CURRENT SENSOR

Abstract

A current sensor 10 according to the present invention comprises a busbar 11, a magnetic sensor 12, a substrate 13 on which the magnetic sensor 12 is mounted, a pair of flat-plate magnetic shields 14A and 14B, and a housing 15 integrally formed with the busbar 11 and the magnetic shield 14B, wherein the magnetic shield 14A, the substrate 13, and the housing 15 are stacked in that order, wherein the magnetic shield 14A has a projection 141 extending from a surface 14Aa opposite the substrate 13, and a hole 142 in the substrate, wherein the substrate 13 has an engagement section 131 that can engage with the projection 141 and a positioning hole 132, wherein the housing 15 has a positioning projection 152, and wherein in a state in which the projection 141 and the engagement section 131 are interdependent,The holes 142 and 132 and the projection 152 are aligned in a straight line parallel to a stacking direction, so that when attaching the magnetic shield, which is designed as a separate part from the housing, to the substrate containing the magnetic detection unit, the magnetic shield can be easily positioned at a predetermined location on the substrate.

Description

Technical field

[0001] The present invention relates to a current sensor with a magnetic shield, wherein the current sensor measures the measured current flowing through a busbar. State of the art

[0002] In recent years, current sensors have been used to measure the current flowing through devices in order to control the power supply systems of vehicles and similar equipment using various devices. PTL 1 describes a current sensor with a pair of magnetic shielding plates enclosing a conductor and a magnetoelectric transducer element, with the aim of improving the accuracy of the current sensor while simultaneously reducing the space lost between the pair of magnetic shielding plates. The pair of magnetic shields in the current sensor described in PTL 1, together with a sensor substrate and a busbar, are integrally formed within a resin packaging as the housing.However, as with this current sensor, miniaturization, weight reduction, and cost reduction are difficult to achieve in a configuration where the magnetic shielding plate and the housing are formed as a single unit. PTL 2 describes a current sensor in which, for the purpose of high-precision current sensing, one of the two magnetic shields that shield external magnetic fields—specifically, the magnetic shield near the magnetic sensing unit with a magnetic sensing element—is attached to a printed circuit board by a mounting element. Citation list for patent literature PTL 1: International Publication No. 2016 / 148032 PTL2: Japanese unexamined patent application no. 2018-96793 Summary of the invention: Technical problem

[0003] The current sensor described in PTL 2 is more advantageous than the current sensor described in PTL 1 with regard to miniaturization, weight reduction, and cost reduction, because the magnetic shield installed near the magnetic sensing unit is configured as a component separate from the housing. In the current sensor described in PTL 2, the relative position between the magnetic shield and the circuit board with the magnetic sensing element is determined by inserting fasteners into the mounting holes provided at the four corners of the magnetic shield. Specifically, the mounting holes of the magnetic shield are aligned with the through-holes formed in the circuit board, and the fasteners are inserted there to secure the magnetic shield to the circuit board.In this way, the magnetic shield is positioned at the predetermined location on the printed circuit board using the hole position as a reference. Accordingly, the present invention provides a current sensor that can be easily positioned at a predetermined location on a substrate when a magnetic shield, configured as a component separate from the housing, is attached to the substrate provided with a magnetic sensing unit. Solution to the problem

[0004] To solve the above-mentioned problem, the present invention comprises the following configuration: a current sensor with a busbar through which a measured current flows, a magnetic sensor arranged opposite the busbar to detect a magnetic field generated by the busbar, a substrate on which the magnetic sensor is mounted, a pair of a flat-plate-like first magnetic shield and a flat-plate-like second magnetic shield, the pair enclosing the busbar, the magnetic sensor, and the substrate, and a housing in which the busbar and the second magnetic shield are provided, the first magnetic shield, the substrate, and the housing being stacked in that order, the first magnetic shield having a projection extending from a first surface opposite the substrate and a first reference section for positioning.wherein the substrate has an engagement section that can be brought into engagement with the projection and a second reference section for positioning, wherein the housing has a third reference section for positioning, and wherein, in a state in which the projection and the engagement section are engaged with each other, the first reference section, the second reference section, and the third reference section are aligned in a straight line parallel to a stacking direction of the first magnetic shield, the substrate, and the housing. Engaging the projection of the first magnetic shield with the engagement section of the substrate facilitates alignment between the first magnetic shield and the substrate.

