Current sensor

Abstract

A current sensor includes: a bus bar whose second portion protrudes from one end edge of a first portion; and a magnetic flux concentrating plate having an orthogonal cross-sectional shape that surrounds an intermediate portion of the first portion of the bus bar in a C-shape, the orthogonal cross-sectional shape extending perpendicular to a length direction of the bus bar, in which the magnetic flux concentrating plate is configured to concentrate a magnetic flux around the intermediate portion, the magnetic flux being generated due to a current flowing through the bus bar, the opening part of the C shape is opened in the protruding direction of the second part; and a sensor section including a Hall element that detects a current using the magnetic flux concentrated by the magnetic flux concentrating plate.

Description

Technical Field

[0001] This invention relates to a current sensor for detecting current from a measured object via a Hall element. Background Technology

[0002] Traditionally, current sensors using Hall elements to detect current from a measured object are known (see, for example, Patent Document 1). In many cases, the current sensor described in Patent Document 1 is configured to allow current from the measured object to flow into a busbar, wherein the current is detected by utilizing the magnetic flux that may be generated by the Hall element as the current flows through the busbar, and wherein the Hall element is located near the busbar. Furthermore, in order to concentrate the magnetic flux around the Hall element and thereby improve the accuracy of the current measurement, a flux concentrator made of a soft magnetic material is provided, which surrounds the Hall element together with the middle portion of the busbar.

[0003] Reference List

[0004] Patent documents

[0005] Patent Document 1: JP 2011-232246 A Summary of the Invention

[0006] In some cases, as described above, curved busbars are used as busbars for current sensors. The curved busbar comprises a first portion and a second portion protruding from one end edge of the first portion, both portions being strip-shaped. In the case of a curved busbar with the aforementioned flux concentrator, the flux concentrator has a higher tendency to cause magnetic saturation than that used for a straight busbar, which may reduce measurement accuracy. It is conceivable that the size of the flux concentrator could be increased to suppress magnetic saturation. However, this would likely increase the size of the sensor itself, and therefore, this is not highly desirable.

[0007] Therefore, the present invention addresses the above-mentioned problems, and the object of the present invention is to provide a current sensor using a curved busbar that can suppress magnetic saturation of the flux concentrator while limiting the increase in size.

[0008] To achieve the above objectives, the current sensor includes: a busbar made of conductive metal, configured such that current from the object being measured can flow through the busbar, wherein the busbar includes a first portion and a second portion in a strip shape, wherein the second portion protrudes from one end edge of the first portion in a protruding direction intersecting the front and back sides of the first portion; and a flux concentrating plate made of a soft magnetic material, wherein the orthogonal cross-sectional shape of the flux concentrating plate is a curved plate shape, the curved plate shape surrounding the first portion of the busbar in a C-shape at the middle portion along the length of the busbar. The orthogonal cross-sectional shape extends orthogonally to the length direction of the busbar, wherein the flux concentrator is configured to concentrate magnetic flux around the intermediate portion, the magnetic flux being generated by the current flowing through the busbar, wherein the C-shaped opening opens in the protruding direction; and a sensor portion including a Hall element for current detection, wherein the Hall element is configured to be positioned between the opening and the intermediate portion and surrounded by the flux concentrator, such that the Hall element detects the current using the magnetic flux concentrated by the flux concentrator.

[0009] As described above, the current sensor using a curved busbar can suppress magnetic saturation of the flux concentrator while limiting the increase in size. Attached Figure Description

[0010] Figure 1 A perspective view of a current sensor according to an embodiment is shown;

[0011] Figure 2 It shows Figure 1 The current sensor shown is in Figure 1 A side view in the direction of arrow V11;

[0012] Figure 3 It shows Figure 1 The current sensor shown is along Figure 1 A cross-sectional view taken from line V12-V12 in the diagram;

[0013] Figure 4 A perspective view of a current sensor according to a reference example is shown, for use with... Figures 1 to 3 The current sensors shown are compared;

[0014] Figure 5 It shows Figure 4 The current sensor shown is in Figure 4 Side view in the direction of arrow V51;

[0015] Figure 6 It schematically shows the situation according to Figure 4 and Figure 5 In the current sensor of the reference example shown, how is the magnetic flux generated when the current flows through the busbar absorbed by the flux concentration plate?

