current sensor

Abstract

The current sensor of the present invention includes: a magnetic sensor capable of sensing a magnetic field generated by the flow of a measured current in a current path; and a shielding member comprising a first shielding member, a second shielding member, and a third shielding member disposed separately from each other. The first shielding member is disposed on the opposite side of the magnetic sensor in a first direction opposite to the magnetic sensor and the current path, and has a first opposing surface opposite to the current path. The second shielding member has a second opposing surface along the first direction, and the third shielding member has a third opposing surface along the first direction. The second and third opposing surfaces of the second and third shielding members are configured to be opposite each other, separated by the magnetic sensor and the current path. The shielding member of the current sensor of the present invention can sufficiently attenuate external magnetic fields and suppress or control magnetic saturation, thereby expanding the current measurement range.

Description

Technical Field

[0001] This invention relates to a current sensor that detects the measured current based on the magnetic field generated by the current flowing in the current path. Background Technology

[0002] For the current sensor described in Patent Document 1, the current path for the flow of the measured current is bent into a U-shape, with both ends of the current path positioned to abut against the long sides of a rectangular insulating substrate. Furthermore, one side of each end of the current path is positioned near the short side of one side of the insulating substrate. A magnetic field control plate, which controls the magnetic field generated by the measured current, is also bent into a U-shape, with one end positioned to abut against the short side of the insulating substrate where the side of the current path is located. A magnetic sensor element for measuring the magnetic field is positioned at the center of the opening width of the magnetic field control plate. Through this magnetic field control plate, the magnetic field generated by the current path can be concentrated around the magnetic sensor element, and external magnetic fields can be weakened, thereby providing magnetic shielding for the magnetic sensor element.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-3974 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the current sensor described in Patent Document 1, the influence of the external magnetic field is suppressed by a magnetic field control plate, which serves as a shielding component. However, the magnetic field generated by the measured current is amplified by the magnetic field control plate. Therefore, the magnetic field can be reliably sensed by a magnetic sensor element positioned at the center of the opening width of the magnetic field control plate. However, the magnetic field control plate has the effect of amplifying the magnetic field on the one hand, but it is also prone to magnetic saturation on the other hand. Therefore, it cannot sense the current and thus cannot function as a current sensor.

[0008] Therefore, the object of the present invention is to provide a current sensor having a shielding component, wherein the shielding component can sufficiently attenuate an external magnetic field and suppress or control magnetic saturation, thereby expanding the current measurement range, for example, expanding the current measurement range of the measured current, and widening the measurable frequency.

[0009] Methods for solving problems

[0010] To solve the above-mentioned problems, the current sensor of the present invention is characterized by comprising: a magnetic sensor capable of sensing a magnetic field generated by the flow of a measured current in a circuit; and a shielding member comprising a first shielding member, a second shielding member, and a third shielding member disposed separately from each other, the first shielding member being disposed on the opposite side of the magnetic sensor in a first direction in which the magnetic sensor and the current path are opposite to each other, and having a first opposing surface opposite to the current path, the second shielding member having a second opposing surface along the first direction, and the third shielding member having a third opposing surface along the first direction, wherein the second and third opposing surfaces of the second and third shielding members are disposed opposite to each other in a manner that separates the magnetic sensor and the current path.

[0011] In this way, by constructing a shielding element that surrounds the busbar through which the current to be measured flows, composed of multiple discontinuous components, the influence of external magnetic fields can be suppressed, and magnetic saturation in the shielding element can be suppressed or controlled, thereby expanding the range of current measurement.

[0012] In the current sensor of the present invention, preferably, in the first direction, the ends of the second shield and the third shield on the first shield side are located closer to the magnetic sensor side than the first opposing surface of the first shield.

[0013] Therefore, the influence of external magnetic fields can be effectively suppressed. In particular, when current sensors with the same configuration in the second direction are arranged side by side with the second and third opposing surfaces facing each other, the magnetic field generated by the current flowing in the adjacent busbar can be effectively shielded, thereby suppressing the influence of the magnetic field on the magnetic sensor.

[0014] In the current sensor of the present invention, preferably, in a second direction in which the second opposing surface and the third opposing surface are opposite to each other, the ends of the second shielding side and the third shielding side of the first shielding member are arranged at a position farther away from the magnetic sensor than the second opposing surface and the third opposing surface.

[0015] Therefore, the influence of external magnetic fields can be effectively suppressed. In particular, the influence of external magnetic fields along a first direction opposite to the magnetic sensor and the current path can be reliably suppressed by the first shielding.

[0016] In the current sensor of the present invention, preferably, the current path extends along a third direction orthogonal to the first direction and the second direction, and when viewed along the first direction, the two ends of the second shield and the third shield, respectively, are located outside the first shield.

[0017] Therefore, the first shielding element, the second shielding element, and the third shielding element can be supported independently during insert molding, thus improving assemblability.

[0018] In the current sensor of the present invention, it is preferable that the first shield, the second shield, and the third shield are separately separated.

