Current sensor and bus bar

Abstract

To provide a current sensor which prevents a bus bar from being deformed when stress is applied to the bus bar in a direction of twisting and bending the bus bar by suppressing the deterioration in strength of the bus bar in association with reduction in thickness, and which is advantageous to reduction in size, height, and weight.SOLUTION: A current sensor 1 includes a bus bar 2 and a magnetic sensor 3. The bus bar 2 includes a portion extending in an X direction, and a protrusion 21 is formed protruding from a plate surface 2S2 on a Z2 side, which faces the magnetic sensor 3 parallel to an XY plane defined by the X direction and a Y direction orthogonal to the X direction, along the X direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a current sensor for measuring a current to be measured flowing through a bus bar and a bus bar used for the current sensor.

Background Art

[0002] In recent years, in order to control a power supply system of a vehicle or the like equipped with various devices, a current sensor for measuring a current to be measured flowing through the devices has been used. Further, recently, in current sensors, needs such as miniaturization, low profile, and weight reduction have been increasing. As one of the means for miniaturizing the current sensor, thinning of the bus bar included in the current sensor can be mentioned. However, when the bus bar is thinned, stress is applied to the bus bar in a direction of twisting or bending the bus bar when fastening the bus bar to an external terminal or the like, which may cause the bus bar to deform or the amount of heat generated when the current to be measured flows through the bus bar to increase. Deformation of the bus bar and an increase in the amount of heat generated may lead to deterioration of the detection accuracy of the current sensor.

[0003] Patent Document 1 discloses a current detection mechanism for suppressing an increase in the amount of heat generated by the bus bar and overheating of the element, and appropriately detecting the current flowing through the bus bar. In the bus bar of the current detection mechanism, a recess recessed from the surface or a through hole penetrating from the surface to the back surface is formed at least at a position facing the magnetic detection element.

[0004] Patent Document 2 discloses a current detection structure for enabling highly accurate measurement by using a highly sensitive magnetic detection element even when a large current flows through the bus bar. In the current detection structure, the magnetic detection element is disposed in a space surrounded by a bus bar formed in a concave shape and is disposed at the center in the width direction of the bus bar, and only a magnetic field generated by a current flowing through an upper wall located at the bottom of the recess of the bus bar can be detected.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 2012-163454 Patent Document 2 Japanese Patent Application Laid-Open No. 2018-151406 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] Patent Document 1 and Patent Document 2 do not describe the problem of strength reduction of the bus bar due to thinning and the solution means for the problem. The present invention suppresses a decrease in the strength of a bus bar due to thinning, and makes it difficult for the bus bar to deform when stress is applied to the bus bar in a direction of twisting or bending the bus bar, and aims to provide a current sensor advantageous for miniaturization, low profile, and weight reduction, and a bus bar used for the current sensor. MEANS FOR SOLVING THE PROBLEMS

[0007] As means for solving the above-described problems, the present invention has the following configuration. In a current sensor including a bus bar and a magnetic sensor, the bus bar includes a portion extending in a first direction, and a convex portion is formed along the first direction on a plate surface defined by the first direction and a second direction orthogonal to the first direction. A current sensor characterized by that. By forming the convex portion along the first direction, the strength of the bus bar is improved, so that when stress is applied to the bus bar in a direction of twisting or bending the bus bar when the bus bar is externally attached, the bus bar is less likely to deform. For this reason, it is possible to provide a current sensor in which the bus bar is thinned and the height, size, and weight are reduced.

[0008] The bus bar has a narrow-width portion provided at a position facing the magnetic sensor in a third direction orthogonal to the first direction and the second direction, and wide-width portions continuous with the narrow-width portion and having a dimension in the second direction larger than that of the narrow-width portion on both sides of the narrow-width portion in the first direction, and the convex portion may be formed in the narrow-width portion. By providing a narrow portion in the bus bar, the influence of the skin effect at high frequencies can be suppressed in the narrow portion. Therefore, by arranging a magnetic sensor opposite to the narrow portion and measuring the induced magnetic field emitted from the narrow portion when a current to be measured flows through the narrow portion with the magnetic sensor, the measurement accuracy of the current sensor is improved.

