example. Specifically, in Patent Document 1, there is a core configuration including a core body made of a bent plate material and a gap portion in which both ends of the bent plate material are arranged to face each other with a predetermined gap therebetween. Proposed.

  Among these, the core body has an inclined portion that is inclined so that the dimension in the minor axis direction of the plate material, that is, the width size of the plate material, is reduced from the side opposite to the gap to the connection portion between the gap portion and the core body. ing. On the other hand, the width dimension of the board | plate material in a gap part is constant.

JP 2008-233303 A

  However, in the above conventional technique, the core body is provided with the inclined portion that reduces the width of the plate material, while the gap portion is not provided with the inclined portion. Magnetic field concentrates on the part. For this reason, there is a problem that the magnetic resistance at the connecting portion between the core body and the gap portion becomes non-uniform, and a desired current detection characteristic cannot be obtained in the current sensor.

  An object of this invention is to provide the current sensor provided with the core which has a uniform magnetoresistive characteristic in view of the said point.

  In order to achieve the above-mentioned object, the invention according to claim 1 has a connecting portion (35) in which a part of the plate (31) is bent, and the plate (31) on the side opposite to the connecting portion (35). One end (32) and the other end (33) are provided with a core (30) disposed opposite to each other with a certain magnetic gap (34) interposed therebetween.

  Further, the current configured to detect the magnitude of the current based on the magnitude of the magnetic flux generated in the core (30) when the current to be measured flows so as to penetrate the hollow portion of the core (30). The sensor is characterized by the following points.

  That is, in the core (30), the width of the plate (31) extends from the end (35a) on the one end (32) side of the connecting portion (35) to the tip (32a) of the one end (32). From the first taper portion (36a) that continuously narrows and the end portion (35b) on the other end portion (33) side of the connecting portion (35) to the tip end (33a) of the other end portion (33). And the second taper portion (37a) in which the width of the plate material (31) is continuously reduced. The connecting portion (35) has a constant width from the end portion (35a) on the one end portion (32) side to the end portion (35b) on the other end portion (33) side, and has a cylindrical shape. It is configured as a bent portion (35) bent at a constant diameter so as to be a semi-cylindrical shape in which the cylinder is divided into two along the central axis so as to pass through the central axis. Furthermore, the end (35a) on the one end (32) side of the bent portion (35) corresponds to the starting point of the first tapered portion (36a), and the other end (33) of the bent portion (35). ) Side end portion (35b) corresponds to the starting point of the second taper portion (37a). And in a board | plate material (31), from the edge part (35a) by the side of the one end part (32) of the bending part (35) to the front-end | tip (32a) of one end part (32) is made into the 1st board part (36). At the same time, if the second plate portion (37) from the end portion (35b) on the other end portion (33) side of the bent portion (35) to the tip end (33a) of the other end portion (33) is the bent portion ( 35), the side opposite to the side corresponding to the first taper part (36a) and the second taper part (37a), and the side opposite to the first taper part (36a) in the first plate part (36). The side surface of the second plate portion (37) opposite to the second taper portion (37a) is located on the same plane.

  Thus, since the core (30) is provided with the first taper portion (36a) and the second taper portion (37a), the core (30) extends from the connecting portion (35) to the tips (32a, 33a). There is no portion where the magnetic field concentrates due to the shape of 30). The bent portion (35) is bent with a constant diameter so as to be a semi-cylindrical shape, and the path of the magnetic flux generated in the bent portion (35) becomes an arc shape with a fixed diameter. Magnetic resistance can be reduced. The core (30) is provided with gently tapered portions (36a, 37a), and the cross-sectional area ratio between the magnetic path and the magnetic gap (34) is increased, so that hysteresis (residual magnetic flux) is reduced. And the occurrence of magnetic saturation can be suppressed. Furthermore, the location where a magnetic field concentrates from the bending part (35) to each front-end | tip (32a, 33a) resulting from the shape of a core (30) can be eliminated. Therefore, uniform magnetoresistance characteristics can be obtained in the core (30).