[0016] Figure 7 It schematically shows the following based on Figures 1 to 3 How to suppress the absorption of magnetic flux by the flux concentration plate in the current sensor of the illustrated embodiment, wherein the magnetic flux is generated when current flows through the busbar;

[0017] Figure 8 It shows according to Figures 1 to 3 The illustrated embodiments and according to Figure 4 and Figure 5 The graphs show the magnetic flux density of the flux concentration plate of the current sensor in the reference example and the magnetic flux density of the flux concentration plate of the current sensor in the standard form with a straight busbar.

[0018] Figure 9 A perspective view of a standard form of current sensor is shown, wherein the magnetic flux density of the flux concentration plate of the current sensor is as follows: Figure 8 The curve is shown; and

[0019] Figure 10 It shows the results based on Figures 1 to 3 The current sensor of the embodiment shown, according to Figure 4 and Figure 5 The current sensor shown in the reference example and as shown in the example Figure 9 The graph shown illustrates that a standard form of current sensor has approximately the same magnetic flux density value at the location of the Hall element.

[0020] Reference tag list

[0021] 1.5 Current Sensors

[0022] 11, 61 busbars

[0023] 12 Magnetic Flux Concentration Plate

[0024] 12a Opening

[0025] 13 Sensors Department

[0026] 111 Part One

[0027] 111a, 61a One end edge

[0028] 111b Middle section

[0029] 111c other edge

[0030] 112 Part Two

[0031] 113 Through Hole

[0032] 121 Base Plate

[0033] 122 arm plate part

[0034] 123 Top Plate

[0035] 131 Hall element

[0036] 132 sensor board

[0037] D11 Prominent Direction

[0038] D12 Busbar Length Direction

[0039] D13 Busbar Width Direction

[0040] D14 Concentrated plate length direction

[0041] G1 and G2 curves

[0042] L1 solid line

[0043] L2 dotted line

[0044] L3 Dashed line

[0045] I Current

[0046] T11 Width Direction

[0047] magnetic flux Detailed Implementation

[0048] The current sensor according to an embodiment will be described below.

[0049] Figure 1 A perspective view of a current sensor according to an embodiment is shown. Figure 2 It shows Figure 1 The current sensor shown is in Figure 1 A side view showing the direction of arrow V11. Additionally, Figure 3 It shows Figure 1 The current sensor shown is along Figure 1 The cross-sectional view taken from line V12-V12 in the diagram.

[0050] According to this embodiment, the current sensor 1 is configured to detect the current I from the object being measured via a Hall element 131. The current sensor 1 includes a busbar 11, a flux concentrator 12, and a sensor section 13.

[0051] Busbar 11 is made of conductive metal and configured to allow current I from the measured object to flow through it. Busbar 11 includes a first portion 111 and a second portion 112. The first portion 111 is a strip-shaped elongated portion, and the second portion 112 is a strip-shaped short portion that protrudes from an end edge 111a of the first portion 111 in the busbar length direction D12 in the projection direction D11, which intersects the front and rear surfaces of the first portion 111, wherein the second portion 112 is shorter than the first portion 111. According to this embodiment, busbar 11 is constructed as a curved member formed only by the first portion 111 and the second portion 112 to form an L-shape in a side view in an orthogonal direction (direction of arrow V11) of busbar 11, which extends orthogonally to the projection direction D11 and the busbar length direction D12. In addition, each of the opposite ends of the L-shaped busbar 11 has a through hole 113 for connection to the object under test, for example by threaded engagement.