[0009] The convex portion may be continuously formed from one wide portion to the other wide portion via the narrow portion. The convex portion continuously formed up to the wide portions on both sides via the narrow portion can suppress a sudden change in strength at the boundary between the narrow portion and the wide portion, and disperse the force over the entire bus bar. Therefore, the strength of the bus bar when thinned is improved.

[0010] The convex portion is formed on the first plate surface of the bus bar, a concave portion is formed on the second plate surface opposite to the first plate surface along the first direction, and the magnetic sensor may be arranged opposite to the concave portion. By providing the concave portion, it is possible to increase the component parallel to the detection surface of the magnetic sensor in the induced magnetic field emitted from the bus bar. Therefore, by arranging the magnetic sensor so as to face the concave portion of the bus bar, the measurement accuracy of the current sensor is improved.

[0011] When the bus bar is viewed along the third direction, the convex portion and the concave portion may be formed at positions where they overlap. The strength of the bus bar can be improved by the convex portion, and the measurement accuracy of the current sensor can be improved by the concave portion. In addition, a bus bar formed at a position where the convex portion and the concave portion overlap can be easily formed by, for example, half-punching, and is also advantageous from the viewpoint of the manufacturing efficiency of the current sensor.

[0012] The bus bar may be provided with a housing for housing the magnetic sensor, and the bus bar may be insert-molded into the housing. By insert-molding the bus bar into the housing, the positional relationship between the bus bar and the magnetic sensor can be fixed and maintained, so that the measurement accuracy of the current sensor is improved.

[0013] In a current sensor including a magnetic sensor and a housing, the housing is provided with an insertion hole into which the bus bar having a convex portion formed on a plate surface along the extending direction of the bus bar can be inserted. The current sensor is characterized by this. The insertion hole may be provided with a guide portion for passing the convex portion. By inserting the bus bar into the insertion hole provided in the housing, a current sensor having the bus bar can be manufactured. Further, by providing a guide portion in the insertion hole, the bus bar can be easily inserted into the insertion hole, so that the manufacturing efficiency of the current sensor is improved.

[0014] A bus bar having a portion extending in a first direction, having a plate surface defined by the first direction and a second direction orthogonal to the first direction, and in a third direction orthogonal to the first direction and the second direction, a narrow-width portion provided at a position facing the magnetic sensor, and on both sides of the narrow-width portion in the first direction, a wide-width portion continuous with the narrow-width portion and having a larger dimension in the second direction than the narrow-width portion, and a convex portion is formed along the first direction in the narrow-width portion. The bus bar is characterized by this.

[0015] By forming a convex portion along the first direction in the narrow-width portion, the strength of the narrow-width portion is improved. Therefore, when stress is applied to the bus bar in a direction of twisting or bending the bus bar, it is difficult to deform, and a bus bar advantageous for miniaturization, low-profile, and weight reduction can be provided.

Effect of the Invention

[0016] According to the present invention, since the strength of the bus bar is improved by the convex portion, it is possible to suppress a decrease in the strength of the bus bar due to thinning, and to make the current sensor low-profile, miniaturized, and lightweight.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 5

Figure 6

Figure 7

Figure 8A

Figure 8B

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Embodiment for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, the same members are denoted by the same reference numerals, and the description thereof will be omitted. In order to show the positional relationship of each member, reference coordinates are shown in each drawing as appropriate. In the reference coordinates, the extending direction of the bus bar is the X direction, the width dimension direction of the bus bar orthogonal to the X direction is the Y direction, and the stacking direction of the bus bar and the magnetic sensor orthogonal to the X direction and the Y direction is the Z direction. The Y direction is the direction of the sensitivity axis of the magnetic sensor, and the X direction and the Z direction are orthogonal to the sensitivity axis.

[0019] FIG. 1 is a perspective view schematically showing the configuration of the main part of the current sensor 1 according to the present embodiment. FIG. 2 is a cross-sectional view schematically showing the configuration of the current sensor 1 along line A-A in FIG. 1. FIG. 3 is a perspective view showing the configuration of the bus bar 2 of the current sensor 1 shown in FIG. 1. In FIGS. 1 and 2, for convenience of explanation, the housing and the like of the current sensor 1 are omitted and the main part is shown.