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

1 is an external view of a current sensor according to a first embodiment of the present invention. It is an exploded view of the case and core of FIG. (A) is the figure which looked at each taper part side among cores, (b) is the side view of a core, (c) is the front view which looked at the magnetic gap side of the core. It is the perspective view which showed distribution of the magnetic flux density which generate | occur | produces in a lamination | stacking core. It is the figure which showed distribution of magnetic flux density about the core divided into the part from which the width | variety becomes narrow continuously among the 1st board part and the 2nd board part, and the part from which the width | variety is constant. It is the figure which showed distribution of magnetic flux density about the core shown by FIG. It is the figure which showed the relationship between to-be-measured current and linearity. It is the figure which showed the relationship between the length of a magnetic gap, and S / N ratio. It is a side view of the core which concerns on 2nd Embodiment. FIG. 10 is a development view of the core shown in FIG. 9. It is a perspective view of the core which concerns on 3rd Embodiment of this invention. 11A is a view of each core portion of the core of FIG. 11, FIG. 11B is a view of the first plate portion of the core of FIG. 11, and FIG. The figure which looked at the 2 plate part side, (d) is the figure which looked at the magnetic gap side of the core of FIG. It is a top view for demonstrating other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the current sensor 10 includes a case 20, a core 30, a circuit unit 40, and a filler 50.

  The case 20 is an appearance of the current sensor 10 and is formed by molding a resin material. In the present embodiment, the case 20 is a quadrangular prism. Such a case 20 has a through hole 21, a housing portion 22, and a connector portion 23.

  The through hole 21 is provided so as to penetrate the one surface 24 of the case 20 and the other surface 25 opposite to the one surface 24. A current to be measured flows so as to penetrate through the through hole 21 via a wiring or the like.

  The accommodating portion 22 is a space portion formed by a portion of the one surface 24 of the case 20 being recessed toward the other surface 25 in a portion of the case 20 excluding the portion constituting the through hole 21. . That is, the accommodating portion 22 is provided around the through hole 21. The housing portion 22 houses the core 30 and the circuit portion 40.

  The connector part 23 is a connection part for electrically connecting the circuit part 40 and the outside. The connector part 23 is provided so as to protrude from the other surface 25 of the case 20 and is connected to a connector of a cable connected to a current detection device (not shown).

  The core 30 is a component that generates a magnetic flux in the core 30 when a current to be measured flows so as to penetrate the hollow portion of the core 30. The core 30 is composed of a single plate material 31, and one end portion 32 and the other end portion 33 of the plate material 31 are arranged to face each other with a certain magnetic gap 34 therebetween. As the core 30, a magnetic material such as permalloy is used.

  When the core 30 is accommodated in the accommodating portion 22 of the case 20, the through hole 21 of the case 20 is positioned in the hollow portion of the core 30. Further, the current to be measured passes through the through hole 21. Therefore, the current to be measured passes through the hollow portion of the core 30.

  The circuit unit 40 is mounted with a hall IC (not shown) for detecting the magnitude of the magnetic flux generated in the core 30 and a circuit chip (not shown) for processing a signal from the hall IC. The Hall IC is disposed in the magnetic gap 34 of the core 30.

  The filler 50 is a sealing member filled in the housing portion 22 in a state where the core 30 and the circuit unit 40 are housed in the housing portion 22 of the case 20. As the filler 50, for example, a material such as urethane is used. Note that the surface of the filler 50 filled in the accommodating portion 22 becomes a part of the one surface 24 of the case 20. The above is the overall configuration of the current sensor 10 according to the present embodiment.

  Next, a specific configuration of the core 30 in the current sensor 10 will be described. As shown in FIG. 3, the core 30 includes a bent portion 35 in which a part of the plate material 31 is bent, and a first plate portion 36 and a second plate that are part of the plate material 31 and are connected to the bent portion 35. Part 37. That is, when the core 30 is expanded, the plate 31 is configured such that the bent portion 35 is sandwiched between the first plate portion 36 and the second plate portion 37.

  Note that the one end portion 32 of the plate material 31 corresponds to the end portion of the first plate portion 36 opposite to the bent portion 35. Further, the other end portion 33 of the plate material 31 corresponds to an end portion of the second plate portion 37 opposite to the bent portion 35.

  As shown in FIG. 3A, the bending portion 35 is bent with a constant diameter so as to be a semi-cylindrical shape. Here, the “semicircle” is a perfect circle divided into two. Therefore, the “semi-cylindrical shape” indicates a state in which the cylinder is divided into two along the central axis so as to pass through the central axis of the cylinder. As a result, the path of the magnetic flux generated in the bent portion 35 becomes an arc shape having a constant diameter, so that the magnetic resistance in the bent portion 35 can be reduced.

