Current sensor

Abstract

This current sensor (10) is provided with: a bus bar (11); a magnetic sensor (12); a substrate (13) provided with the magnetic sensor (12); a pair of flat plate type magnetic shields (14A, 14B); and a housing (15) in which the bus bar (11) and the magnetic shield (14B) are integrally formed, the magnetic shield (14A), the substrate (13), and the housing (15) are stacked in this order, the magnetic shield (14A) having a protruding portion (141) protruding from an opposing surface (14Aa) opposing the substrate (13) and a substrate hole (142), the substrate (13) having an engaging portion (131) capable of engaging with the protruding portion (141) and a hole (132) for positioning, the housing (15) having a projection (152) for positioning, and the magnetic shield (14A), the substrate (13), and the housing (15) being stacked in this order. When the protruding part (141) and the clamping part (131) are clamped, the hole (142), the hole (132) and the protrusion (152) are arranged on a straight line parallel to the stacking direction, so that when the magnetic shielding piece which is formed by being separated from the box body is fixed on a substrate provided with a magnetic detection part, the magnetic shielding piece can be easily configured at a specified position on the substrate.

Description

Technical Field

[0001] This invention relates to a current sensor with a magnetically shielded component for measuring the current flowing through a busbar. Background Technology

[0002] In recent years, current sensors that measure the current flowing through the equipment have been used to control the power systems of vehicles and other devices equipped with various devices.

[0003] Patent Document 1 describes a current sensor comprising a pair of magnetic shielding plates sandwiching a conductor and a magnetoelectric conversion element, with the aim of improving the accuracy of the current sensor by reducing the useless space between the pair of magnetic shielding plates. In this current sensor, the pair of magnetic shielding plates, along with the sensor substrate and busbar, are integrally formed with a resin encapsulation that serves as a housing. However, as with this current sensor, it is difficult to achieve miniaturization, weight reduction, and cost reduction in a configuration where the magnetic shielding plates and housing are integrally formed.

[0004] Patent document 2 describes a current sensor for cutting off external magnetic fields by means of a pair of magnetic shielding components for high-precision current detection, wherein the magnetic shielding component with magnetic detection element is fixed to the circuit board by a fixing component.

[0005] Existing technical documents Patent documents Patent Document 1: International Publication No. WO2016 / 148032 Patent Document 2: Japanese Patent Application Publication No. 2018-96793 Summary of the Invention

[0006] The problem that the invention aims to solve The current sensor described in Patent Document 2 is advantageous over the current sensor described in Patent Document 1 in terms of miniaturization, weight reduction, and cost reduction because the magnetic shielding component located on the magnetic detection side is separately constructed from the housing. In the current sensor described in this document, the relative position of the magnetic shielding component and the circuit board on which the magnetic detection element is located is fixed when the fixing members are inserted into the fixing holes located at the four corners of the magnetic shielding component. That is, the fixing holes of the magnetic shielding component are overlapped with the through holes formed in the circuit board, and the fixing members are inserted therein to fix the magnetic shielding component to the circuit board. In this way, the magnetic shielding component is positioned at a predetermined position on the circuit board based on the position of the holes.

[0007] Therefore, the object of the present invention is to provide a current sensor that can be easily positioned at a predetermined position on the substrate when a magnetic shielding component, which is separately formed from the housing, is fixed to a substrate provided with a magnetic detection unit.

[0008] Methods for solving problems As a means of solving the above-mentioned problems, the present invention has the following configuration.

[0009] A current sensor comprises: a busbar through which a measured current flows; a magnetic sensor disposed opposite the busbar to sense a magnetic field emitted by the busbar; a substrate on which the magnetic sensor is disposed; a pair of flat first magnetic shielding members and a second magnetic shielding member sandwiching the busbar, the magnetic sensor, and the substrate; and a housing on which the busbar and the second magnetic shielding member are disposed, wherein the first magnetic shielding member, the substrate, and the housing are stacked sequentially, characterized in that the first magnetic shielding member has a protrusion protruding from a first surface opposite the substrate and a first reference portion for positioning, the substrate has an engaging portion capable of engaging with the protrusion and a second reference portion for positioning, and the housing has a third reference portion for positioning, wherein, in the state where the protrusion engages with the engaging portion, the first reference portion, the second reference portion, and the third reference portion are arranged on a straight line parallel to the stacking direction of the first magnetic shielding member, the substrate, and the housing.

[0010] By engaging the protrusion in the first magnetic shield with the engaging portion of the substrate, the alignment of the first magnetic shield with the substrate becomes easier.

[0011] Alternatively, the first magnetic shielding component may be stacked with multiple thin plate components, and the protrusion may be a stamped joint formed by riveting the multiple thin plate components in the stacking direction.

[0012] By using the stamped joint formed during the riveting of the first magnetic shielding component, which has multiple thin plate components stacked together, as a protrusion and engaging it with the engaging part of the substrate, it is possible to reduce component processing costs and time, and suppress manufacturing costs.

[0013] Alternatively, the first reference portion may be disposed in one of the plurality of thin plate components of the first magnetic shielding member, adjacent to the substrate.