[0020] The current sensor 1 of the present embodiment includes a bus bar 2 and a magnetic sensor 3. The bus bar 2 shown in FIG. 3 extends in the X direction among the X direction, the Y direction, and the Z direction that are orthogonal to each other. The bus bar 2 is a conductor through which the current to be measured flows, and is formed in a plate shape, for example, of copper, brass, aluminum, or the like. The normal direction of the plate surface 2S of the bus bar 2 facing the magnetic sensor 3 is the Z direction. Although the illustrated bus bar 2 extends entirely in the X direction (first direction), one or both ends protruding from the housing of the current sensor not shown may be bent.

[0021] The bus bar 2 has a convex portion 21 formed along the X direction on the plate surface 2S2 on the Z2 side, which is parallel to the XY plane defined by the X direction (first direction) and the Y direction (second direction). By providing the convex portion 21, the strength of the bus bar 2 is improved, so that when a force is applied to the bus bar 2 from the outside during assembly or connection to a connection portion, etc., the bus bar 2 is less likely to deform. Thus, by providing the convex portion 21 to improve the strength of the bus bar 2, even if the bus bar 2 is thinned, it is less likely to deform. Therefore, by reducing the plate thickness of the bus bar 2, the bus bar 2 can be thinned, so that the current sensor 1 can be made lighter, lower-profile, and smaller.

[0022] Also, by providing the convex portion 21, the surface area of the bus bar 2 increases, and the efficiency of releasing heat generated from the bus bar 2 when the current to be measured flows is increased. By improving the heat dissipation effect from the bus bar 2, it may be possible to suppress the temperature rise of the bus bar 2.

[0023] The bus bar 2 has a narrow portion 22 provided at a position facing the magnetic sensor 3 in the Z direction (third direction) orthogonal to the X direction and the Y direction. The bus bar 2 also has wide portions 23A and 23B that are continuous with the narrow portion 22 on both sides of the narrow portion 22 in the X direction. The dimension W23 of the wide portions 23A and 23B in the Y direction is larger than the dimension W22 of the narrow portion 22 in the Y direction.

[0024] The convex portion 21 is continuously formed across the narrow-width portion 22 from one wide-width portion 23A to the other wide-width portion 23B. That is, the length L21 of the convex portion 21 in the X direction is greater than the length L22 of the narrow-width portion 22 in the X direction, and the end portion 21Ea of the convex portion 21 is located in the wide-width portion 23A, and the end portion 21Eb of the convex portion 21 is located in the wide-width portion 23B. In this way, with the configuration in which the convex portion 21 formed across the entire X direction of the narrow-width portion 22 extends to the wide-width portions 23 on both sides of the narrow-width portion 22, the strength of the narrow-width portion 22 is improved, and the change in strength at the boundary between the narrow-width portion 22 and the wide-width portion 23 can be suppressed. Therefore, when the bus bar 2 is deformed, the concentration of force on the narrow-width portion 22 can be suppressed, and the force can be dispersed to the entire bus bar 2 including the wide-width portions 23 on both sides of the narrow-width portion 22 via the convex portion 21. Therefore, it becomes possible to thin the bus bar 2 while maintaining the strength.

[0025] On the plate surface 2S1 on the Z1 side, which is the opposite side of the plate surface 2S2 on the Z2 side where the convex portion 21 is provided, of the bus bar 2, a concave portion 24 is formed at a position overlapping the convex portion 21 when viewed along the Z direction. When forming the convex portion 21 provided with its longitudinal direction along the X direction on the plate surface 2S2 by half-punching, at the same time, the concave portion 24 can be formed along the X direction at the same location (the back side of the convex portion 21) on the plate surface 2S1. Therefore, the bus bar 2 formed at the position where the convex portion 21 and the concave portion 24 overlap when viewed along the Z direction can be efficiently manufactured.

[0026] In addition, in FIG. 2, an aspect is shown in which the convex portion 21 is formed on the plate surface 2S2 of the bus bar 2 and the concave portion 24 is formed on the plate surface 2S1. However, an aspect in which the convex portion 21 is formed on one of the plate surface 2S2 and the plate surface 2S1 of the bus bar 2 and the other is a flat surface without forming the concave portion 24, or an aspect in which the convex portion 21 is formed on both the plate surface 2S2 and the plate surface 2S1 of the bus bar 2 may also be used.