  The core 30 has a first taper portion 36 a on the first plate portion 36 and a second taper portion 37 a on the second plate portion 37. Specifically, as shown in FIG. 3B, the first taper portion 36 a extends from the end portion 35 a on the one end portion 32 side of the bent portion 35 to the tip end 32 a of the one end portion 32. The width | variety of the 1st board part 36 is formed so that it may become narrow continuously.

  Here, “the end portion 35 a on the one end portion 32 side of the bent portion 35” refers to one end portion in the circumferential direction of the semi-cylindrical bent portion 35. An end portion 35a of the bent portion 35 indicates a portion of the bent portion 35 connected to the first plate portion 36, and corresponds to the starting point of the first tapered portion 36a. The end point of the first taper portion 36 a corresponds to the tip 32 a of the one end portion 32 of the first plate portion 36.

  On the other hand, in the second taper portion 37a, the width of the second plate portion 37 of the plate 31 is continuous from the end portion 35b on the other end portion 33 side of the bent portion 35 to the tip end 33a of the other end portion 33. Thus, it is formed to be narrow. Here, “the end 35 b of the bent portion 35 on the other end 33 side” refers to the other end in the circumferential direction of the semi-cylindrical bent portion 35. That is, the end 35b of the bent portion 35 corresponds to the start point of the second taper portion 37a, and the tip 33a of the other end portion 33 of the second plate portion 37 corresponds to the end point of the second taper portion 37a.

  The “width of the first plate portion 36” is not the thickness of the plate material 31 constituting the first plate portion 36 but the width dimension of the first plate portion 36 in the minor axis direction. Similarly, the “width of the second plate portion 37” is the width dimension of the second plate portion 37 in the minor axis direction.

  Here, the side of the bent portion 35 opposite to the side corresponding to the first tapered portion 36a and the second tapered portion 37a, the side of the first plate portion 36 opposite to the first tapered portion 36a, and The side surface of the second plate portion 37 opposite to the second taper portion 37a is located on the same plane.

  Then, as shown in FIG. 3C, the first plate so that one end 32 of the first plate portion 36 forms a magnetic gap 34 with the other end 33 of the second plate portion 37. The middle part of the part 36 is bent. Thereby, the opposing distance between the inner wall surface at the end portion 35a on the one end portion 32 side of the bent portion 35 of the core 30 and the inner wall surface at the end portion 35b on the other end portion 33 side of the bent portion 35 is the magnetic gap. It is longer than 34. That is, when the opposing distance of the portion connected to the bent portion 35 side of each plate portion 36, 37, that is, the inner diameter (diameter) of the bent portion 35 is defined as L1, and the magnetic gap 34 is defined as L2, the condition of L1> L2 is satisfied. The core 30 is configured to satisfy. In the core 30 that satisfies such a condition, the diameter of the bent portion 35 is increased, so that the magnetic resistance can be reduced.

  Further, the first plate portion 36 is connected to the end portion 35 a on the one end portion 32 side of the bending portion 35 along the tangential direction of the end portion 35 a on the one end portion 32 side of the bending portion 35. Similarly, the second plate portion 37 is connected to the end portion 35b on the other end 33 side of the bent portion 35 along the tangential direction of the end portion 35b on the other end portion 33 side of the bent portion 35. ing. Thereby, the magnetic flux supplemented by the bending part 35 can be efficiently guided to the first plate part 36 and the second plate part 37.

  The core 30 having the above-described configuration is formed by forming a first taper portion 36a and a second taper portion 37a by pressing one plate material 31 and performing bending press on the plate material 31. Since the core 30 can be configured by simply cutting out a part of the plate material 31 in order to provide the respective tapered portions 36a and 37a, the magnetic material can be used efficiently, and the magnetic material can be used without waste. Moreover, since it can be comprised with the board | plate material 31 of 1 sheet, it becomes possible to implement | achieve the core 30 of small size and light weight and low price.

  Next, a current detection method of the current sensor 10 will be described. When a current flows in a state where wiring or the like is passed through the through hole 21 of the current sensor 10, a magnetic flux corresponding to the magnitude of the current is generated in the core 30. Further, this magnetic flux leaks into the magnetic gap 34.

  Here, since the tapered portions 36a and 37a are provided in the core 30, the cross-sectional area ratio between the magnetic path and the magnetic gap 34 is large. For this reason, a hysteresis (residual magnetic flux) can be reduced and generation | occurrence | production of magnetic saturation can be suppressed.