[0052] The flux concentrator 12 is made of a soft magnetic material and has a curved, plate-like orthogonal cross-sectional shape that surrounds the middle portion 111b of the first portion 111 of the busbar 11 in a C-shape along the length direction D12 of the busbar. This orthogonal cross-sectional shape extends orthogonally to the length direction D12 of the busbar. The flux concentrator 12 concentrates the magnetic flux... ( Figure 2 The magnetic flux is concentrated around the middle portion 111b of the first part 111, and the magnetic flux is generated by the current I flowing through the busbar 11. Furthermore, the flux concentrator 12 is positioned relative to the middle portion 111b of the first part 111 such that the C-shaped opening 12a opens in the protruding direction D11 of the second part 112. Additionally, the flux concentrator 12 is located in the busbar length direction D12 closer to one end edge 111a than to the other end edge 111c of the first part 111, which is the end edge from which the second part 112 protrudes from the first part 111. More specifically, the flux concentrator 12 is positioned in the busbar length direction D12 closer to that end edge 111a than the middle portion of the first part 111.

[0053] According to this embodiment, the flux concentrator 12 is a rectangular tubular curved component, wherein the peripheral wall of the flux concentrator 12 is partially cut off to form an opening 12a. The flux concentrator 12 according to this embodiment includes a bottom plate portion 121, a pair of arm plate portions 122 and a pair of top plate portions 123.

[0054] The bottom plate portion 121 of the flux concentrator 12 faces the side opposite to the side of the middle portion 111b of the first portion 111 where the Hall element 131 is positioned. The bottom plate portion 121 is a rectangular plate extending in the length direction D14 of the concentrator plate beyond the width dimension T11 of the first portion 111, which extends along the busbar width direction D13 of the first portion 111. A pair of arm plate portions 122 are a pair of rectangular plate portions protruding from opposite end edges of the bottom plate portion 121 in the length direction D14 of the concentrator plate towards the protruding direction D11 of the second portion 112. A pair of top plate portions 123 are a pair of rectangular plate portions, each extending from one of the protruding end edges of the pair of arm plate portions 122 along the length direction D14 of the concentrator plate, facing the side of the middle portion 111b of the first portion 111 where the Hall element 131 is positioned. Furthermore, the extended edges of the pair of top plate portions 123 are spaced apart from each other, thereby forming together the opening 12a of the flux concentration plate 12.

[0055] The sensor unit 13 includes a Hall element 131 for current detection, wherein the Hall element 131 is positioned between the opening 12a and the intermediate portion 111b of the first portion 111, and is surrounded by the magnetic flux concentration plate 12. In this case, the Hall element 131 is positioned in the protruding direction D11 of the second portion 112 closer to the opening 12a of the magnetic flux concentration plate 12 than the first portion 111. The sensor unit 13 uses the Hall element 131 to detect the magnetic flux concentrated by the magnetic flux concentration plate 12. The sensor unit 13 includes a Hall element 131 and a sensor plate 132 to detect current I. The Hall element 131 utilizes magnetic flux... A rectangular flat element is used to detect the current I flowing through the busbar 11. The sensor board 132 is a rectangular flat circuit board on which the Hall element 131 is mounted, wherein, for example, a circuit for amplifying the detection result obtained by the Hall element 131 is formed on the sensor board 132.

[0056] Here, before continuing with the description of the current sensor 1, a reference example for comparison with the current sensor 1 according to this embodiment will be described.

[0057] Figure 4 A perspective view of a current sensor according to a reference example is shown, for use with... Figures 1 to 3 The current sensors shown are compared. Figure 5 It shows Figure 4 The current sensor shown is in Figure 4 The side view in the direction of arrow V51. Note that in... Figure 4 and Figure 5 In, only with Figures 1 to 3The components shown are equivalent to, and only those components that require further explanation are used with, the components shown. Figures 1 to 3 The components shown are identified by the same reference numerals. Furthermore, the current sensor 5 according to the reference example includes... Figure 1 and Figure 3 The sensor unit shown in sensor unit 13 is the same as the sensor unit in the diagram. However, Figure 4 The sensor section is omitted from the text.