[0027] The magnetic sensor 3 is disposed on the surface of the Z1 side of the substrate 4 so as to face the plate surface 2S of the bus bar 2, and detects the induced magnetic field from the bus bar 2 generated when the current to be measured flows through the bus bar 2. As the magnetic detection element of the magnetic sensor 3, for example, a magnetoresistive effect element such as a giant magnetoresistive effect element (GMR element) or a tunnel magnetoresistive effect element (TMR element), a Hall element, or the like can be used. Note that the configurations shown in FIGS. 1 and 2 are examples in the case where a magnetoresistive effect element is used as the magnetic detection element, but when other magnetic detection elements are used, it is necessary to appropriately change the orientation of the detection surface and arrange them.

[0028] Since the magnetic sensor 3 faces the narrow portion 22 of the bus bar 2, it measures the induced magnetic field from the narrow portion 22 when the current to be measured flows through the bus bar 2. Therefore, the shape of the narrow portion 22 affects the performance of the current sensor 1. That is, the relationship between the magnetic sensor 3 and the narrow portion 22 is important. When the narrow portion 22 is deformed, the relationship between the magnetic sensor 3 and the narrow portion 22 changes or the way the induced magnetic field is generated changes, and the measurement accuracy of the current sensor 1 may decrease.

[0029] In recent years, in addition to the bus bar integrated type current sensor in which the bus bar 2 is insert-molded into the housing of the current sensor 1, a bus bar separate type current sensor has been proposed in which the bus bar 2 is inserted into and attached to the insertion hole of the housing. In this bus bar separate type current sensor, there is a high risk that the narrow portion 22 will be deformed when the bus bar 2 is attached to the current sensor 1 or when the bus bar 2 is connected to the outside. Further, as described above, in the bus bar 2, the narrow portion 22, which has relatively low strength and is easily deformed, is a part that has a great influence on the measurement accuracy of the current sensor 1. For this reason, when the bus bar 2 is thinned, it is necessary to improve the strength of the narrow portion 22 in order to prevent the measurement accuracy of the current sensor 1 from decreasing due to the deformation of the narrow portion 22.

[0030] Therefore, in order to suppress the deformation of the narrow portion 22, the current sensor 1 of the present embodiment is provided with a convex portion 21 in the narrow portion 22. Thereby, even when the thickness of the bus bar 2 is reduced by improving the strength of the narrow portion 22, it is possible to prevent a decrease in measurement accuracy due to the deformation of the narrow portion 22. Further, by forming a concave portion 24 on the opposite surface of the convex portion 21, it is possible to increase the Y-direction component of the induced magnetic field generated on the side of the narrow portion 22 where the concave portion 24 is located. Therefore, as shown in FIG. 7, by arranging the magnetic sensor 3 on the side facing the concave portion 24, the measurement accuracy of the magnetic field of the current sensor 1 can be improved.

[0031] On the Z1 side of the bus bar 2 and the Z2 side of the substrate 4 on which the magnetic sensor 3 is mounted, magnetic shields 5 are provided by metal plate-like bodies or the like, respectively. The magnetic shield 5 can be configured, for example, by stacking a plurality of plate-like bodies having the same shape. Since the magnetic shield 5 can suppress external magnetic noise with respect to the magnetic sensor 3, the measurement accuracy of the current sensor 1 is improved. Although FIG. 1 shows a pair of flat magnetic shields 5, the magnetic shield 5 may be composed of only one of them. Further, when the magnetic shield 5 is viewed along the X direction, it may have a U-shaped configuration.

[0032] FIG. 14 is a perspective view schematically showing the configuration of a main part of a conventional current sensor 100. FIG. 15 is a perspective view showing the configuration of the bus bar 102 of the current sensor 100 in FIG. 14. As shown in these figures, the bus bar 102 provided in the conventional current sensor 100 is different from the bus bar 2 provided in the current sensor 1 in that the convex portion 21 is not provided in the narrow portion 22. Conventionally, a configuration in which the plate surfaces on both sides of the narrow portion 22 are formed as planes has been adopted.