  The magnetic flux leaking into the magnetic gap 34 is detected by the Hall IC. The circuit unit 40 processes a signal corresponding to the magnitude of the magnetic flux detected by the Hall IC. Thus, the magnitude of the current is detected. A signal corresponding to the magnitude of the current detected by the current sensor 10 is output to the outside via the connector unit 23.

  Then, the effect by the shape of the core 30 which concerns on this embodiment is demonstrated. First, a description will be given of how the inventors arrived at the idea of the shape of the core 30 shown in FIG.

  A conventional core is obtained by laminating and integrating a plurality of thin plate-like core pieces. Such a laminated core is configured by pressing so that a laminate of a plurality of thin plate-like magnetic bodies is formed into a ring shape. However, as a result of examining the distribution of magnetic flux density generated inside the laminated core by the inventors, it was found that the laminated core has many unnecessary portions.

  Specifically, as shown in FIG. 4, it was found that almost no magnetic flux flows outside the laminated core 60, whereas the magnetic flux is concentrated on the inner side where the magnetic path becomes shorter. Therefore, the inventors have thought that the use of only the inner part of the laminated core 60 where the magnetic flux is concentrated enables the laminated core 60 to be reduced in size and weight. In addition, the inventors considered that the core 30 may be formed by bending a single plate material 31 instead of laminating a plurality of core pieces.

  Here, when the magnetic flux density is B, the magnetic resistance is Rm, the current to be measured is I, and the cross-sectional area of the laminated core 60 is S, the magnetic flux density B of the laminated core 60 is B = (I / Rm) × (1 / S). That is, decreasing the cross-sectional area S increases the magnetic flux density B. However, while it is preferable for the magnetic circuit design to increase the cross-sectional area of the magnetic path, in order to concentrate the magnetic flux density in the magnetic gap 34, it is necessary to reduce the cross-sectional area of the portion constituting the magnetic gap 34 in the core 30. is there. Therefore, the inventors have devised a core 30 having a shape in which the widths of the first plate portion 36 and the second plate portion 37 are continuously narrowed from the bent portion 35, as shown in FIG.

  Next, the width of the first plate portion 36 and the second plate portion 37 of the core 30 is continuously narrowed, that is, the portion constituting the magnetic gap 34 in the first plate portion 36 and the second plate portion 37. The effect of not having a constant width will be described.

  The inventors examined the distribution of the magnetic flux density of the core 30 in which the width of the portion constituting the magnetic gap 34 is constant, and the distribution of the magnetic flux density of the core 30 shown in FIG. The results are shown in FIGS.

  As shown in FIG. 5, each of the third plate portion 71 and the fourth plate portion 72 of the core 70 is divided into a portion where the width is continuously narrowed and a portion where the width is constant, It can be seen that the magnetic flux density is concentrated in the constricted portions 71a and 72a, which are the connecting portions. This is because the magnetic resistance varies unevenly in the constricted portions 71a and 72a. That is, the shape of the constricted portions 71a and 72a is not a gradual change but is a corner portion, which causes the magnetic resistance to change abruptly. A magnetic gap 73 is formed by a portion of the third plate portion 71 and the fourth plate portion 72 that has a constant width.

  On the other hand, as shown in FIG. 6, the widths of the first plate portion 36 and the second plate portion 37 of the core 30 according to this embodiment are continuously narrow regardless of the magnetic gap 34 portion. In the first plate portion 36 and the second plate portion 37, there is no portion where the magnetic flux density is concentrated. That is, in this embodiment, since the pole changing part for concentrating the magnetic flux density is not provided in the first plate part 36 and the second plate part 37 of the core 30, the first plate part 36 and the second plate part 37 are magnetic. The resistance can be changed uniformly.

  In addition to the constricted portions 71a and 72a, the changing portion corresponds to a portion where the third plate portion 71 and the fourth plate portion 72 are bent at a right angle. It can be said that the pole changing portion is a portion where the magnetic resistance changes rapidly.

  Here, in this embodiment, the intermediate portion of the first plate portion 36 is bent in order to adjust the width of the magnetic gap 34, but this bent shape is not a right angle but an R shape having a curved plate surface. ing. For this reason, the magnetic resistance does not change unevenly in the intermediate portion of the first plate portion 36. Therefore, concentration of magnetic flux density can be avoided.