[0014] By providing a positioning reference portion on the first thin-plate component among the plurality of thin-plate components constituting the first magnetic shield, it is easier to position the first magnetic shield at a predetermined location on the substrate compared to providing it on all thin-plate components. For example, when using a shielding hole penetrating the first magnetic shield as the first reference portion, the length of the shielding hole can be shortened by providing it only on the first thin-plate component. Therefore, it is easier to insert a fixing component. Furthermore, since the length of this component is shortened, the strength of fixing the first magnetic shield is improved, and it is beneficial for miniaturization and height reduction of the current sensor.

[0015] Alternatively, the protrusions and the engaging portions may be provided in multiple pairs.

[0016] By providing multiple pairs of protrusions and engaging parts, the engagement of each pair is facilitated, making it easy to position the first magnetic shielding member and the substrate, and also enabling the positioning to be maintained.

[0017] Alternatively, the first reference portion is a shielding hole that passes through the first magnetic shielding member, the second reference portion is a substrate hole that passes through the substrate, and the third reference portion is a fixing protrusion. The fixing protrusion has an anti-detachment portion at its front end. When the fixing protrusion is inserted into the shielding hole and the substrate hole, the first magnetic shielding member and the substrate are fixed to the housing by the anti-detachment portion.

[0018] With the fixed protrusion inserted through the shielding hole and the substrate hole, the first magnetic shield and the substrate are fixed to the housing by the anti-detachment part, thereby positioning the first magnetic shield, the substrate and the housing in a specified position and fixing them in a stacked state.

[0019] Alternatively, the first magnetic shielding component may be stacked with multiple thin plate components, and the anti-detachment portion may contact the exposed portion of the second surface of the thin plate component other than the second thin plate component which has the largest distance from the stacking direction of the substrate, on the side opposite to the first surface of the substrate.

[0020] Alternatively, when either of the thin plate components disposed between the first thin plate component and the second thin plate component adjacent to the substrate is designated as the third thin plate component, the first magnetic shielding member continuously forms holes or cutouts from the second thin plate component to the third thin plate component along the stacking direction, and the second surface exposed from the holes or cutouts is the exposed portion.

[0021] Alternatively, it may include a fixing screw, a first reference portion being a shielding hole through which the first magnetic shielding member passes, a second reference portion being a substrate hole through which the substrate passes, and a third reference portion being a threaded hole capable of engaging with the fixing screw. With the fixing screw inserted in the shielding hole and the substrate hole, the first magnetic shielding member and the substrate are fixed to the housing by the screw head of the fixing screw.

[0022] With the fixing screw inserted through the shielding hole and the substrate hole, the first magnetic shield and the substrate are fixed to the housing by the screw head of the fixing screw, thereby fixing the first magnetic shield, the substrate and the housing in a stacked position.

[0023] Alternatively, the first magnetic shielding component may be stacked with multiple thin plate components, and the screw head may contact the exposed portion of the second surface of the thin plate component other than the second thin plate component which has the largest distance from the stacking direction of the substrate, on the side opposite to the first surface of the substrate.

[0024] Alternatively, when either of the thin plate components disposed between the first thin plate component and the second thin plate component adjacent to the substrate is designated as the third thin plate component, the first magnetic shielding member continuously forms holes or cutouts from the second thin plate component to the third thin plate component along the stacking direction, and the second surface exposed from the holes or cutouts is the exposed portion.

[0025] Alternatively, the first magnetic shielding member may be stacked with a plurality of thin plate components, wherein the first thin plate component of the plurality of thin plate components adjacent to the substrate has an exposed portion on the second surface opposite to the first surface opposite to the substrate, and the exposed portion constitutes part of a stepped portion or a concave portion.

[0026] Based on the above configuration, compared to the case where the anti-detachment part or screw head is located on the second surface of the second thin plate component in the first magnetic shield, the length of the fixing protrusion or fixing screw is shortened. Therefore, the operation of stacking the first magnetic shield becomes easier, and in addition, the first magnetic shield and the substrate can be more firmly fixed relative to the housing.

[0027] Invention Effects According to the present invention, a current sensor can be provided in which, since the alignment of the first magnetic shielding member with the substrate becomes easy, the magnetic shielding member, which is separately formed from the housing, can be easily positioned at a predetermined position on the substrate when it is fixed to the substrate on which the magnetic detection unit is provided. Attached Figure Description

[0028] Figure 1 This is a perspective view schematically showing the appearance of the current sensor according to the first embodiment.

[0029] Figure 2 It is a schematic representation Figure 1 A cross-sectional view of the main components of the AA line current sensor.

[0030] Figure 3 It is a schematic representation Figure 2 A cross-sectional view of the configuration of a modified example of a current sensor.

[0031] Figure 4 yes Figure 3 A top view of the current sensor.

[0032] Figure 5This is an explanatory diagram of the structure of a magnetic shielding component with a conventional layered structure.

[0033] Figure 6 This is an explanatory diagram of the structure of a magnetic shielding member having the stacked structure in the current sensor of the present invention.