[0033] FIG. 4A is a perspective view showing the simulation result of the displacement that occurs when a force in the Z1 direction is applied to the end portion on the X1 side in a state where the end portion on the X2 side of the bus bar 2 in FIG. 3 is fixed. FIG. 4B is a perspective view showing the simulation result of the displacement, which was performed under the same conditions as the bus bar 2 in FIG. 3, for the bus bar 102 in FIG. 15.

[0034] In the simulation results shown in FIGS. 4A and 4B, the differences in displacements at each part are not shown as differences in shades of color. This is because the shades of color in the simulation results represent the ratio of the displacement amount of each part to the maximum displacement amount in the bus bar 2 or the bus bar 102, rather than the magnitude of the displacement amount of each part. That is, the simulation results of FIGS. 4A and 4B do not mean that the deformation amounts of the parts shown in the same shade are the same when comparing the two.

[0035] The displacement amount of each part is shown as a numerical value attached to the scale shown on the right side in each simulation result. For example, looking at the numerical value indicating the displacement amount at the tip of the X1 side, it is 1.274e+01 (mm) in FIG. 4A and 1.326e+01 (mm) in FIG. 4B, and it can be seen that there is a difference in the displacement amount. The approximate values evaluated considering the numerical values shown on the scale are that the displacement amount of the narrow part 22 having the convex part 21 shown in FIG. 4A is 2.548 to 5.095, and the displacement amount of the narrow part 22 not having the convex part 21 shown in FIG. 4B is 2.653 to 6.632. From these results, it can be seen that by providing the convex part 21 in the narrow part 22, the displacement amount of the narrow part 22 is suppressed.

[0036] (Modification example) FIG. 5 is a perspective view showing the configuration of a modification example of the bus bar 2 of the current sensor 1 in FIG. 1. The bus bar 2 shown in the figure has the same configuration such as dimensions as the bus bar 2 shown in FIGS. 3 and 4A. The bus bar 2 shown in FIGS. 3 and 4A is formed by, for example, half punching, while the convex part 21 and the concave part 24 of the bus bar 2 shown in FIG. 5 can be formed by, for example, bead processing. In bead processing, like half punching, the convex part 21 and the concave part 24 can be processed simultaneously.

[0037] FIG. 6 is a perspective view schematically showing the configuration of a main part of a modification example of the current sensor 1 in FIG. 1. FIG. 7 is a cross-sectional view schematically showing the structure of the current sensor 1 in FIG. 6 along line A-A. As shown in these figures, the above-described modified example has a configuration in which the bus bar 2 in the current sensor 1 of FIG. 1 is turned over in the Z direction. That is, the bus bar 2 of the current sensor 1 according to the modified example has a convex portion 21 formed on the plate surface (first plate surface) 2S1 on the side opposite to the magnetic sensor 3 (Z1 side), and a concave portion 24 formed along the X direction on the plate surface (second plate surface) 2S2 on the side opposite to the plate surface 2S1 (Z2 side). And as shown in FIGS. 6 and 7, the magnetic sensor 3 is disposed to face the concave portion 24 of the bus bar 2.

[0038] Thus, when the concave portion 24 is provided on the back side of the convex portion 21, in the vicinity of the concave portion 24, the magnetic field component facing the Y direction, which is parallel to the plate surface 2S2 and orthogonal to the X direction in the induced magnetic field of the bus bar 2, which is the detection target of the magnetic sensor 3, increases. Therefore, by providing the concave portion 24 on the plate surface 2S2 on the side of the bus bar 2 facing the magnetic sensor 3, the measurement accuracy of the magnetic sensor 3 is improved, and the current sensor 1 with good measurement accuracy is obtained.

[0039] As shown in FIGS. 6 and 7, the bus bar 2 is formed at a position where the convex portion 21 and the concave portion 24 overlap when viewed along the Z direction. The bus bar 2 formed at a position where the convex portion 21 and the concave portion 24 overlap when viewed along the Z direction can be easily formed by half punching or the like, and thus is advantageous from the viewpoint of the manufacturing efficiency of the bus bar 2. Further, the strength of the bus bar 2 is improved by the convex portion 21, and the measurement accuracy of the current sensor 1 is improved by arranging the magnetic sensor 3 so as to face the concave portion 24.