  Further, since the widths of the first plate portion 36 and the second plate portion 37 of the core 30 are continuously narrowed, the portions of the first plate portion 36 and the second plate portion 37 that constitute the magnetic gap 34 are cut off. The area can be reduced, and consequently the magnetic flux density can be concentrated. Therefore, the core 30 according to the present embodiment can suppress a sudden increase in magnetic resistance and can constitute a magnetic circuit that efficiently guides the magnetic flux to the magnetic gap 34.

  Subsequently, the inventors examined the linearity with respect to the current to be measured in each of the cores 30 and 70 shown in FIGS. “Linearity” is the rate of change of the gradient of magnetic flux density corresponding to the current value. For example, if the linearity is 0%, it indicates that there is no change in the gradient of the magnetic flux density with respect to the current value. That is, the current value and the magnetic flux density are proportional. On the other hand, when the linearity is a negative value, it indicates that the gradient of the magnetic flux density with respect to the current value is small. In this case, the magnetic flux density tends to saturate even if the current value increases.

  As shown in FIG. 7, in the core 70 shown in FIG. 5, the linearity decreases as the current value of the current to be measured increases. This is considered that the linearity deteriorated due to the sudden magnetic saturation caused by the constricted portions 71a and 72a of the core 70. On the other hand, in the core 30 according to this embodiment shown in FIG. 6, even if the current value of the current to be measured is increased, the linearity is only slightly lowered. That is, since the core 30 according to the present embodiment does not have the constricted portions 71a and 72a as the pole changing portions, rapid magnetic saturation does not occur as the current value increases. Therefore, the core 30 according to the present embodiment can suppress a decrease in linearity with respect to the current to be measured.

  Further, the inventors examined the S / N ratio of the current to be measured with respect to the length of the magnetic gaps 34 and 73 in each of the cores 30 and 70 in FIGS. In the core 70 of FIG. 5, the length of the magnetic gap 73 corresponds to the length from the tip of the portion where the width of the third plate portion 71 and the fourth plate portion 72 is constant to the bent portion side. . In the core 30 of FIG. 6, the length of the magnetic gap 34 corresponds to the length from the tips 32 a and 33 a of the first plate portion 36 and the second plate portion 37 to the bent portion 35 side.

  As shown in FIG. 8, in each of the cores 30 and 70 shown in FIGS. 5 and 6, the S / N ratio of the current to be measured increases as the magnetic gaps 34 and 73 become shorter. However, the S / N ratio of the core 30 according to the present embodiment is generally higher than the S / N ratio of the core 70 shown in FIG. This is because the core 30 according to this embodiment does not have the constricted portions 71a and 72a as the changing portions, and the core 70 shown in FIG. 5 has the constricted portions 71a and 72a as the changing portions. Because. That is, the core 30 according to the present embodiment has an area of the plate material 31 that is larger than the core 70 shown in FIG. Can be increased.

  As described above, the present embodiment is characterized in that the core 30 is provided with the first tapered portion 36a and the second tapered portion 37a. Thereby, the location where a magnetic field concentrates from the bending part 35 to each front-end | tip 32a, 33a resulting from the shape of the core 30 can be eliminated. In other words, there is no portion where the magnetic field concentrates in each of the plate portions 36 and 37 of the core 30. Therefore, uniform magnetoresistance characteristics can be obtained in the core 30.

  Further, the core 30 according to the present embodiment has a shape in which the intermediate portion of the first plate portion 36 is bent, but the second plate portion 37 is not bent. For this reason, when the plate material 31 is bent, an intermediate portion between the bent portion 35 and the first plate portion 36 can be formed with the second plate portion 37 as a reference. That is, since the second plate portion 37 serves as a processing reference, the processing accuracy of the bent portion 35 and the intermediate portion of the first plate portion 36 can be improved. For this reason, it is possible to prevent the magnetic gap 34 from exceeding a dimensional tolerance by processing.

  Further, since the intermediate portion of the first plate portion 36 is bent, a space can be secured on the one end portion 32 side of the first plate portion 36. Therefore, the space efficiency of the accommodating part 22 of the case 20 can be improved.

  In addition, regarding the correspondence between the description of the present embodiment and the description of the claims, the bent portion 35 corresponds to the “connecting portion” of the claims.

(Second Embodiment)
In the present embodiment, parts different from the first embodiment will be described. As shown in the side view of FIG. 9 and the development view of FIG. A configuration having two corners 35d may also be used. In FIGS. 9 and 10, the corners 35c and 35d are indicated by hatching.