[0019] Therefore, the shielding component can be segmented in a way that effectively suppresses the influence of various external magnetic fields, thereby effectively suppressing the influence of external magnetic fields and adjusting the current measurement range.

[0020] Invention Effects

[0021] According to the present invention, a current sensor is provided that can expand the current measurement range by sufficiently attenuating the external magnetic field and suppressing or controlling magnetic saturation. Attached Figure Description

[0022] Figure 1 (a) is a perspective view showing the configuration of the current sensor according to the first embodiment of the present invention. Figure 1 (b) for in Figure 1 (a) is a perspective view of the current sensor, omitting the illustration of the base component.

[0023] Figure 2 (a) View from the front Figure 1 (b) Front view Figure 2 (b) to indicate Figure 2 (a) Top view of the configuration of the busbar on the left and the first shield, second shield and third shield arranged in a manner surrounding the busbar.

[0024] Figure 3 (a) is an enlarged representation Figure 2 (a) is a front view of the configuration of the busbar on the left, the magnetic sensor corresponding to the busbar, and the first, second, and third shields arranged to surround the busbar and the magnetic sensor. Figure 3 (b) for in Figure 3 (a) is a top view of the busbars, omitting the diagram.

[0025] Figure 4 (a) is a perspective view of the base component viewed from above. Figure 4 (b) is a perspective view of the base component viewed from below.

[0026] Figure 5 A top view showing the configuration of the base component, the second shield, the third shield, and the magnetic sensor.

[0027] Figure 6 A bottom view that hypothetically shows the position of the first shielding member relative to the base component on which the second and third shielding members are disposed.

[0028] Figure 7(a) A front view showing, in an enlarged view, the busbar, the magnetic sensor corresponding to the busbar, and the configuration of the first shield, the second shield, and the third shield arranged to surround the busbar and the magnetic sensor in the second embodiment. Figure 7 (b) A front view showing, in an enlarged view, the configuration of the busbar, the magnetic sensor corresponding to the busbar, and the first shield, the second shield, and the third shield arranged to surround the busbar and the magnetic sensor in the third embodiment.

[0029] Figure 8 A front view showing the configuration of the busbar, the magnetic sensor corresponding to the busbar, and the first, second, and third shields arranged to surround the busbar and the magnetic sensor in the fourth embodiment. Detailed Implementation

[0030] Hereinafter, a current sensor according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In each figure, X-Y-Z coordinates are shown as reference coordinates. In the following description, the Z1-Z2 direction is referred to as the vertical direction (first direction), the X1-X2 direction as the front-back direction (third direction), and the Y1-Y2 direction as the left-right direction (second direction). The X1-X2 direction and the Y1-Y2 direction are perpendicular to each other, and the X-Y plane including the X1-X2 direction and the Y1-Y2 direction is perpendicular to the Z1-Z2 direction. Furthermore, the state of viewing the lower side (Z2 side) from the upper side (Z1 side) is sometimes referred to as a top-down view.

[0031] <First Implementation>

[0032] like Figure 1 , Figure 2 or Figure 3 As shown, the current sensor 10 of the first embodiment includes: a base component 11; a substrate 20; three magnetic sensors 21, 22, and 23; three busbars 31, 32, and 33 serving as current paths; three first shields 41, 51, and 61; three second shields 42, 52, and 62; and three third shields 43, 53, and 63.

[0033] The base component 11 is obtained by insert molding a non-magnetic material together with three busbars 31, 32, 33, three first shielding elements 41, 51, 61, three second shielding elements 42, 52, 62, and three third shielding elements 43, 53, 63. The base component 11 has a rectangular shape extending in the left-right direction (Y1-Y2 direction) when viewed from above (Z1 side) and from below (Z2 side). Figure 4As shown in (a), the external shape is formed by four outer wall portions 12 corresponding to the four sides of a rectangle. When viewed from above, a base 13 is provided recessed downwards on the inner side of each of the four outer wall portions 12. Thus, the upper surface 13a of the base 13 is located below the upper surface of the outer wall portion 12. On the other hand, as... Figure 4 As shown in (b), the bottom surface 13b of the base 13 forms a plane that is integral with the outer wall portion 12.

[0034] like Figure 1 (a), (b) and Figure 2 As shown in (a), the substrate 20 is a rectangular plate material in plan view that extends along the left-right direction (Y1-Y2 direction) and is disposed inside the four outer wall portions 12 of the base member 11 and above the base portion 13. On the substrate 20, a first through hole 20a, a second through hole 20b, a third through hole 20c, and a fourth through hole 20d are formed sequentially from left to right, respectively, through the thickness direction (vertical direction, Z1-Z2 direction). The first through hole 20a is configured to allow the leftmost second shield 42 to be inserted vertically; the second through hole 20b is configured to allow the third shield 43 and the second shield 52, which are opposite the second shield 42, to be inserted in a separated state; the third through hole 20c is configured to allow the third shield 53 and the second shield 62, which are opposite the second shield 52, to be inserted in a separated state; and the fourth through hole 20d is configured to allow the rightmost third shield 63 to be inserted.