[0034] Figure 7 It is a schematic representation Figure 2 A cross-sectional view of the configuration of other variations of the current sensor.

[0035] Figure 8 It is a schematic representation Figure 2 A cross-sectional view of the configuration of other variations of the current sensor.

[0036] Figure 9 It is a schematic representation Figure 8 A top view of the current sensor's structure.

[0037] Figure 10 This is a cross-sectional view schematically showing the configuration of the current sensor according to the second embodiment.

[0038] Figure 11 This is a top view schematically showing the configuration of the current sensor according to the second embodiment.

[0039] Figure 12 It is a schematic representation Figure 10 A cross-sectional view of the configuration of a modified example of a current sensor.

[0040] Figure 13 It is a schematic representation Figure 12 A top view of the current sensor's structure.

[0041] Figure 14 This is a schematic cross-sectional view showing the structure of a conventional current sensor.

[0042] Figure 15 This is a schematic cross-sectional view illustrating the configuration of a current sensor without a cover. Detailed Implementation

[0043] [First Implementation Method] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, the same reference numerals are used to denote the same components, and descriptions are omitted where appropriate. Reference coordinates are appropriately shown in each drawing to indicate the positional relationship of the components. In the reference coordinates, the width dimension direction of the generatrix is ​​defined as the X direction (third direction), the extension direction of the generatrix orthogonal to the X direction is defined as the Y direction (second direction), and the stacking direction of the generatrix orthogonal to both the X and Y directions and the magnetic sensor is defined as the Z direction (first direction). The X direction is the direction of the sensitivity axis of the magnetic sensor, and the Y and Z directions are orthogonal to the sensitivity axis.

[0044] Figure 14 This is a schematic cross-sectional view illustrating the configuration of a conventional current sensor 100. The current sensor 100 shown in this figure includes a busbar 101 through which the measured current flows and a pair of parallel-plate type magnetic shielding members 104A and 104B sandwiching a magnetic sensor 102 disposed on a substrate 103. Magnetic shielding member 104A is embedded in a cover 106, and magnetic shielding member 104B is embedded in a housing 105. Thus, in the configuration having a housing 105 and a cover 106 with magnetic shielding members 104B and 104A respectively embedded, it is difficult to miniaturize and thin the current sensor 100, and it is also disadvantageous in terms of cost reduction. Therefore, the following description will illustrate a current sensor that is advantageous in terms of miniaturization, thinness, and cost reduction, and which does not have a cover 106 for holding the magnetic shielding member 104A, thus implementing the present invention.

[0045] Figure 15 This is a schematic cross-sectional view illustrating the configuration of a current sensor 110 without a cover. The current sensor 110 shown in this figure lacks a cover, therefore, magnetic shield 104A of the pair of magnetic shields 104A and 104B is directly disposed on the substrate 103. Thus, when the magnetic shield 104A, disposed on the side of the magnetic sensor 102, is directly disposed on the substrate 103 with reference to the busbar 101, it is difficult to position the magnetic shield 104A at a predetermined position on the substrate 103. Therefore, the current sensor of the present invention has a configuration for stably and easily determining the position of the magnetic shield 104A relative to the substrate 103 with high accuracy. Hereinafter, embodiments of the current sensor of the present invention will be described.

[0046] Figure 1 This is a perspective view schematically showing the appearance of the current sensor 10 of this embodiment.

[0047] Figure 2 It is a schematic representation Figure 1 A cross-sectional view of the main components of the AA line current sensor 10.

[0048] The current sensor 10 includes a busbar 11, a magnetic sensor 12, a substrate 13, a pair of flat magnetic shielding members 14A (first magnetic shielding member) and magnetic shielding member 14B (second magnetic shielding member), and a housing 15. The magnetic shielding member 14A, substrate 13, magnetic sensor 12, busbar 11 and magnetic shielding member 14B are stacked sequentially from Z2 to Z1, and the busbar 11 and magnetic shielding member 14B are disposed in the housing 15.

[0049] Busbar 11 is a plate-shaped conductor formed to carry the current being measured, and is made of materials such as copper, brass, or aluminum.

[0050] A magnetic sensor 12 detects the magnetism emitted by the busbar 11 when a measured current flows through it. It is disposed on a surface 13a of the substrate 13 on the Z1 side, opposite the busbar 11 in the Z direction. The sensing surface of the magnetic sensor 12 is the surface directly opposite the busbar 11, and its sensitivity axis is oriented in a direction parallel to the sensing surface. Near the sensing surface of the magnetic sensor 12, the induced magnetic field generated when the measured current flows through the busbar 11 includes a significant X-direction component. Therefore, by arranging the magnetic sensor 12 with its sensitivity axis parallel to the X-direction, the magnetism emitted by the busbar 11 can be sensed with high precision.

[0051] As the detection element in the magnetic sensor 12, a magnetoresistive element, a Hall element, or the like can be used. Furthermore, the above configuration illustrates the case where a magnetoresistive element is used as the detection element of the magnetic sensor 12. When using other detection elements, it is necessary to appropriately change the orientation of the sensing surface, etc., to configure them.