  Specifically, in the width direction perpendicular to the longitudinal direction of the plate material 31, the width of the bent portion 35 is larger than the width of the portion of the first plate portion 36 connected to the bent portion 35. Therefore, a portion of the bent portion 35 that is cut by the virtual first tapered portion 36a in the bent portion 35 when the first tapered portion 36a is extended into the bent portion 35 becomes the first corner portion 35c. In other words, of the end portion 35a of the bent portion 35, the corner portion on the first taper portion 36a side of the first plate portion 36 is the first corner portion 35c.

  Similarly to the first corner 35c, the second corner 35d is a virtual second taper 37a in the bent portion 35 when the second tapered portion 37a of the bent portion 35 is extended into the bent portion 35. The portion cut out by the above becomes the second corner 35d. In other words, of the end portion 35b of the bending portion 35, the corner portion on the second taper portion 37a side of the second plate portion 37 is the second corner portion 35d.

  As described above, by providing the corners 35c and 35d on the core 30, burrs during press working can be suppressed.

  Even if the bent portion 35 is provided with the first corner portion 35 c, the first tapered portion 36 a is the first of the plate materials 31 from the end portion 35 a of the bent portion 35 to the tip end 32 a of the one end portion 32. The width of the plate portion 36 is formed to be continuously narrowed. Similarly, even if the bent portion 35 is provided with the second corner portion 35d, the second tapered portion 37a extends from the end portion 35b of the bent portion 35 to the tip end 33a of the other end portion 33. The second plate portion 37 is formed so that the width thereof is continuously narrowed. Further, the corner portions 35 c and 35 d do not affect the magnetic characteristics of the core 30.

(Third embodiment)
In the present embodiment, parts different from the first and second embodiments will be described. As shown in FIG. 11, the core 80 according to the present embodiment is connected to the connecting portion 82, which is a part of the plate material 81 and a connecting portion 82 in which a part of one plate material 81 is bent. The fifth plate portion 83 and the sixth plate portion 84 are configured. That is, when the core 80 is expanded, the plate member 81 is configured such that the connecting portion 82 is sandwiched between the fifth plate portion 83 and the sixth plate portion 84.

  One end portion 85 of the plate member 81 corresponds to the end portion of the fifth plate portion 83 opposite to the connecting portion 82. The other end 86 of the plate 81 corresponds to the end of the sixth plate 84 that is opposite to the connecting portion 82. In addition, one end portion 85 and the other end portion 86 of the plate material 81 are disposed to face each other with a certain magnetic gap 87 interposed therebetween.

  As shown in FIG. 12A, the connecting portion 82 includes a bent portion 88, a first connecting portion 89, and a second connecting portion 90. The width of the connecting portion 82 is constant. The bent portion 88 is bent with a constant diameter so as to be a semi-cylindrical shape, similar to the bent portion 35 described above.

  The first connecting portion 89 is a plate-like portion that connects the bent portion 88 and the fifth plate portion 83. One end portion 89 a of the first connection portion 89 is connected to one end portion 88 a of the bending portion 88, and the other end portion 89 b of the first connection portion 89 is connected to the fifth plate portion 83. Is connected to one end 83a. The first connection portion 89 is connected to the end portion 88 a on the one end portion 85 side of the bending portion 88 along the tangential direction of the end portion 88 a on the one end portion 85 side of the bending portion 88. Thereby, the magnetic flux supplemented by the bending part 88 can be efficiently guided to the first connection part 89.

  The first connection portion 89 has a first corner portion 89c provided on the other end 89b side. The first corner portion 89 c is a portion provided by the width of the other end portion 89 b side of the first connection portion 89 being larger than the maximum width of one end portion 83 a of the fifth plate portion 83. is there.

  The second connection portion 90 is a plate-like portion that connects the bent portion 88 and the sixth plate portion 84. One end 90 a of the second connection part 90 is connected to the other end 88 b of the bent part 88, and the other end 90 b of the second connection part 90 is of the sixth plate part 84. Is connected to one end portion 84a. And the 2nd connection part 90 is connected to the edge part 88b by the side of the other end part 86 side of the bending part 88 along the tangential direction of the edge part 88b by the side of the other end part 86 of the bending part 88. Yes. Thereby, the magnetic flux supplemented by the bending part 88 can be efficiently guided to the second connection part 90.