[0005] The first magnetic shield can comprise a multitude of thin plate elements stacked on top of each other, with the protrusion being a press fit where the multitude of thin plate elements are crimped in one stacking direction. By using the press fit as a protrusion when crimping the first magnetic shield, which consists of a multitude of stacked thin plate elements, and by having the press fit engage in the substrate's engagement area, component processing costs and labor hours can be reduced, thereby lowering manufacturing costs.

[0006] The first reference section can be provided on a first thin plate element among the plurality of thin plate elements contained in the first magnetic shield, with the first thin plate element adjacent to the substrate. By providing the first reference section for positioning on the first thin plate element among the plurality of thin plate elements forming the first magnetic shield, it is easier to position the first magnetic shield at a predetermined location on the substrate compared to providing the first reference sections for positioning on all thin plate elements. For example, if the shielding hole penetrating the first magnetic shield is provided as the first reference section, the length of the shielding hole can be shortened by providing the shielding hole only on the first thin plate element. This allows for easy insertion of the fastener.Furthermore, since the length of the component is reduced, the strength for attaching the first magnetic shield is improved, which is advantageous for miniaturization and reduction of the height of the current sensor.

[0007] The protrusion and engagement section are provided in multiple pairs. By providing multiple pairs of protrusions and engagement sections, and by interlocking each pair, positioning between the first magnetic shield and the substrate is facilitated, and the positioned state can be maintained.

[0008] The first reference section can be a shielding hole penetrating the first magnetic shield, wherein the second reference section can be a substrate hole penetrating the substrate, wherein the third reference section can be a mounting projection, wherein the mounting projection can have an anti-slip section at a distal end of the mounting projection, and wherein, in a state where the mounting projection is inserted through the shielding hole and the substrate hole, the first magnetic shield and the substrate can be secured to the housing by the anti-slip section.Once the mounting protrusions are inserted through the shield hole and the substrate hole, it is possible to position the first magnetic shield, the substrate and the housing in their predetermined positions and secure them in a stacked state by attaching the first magnetic shield and the substrate to the housing with the anti-slip section.

[0009] The first magnetic shield can comprise a plurality of thin plate elements stacked together, wherein the anti-slip section can touch an exposed section of a thin plate element of the plurality of thin plate elements, wherein the thin plate element is other than a second thin plate element having the greatest distance from the substrate in the stacking direction, wherein the exposed section has a first surface facing the substrate and a second surface on the opposite side of the first surface, the second surface being exposed.

[0010] If a thin plate element arranged between a first thin plate element adjacent to the substrate and the second thin plate element is designated as a third thin plate element, the first magnetic shield may have a hole or cut-out section formed continuously along the stacking direction from the second thin plate element to the third thin plate element, the second surface exposed by the hole or cut-out section being the exposed section.

[0011] The current sensor can further comprise a mounting screw, wherein the first reference section can be a shielding hole penetrating the first magnetic shield, wherein the second reference section can be a substrate hole penetrating the substrate, wherein the third reference section can be a screw hole that can be threaded to engage with the mounting screw, and wherein the first magnetic shield and the substrate can be attached to the housing by a screw head of the mounting screw in a state in which the mounting screw is inserted through the shielding hole and the substrate hole.When the mounting screws are inserted through the shield hole and the substrate hole, the first magnetic shield and the substrate are secured to the housing by the screw head of the mounting screw, making it possible to stack and secure the first magnetic shield, the substrate, and the housing at a predetermined location.

[0012] The first magnetic shield can comprise a plurality of thin plate elements stacked together, wherein the screw head can touch an exposed section of one of the plurality of thin plate elements, the thin plate element being other than a second thin plate element having the greatest distance from the substrate in the stacking direction, the exposed section having a first surface facing the substrate and a second surface on the opposite side of the first surface, the second surface being exposed.