[0052] The magnetic shielding elements 14A and 14B are arranged such that the busbar 11, the magnetic sensor 12, and the substrate 13 are sandwiched in the Z direction, and are made of metal plates or the like. The magnetic shielding elements 14A and 14B can suppress magnetic noise relative to the magnetic sensor 12, thus improving the measurement accuracy of the current sensor 10.

[0053] The housing 15 can be configured such that the busbar 11 and the magnetic shield 14B are integrally formed by insert molding or the like. Alternatively, the housing 15, which has the magnetic shield 14B integrally formed by insert molding, can be configured such that the busbar 11 is inserted from the rear to provide the busbar 11.

[0054] The magnetic shielding member 14A has a protrusion 141 protruding from the opposing surface 14Aa (first surface) opposite to the substrate 13. In addition, as the first reference part, it has a hole 142 (shielding hole) that extends along the Z direction and can be inserted through the fixing protrusion 152 described later.

[0055] The substrate 13 has an engaging portion 131 on its opposing surface 13b, which is opposite to the surface 13a where the magnetic sensor 12 is located and opposite the magnetic shield 14A, and which is capable of engaging with the protrusion 141. The engaging portion 131 only needs to be able to engage with the protrusion 141, so it can be replaced by a through hole in the Z direction, for example, a recess that does not penetrate in the Z direction corresponding to the shape of the protrusion 141.

[0056] By engaging the protrusion 141 of the magnetic shield 14A with the engaging portion 131 of the substrate 13, the relative positional relationship between the magnetic shield 14A and the substrate 13 can be easily determined. That is, by engaging the protrusion 141 with the engaging portion 131, the magnetic shield 14A and the substrate 13 can be easily aligned.

[0057] From the perspective of reliable and easy alignment, such as Figure 2 As shown, the current sensor 10 preferably has multiple pairs of protrusions 141 and engaging portions 131. By providing multiple pairs of protrusions 141 and engaging portions 131, the magnetic shield 14A and the substrate 13 are easily positioned by engaging each pair, and the alignment can be reliably maintained.

[0058] The substrate 13 has a through hole 132 in the Z direction through which the fixing protrusion 152 described later can be inserted, serving as a second reference portion for positioning. By engaging the protrusion 141 with the engaging portion 131, the magnetic shield 14A is positioned at a predetermined location on the substrate 13, thus the hole 142 of the magnetic shield 14A overlaps with the hole 132 (substrate hole) of the substrate 13. That is, when viewed along the Z direction, the hole 142 of the magnetic shield 14A and the hole 132 of the substrate 13 can be made to coincide and become a continuous hole.

[0059] The housing 15, made of resin or the like, is integrally formed with the insert-molded busbar 11 and the magnetic shielding member 14B. The housing 15 has a receiving recess 151 on the side opposite to the substrate 13. Furthermore, in the receiving recess 151, a fixing protrusion 152 protruding in the Z2 direction serves as a third reference portion for positioning.

[0060] By engaging the protrusion 141 with the engaging portion 131, holes 142 and 132 overlap when viewed along the Z direction. Therefore, the fixing protrusion 152, serving as a third reference portion, can be easily inserted into holes 142 and 132. The insertion of the fixing protrusion 152 defines the positional relationship between the magnetic shielding member 14A, the substrate 13, and the housing 15. In this state, holes 142, 132, and the fixing protrusion 152 are arranged on a straight line L parallel to the stacking direction (Z direction) of the magnetic shielding member 14A, the substrate 13, and the housing 15.

[0061] With the fixing protrusion 152 inserted into holes 142 and 132, the magnetic shield 14A and the substrate 13 are fixed relative to the housing 15 by means of the anti-detachment portion 153 provided at the Z2 side end (front end) of the fixing protrusion 152. Furthermore, the anti-detachment portion 153 is formed by, for example, heat-riveting the Z2 side end (front end) of the fixing protrusion 152 after it has been inserted into holes 142 and 132.

[0062] The external dimensions of the anti-detachment part 153 when viewed along the Z direction are larger than the inner diameters of the holes 142 and 132. Furthermore, the anti-detachment part 153 is in close contact with the Z2 side surface 14Ab of the magnetic shield 14A. Therefore, the anti-detachment part 153 functions as a retaining member that holds the magnetic shield 14A and the substrate 13 in a predetermined position within the housing 15.

[0063] The positional relationship between the magnetic shielding component 14A, the substrate 13, and the housing 15 is such that the magnetic sensor 12 of the substrate 13 is positioned opposite the busbar 11 within the receiving recess 151, and is fixed by the anti-detachment part 153.

[0064] As described above, the current sensor 10 can determine the relative positions of the magnetic shielding 14A, the substrate 13, and the housing 15 when the magnetic shielding 14A, the substrate 13, the busbar 11, and the magnetic shielding 14B are stacked in a manner arranged sequentially from Z2 to Z1. By fixing the substrate 13 and the magnetic shielding 14A at a predetermined position with the housing 15 as a reference, it is possible to prevent the positional displacement of the busbar 11, the magnetic shielding 14A, and the magnetic shielding 14B relative to the magnetic sensor 12 disposed on the substrate 13. Therefore, a current sensor 10 with good measurement accuracy is achieved by suppressing errors caused by positional displacement.