[0035] like Figure 2 As shown in (a), three magnetic sensors 21, 22, and 23 are arranged sequentially from left to right on the lower surface of the substrate 20. Figure 2 (a) Figure 3 As shown in (a) and (b), the first magnetic sensor 21 on the left is positioned in the middle between a pair of opposing shields 42 and 43 (second shield 42 and third shield 43) in the left-right direction, and is positioned above the first shield 41 and the first busbar 31 located above the first shield 41 in the up-down direction.

[0036] Similar to the first magnetic sensor 21, the second magnetic sensor 22 is positioned horizontally between a pair of opposing shields 52 and 53 (second shield 52 and third shield 53), and vertically above the first shield 51 and the second busbar 32 located above the first shield 51. Similarly, the third magnetic sensor 23 is also positioned horizontally between a pair of opposing shields 62 and 63 (second shield 62 and third shield 63), and vertically above the first shield 61 and the third busbar 33 located above the first shield 61.

[0037] The three busbars 31, 32, and 33, serving as current paths, form elongated plates of the same shape extending along the front-to-back direction (X1-X2 direction), and are configured such that their upper and lower surfaces are orthogonal to the vertical direction. For example... Figure 2 As shown in (a), the upper surfaces of the three busbars 31, 32, and 33 are respectively opposed to the three magnetic sensors 21, 22, and 23, and their lower surfaces are respectively opposed to the three first shields 41, 51, and 61. More specifically, in the vertical direction, the left first busbar 31 is configured to be opposite to the left magnetic sensor 21 and the left first shield 41 between the left magnetic sensor 21 and the left first shield 41, respectively. The central second busbar 32 in the horizontal direction is configured to be opposite to the central second magnetic sensor 22 and the central first shield 51 between the central second magnetic sensor 22 and the central first shield 51, respectively. Moreover, the right third busbar 33 is configured to be opposite to the right third magnetic sensor 23 and the right first shield 61 between the right third magnetic sensor 23 and the right first shield 61, respectively.

[0038] like Figure 2 As shown in (b), the first busbar 31 on the left side includes: a central rectangular portion 31a in the longitudinal direction (front-back direction, X1-X2 direction), two intermediate portions 31b extending from both ends of the central portion 31a in the longitudinal direction, and two outer portions 31c extending from both ends of the intermediate portions 31b in the longitudinal direction. The first busbar 31 has a symmetrical shape in its width direction (left-right direction, Y1-Y2 direction), and the intermediate portions 31b are wider than the central portion 31a, and the outer portions 31c are wider than the intermediate portions 31b. The top view shape of the first busbar 31 is the same as the top view shape 33 of the second busbar 32 and the third busbar.

[0039] Next, taking the first shielding member 41 on the left and its corresponding second shielding member 42 and third shielding member 43 as examples, the first, second, and third shielding members will be explained. The assembly of the first shielding member 51, second shielding member 52, and third shielding member 53 in the center of the left and right directions and the assembly of the first shielding member 61, second shielding member 62, and third shielding member 63 on the right side also have the same configuration.

[0040] Furthermore, the number of combinations of the first, second, and third shielding components, their corresponding busbars, and the magnetic sensor, which serve as current sensors, is not limited to the following. Figure 1 The three shown can be, for example, one, two, or more than four.

[0041] like Figure 2 (a) and Figure 3 As shown in (a), the first shielding member 41, the second shielding member 42, and the third shielding member 43 are composed of five magnetic shielding plates made of the same magnetic material stacked together. These shielding members 41, 42, and 43 are preferably formed of a soft magnetic material such as electromagnetic steel or permalloy. The second shielding member 42 and the third shielding member 43 have the same shape as each other.

[0042] The first shielding member 41 is configured to extend along the left-right direction (Y1-Y2 direction), with its upper surface first opposing surface 41a opposite the lower surface of the first busbar 31. Figure 2 As shown in (b), the part opposite to the first shield 41 in the first busbar 31 is the central part 31a.

[0043] The second shielding member 42 and the third shielding member 43 are arranged opposite each other in the left-right direction (Y1-Y2 direction) at the same height in the vertical direction. Thus, the second opposing surface 42a of the second shielding member 42 and the third opposing surface 43a of the third shielding member 43 are opposite each other.

[0044] like Figure 3As shown in (a), in the left-right direction (Y1-Y2 direction), the two end faces 41b and 41c of the first shield 41 are located outside the outer surface 42b of the second shield 42 and the outer surface 43b of the third shield 43, respectively. Specifically, the left end face 41b of the first shield 41 (the end face on the side of the second shield 42) is located to the left of the second opposing surface 42a of the second shield 42 by a distance D11, and the right end face 41c (the end face on the side of the third shield 43) is located to the right of the third opposing surface 43a of the third shield 43 by a distance D11. Here, the distance D11 is greater than the thickness of the second shield 42 and the third shield 43 in the left-right direction. Therefore, in the left-right direction, the end of the first shield 41 on the second shield 42 side (first end face 41b) and the end of the third shield 43 side (second end face 41c) are respectively arranged at positions farther away from the magnetic sensor 21 than the second opposing surface 42a and the third opposing surface 43a.