[0040] FIG. 8A is a simulation result showing the intensity of the induced magnetic field around the bus bar 2 of the current sensor 1 in FIGS. 6 and 7. FIG. 8B is a simulation result showing the intensity of the induced magnetic field around the bus bar 102 of the conventional current sensor 100 in FIG. 14. The black arrows shown in FIGS. 8A and 8B schematically show a part of the induced magnetic field generated around the bus bars 2 and 102.

[0041] The induced magnetic field formed in the vicinity of the plate surface 2S (see FIG. 15) on the Z2 side of the bus bar 102 where the concave portion 24 is not formed is formed in an arc shape that is separated from the plate surface 2S near the center rather than near both ends in the Y direction of the bus bar 102, as shown in FIG. 8B.

[0042] On the other hand, in the case of the bus bar 2 in which the concave portion 24 is provided on the back side of the convex portion 21, as shown in FIG. 8A, an induced magnetic field substantially parallel to the Y direction is formed in the vicinity of the plate surface 2S2 (see FIG. 7) on the Z2 side where the concave portion 24 is formed. That is, it can be said that the induced magnetic field generated in the vicinity of the concave portion 24 contains more components parallel to the Y direction of the induced magnetic field that can be detected by the magnetic sensor 3 than the induced magnetic field when there is no concave portion 24. Therefore, by arranging the magnetic sensor 3 so as to face the concave portion 24, the magnetic sensor 3 can accurately measure the induced magnetic field of the bus bar 2 generated when the current to be measured flows.

[0043] Next, a case where the convex portion 21 is not provided on the bus bar 2 and only the concave portion 24 is provided will be compared as a reference example. FIG. 9 is a simulation result showing the direction and intensity of the peripheral induced magnetic field for a modified example of the bus bar 2 of the current sensor 1 in FIG. 6. FIG. 10 is a simulation result showing the direction and intensity of the induced magnetic field around the bus bar of the reference example. From the simulation results shown in these figures, it is also shown that by providing the concave portion 24 on the plate surface of the bus bar 2, an induced magnetic field with a large Y-direction component is formed in the vicinity of the concave portion 24.

[0044] When compared with the conventional structure shown in FIG. 8B, the structure of the reference example also seems to have more Y-direction components in the induced magnetic field formed around the concave portion 24. However, an induced magnetic field is also formed along the inner surface shape of the concave portion 24, and compared with the structure of the present embodiment shown in FIG. 9, an induced magnetic field with many Y-direction components is not formed in the vicinity of the concave portion 24.

[0045] Also, when only the concave portion 24 is provided on the bus bar 2 without providing the convex portion 21, if the bus bar 2 is thinned as a means for miniaturizing / lowering the height of the current sensor 1, the strength becomes weaker compared to the case where it is thinned while maintaining the conventional structure (without the concave portion 24).

[0046] In addition, when the concave portion 24 is formed by press working, since there is no place for the metal in the recessed portion to escape, the hardness of the bus bar 2 increases due to the compression of the base material around the concave portion 24. On the other hand, the elasticity decreases. Therefore, when any bending stress is applied near the concave portion 24, it is likely to break. For this reason, it is preferable to form the convex portion 21 and the concave portion 24 at the same location on the plate surface 2S2 and the plate surface 2S1 by half-punching.

[0047] From the above, by providing the convex portion 21 on the bus bar 2 and providing the concave portion 24 on the back side of the convex portion 21, the induced magnetic field of the bus bar 2 can be accurately measured by the magnetic sensor 3, and the bus bar 2 can be made such that the strength reduction can be suppressed even when it is thinned. The method of forming the convex portion 21 and the concave portion 24 is not limited to half-punching, and other methods than half-punching may be used.

[0048] FIG. 11 is a perspective view schematically showing the configuration of another modification of the current sensor 1 in FIG. 1. The current sensor 1 shown in the figure includes a housing 6 made of resin or the like that houses the magnetic sensor 3 (see FIG. 2), and the bus bar 2 is insert-molded into the housing 6. With the configuration in which the bus bar 2 is insert-molded into the housing 6, the bus bar 2 and the magnetic sensor 3 can be in a predetermined positional relationship and this positional relationship can be reliably maintained. Therefore, the current sensor 1 has good measurement accuracy.