[0065] (Modified example) Figure 3 as well as Figure 4 It is a schematic representation Figure 2 A cross-sectional view and a top view of the configuration of a modified current sensor 20 of the current sensor 10.

[0066] The current sensor 20 shown in these figures is... Figure 2 The difference in the current sensor 10 is that, instead of magnetic shielding members 14A and 14B which are made of a single metal plate, it has magnetic shielding members 24A and 24B which are made of multiple overlapping metal plates of the same shape.

[0067] Before describing the magnetic shield 24A of the current sensor 20, the structure of the magnetic shield 114A, which has a conventional stacked structure, will be described.

[0068] Figure 5This is an explanatory diagram of the structure of a conventional magnetic shield 114A with a stacked structure. As shown in (a) of the figure, the magnetic shield 114A has a structure in which multiple metal plates are stacked and riveted together from the top (Z2 side) by striking with a punch. (b) shows the cross-sectional structure of the portion shown by line BB in (a).

[0069] By simply overlapping multiple metal plates and riveting them together with a punch, a shape similar to the protrusion 141 of the magnetic shield 14A shown in the first embodiment can be formed. If there are deviations in the amount of protrusion or the shape of such a part, problems such as tilting may occur even when it is placed on a plane.

[0070] In the magnetic shielding component 114A with the conventional layered structure, such as Figure 5 As shown in (b), a hole 1141 is provided in the metal plate 114A1 located at the bottommost side (Z1 side). When viewed along the Z direction, the portion overlapping the hole 1141 is struck from the upper surface 114Ab with a punch to rivet the metal plates 114A1 to 114A4. At this time, the protrusion of the metal plate 114A2 adjacent to the metal plate 114A1 is pressed into the hole 1141. As a result, a protrusion is not formed from the opposing surface 114Aa on the lower side shown by the single-dotted line of the magnetic shield 114A.

[0071] Figure 6 This is an explanatory diagram of the structure of the magnetic shield 24A with a stacked structure in the current sensor 20. As shown in (a) of the figure, the magnetic shield 24A is similar to the structure of the magnetic shield 24A in that it consists of multiple overlapping metal plates riveted together by striking from the top (Z2 side) with a punch. Figure 5 It is the same as the previous magnetic shielding component 114A.

[0072] However, in the magnetic shielding component 24A, such as Figure 6 As shown in the cross-sectional view (b), in the riveting portion marked with line BB in (a), no hole is provided in the metal plate 24A1 located at the bottom. Therefore, in all of the metal plates 24A1 to 24A4, a recess is formed on the upper surface 24Ab of the riveting portion, and a protrusion is formed on the opposing surface 24Aa opposite to the lower substrate 13. Therefore, the stamped joint portion 241, which is formed when riveting by punching and protrudes from the lower opposing surface 24Aa indicated by a single-dot dashed line, is used for the alignment of the magnetic shield 24A and the substrate 13. That is, the stamped joint portion 241 riveted in the stacking direction in the magnetic shield 24A is used as a protrusion that engages with the engaging portion 131 of the substrate 13.

[0073] As described above, in the magnetic shielding member 24A, a portion of the stamped joint 241 required for processing protrudes from the opposing surface 24Aa of the magnetic shielding member 24B opposite to the substrate 13, serving as a protrusion that engages with the engaging portion 131 of the substrate 13. In this way, by using the stamped joint 241 as a protrusion, the alignment of the magnetic shielding member 24A with the substrate 13 becomes easier, and component processing costs and time can be reduced, thus suppressing the manufacturing cost of the magnetic shielding member 24A.

[0074] Furthermore, the magnetic shielding member 24B may have a structure with a protrusion on one side, similar to the magnetic shielding member 24A, or it may have a structure without a protrusion, similar to the conventional magnetic shielding member 114A.

[0075] Figure 7 It is shown schematically. Figure 3 A cross-sectional view of a current sensor 30, which is another variation of the current sensor 20.

[0076] The current sensor 30 is different from the current sensor 10 in that it has a fixing screw 31 and a threaded hole 154 in the housing 15 that can engage with the fixing screw 31 as a third reference part. In addition, when viewed along the Z direction, the inner diameters of the hole 242 (first shielding hole) and the hole 132 are larger than the threaded portion of the fixing screw 31 and smaller than the outer diameter of the screw head 32.

[0077] With the fixing screw 31 inserted into holes 242 and 132, the magnetic shield 24A and the substrate 13 are fixed to the housing 15 by the screw head 32 of the fixing screw 31. Thus, the fixing screw 31 can be used as a retaining member to fix the magnetic shield 24A, the substrate 13 and the housing 15 in a stacked position.