  Moreover, the 2nd connection part 90 has the 2nd corner | angular part 90c provided in the other edge part 90b side. Similarly to the first corner portion 89 c, the second corner portion 90 c has a width on the other end portion 90 b side of the second connection portion 90 that is greater than the maximum width of one end portion 84 a of the sixth plate portion 84. Is a part provided by being large.

  The first corner portion 89c and the second corner portion 90c serve to suppress burrs when the plate material 81 is pressed.

  As shown in FIGS. 12A and 12B, the fifth plate portion 83 has a third tapered portion 83b. The third taper portion 83 b is a portion formed so that the width of the fifth plate portion 83 is continuously narrowed from one end portion 83 a of the fifth plate portion 83 to the tip end 85 a of the one end portion 85. It is. Even if the first connecting portion 89 is provided with the first corner portion 89c, the third tapered portion 83b extends from the end portion 89b of the first corner portion 89c to the tip end 85a of the one end portion 85. The width is continuously narrowed.

  As shown in FIG. 12C, the sixth plate portion 84 has a fourth tapered portion 84b. The fourth taper portion 84b is formed so that the width of the sixth plate portion 84 is continuously narrowed from one end portion 84a of the sixth plate portion 84 to the tip end 86a of the other end portion 86. Part. Even if the second connecting portion 90 is provided with the second corner portion 90c, the fourth tapered portion 84b extends from the end portion 90b of the second corner portion 90c to the tip end 86a of the other end portion 86. The width 84 is continuously narrowed.

  In the configuration of the core 80 described above, the other of the second connection portions 90 is formed such that one end portion 85 of the fifth plate portion 83 forms a magnetic gap 87 with the other end portion 86 of the sixth plate portion 84. One end portion 83a of the end portion 90b and the fifth plate portion 83 is bent. Thereby, as shown in FIG. 12A, the hollow portion of the core 80 is L-shaped. Moreover, since the whole core 80 is L-shaped, the space efficiency of the core 80 can be improved. As in the first embodiment, the space efficiency can be further improved by bending the intermediate portion of the fifth plate portion 83.

  Here, the second connecting portion 90 and the second connecting portion 90 and the inner gap (diameter) of the bent portion 88 are longer than the magnetic gap 87 by facing each other at the end portions 88 a and 88 b of the bent portion 88 of the core 80. The fifth plate portion 83 is bent. The second connection portion 90 and the fifth plate portion 83 are bent so as to have a shape that is not a pole changing portion, that is, an R shape. Thereby, the magnetic resistance of the core 80 can be reduced.

  In the plate 81, the side of the connecting portion 82 opposite to the side corresponding to the third taper 83b and the second taper 37a, and the side of the fifth plate 83 opposite to the third taper 83b. The side surface and the side surface of the sixth plate portion 84 opposite to the fourth taper portion 84b are located on the same plane.

  According to the shape of the core 80 as described above, since the width of the core 80 is wide as shown in FIG. 12D, a thick bus bar or the like can be measured. Further, by using the sixth plate portion 84 as a processing reference, the processing accuracy of the bent portion of the core 80 can be improved.

  As for the correspondence between the description of the present embodiment and the description of the claims, the bent portion 88, the first connecting portion 89, and the second connecting portion 90 correspond to the “connecting portion” in the claims. . The third taper portion 83b corresponds to a “first taper portion” in the claims, and the fourth taper portion 84b corresponds to a “second taper portion” in the claims.

(Other embodiments)
The configuration of the current sensor 10 shown in each of the above embodiments is an example, and is not limited to the configuration shown above, and other configurations that can realize the present invention can be used. For example, the bending portion 35 of the core 30 is an example of a semi-cylindrical shape, and may be bent, for example, in an arc shape within a range that does not affect the magnetoresistance characteristics of the core 30.

  In each of the above embodiments, the cores 30 and 70 are configured by the single plate materials 31 and 81, but may be configured by a plurality of plate materials 31 and 81. For example, the cores 30 and 70 may be formed by laminating and bending two pressed plate materials 31 and 81. As described above, by laminating the plurality of plate materials 31 and 81, a path of magnetic flux can be positively created by the skin effect of the plate materials 31 and 81. In particular, when the current to be measured is an alternating current, the skin effect is enhanced, so that there is an advantage in that the cores 30 and 70 are constituted by a plurality of plate materials 31 and 81.