[0049] FIG. 12 is an exploded perspective view schematically showing the configuration of another modification of the current sensor 1 in FIG. 1. FIG. 13 is a perspective view showing the state in which the current sensor 1 in FIG. 12 is assembled. As shown in these figures, the present invention can be implemented as a current sensor 1 including a magnetic sensor 3 (see FIG. 2) and a housing 6. Instead of configuring the bus bar 2 to be integrally formed with the housing 6, by making the bus bar 2 attachable to the housing 6, the degree of freedom in the shape of the bus bar 2 increases, and thus the versatility of the current sensor 1 is improved.

[0050] The housing 6 is provided with an insertion hole 61 into which the bus bar 2 having a convex portion 21 formed on the plate surface 2S2 along the extending direction of the bus bar 2 can be inserted. And the insertion hole 61 is provided with a guide portion 610 for passing the convex portion 21 of the bus bar 2. By providing the guide portion 610 in the insertion hole 61 of the housing 6, the bus bar 2 can be easily inserted into the insertion hole 61.

[0051] The embodiments disclosed in this specification are illustrative in all respects and are not limited to this embodiment. The scope of the present invention is shown not by the description of only the above-described embodiments but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Industrial Applicability

[0052] The present invention is useful as a current sensor for measuring a measured current flowing through a device and a bus bar used for the current sensor in order to control, for example, a power supply system of a vehicle or the like equipped with various devices.

Explanation of Signs

[0053] 1: Current sensor 2: Bus bar 2S: Plate surface 2S1: Plate surface 2S2: Plate surface 21: Convex portion 21Ea: End portion 21Eb: End portion 22: Narrow portion 23: Wide portion 23A: Wide portion 23B: Wide portion 24: Concave portion 3: Magnetic sensor 4: Substrate 5: Magnetic shield 6: Housing 61: Insertion hole 610: Guide part 100: Current sensor 102: Bus bar L21: Length L22: Length W22: Dimension W23: Dimension

Claims

1. In a current sensor including a bus bar and a magnetic sensor, the bus bar includes a portion extending in a first direction, and a convex portion is formed along the first direction on a plate surface defined by the first direction and a second direction orthogonal to the first direction. The current sensor is characterized by this.

2. The bus bar, in a third direction orthogonal to the first direction and the second direction, has a narrow portion provided at a position facing the magnetic sensor, and on both sides of the narrow portion in the first direction, has wide portions continuous with the narrow portion and having a dimension in the second direction larger than that of the narrow portion. The current sensor according to claim 1, wherein the convex portion is formed in the narrow portion.

3. The current sensor according to claim 2, wherein the convex portion is continuously formed from one wide portion to the other wide portion via the narrow portion.

4. The bus bar, has the convex portion formed on a first plate surface, has a concave portion formed along the first direction on a second plate surface opposite to the first plate surface, and the magnetic sensor is disposed to face the concave portion. The current sensor according to claim 2.

5. The current sensor according to claim 4, wherein the bus bar is formed at a position where the convex portion and the concave portion overlap when viewed along the third direction.

6. including a housing for housing the magnetic sensor, and the bus bar is insert-molded into the housing. The current sensor according to claim 1.

7. In a current sensor including a magnetic sensor and a housing, the housing is characterized by including an insertion hole into which the bus bar having a convex portion formed on a plate surface along the extending direction of the bus bar can be inserted.

8. The current sensor according to claim 7, wherein the insertion hole includes a guide portion for passing the convex portion through.

9. A bus bar including a portion extending in a first direction, having a plate surface defined by the first direction and a second direction orthogonal to the first direction, in a third direction orthogonal to the first direction and the second direction, having a narrow portion provided at a position facing the magnetic sensor, and on both sides of the narrow portion in the first direction, having wide portions continuous with the narrow portion and having a dimension in the second direction larger than that of the narrow portion. The bus bar is characterized in that a convex portion is formed along the first direction in the narrow portion.

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