[0078] Figure 8 as well as Figure 9 It is a schematic representation of as Figure 3 The figures show a cross-sectional view and a top view of the current sensor 35, another variation of the current sensor 20. As shown in these figures, the current sensor 35 differs from the current sensor 20 in that the magnetic shield 24A, the substrate 13, and the housing 15 are secured by two fixing protrusions 152 and two fixing screws 31.

[0079] Similar to the current sensor 35, different fixing mechanisms can be used to secure the magnetic shield 24A, the substrate 13, and the housing 15. These different fixing mechanisms can also be configured to be compatible with... Figure 9Different combinations and configurations are possible. For example, one fixing protrusion 152 and three fixing screws 31 can be combined, or three fixing protrusions 152 and one fixing screw 31 can be combined. Alternatively, it can be configured such that an anti-detachment part 153 is provided at the front end of all or part of each fixing protrusion 152.

[0080] exist Figure 9 The example shown is that the magnetic shield 24A is provided with four fixing mechanisms, but the number of fixing mechanisms is not limited to four. For example, it can also be set to two, three, five or more.

[0081] [Second Implementation] Figure 10 as well as Figure 11 These are schematic cross-sectional and top views illustrating the configuration of the current sensor 40 according to this embodiment. As shown in the figures, the current sensor 40 differs from the previous embodiment in that it includes a magnetic shield 44A instead of a magnetic shield 24A. Figure 3 The current sensor 20 is different.

[0082] The hole 442 of the magnetic shielding member 44A, which serves as the first reference part, is provided only in the thin plate member 44A1 (first thin plate member) that is adjacent to the substrate 13 among the multiple thin plate members 44A1, 44A2, 44A3, and 44A4 of the magnetic shielding member 44A.

[0083] In other words, when viewing the multiple sheet metal components 44A1, 44A2, 44A3, and 44A4 from the Z2 side, sheet metal component 44A1 has an exposed portion 444 extending from sheet metal components 44A2, 44A3, and 44A4, and a hole 442 is provided in the exposed portion 444. In addition, when the Z2 side is set as the upper side, the exposed portion 444 is located at a lower position (Z1 side) relative to the upper surface of the sheet metal component 44A4, forming a stepped portion 445.

[0084] By forming a hole 442 in the exposed portion 444 of the thin plate member 44A1, the anti-detachment portion 153 can be disposed on the stepped portion 445. Therefore, compared to disposing the anti-detachment portion 153 on the upper surface of the thin plate member 44A4, the amount of protrusion of the anti-detachment portion 153 relative to the upper surface of the thin plate member 44A4 can be reduced. That is, miniaturization / lower height in the Z direction can be achieved.

[0085] Furthermore, by forming a hole 442 in the exposed portion 444 of the thin plate member 44A1, the depth of the hole 442 in the stacking direction is shortened. Therefore, the operation of inserting the hole 442 into the fixing protrusion 152 becomes easier. Additionally, the shorter length of the fixing protrusion 152 in the Z direction increases its strength. Therefore, by inserting the hole 442 of the magnetic shielding member 44A and the hole 132 of the substrate 13 into the fixing protrusion 152 of the housing 15 and then fixing them, the magnetic shielding member 44A and the substrate 13 can be more securely fixed to the housing 15.

[0086] In addition, Figure 10 In the magnetic shielding member 44A shown, cutouts 443 are continuously formed from the thin plate member 44A4 (the second thin plate member) with the largest distance from the substrate 13 in the stacking direction (Z direction) among the thin plate members 44A1 to 44A4, to the thin plate member 44A2 (the third thin film member) adjacent to the thin plate member 44A1. That is, cutouts 443 are formed in the thin plate members 44A2 to 44A4 other than the thin plate member 44A1, and holes 442 are formed in the exposed portion 444 of the thin plate member 44A1 that is exposed when viewed from the surface 44Ab (second surface) of the magnetic shielding member 44A.

[0087] As described above, in the thin plate components 44A2 and 44A3 (third thin plate components) disposed between the thin plate component 44A1 (first thin plate component) and the thin plate component 44A4 (second thin plate component), the magnetic shielding member 44A has holes or cutouts 443 continuously formed from the thin plate component 44A4 to the thin plate component 44A2 along the lamination direction (Z direction). Furthermore, when viewed from the Z2 to Z1 direction, the surface 44Ab exposed from the cutout 443 is the exposed portion 444.

[0088] In the magnetic shielding member 44A, only the thin plate member 44A1, which serves as the first thin plate member, has a hole 442 as the first reference portion, and a stepped portion 445 is formed by the exposed portion 444 of the thin plate member 44A1 and the end faces of the thin plate members 44A2 to 44A4 in the Y direction. That is, a portion of the stepped portion 445 is formed by the exposed portion 444.

[0089] like Figure 11 As shown, when viewed along the Z direction, the anti-detachment part 153 contacts the exposed part 444, and the exposed part 444 serves as a holding surface. The anti-detachment part 153 holds the magnetic shield 44A and the substrate 13 in place. In this way, the magnetic shield 44A can be fixed at a predetermined position on the housing 15.