[0058] Although according to such Figure 4 and Figure 5 The current sensor 5 in the reference example shown includes a current sensor 5 with Figures 1 to 3 The current sensor of the illustrated embodiment has a similar L-shaped busbar 11 and a similar C-shaped flux concentrator 12, but the flux concentrator 12 is positioned relative to the busbar 11 in a different manner. In the current sensor 5 according to the reference example, the flux concentrator 12 is positioned such that the C-shaped opening 12a opens in the direction opposite to the protruding direction D11 of the second portion 112. Furthermore, the flux concentrator 12 of the current sensor 5 according to the reference example is located at the middle of the first portion 111 in the length direction D12 of the busbar. It should be noted that... Figure 4 and Figure 5 A current sensor 5 according to a reference example is shown, which is in conjunction with... Figure 1 and Figure 2 The current sensor shown is positioned with the opposite orientation, that is, the protruding direction D11 of the second part 112 is in... Figure 4 and 5 The middle is shown as oriented downwards.

[0059] In the current sensor 5 according to the reference example, the magnetic flux generated when current I flows through the busbar 11 It is absorbed by the flux concentration plate 12 in the following manner.

[0060] Figure 6 It schematically shows the situation according to Figure 4 and Figure 5 The current sensor in the reference example shown is used to illustrate how the magnetic flux generated when current flows through the busbar is absorbed by the flux concentration plate. Figure 6 by Figure 4 Plan view on direction V52 and Figure 6 The plan view on direction V53 shows the current sensor 5 according to the reference example. Figure 6 The direction V53 is the direction of the current sensor 5 as observed from the protruding side of the second part 112 of the busbar 11, according to the reference example.

[0061] According to the reference example, the flux concentrator plate 12 of the current sensor 5 is positioned such that the base plate portion 121 faces the protruding side of the second portion 112. In the above arrangement, when current I flows through the busbar 11, the magnetic flux generated around the base plate portion 121 of the flux concentrator plate 12 around each of the first portion 111 and the second portion 112... In the C-shaped magnetic flux concentrator 12, the uninterrupted base plate 121 absorbs magnetic flux. Therefore, the magnetic flux around each of the first part 111 and the second part 112 Together they are absorbed by the base plate 121, which increases the magnetic flux density in the magnetic flux concentration plate 12.

[0062] like Figure 5 As shown, in the current sensor 5 according to the reference example, the flux concentration plate 12 is located at the middle of the first portion 111 along the length direction D12 of the busbar. As a result, the base plate portion 121 also absorbs magnetic flux. This is the magnetic flux generated around the first part 111 surrounded by the magnetic flux concentrator 12. The portion of the second portion 112 that protrudes from one end edge 111a of the first portion 111 further increases the magnetic flux density in the flux concentration plate 12.

[0063] Compared to the current sensor 5 according to the reference example, such as Figures 1 to 3 The current sensor 1 according to the embodiment shown is configured such that when current I flows through busbar 11, it suppresses the magnetic flux concentration plate 12 on the magnetic flux as described below. Absorption.

[0064] Figure 7 It schematically shows the situation according to Figures 1 to 3 The embodiment shown illustrates how the current sensor suppresses the absorption of magnetic flux by the flux concentration plate, where the magnetic flux is generated when current flows through the busbar. Figure 7 by Figure 1 Plan view on direction V13 and Figure 7 The plan view on direction V14 shows the current sensor 1 according to this embodiment. Figure 7 The direction V14 is the direction of the current sensor 1 according to this embodiment when viewed from the protruding side of the second part 112 of the busbar 11. It should be noted that, for ease of reference with... Figure 6 The current sensor 5 of the illustrated embodiment is compared, the Figure 7 The flux concentration plate 12 is shown in such a way that it is located in the middle of the first part 111 in the length direction D12 of the busbar.