[0045] Thus, in the left-right direction, the two ends of the first shield 41 are positioned further outward than the outer sides 42b of the second shield 42 and 43b of the third shield 43, thereby suppressing the influence of the external magnetic field present in the surrounding area, including the magnetic field generated by the current being measured flowing in the adjacent second busbar 32.

[0046] Furthermore, in the vertical direction (Z1-Z2 direction), the lower surfaces 42c of the second shield 42 and 43c of the third shield 43 are separated from the first opposing surface 41a of the first shield 41 by a distance D12. In other words, in the vertical direction (first direction), the ends of the second shield 42 and the third shield 43 on the first shield 41 side (lower side) are located closer to the magnetic sensor 21 than the first opposing surface 41a of the first shield 41. Here, depending on the specifications of the current sensor 10, the operating environment, etc., the distance D12 is set to shield the external magnetic field relative to the magnetic sensor 21 surrounded by the first shield 41, the second shield 42, and the third shield 43, suppressing the external magnetic field within a specified range and making it difficult to achieve magnetic saturation.

[0047] The second shield 42 and the third shield 43 are arranged at a distance D12 relative to the first shield 41, thereby suppressing the influence of the external magnetic field present in the surrounding area, including the magnetic field generated by the current being measured flowing in the adjacent second busbar 32.

[0048] like Figure 3As shown in (b), in the front-rear direction (X1-X2 direction), the two end faces 42d and 42e of the second shield 42 are located outside the two end faces 41d and 41e of the first shield 41 by a distance D13. Similarly, the two end faces 43d and 43e of the third shield 43 are located outside the two end faces 41d and 41e of the first shield 41 by a distance D13. In other words, when viewed along the vertical direction (first direction), the two ends (two end faces 42d and 42e) of the second shield 42 and the two ends (two end faces 43d and 43e) of the third shield 43 in the front-rear direction (third direction) are located outside the first shield 41.

[0049] In the front-back direction, the two ends of the second shield 42 and the third shield 43 are positioned further outward than the two ends of the first shield 41. Thus, during insert molding, the first shield 41, the second shield 42, and the third shield 43 can be pressed individually, thereby enabling easy manufacturing with high positional accuracy.

[0050] Reference Figure 4 , Figure 5 as well as Figure 6 The manufacturing process of the current sensor 10 is explained.

[0051] The base component 11, the three busbars 31, 32, 33, the three first shields 41, 51, 61, the three second shields 42, 52, 62, and the three third shields 43, 53, 63 are manufactured by insert molding.

[0052] like Figure 4 As shown in (a) and (b), bottomed upper pressure holes (h11-h16, h21-h24, h31-h34) are formed on the base 13 of the base component 11 from the upper surface 13a downwards, and bottomed lower pressure holes (h41-h52, h61-h66, h71-76) are recessed from the bottom surface 13b upwards. When inserting the busbars 31, 32, and 33 into the base component 11 in an integrated manner, the first shield 41, second shield 42, and third shield 43 need to be positioned at predetermined positions within the mold. Therefore, these upper and lower pressure holes are designed to hold the pins against the first shield 41, second shield 42, and third shield 43. After the insert is formed, the pin is removed, and thus, the above-mentioned upper and lower pressure holes h11~h16, h21~h24, h31~h34, h41~h52, h61~h66, and h71~76 are recessed at the position where the pin is pushed.

[0053] Regarding the upper pressure holes formed on the upper surface 13a, firstly, in the center of the front-rear direction, firstly, upper pressure holes h11, h12, h13, h14, h15, and h16 are formed sequentially from left to right. At a position rear of these first upper pressure holes h11 to h16, secondly, upper pressure holes h21, h22, h23, and h24 are formed sequentially from left to right. At a position forward of the first upper pressure holes h11 to h16, corresponding to the positions of the second upper pressure holes h21 to h24 in the front-rear direction, thirdly, upper pressure holes h31, h32, h33, and h34 are formed sequentially from left to right.

[0054] Regarding the lower pressure holes formed on the bottom surface 13b, firstly, in the center of the front-rear direction, from left to right, the first lower pressure holes h41, h42, h43, h44, h45, h46, h47, h48, h49, h50, h51, and h52 are formed sequentially. Among them, the three pairs of pressure holes h42, h43, h46, h47, and h50 are symmetrically arranged in the front-rear direction. Among these first lower pressure holes, at the front position of the pressure holes h41, h44, h45, h48, h49, and h52, the second lower pressure holes h61, h62, h63, h64, h65, and h66 are formed sequentially from left to right. At the rear position, at the position corresponding to the second lower pressure holes h61 to h66 in the front-back direction, the third lower pressure holes h71, h72, h73, h74, h75, and h76 are formed sequentially from left to right.