[0090] exist Figure 10 , Figure 11In the current sensor 40 shown, when the magnetic shielding member 44A is viewed along the stacking direction, the thin plate member 44A1 that is in contact with the substrate 13 is formed to be larger than the other thin plate members 44A2 to 44A4. Furthermore, a hole 442 (shielding hole) serving as a first reference portion is formed in the exposed portion 444 of the thin plate member 44A1 that extends from the other thin plate members 44A2 to 44A4.

[0091] exist Figure 10 In this case, sheet metal parts 44A2 to 44A4 have the same shape and size, and are all formed in a shape different from that of sheet metal part 44A1. However, this is not a limitation. For example, sheet metal part 44A2 may be formed in the same shape and size as sheet metal part 44A1, while sheet metal parts 44A3 to 44A4 may be formed in a shape different from that of sheet metal part 44A1. In this case, when viewed from the Z2 direction to the Z1 direction, the portion protruding from sheet metal parts 44A3 to 44A4 on the Z2 side of sheet metal part 44A2 becomes the exposed portion 444, and the hole 442 may also be provided through sheet metal parts 44A2 and 44A1.

[0092] That is, when multiple thin plate components (large plate components) that are continuously stacked, including thin plate component 44A1, are formed to have the same shape and size, and have portions that extend from the remaining thin plate components (small plate components) including thin plate component 44A4, an exposed portion 444 may be formed on the Z2 side of the large plate component that is furthest from the substrate 13, and a hole 442 that penetrates through the entire large plate component may be formed in the exposed portion 444.

[0093] According to this configuration, when viewed along the lamination direction, any one of the thin plate components 44A1 to 44A3 among the thin plate components 44A1 to 44A4 is exposed. That is, the thin plate component other than the one with the largest distance from the substrate 13 in the lamination direction, is formed with an exposed portion 444 on the side opposite to the opposing surface 44Aa that faces the substrate 13. Furthermore, the magnetic shield 44A, the substrate 13, and the housing 15 are fixed by contact between the anti-detachment portion 153 and the exposed portion 444.

[0094] Furthermore, compared to the case where the exposed portion 444 is formed in the thin plate component 44A4, the hole 442 is shorter. Therefore, the hole 442 can be easily inserted into the fixing protrusion 152. In addition, the shorter fixing protrusion 152 increases the strength of the current sensor 40.

[0095] In addition, Figure 10 , Figure 11The diagram shows a method of fixing using the anti-detachment part 153, but a screw head 32 can also be used instead of part or all of the anti-detachment part 153. When the fixing screw 31 is used instead of the fixing protrusion 152, by providing one or more holes 442 in the thin plate parts 44A1 to 44A3 other than the thin plate part 44A4, the length of the hole 442 in the Z direction is shortened, thereby reducing the workload of fixing the magnetic shield 44A and the substrate 13 to the housing 15 and improving the fixing strength.

[0096] In addition, Figure 10 , Figure 11 In the middle, the cutout portion 443 is formed integrally at both ends of the Y direction, but it can also be formed only around the first reference portion (hole 442). By reducing the cutout area, the degradation of shielding performance can be suppressed.

[0097] (Modified example) Figure 12 as well as Figure 13 It is a schematic representation of as Figure 10 A cross-sectional view and a top view of the configuration of a modified current sensor 50, which is a current sensor 40.

[0098] The magnetic shielding 44A of the current sensor 50 shown in these figures differs from that of the current sensor 40 in that a hole 446 is formed in the thin plate members 44A2-44A4 instead of the cutout 443. In the current sensor 50, when viewed from the Z2 direction to the Z1 direction, a concave portion 447 is formed by the exposed portion 444 of the thin plate member 44A1 exposed from the hole 446 and the Y-direction end faces of the thin plate members 44A2-44A4.

[0099] The magnetic shield 44A of the current sensor 50 has holes 446 continuously formed from the thin plate members 44A4 to 44A2 along the stacking direction. The magnetic shield 44A and the substrate 13 are fixed to the housing 15 by contacting the exposed portion 444 of the thin plate member 44A4 exposed from the holes 446 with the anti-detachment portion 153.

[0100] When the hole 446 is formed on the thin plate members 44A2 to 44A4, similarly to the case where the cutout 443 is formed, an exposed portion 444 can be formed on the Z2 side of the large plate member furthest from the substrate 13, and a hole 442 penetrating the entire large plate member can be formed in the exposed portion 444. According to this configuration, compared to the case where the exposed portion 444 is formed on the thin plate member 44A4, the length of the hole 442 formed in the exposed portion 444 in the stacking direction is shorter. Therefore, the hole 442 can be easily inserted into the fixing protrusion 152, and the strength of the current sensor 50 is improved.

[0101] [Industrial Applicability] The present invention is useful, for example, as a current sensor for measuring the current flowing through a device in order to control a power system of a vehicle equipped with various devices.