[0065] According to this embodiment, the flux concentrator plate 12 of the current sensor 1 is positioned such that the opening 12a between a pair of top plate portions 123 faces the protruding side of the second portion 112. When current I flows through the busbar 11 in the above arrangement, the magnetic flux generated around the opening 12a of the flux concentrator plate 12 around each of the first portion 111 and the second portion 112 is... In the C-shaped magnetic flux concentrator 12, the base plate 121 faces the opening 12a and absorbs magnetic flux as described above. On the side of the magnetic flux concentrator 12, including the opening 12a, magnetic flux is released. Therefore, the magnetic flux released through the magnetic flux concentrating plate 12, including the opening 12a, is... It impeded the magnetic flux around part 112. This prevents it from reaching the flux concentration plate 12. Even the magnetic flux around the second part 112 It is absorbed in this side of the magnetic flux concentration plate 12, including the opening 12a. It will also be released through this side. As a result, the magnetic flux concentration plate 12 suppresses the magnetic flux around the second part 112. The absorption of magnetic flux reduces the magnetic flux density in the magnetic flux concentration plate 12 by a corresponding amount.

[0066] In addition, such as Figure 1 and Figure 2 As shown, according to this embodiment, the flux concentrator 12 of the current sensor 1 is located in the busbar length direction D12 at a position where the second portion 112 protrudes from one of the opposite end edges of the first portion 111. This results in the suppression of the magnetic flux generated around the first portion 111. The absorption from a portion of one end edge 111a further reduces the magnetic flux density in the flux concentration plate 12 by a corresponding amount.

[0067] Figure 8 It shows according to Figures 1 to 3 The illustrated embodiments and according to Figure 4 and Figure 5 The graphs show the magnetic flux density of the flux concentration plate of the current sensor in the reference example and the magnetic flux density of the flux concentration plate of the current sensor in the standard form with a straight busbar. Figure 9 A perspective view of a standard form of current sensor is shown, wherein the magnetic flux density of the flux concentration plate of the current sensor is as follows: Figure 8 The graph is shown below. It should be noted that... Figure 9 In, only with Figures 1 to 5 The components shown are equivalent to, and only those components that require further explanation are used with, the components shown. Figures 1 to 5The components shown are identified by the same reference numerals. Furthermore, the standard form current sensor 6 includes components with… Figure 1 and Figure 3 The sensor unit shown in sensor unit 13 is the same as the sensor unit in the diagram. However, Figure 9 The sensor section is omitted from the text.

[0068] First, the description will be as follows Figure 9 The current sensor 6 is shown in a standard form. This standard form of current sensor 6 includes a busbar 61, which allows the current I from the measured object to flow into the busbar 61, wherein, with Figures 1 to 5 Unlike the L-shaped busbar 11 shown, busbar 61 is a simple straight shape. Figures 1 to 5 Similar to the flux concentrator shown, the flux concentrator 12 surrounding the straight busbar 61 is also C-shaped.

[0069] By comparing the magnetic flux density in the flux concentration plate 12 of the standard current sensor 6, the current sensor 1 according to the above embodiment, and the current sensor 5 according to the above reference example, the following results are obtained: Figure 8 The result is shown in graph G1. Figure 8 Graph G1 illustrates the change in magnetic flux density in each form of the flux concentrator 12 by showing the change in magnetic flux density obtained as the distance between the flux concentrator 12 and one end edge 111a of the second portion 112 protruding from it. For the standard form of the current sensor 6 with a straight busbar 61, the change in magnetic flux density obtained as the distance between the flux concentrator 12 and one end edge 61a of the busbar 61 is shown. In graph G1, the distance to the flux concentrator 12 [mm] and the magnetic flux density of the flux concentrator 12 [mT] are shown along the horizontal and vertical axes, respectively. The magnetic flux density of the current sensor 1 according to the embodiment and the magnetic flux density of the current sensor 5 according to the reference example are shown by the solid line L1 and the dashed line L2, respectively. Furthermore, the magnetic flux density of the standard form of the current sensor 6 is shown by the dashed line L3.