[0055] During insert molding, after molding is completed, pins (not shown) are formed at the positions of the upper pressure holes h11~h16, h21~h24, and h31~h34 for positioning the second shield 42 and the third shield 43 in the X-Y plane. These pins are removed after molding (see reference). Figure 5 The marks left after the pin is removed become the various types of indentations mentioned above. For example... Figure 5 As shown, for example, in the case of the leftmost second shield 42, the left side is restricted by a pin located at the position of the rear pressure hole h21 and the position of the upper pressure hole h31 located at the position of the front side, and the right side (second opposing surface 42a) is restricted by a pin located at the position of the pressure hole h11 located at the center in the front-rear direction.

[0056] On the other hand, for the lower pressure holes, after molding, the positions of the first lower pressure holes h41, h42, h43, h44, h45, h46, h47, h48, h49, h50, h51, and h52 are configured with pins for positioning the first shielding components 41, 51, and 61 in the vertical direction, and the pins are removed after molding (refer to...). Figure 6The marks left after the pins were removed become the various indentations mentioned above. For example, the first shielding member 41 on the left was... Figure 6 The configuration shown is pin positioning at the locations of the four first lower side pressure holes h41, h42, h43, and h44 on the left side.

[0057] Furthermore, the second lower pressure holes h61-h66 are located forward of the first shielding members 41, 51, and 61, and the third lower pressure holes h71-h76 are located rearward of the first shielding members 41, 51, and 61. Pins for positioning the second shielding member 42 and the third shielding member 43 in the vertical direction are disposed in these lower pressure holes h61-h66 and h71-h76, and these pins are removed after molding. For example, the leftmost second shielding member 42 is fixed in the vertical direction by pins respectively disposed in the second lower pressure hole h61 and the corresponding third lower pressure hole h71 in the front-rear direction.

[0058] Once the insert molding is complete, the positioning pins are removed, forming upper pressure holes h11-h16, h21-h24, h31-h34 and lower pressure holes h41-h52, h61-h66, h71-76 at the removed pin locations. Then, a substrate 20 is disposed on the base 13. The substrate 20 is configured such that: the leftmost second shield 42 is located within the first insertion hole 20a; the third shield 43 and its rightmost second shield 52 are parallel to each other within the second insertion hole 20b; the third shield 53 and its rightmost second shield 62 are parallel to each other within the third insertion hole 20c; and the rightmost third shield 63 is located within the fourth insertion hole 20d.

[0059] Before the substrate 20 is placed on the base 13, three magnetic sensors 21, 22, and 23 are pre-positioned on the lower surface of the substrate 20.

[0060] In the current sensor 10 of the first embodiment, the magnetic sensor 21 and the first busbar 31, which are vertically opposed to each other, are sandwiched between the second shield 42 and the third shield 43 in the left-right direction, and are surrounded by the first shield 41 below. The first opposing surface 41a of the first shield 41 is separated from the second shield 42 and the third shield 43 by a distance D12. In this configuration, when the current to be measured flows in the first busbar 31, which serves as the current path, a magnetic field is generated. The three shields 41, 42, and 43 surrounding the first busbar 31 from three directions function as magnetic yokes to this magnetic field. Furthermore, by separating the three shields 41, 42, and 43 with a distance D12 between them, the concentration of the magnetic force can be controlled by the magnitude of the distance D12, preventing magnetic saturation in the three shields 41, 42, and 43. This expands the current measurement range, for example, by increasing the current measurement range of the measured current and widening the measurable frequency.

[0061] Here, simulation results of Embodiment 1 based on the configuration of the current sensor 10 according to the first embodiment will be explained.

[0062] The configuration of Example 1 and the comparative example is as follows.

[0063] <Example 1>

[0064] The first shielding element 41 is made of electromagnetic steel plate and soft magnetic materials such as permalloy, and is a five-layered structure with a total thickness of 1.5 mm (Z1-Z2 direction), a width of 13 mm (Y1-Y2 direction), and a length of 6 mm (X1-X2 direction). The second shielding element 42 is made of electromagnetic steel plate and soft magnetic materials such as permalloy, and is a five-layered structure with a total thickness of 1.5 mm (Y1-Y2 direction), a height of 9.5 mm (Z1-Z2 direction), and a length of 8 mm (X1-X2 direction). The third shielding element 43 is made of the same material and has the same shape as the second shielding element 42. The distances from D11 are 2 mm, D12 is 0.5 mm, and D13 is 1 mm. The first busbar 31 is positioned 1.5 mm above the first opposing surface 41a of the first shielding element 41, and the magnetic sensor 21 is positioned further above it.

[0065] <Comparative Example>

[0066] In the comparative example, the shielding element forms a continuous U-shape with an upper opening when viewed from the front view, unlike the first, second, and third shielding elements of Example 1 which are segmented. The material and length (X1-X2 direction) of the shielding element are the same as in Example 1, and the thickness and width (or height) of the portions corresponding to the first, second, and third shielding elements of Example 1 are the same as those in Example 1. The shape of the magnetic sensor and the busbar, as well as their positions relative to the inner surface (opposing surface) of the shielding component, are the same as in Example 1.