[0102] Explanation of reference numerals in the attached figures 10 Current Sensor 11 busbars 12 Magnetic Sensors 13 substrate 13a side 13b Opposite surface 131 Card Section 132 holes 14A Magnetic Shielding 14Aa Opposite surface 14Ab side 14B Magnetic Shielding 141 Protrusion 142 holes 15. Housing 151 Storage Recess 152 Fixing protrusion 153 Anti-hair loss section 154 threaded hole 20 Current Sensor 24A Magnetic Shielding 24A1~24A4: Metal plates 24Aa Opposite surface 24Ab side 24B Magnetic Shielding 241 Stamped joint 242 holes 30 Current Sensor 31 Fixing screws 32 screw head 35 Current Sensor 40 Current Sensor 44A Magnetic Shielding 44A1~44A4: Thin-plate components 44Aa Opposite surface 44Ab side 442 holes 443 Incision site 444 Exposed area 445 Step section 446 Hole 447 Concave portion 50 Current Sensor 100 Current Sensor 101 busbar 102 Magnetic Sensor 103 substrate 104A and 104B magnetic shielding components 105 Housing 106 masks 110 Current Sensor 114A Magnetic Shielding 114A1 and 114A2 metal plates 114Aa Opposite surface 114Ab side 1141 Hole L: Straight line

Claims

1. A current sensor comprising: a busbar through which a measured current flows; a magnetic sensor disposed opposite the busbar for sensing a magnetic field emitted by the busbar; a substrate on which the magnetic sensor is disposed; a pair of flat first magnetic shielding members and a second magnetic shielding member sandwiching the busbar, the magnetic sensor, and the substrate; and a housing on which the busbar and the second magnetic shielding members are disposed, wherein the first magnetic shielding members, the substrate, and the housing are sequentially stacked, characterized in that... The first magnetic shielding member has a protrusion protruding from a first surface opposite to the substrate and a first reference portion for positioning. The substrate has an engaging portion that engages with the protrusion and a second reference portion for positioning. The housing has a third reference part for positioning. When the protrusion is engaged with the engaging portion, the first reference portion, the second reference portion, and the third reference portion are arranged on a straight line parallel to the stacking direction of the first magnetic shield, the substrate, and the housing.

2. The current sensor according to claim 1, characterized in that, The first magnetic shielding component is composed of multiple thin plate parts stacked together. The protrusion is a stamped joint formed by riveting multiple sheet metal components in the stacking direction.

3. The current sensor according to claim 2, characterized in that, The first reference portion is disposed in the first thin plate component adjacent to the substrate among the plurality of thin plate components of the first magnetic shield.

4. The current sensor according to claim 1, characterized in that, The protrusions and the engaging parts are provided in multiple pairs.

5. The current sensor according to claim 1, characterized in that, The first reference portion is a shielding hole that penetrates the first magnetic shielding component. The second reference portion is a substrate hole that penetrates the substrate. The third reference part is a fixing protrusion. The fixing protrusion has an anti-detachment part at its front end. With the fixing protrusion inserted through the shielding hole and the substrate hole, the first magnetic shield and the substrate are fixed to the housing by the anti-detachment part.

6. The current sensor according to claim 5, characterized in that, The first magnetic shielding component is composed of multiple thin plate parts stacked together. The anti-detachment portion contacts the exposed portion of the second surface of the thin plate component, which is the side opposite to the first surface of the substrate, on the thin plate component other than the second thin plate component, which has the largest distance from the stacking direction of the substrate.

7. The current sensor according to claim 6, characterized in that, When either of the thin plate components disposed between the first thin plate component and the second thin plate component adjacent to the substrate is designated as the third thin plate component, the first magnetic shielding member continuously forms holes or cutouts from the second thin plate component to the third thin plate component along the stacking direction, and the second surface exposed from the holes or cutouts is the exposed portion.

8. The current sensor according to claim 1, characterized in that, Equipped with fixing screws, The first reference portion is a shielding hole that penetrates the first magnetic shielding component. The second reference portion is a substrate hole that penetrates the substrate. The third reference part is a threaded hole that can be screwed into the fixing screw. With the fixing screw inserted through the shielding hole and the substrate hole. The first magnetic shield and the substrate are fixed to the housing by the screw head of the fixing screw.

9. The current sensor according to claim 8, characterized in that, The first magnetic shielding component is composed of multiple thin plate parts stacked together. The screw head contacts the exposed portion of the second surface of the sheet metal component, which is the largest in distance from the stacking direction of the substrate among the plurality of sheet metal components, on the opposite side of the first surface opposite the substrate.

10. The current sensor according to claim 9, characterized in that, When either of the thin plate components disposed between the first thin plate component and the second thin plate component adjacent to the substrate is designated as the third thin plate component, the first magnetic shielding member continuously forms holes or cutouts from the second thin plate component to the third thin plate component along the stacking direction, and the second surface exposed from the holes or cutouts is the exposed portion.

11. The current sensor according to claim 7 or 10, characterized in that, The first magnetic shielding member has a plurality of thin plate components stacked on top of each other. The first thin plate component adjacent to the substrate has an exposed portion on the second surface opposite to the first surface opposite to the substrate. The exposed portion forms part of a stepped portion or a concave portion.

Images