[0070] Figure 8 The comparison of the magnetic flux density in the graph G1 shows that, in the current sensor 1 according to the embodiment, where the opening 12a of the magnetic flux concentration plate 12 faces the protruding side of the second part 112, the magnetic flux density is suppressed the most. On the other hand, in the current sensor 5 of the reference example, where the opening 12a faces the side opposite to the protruding side of the second part 112, as described above, the highest magnetic flux density exists at the absorbing base plate portion 121 because absorption of the magnetic flux around the second part 122 occurs in the base plate portion 121. The standard form current sensor 6, without the protruding second part 112, has a moderate magnetic flux density between that of the embodiment and the reference example.

[0071] Furthermore, according to this embodiment, the magnetic flux density in the current sensor 1 gradually increases in the direction of increasing distance between the magnetic flux concentration plate 12 and an end edge 111a having a second portion 112 protruding from it. This is because the base plate portion 121 absorbs magnetic flux from the region between the end edge 111a of the first portion 111 and the magnetic flux concentration plate 12. The magnetic flux density increases. On the other hand, in the current sensor 5 according to the reference example, the magnetic flux density gradually decreases in the direction of increasing distance between the magnetic flux concentration plate 12 and one end edge 111a. This is because the magnetic flux absorbed from the second part 112... The reduction exceeds the magnetic flux absorbed from the first part 111. The increase in flux density. Regardless of the position of the flux concentration plate 12, the flux density in the standard form current sensor 6 has a roughly constant value.

[0072] As described above, although the three forms, including the embodiments, differ from each other in terms of magnetic flux density in the magnetic flux concentration plate 12, as described below, the magnetic flux density has approximately the same value at the location of the Hall element 131 used for magnetic flux detection.

[0073] Figure 10 It shows the results based on Figures 1 to 3 The current sensor of the embodiment shown, according to Figure 4 and Figure 5 The current sensor shown in the reference example and as shown in the example Figure 9 The diagram shows a standard form of current sensor with approximately the same magnetic flux density value at the location of the Hall element. Similarly, in... Figure 10 In graph G2, the distance [mm] to the magnetic flux concentration plate 12 is shown along the horizontal axis. On the other hand, the magnetic flux density [mT] at the location of the Hall element 131 is shown along the vertical axis. The magnetic flux density of the current sensor 1 according to the embodiment and the magnetic flux density of the current sensor 5 according to the reference example are shown by the solid line L1 and the dashed line L2, respectively. In addition, the magnetic flux density in the standard form of the current sensor 6 is shown by the dashed line L3.

[0074] From such Figure 10 The comparison of the three types of magnetic flux density shown in graph G2 reveals that the current sensor 1 according to the embodiment, the current sensor 5 according to the reference example, and the current sensor 6 of the standard form have approximately the same magnetic flux density value at the location of the Hall element 131. This means that the current sensor 1 according to this embodiment, while suppressing the magnetic flux density of the magnetic flux concentration plate 12 to a smaller amount than other forms, ensures that the Hall element 131 detects a sufficiently large magnetic flux for measuring the current, wherein the magnetic flux is the same as that of the other forms.

[0075] As mentioned above, Figures 1 to 3 The current sensor 1 shown according to the embodiment provides the following effect: According to this embodiment, a C-shaped flux concentrator 12 is arranged around the middle portion 111b of the first portion 111 of the curved busbar 11, wherein the C-shaped opening 12a opens in the protruding direction D11 of the second portion 112. The side of the C-shaped flux concentrator 12 facing the opening 12a absorbs magnetic flux. The magnetic flux is released from one side of the magnetic flux concentrator 12, including the opening 12a. Because the flux concentrator 12 is positioned such that the opening 12a faces the protruding direction D11 of the second part 112, it is difficult for the flux concentrator 12 to absorb the magnetic flux generated around the second part 112. This suppresses magnetic saturation of the flux concentrator 12. Thus, proper positioning of the C-shaped flux concentrator 12 can suppress magnetic saturation when using the curved busbar 11, thereby eliminating the need to increase the size of the flux concentrator 12 and thus suppressing an increase in the size of the current sensor 1. In other words, this embodiment using the curved busbar 11 can suppress magnetic saturation of the flux concentrator 12 while limiting the increase in size.