[0067] According to the simulation, as shown in Table 1, in the comparative example, the maximum magnetic flux density was 1.6T, and the influence from adjacent busbars was 0.1%. In contrast, in Example 1, the maximum magnetic flux density was 0.4T, and the influence from adjacent busbars was 0.7%. Furthermore, the adjacent influence in the comparative example was 0.1%, while in Example 1 it was 0.7%, slightly larger than the comparative example. However, this is due to the gap formed by separating the shielding, making it slightly more susceptible to adjacent influences, which is acceptable in a practical product. That is, the degree of influence is not significant enough to greatly affect the measurement accuracy of the current sensor 10, but rather within an acceptable range while prioritizing the suppression of magnetic saturation. Moreover, in Example 1, the current until magnetic saturation is reached is approximately twice that of the comparative example. Therefore, it can be seen that in the configuration of Example 1, the current measurement range can be expanded, and the influence of external magnetic fields such as the magnetic field generated by the current flowing in the adjacent busbars can be fully suppressed, while the magnetic field generated by the current being measured flowing in the busbar 31 is amplified by the first shield 41, the second shield 42 and the third shield 43, which function as a yoke.

[0068] [Table 1]

[0069]

[0070] The following are examples of variations.

[0071] The configuration of the first, second, and third shielding components can be arbitrarily set according to the specifications of the current sensor 10. For example, the number of layers can be set to any number other than five, or it can be a single layer. Alternatively, it can be a configuration obtained by further dividing any one or more of the first, second, and third shielding components. By changing the configuration in this way, the influence of the external magnetic field can be suppressed while the measurement range can be controlled according to the specifications of the current being measured.

[0072] <Second Implementation>

[0073] exist Figure 7In the second embodiment shown in (a), in the left-right direction (second direction), the two end faces 241b and 241c of the first shield 241 are respectively positioned closer to the magnetic sensor 221, i.e., on the inner side, than the second opposing face 242a of the second shield 242 and the third opposing face 243a of the third shield 243. Similarly to the first embodiment, the busbar 231 is positioned between the magnetic sensor 221 and the first shield 241 in the up-down direction (Z1-Z2 direction), with its upper and lower surfaces facing the magnetic sensor 221 and the first shield 241, respectively. Other configurations are the same as in the first embodiment, therefore detailed descriptions are omitted.

[0074] In the left-right direction, the left end face 241b of the first shielding member 241 is separated from the second opposing surface 242a by a distance D21, and the right end face 241c of the first shielding member 241 is also separated from the third opposing surface 243a by a distance D21. Furthermore, in the up-down direction, the first opposing surface 241a, which is the upper surface of the first shielding member 241, is separated from the lower surface 242c of the second shielding member 242 and the lower surface 243c of the third shielding member 243 by a distance D22.

[0075] An embodiment 2, which includes the following configuration in the current sensor of the second embodiment, is simulated.

[0076] <Example 2>

[0077] The first shielding element 241 is made of electromagnetic steel plate and soft magnetic materials such as permalloy, and is a five-layered structure with a total thickness of 1.5 mm (Z1-Z2 direction), a width of 8 mm (Y1-Y2 direction), and a length of 6 mm (X1-X2 direction). The second shielding element 242 is made of electromagnetic steel plate and soft magnetic materials such as permalloy, and is a five-layered structure with a total thickness of 1.5 mm (Y1-Y2 direction), a height of 9.5 mm (Z1-Z2 direction), and a length of 6 mm (X1-X2 direction). The third shielding element 243 is made of the same material and has the same shape as the second shielding element 242. The distance between the shielding element and the shielding element is 0.5 mm, and the distance between the shielding element and the shielding element is 0.5 mm. The busbar 231 is positioned 1.5 mm above the first opposing surface 241a of the first shielding element 241, and the magnetic sensor 221 is positioned further above it.

[0078] According to the simulation, as shown in Table 1, in Example 2, the maximum magnetic flux density is 0.8T, and the influence from adjacent busbars is 0.3%. Furthermore, in Example 2, the current until magnetic saturation is reached is approximately four times that of the comparative example described above. Therefore, it can be seen that in the configuration of Example 2, by suppressing the magnitude in the left-right direction to be smaller than that of Example 1 (first embodiment), the current measurement range can be expanded. Furthermore, while sufficiently suppressing the influence of external magnetic fields such as the magnetic field generated by the current flowing in adjacent busbars, the magnetic field generated by the current being measured flowing in busbar 231 can be amplified by the first shield 241, the second shield 242, and the third shield 243, which function as a magnetic yoke.

[0079] <Third Implementation Method>

[0080] exist Figure 7 In the third embodiment shown in (b), in the left-right direction (second direction), the two end faces 341b and 341c of the first shield 341 are respectively positioned closer to the magnetic sensor 321, i.e., on the inner side, than the second opposing face 342a of the second shield 342 and the third opposing face 343a of the third shield 343. Similarly to the first embodiment, the busbar 331 is positioned between the magnetic sensor 321 and the first shield 341 in the up-down direction (Z1-Z2 direction), with its upper and lower surfaces facing the magnetic sensor 321 and the first shield 341, respectively. Other configurations are the same as in the first embodiment, therefore detailed descriptions are omitted.