[0013] If a thin plate element arranged between a first thin plate element adjacent to the substrate and the second thin plate element is designated as a third thin plate element, the first magnetic shield may have a hole or cut-out section formed continuously along the stacking direction from the second thin plate element to the third thin plate element, the second surface exposed by the hole or cut-out section being the exposed section.

[0014] The first magnetic shield can comprise a plurality of thin plate elements stacked together, wherein a first thin plate element of the plurality of thin plate elements contained in the first magnetic shield, wherein the first thin plate element adjoins the substrate, can have an exposed section with a first surface facing the substrate and a second surface on the opposite side of the first surface, wherein the second surface is exposed and wherein the exposed section can form part of a step section or a recess section.

[0015] With the above configuration, the length of the mounting protrusion or screw is shorter than when the anti-slip section or screw head is positioned on the second face of the second thin plate element of the first magnetic shield. This facilitates stacking the first magnetic shield and allows for a more secure attachment of the first magnetic shield and the substrate to the housing. Advantageous effects of the invention

[0016] The present invention facilitates the alignment between the first magnetic shield and the substrate, making it possible to provide a current sensor which, when attaching the magnetic shield, configured as a part separate from the housing, to the substrate comprising a magnetic sensing unit, can be easily positioned at a predetermined location on the substrate. Brief description of the drawings [ Fig. 1] Fig. Figure 1 is a perspective view that schematically shows the appearance of the current sensor according to the first embodiment. [ Fig. 2] Fig. Figure 2 is a schematic cross-sectional view showing the configuration of the main part of the current sensor along line AA. Fig. 1 shows. [ Fig. 3] Fig. 3 is a schematic cross-sectional view showing the configuration of a modification of the in Fig. The current sensor shown is shown in the 2nd image. [ Fig. 4] Fig. 4 is a top view of the in Fig. 3 current sensors shown. [ Fig. 5] Fig. Figure 5 is an explanatory diagram of the structure of a magnetic shield with a stacked structure according to the state of the art. [ Fig. 6] Fig. Figure 6 is an explanatory diagram of the structure of the magnetic shielding with a stacked structure in the current sensor of the present invention. [ Fig. 7] Fig. 7 is a schematic cross-sectional view showing the configuration of a further modification of the in Fig. The current sensor shown is shown in the 2nd image. [ Fig. 8] Fig. 8 is a schematic cross-sectional view showing the configuration of a further modification of the in Fig. The current sensor shown is shown in the 2nd image. [ Fig. 9] Fig. Figure 9 is a schematic top view showing the configuration of the current sensor. Fig. 8 shows. [ Fig. 10] Fig. Figure 10 is a schematic cross-sectional view showing the configuration of the current sensor according to the second embodiment. [ Fig. 11] Fig. Figure 11 is a schematic top view showing the configuration of the current sensor according to the second embodiment. [ Fig. 12] Fig. 12 is a schematic cross-sectional view showing the configuration of a modification of the in Fig. The current sensor shown in the 10 images is shown. [ Fig. 13] Fig. Figure 13 is a schematic top view showing the configuration of the current sensor. Fig. 12 shows. [ Fig. 14] Fig. Figure 14 is a schematic cross-sectional view showing the configuration of a state-of-the-art current sensor. [ Fig. 15] Fig. Figure 15 is a schematic cross-sectional view showing the configuration of a current sensor without a cover. Description of the embodiments: First embodiment

[0017] The following describes embodiments of the present invention with reference to the accompanying drawings. Identical components are assigned the same part numbers in each drawing, and explanations are omitted where necessary. To indicate the positional relationship between the respective components, reference coordinates are provided in each drawing where appropriate. In the reference coordinates, the direction in the lateral extent of the busbar is defined as the X-direction (third direction), the direction of the extent of the busbar perpendicular to the X-direction is defined as the Y-direction (second direction), and the stacking direction in which the busbar and the magnetic sensor are stacked, perpendicular to both the X-direction and the Y-direction, 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 direction and the Z direction are perpendicular to the sensitivity axis.