[0076] According to this embodiment, the busbar 11 is an L-shaped component, and the flux concentrator 12 is located closer to the first end edge 111a than to the second end edge 111c opposite to the first end edge 111a. The second portion 112 protrudes from one end edge 111a of the first portion 111. With this configuration, the magnetic flux generated around the first portion 111 surrounded by the flux concentrator 12 is... In the middle, a portion of the magnetic flux from one side of the first part 111, including an end edge 111a. Absorption is suppressed, and the first end edge 111a is the second part 112 protruding from its end edge. This further suppresses magnetic saturation of the flux concentration plate 12.

[0077] Furthermore, according to this embodiment, the flux concentrator 12 is positioned closer to one end edge 111a than the middle of the first portion 111. This arrangement further reduces the distance between one end edge 111a of the first portion 111 and the flux concentrator 12, thereby increasing the flux from the side of the first portion 111 including one end edge 111a. The absorption was suppressed, which led to further suppression of magnetic saturation of the flux concentration plate 12.

[0078] Furthermore, the flux concentrator 12 according to this embodiment includes a bottom plate portion 121, a pair of arm plate portions 122, and a pair of top plate portions 123. Compared to a C-shaped flux concentrator formed by a hollow cylinder with its peripheral walls partially removed, this structure can reduce the distance between the inner surface of the flux concentrator 12 and the first portion 111, which further suppresses the increase in the size of the flux concentrator 12.

[0079] Furthermore, according to this embodiment, the Hall element 131 is closer to the opening 12a of the flux concentration plate 12 in the protruding direction D11 of the second portion 112 than the first portion 111. With this configuration, the Hall element 131 is positioned to receive a large amount of magnetic flux emitted from the flux concentration plate 12 on the side of the flux concentration plate 12 including the opening 12a. The region traversed. This allows the Hall element 131 to utilize magnetic flux. The sensitivity of current measurement is improved.

[0080] It should be noted that the above embodiments only show representative forms of current sensors. Current sensors are not limited to these, but can be modified and implemented in various ways.

[0081] For example, as an example of a current sensor, the above embodiment shows a current sensor 1 including a sensor section 13, wherein the sensor section 13 is fixed when the Hall element 131 is positioned relative to the busbar 11, and no specific fixing method is specified for fixing the sensor section 13. However, the fixing method of the sensor section in the current sensor is not limited to a specific fixing method, but any fixing method can be used.

[0082] Furthermore, as an example of a current sensor, the above embodiment shows a current sensor 1 including a busbar 11 and a flux concentrator 12, each of which is formed by a bent component. However, the current sensor is not limited to this. That is, the busbar and / or flux concentrator as a current sensor can be components formed, for example, by cutting and / or by welding multiple metal parts together, wherein any processing method can be used for the busbar and flux concentrator.

[0083] Furthermore, as an example of a current sensor, the above embodiment shows a current sensor 1, which includes a flux concentrator 12 located near one end edge 111a of a first portion 111 of an L-shaped busbar 11, wherein a second portion 112 of the L-shaped busbar 11 protrudes from this end edge 111a. However, the current sensor is not limited to this. For example, the busbar can be constructed as a U-shaped component in a side view, including a pair of second portions protruding from opposite end edges of the first portion. Moreover, in the case of an L-shaped busbar, the flux concentrator can be positioned at any location along the length of the busbar at the first portion. However, as described above, by positioning the flux concentrator 12 near one end edge 111a from which the second portion 112 of the first portion 111 of the L-shaped busbar 11 protrudes, magnetic saturation of the flux concentrator 12 can be further suppressed.