[0081] In the left-right direction, the left end face 341b of the first shielding member 341 is separated from the second opposing surface 342a by a distance D31, and the right end face 341c of the first shielding member 341 is also separated from the third opposing surface 343a by a distance D31. Furthermore, in the up-down direction, the lower surface 341d of the first shielding member 341 is positioned at the same location as the lower surface 342c of the second shielding member 342 and the lower surface 343c of the third shielding member 343.

[0082] An embodiment 2, which includes the following configuration in the current sensor of the third embodiment, is simulated.

[0083] <Example 3>

[0084] The first shielding element 341 is made of electromagnetic steel plate and soft magnetic materials such as permalloy, and is a five-layered structure with a total thickness of 1.5 mm (Z1-Z2 direction), a width of 7 mm (Y1-Y2 direction), and a length of 6 mm (X1-X2 direction). The second shielding element 342 is made of electromagnetic steel plate and soft magnetic materials such as permalloy, and is a five-layered structure with a total thickness of 1.5 mm (Y1-Y2 direction), a height of 11.5 mm (Z1-Z2 direction), and a length of 6 mm (X1-X2 direction). The third shielding element 343 is made of the same material and has the same shape as the second shielding element 342. The distance from D31 is 1 mm. The busbar 331 is positioned 1.5 mm above the first opposing surface 341a of the first shielding element 341, and the magnetic sensor 321 is positioned further above it.

[0085] According to the simulation, as shown in Table 1, in Example 3, the maximum magnetic flux density is 0.6T, and the influence from adjacent busbars is 1.6%. Furthermore, in Example 3, the current until magnetic saturation is reached is approximately 2.5 times that of the comparative example described above. Therefore, it can be seen that in the configuration of Example 3, by suppressing the magnitude in the vertical direction to be smaller than that of Example 1 (first embodiment), the current measurement range can be expanded. Furthermore, while sufficiently suppressing the influence of external magnetic fields such as the magnetic field generated by the current flowing in adjacent busbars, the magnetic field generated by the current being measured flowing in busbar 331 can be amplified by the first shield 341, the second shield 342, and the third shield 343, which function as a magnetic yoke.

[0086] <Fourth Implementation>

[0087] exist Figure 8In the fourth embodiment shown, viewed from the front view, the U-shaped shield with an opening at the top is divided into vertically extending portions on the left and right sides. This constitutes a first shield 441 that opposes the busbar 431 in the vertical direction (first direction), and a second shield 442 and a third shield 443 that extend vertically and are opposed to each other in the horizontal direction. The second opposing surface 442a of the second shield 442 and the third opposing surface 443a of the third shield 443 are opposed to each other. The left and right ends of the first shield 441 have a U-shaped curvature and are bent upwards, with each upper end surface 441b, 441c facing the lower surface 442c of the second shield 442 and the lower surface 443c of the third shield 443, respectively, at a distance D41. Similar to the first embodiment, the busbar 431 is disposed in the vertical direction (Z1-Z2 direction) between the magnetic sensor 421 and the first opposing surface 441a of the upper surface of the planar portion of the first shield 441, with the upper and lower surfaces respectively opposing the magnetic sensor 421 and the first opposing surface 441a. Other configurations are the same as in the first embodiment, so detailed descriptions are omitted.

[0088] In the fourth embodiment, the current measurement range can be expanded by dividing the overall U-shaped shield into three components under the main view. At the same time, the influence of external magnetic fields, such as the magnetic field generated by the current flowing in the adjacent busbars, can be fully suppressed, while the magnetic field generated by the current being measured flowing in the busbar 431 is amplified by the first shield 441, the second shield 442, and the third shield 443, which function as a yoke.

[0089] The present invention has been described with reference to the above embodiments, but the present invention is not limited to the above embodiments. Improvements or modifications can be made within the scope of the ideas of the present invention for the purpose of improvement.

[0090] Industrial availability

[0091] As described above, the current sensor of the present invention is useful at points where the external magnetic field can be sufficiently attenuated and magnetic saturation can be suppressed or controlled.

[0092] Explanation of reference numerals in the attached figures

[0093] 10 Current Sensor

[0094] 11 Base components

[0095] 12. Outer wall section

[0096] 13 bases

[0097] upper surface of base 13a

[0098] 13b base bottom surface

[0099] 20 substrates

[0100] 20a First Through Hole

[0101] 20b Second Through Hole

[0102] 20c Third Through Hole

[0103] 20d fourth through hole

[0104] 21 First Magnetic Sensor

[0105] 22 Second magnetic sensor

[0106] 23 Third magnetic sensor

[0107] 31 First Busbar (Current Path)

[0108] 31a Central Department

[0109] 31b Middle section

[0110] 31c outer side

[0111] 32. Second busbar (current path)

[0112] 33. Third busbar (current path)

[0113] 41 First shielding component

[0114] 41a First Opposite Surface

[0115] 41b The left end face (first end face, end portion) of the first shielding component

[0116] 41c The right end face (second end face, end) of the first shielding component

[0117] 41d Rear end face (end) of the first shielding component

[0118] 41e The front end face (end) of the first shielding component

[0119] 42 Second shielding component

[0120] 42a Second Opposite Surface

[0121] 42b outer side of the second shielding component

[0122] 42c Lower surface of the second shielding component

[0123] 42d Rear end face (end) of the second shielding component

[0124] 42e The front end face (end) of the second shielding component

[0125] 43 Third shielding component

[0126] 43a Third Opposite Surface

[0127] 43b The outside of the third shielding component

[0128] The lower surface of the 43c third shielding component

[0129] The rear end face (end) of the third shielding component 43d.