  In the said 3rd Embodiment, although the 1st corner | angular part 89c was provided in the 1st connection part 89 and the 2nd corner | angular part 90c was provided in the 2nd connection part 90, this is an example of a structure. Therefore, the first corner 89c and the second corner 90c may not be provided in the core 80. In this case, the width on the other end 89 b side of the first connection portion 89 and the maximum width of one end 83 a of the fifth plate portion 83 are the same. Similarly, the width on the other end 90 b side of the second connection portion 90 is the same as the maximum width of one end 84 a of the sixth plate portion 84.

  Further, as shown in FIG. 13, two Hall ICs 100 may be arranged side by side in the magnetic gap 34 of the core 30. In this case, the part which comprises the magnetic gap 34 among the cores 30, ie, the part which comprises the magnetic gap 34 among the 1st board part 36 and the 2nd board part 37, is opposingly arranged so that it may become parallel. Thereby, the current to be measured can be measured in two ranges. Similarly, when two Hall ICs 100 are arranged in the magnetic gap 34 of the core 80 shown in the third embodiment, portions of the fifth plate portion 83 and the sixth plate portion 84 that constitute the magnetic gap 87 are parallel. It suffices if they are arranged so as to face each other.

30 Core 31 Plate member 32 One end portion of plate member 32a Tip of one end portion 33 Other end portion of plate member 33a Tip of other end portion 34 Magnetic gap 35 Bending portion 35a, 35b End portion of bending portion 36a First taper portion 37a Second taper portion

Claims (4)

While having a connection part (35) where a part of board material (31) was bent, one end part (32) and the other end part (33) of the board material (31) on the opposite side to the connection part (35) Comprises a core (30) arranged oppositely via a constant magnetic gap (34),
A current configured to detect the magnitude of the current based on the magnitude of the magnetic flux generated in the core (30) when the current to be measured flows through the hollow portion of the core (30). A sensor,
The core (30)
The width of the plate (31) is continuously narrow from the end (35a) on the one end (32) side of the connecting portion (35) to the tip (32a) of the one end (32). A first taper portion (36a),
The width of the plate (31) continues from the end (35b) on the other end (33) side of the connecting portion (35) to the tip (33a) of the other end (33). A second taper portion (37a) that becomes narrower,
Have
The connecting portion has a constant width of the plate (31) from the end (35a) on the one end (32) side to the end (35b) on the other end (33) side. And a bent portion (35) bent at a constant diameter so as to be a semi-cylindrical shape in which the cylinder is divided into two along the central axis so as to pass through the central axis of the cylinder,
An end portion (35a) on the one end portion (32) side of the bent portion (35) corresponds to a starting point of the first tapered portion (36a), and the other end of the bent portion (35). The end (35b) on the side of the portion (33) corresponds to the starting point of the second tapered portion (37a);
In the plate (31), the first plate (36) extends from the end (35a) on the one end (32) side of the bent portion (35) to the tip (32a) of the one end (32). And the second plate portion (37) from the end portion (35b) on the other end portion (33) side of the bent portion (35) to the tip end (33a) of the other end portion (33). Then, the side of the bent portion (35) opposite to the side corresponding to the first tapered portion (36a) and the second tapered portion (37a), the first plate portion (36) of the first side. The side surface opposite to the first taper portion (36a) and the side surface of the second plate portion (37) opposite to the second taper portion (37a) are located on the same plane. And current sensor. In the first taper portion (36a), the width of the plate material (31) is continuously narrowed at a constant rate of change, or the width of the plate material (31) is continuously narrowed linearly,
The second taper portion (37a) is characterized in that the width of the plate material (31) is continuously narrowed at a constant rate of change, or the width of the plate material (31) is continuously narrowed linearly. The current sensor according to claim 1. The first plate portion (36) has an end portion on the one end portion (32) side along the tangential direction of the end portion (35a) on the one end portion (32) side of the bent portion (35). 35a),
The second plate portion (37) is an end on the other end portion (33) side along the tangential direction of the end portion (35b) on the other end portion (33) side of the bent portion (35). The current sensor according to claim 1, wherein the current sensor is connected to the portion (35 b).   The inner wall surface at the end (35a) on the one end (32) side of the bent portion (35) and the end (35b) on the other end (33) side of the bent portion (35). The current sensor according to any one of claims 1 to 3, wherein a facing distance from an inner wall surface is longer than the magnetic gap (34).