[0084] Furthermore, as an example of a current sensor, the above embodiment shows a current sensor 1 including a flux concentrator 12, wherein the flux concentrator 12 is positioned closer to an end edge 111a than the middle of the first portion 111 of the L-shaped busbar 11. However, the current sensor is not limited to this. Moreover, in the case of an L-shaped busbar, for example, the flux concentrator can be positioned at the middle of the first portion. However, as described above, by positioning the flux concentrator 12 closer to an end edge 111a than the middle of the first portion 111, magnetic saturation of the flux concentrator 12 can be further suppressed.

[0085] Furthermore, as an example of a C-shaped flux concentrator, the above embodiment shows a flux concentrator 12 including a base plate portion 121, a pair of arm plate portions 122, and a pair of top plate portions 123. However, the C-shaped flux concentrator is not limited to this, and can be, for example, formed from a hollow cylinder with its peripheral walls partially removed. However, as described above, by having a base plate portion 121, a pair of arm plate portions 122, and a pair of top plate portions 123, the increase in the size of the flux concentrator 12 can be further suppressed.

[0086] As an example of a current sensor, the above embodiment also shows a current sensor 1 including a Hall element 131, wherein the Hall element 131 is located near the opening 12a of the flux concentration plate 12. However, the current sensor is not limited to this, and the Hall element can be located at any position between the first portion of the busbar and the inner surface of the flux concentration plate, as long as it can detect the magnetic flux used for current measurement. However, as described above, by positioning the Hall element 131 near the opening 12a of the flux concentration plate 12, the sensitivity of the current measurement can be improved.

Claims

1. A current sensor, the current sensor comprising: A busbar made of conductive metal, configured to allow current from the object being measured to flow through it. The busbar comprises a first part and a second part, wherein the first part is strip-shaped. The second portion protrudes from one end edge of the first portion in a protruding direction, the protruding direction intersecting the front and back surfaces of the first portion; A flux concentrator made of soft magnetic material. The flux concentration plate has an orthogonal cross-sectional shape that is curved, with the curved plate forming a C-shape around the middle portion of the first part of the busbar along its length. The orthogonal cross-sectional shape extends orthogonally to the length direction of the busbar. The flux concentrator is configured to concentrate magnetic flux around the central portion, the magnetic flux being generated by the current flowing through the busbar. Wherein, the C-shaped opening opens in the protruding direction; and The sensor section includes a Hall element for current detection. The Hall element is positioned between the opening and the middle portion, and is surrounded by the magnetic flux concentration plate, so that the Hall element uses the magnetic flux concentrated by the magnetic flux concentration plate to detect the current.

2. The current sensor according to claim 1, in, The busbar is formed solely by the first and second portions to form an L-shape in a side view along an orthogonal direction extending orthogonally to the protruding direction and the length direction of the busbar. The flux concentrator is located in the length direction of the busbar as follows: closer to one end edge of the first part than to the other end edge opposite to one end edge of the first part; wherein, the one end edge is the end edge of the second part that protrudes from the first part.

3. The current sensor according to claim 2, in, The flux concentrator is closer to one end edge in the length direction of the busbar than the middle of the first portion.

4. The current sensor according to claim 1, wherein, The flux concentration plate includes: The base plate extends in the length direction of the concentrator plate beyond the width dimension of the first part, so as to face the side opposite to the side of the middle part where the Hall element is disposed in the front and back of the first part, the length direction of the concentrator plate extending along the width direction of the busbar of the first part. A pair of arm plate portions, which protrude from opposite end edges of the base plate portion in the projection direction of the second portion along the length of the central plate; and A pair of top plates, each of which extends along the length of the central plate from one of the protruding end edges of the pair of arm plates to face the side of the middle portion where the Hall element is disposed, wherein the extending end edges of the pair of top plates are spaced apart from each other to together form the opening.

5. The current sensor according to claim 1, in, The Hall element is located on the flux concentration plate at a position closer to the opening in the protruding direction than the first portion.

Images