[0130] 43e The front end face (end) of the third shielding component

[0131] 51 First Shielding Component

[0132] 52 Second Shielding Component

[0133] 53 Third shielding component

[0134] 61 First shielding component

[0135] 62 Second Shielding Component

[0136] 63 Third shielding component

[0137] 221 Magnetic Sensor

[0138] 231 Busbar (Current Path)

[0139] 241 First shielding component

[0140] 241a First Opposite Surface

[0141] The left end face (end) of the first shielding component 241b

[0142] The right end face (end) of the first shielding component of 241c.

[0143] 242 Second Shielding Component

[0144] 242a Second Opposite Surface

[0145] The lower surface of the second shielding component of 242c

[0146] 243 Third Shielding Component

[0147] 243a Third Opposite Surface

[0148] The lower surface of the third shielding component of 243c

[0149] 321 Magnetic Sensor

[0150] 331 Busbar (Current Path)

[0151] 341 First shielding component

[0152] 341a First Opposite Surface

[0153] The left end face (end) of the first shielding component of 341b

[0154] The right end face (end) of the first shielding component of the 341c.

[0155] The lower surface of the first shielding component of 341d

[0156] 342 Second Shielding Component

[0157] 342a Second Opposite Surface

[0158] The lower surface of the second shielding component of 342c

[0159] 343 Third Shielding Component

[0160] 343a Third Opposite Surface

[0161] The lower surface of the third shielding component of 343c

[0162] 421 Magnetic Sensor

[0163] 431 Busbar (Current Path)

[0164] 441 First shielding component

[0165] 441a First Opposite Surface

[0166] The upper surface of the first shielding component of 441b and 441c

[0167] 442 Second Shielding Component

[0168] 442a Second Opposite Surface

[0169] 442c Lower surface of the second shielding component

[0170] 443 Third Shielding Component

[0171] 443a Third Opposite Surface

[0172] 443c Lower surface of the third shielding component

[0173] D11 Distance from the second opposing surface (third opposing surface) to the end face of the first shielding member. D12 Distance from the lower surface of the second shielding member (third shielding member) to the first opposing surface.

[0174] D13 is the distance from the end face of the first shield to the end face of the second (third) shield.

[0175] D21 Distance from the end face of the first shield to the second (third) opposing face. D22 Distance from the lower surface of the second shield (third shield) to the first opposing surface

[0176] D31 Distance from the end face of the first shield to the second (third) opposing surface D41 is the distance from the upper surface of the first shielding element to the lower surface of the second (third) shielding element.

[0177] Upper pressure holes (center side) of h11, h12, h13, h14, h15, and h16

[0178] h21, h22, h23, h24 Upper pressure holes (rear side)

[0179] Upper pressure holes (front side) of h31, h32, h33, and h34

[0180] h41, h42, h43, h44, h45, h46, h47, h48, h49 Lower pressure holes (center side)

[0181] H50, H51, and H52 lower pressure holes (center side)

[0182] h61, h62, h63, h64, h65, h66 lower pressure holes (front side)

[0183] h71, h72, h73, h74, h75, h76 Lower pressure holes (rear side)

Claims

1. A current sensor, characterized in that, have: A magnetic sensor is capable of sensing the magnetic field generated by the flow of a measured current in a current path; and The shielding component comprises a first shielding element, a second shielding element, and a third shielding element that are separately configured with each other. The first shielding member is disposed on the opposite side of the magnetic sensor in a first direction where the magnetic sensor and the current path are opposite to each other, and has a first opposing surface opposite to the current path. The second shielding member described above has a second opposing surface along the first direction described above. The aforementioned third shielding member has a third opposing surface along the aforementioned first direction. In the second and third shielding components described above, the second and third opposing surfaces are configured to face each other across the magnetic sensor and the current path. In the first direction described above, the ends of the second and third shielding members on the first shielding member side are located closer to the magnetic sensor side than the first opposing surface of the first shielding member. In the second direction in which the second opposing surface and the third opposing surface are opposite to each other, the ends of the second shielding side and the third shielding side of the first shielding member are arranged at a position closer to the magnetic sensor than the second opposing surface and the third opposing surface.

2. The current sensor according to claim 1, wherein, The aforementioned current path extends along a third direction orthogonal to the aforementioned first direction and the aforementioned second direction. When viewed along the first direction, the two ends of the third-direction shielding member, the second shielding member, and the third shielding member are located outside the first shielding member.

3. The current sensor according to claim 1 or 2, wherein, The first shielding component, the second shielding component, and the third shielding component are respectively separated.

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