[0018] Fig. Figure 14 is a schematic cross-sectional view showing the configuration of a prior art current sensor 100. The current sensor 100 shown in the figure comprises a pair of parallel, plate-shaped magnetic shields 104A and 104B enclosing a busbar 101, through which the measured current flows, and a magnetic sensor 102 provided on a substrate 103. The magnetic shield 104A is injection-molded into a cover 106, and the magnetic shield 104B is injection-molded into a housing 105. Therefore, in a configuration comprising the housing 105 and the cover 106, with the magnetic shields 104B and 104A being injection-molded into the housing 105 and the cover 106 respectively, it is difficult to miniaturize and thin the current sensor 100, which is disadvantageous with regard to cost reduction.Therefore, one aspect of the implementation of the present invention is described below as a current sensor which does not include a cover 106 that holds the magnetic shield 104A, wherein the current sensor offers advantages in terms of miniaturization, thinness and low cost.

[0019] Fig. Figure 15 is a schematic cross-sectional view showing the configuration of a current sensor 110 without a cover. Since the current sensor 110 shown in the figure does not include a cover, the magnetic shield 104A of the pair of magnetic shields 104A and 104B is provided directly on the substrate 103. Therefore, if the magnetic shield 104A is placed directly on the substrate 103, with the magnetic shield located close to the magnetic sensor 102 relative to the busbar 101, it is difficult to position the magnetic shield 104A at a predetermined location on the substrate 103. Therefore, the current sensor of the present invention has a configuration with which the position of the magnetic shield 104A relative to the substrate 103 can be determined stably, easily, and accurately. Embodiments of the current sensor of the present invention are described below.

[0020] Fig. Figure 1 is a perspective view that schematically shows the appearance of the current sensor 10 according to the present embodiment. Fig. Figure 2 is a schematic cross-sectional view showing the configuration of the main part of the current sensor 10 along line AA in Fig. Figure 1 shows the current sensor 10 comprising a busbar 11, a magnetic sensor 12, a substrate 13, a pair of a flat-plate magnetic shield 14A (first magnetic shield) and a flat-plate magnetic shield 14B (second magnetic shield), and a housing 15. The magnetic shield 14A, the substrate 13, the magnetic sensor 12, the busbar 11, and the magnetic shield 14B are stacked in this order in the direction from Z2 to Z1, with the busbar 11 and the magnetic shield 14B being located inside the housing 15.

[0021] The busbar 11 is a conductor shaped like a plate through which the measured current flows and is made of a material such as copper, brass, or aluminum. The magnetic sensor 12 detects the magnetic field generated by the busbar 11 when the measured current flows and is attached to a Z1 side face 13a of the substrate 13, with the face 13a opposite the busbar 11 in the Z direction. The sensing surface of the magnetic sensor 12 is opposite the busbar 11, and the sensitivity axis is aligned parallel to the sensing surface. The induced magnetic field generated when the measured current flows through the busbar 11 near the sensing surface of the magnetic sensor 12 contains a large number of components in the X direction.By positioning the magnetic sensor 12 so that the sensitivity axis is parallel to the X direction, the magnetic field generated by the busbar 11 can be detected with high accuracy.

[0022] A magnetoresistive element, a Hall effect sensor, or a similar device can be used as the sensing element of the magnetic sensor 12. It should be noted that the configuration above shows an example where the magnetoresistive element is used as the sensing element of the magnetic sensor 12. If a different sensing element is used, the orientation and position of the sensing surface must be adjusted accordingly.

[0023] The magnetic shields 14A and 14B are arranged to enclose the busbar 11, the magnetic sensor 12, and the substrate 13 in the Z-direction and consist of metal plate-like bodies or the like. The magnetic shields 14A and 14B suppress magnetic interference that affects the magnetic sensor 12 and thereby improve the measurement accuracy of the current sensor 10.

[0024] The housing 15 can, for example, be integrally formed with the busbar 11 and the magnetic shield 14B using insert technology. Alternatively, the busbar 11 can be inserted into the housing 15 after the magnetic shield 14B has been integrally cast into the housing 15 using insert technology.

[0025] The magnetic shield 14A comprises a projection 141 that extends from a counter surface 14Aa (first surface), the counter surface 14Aa being opposite the substrate 13. Additionally, the magnetic shield 14A has a hole 142 (shielding hole) as its first reference section, which penetrates in the Z-direction and through which a fastening projection 152, described later, can be inserted.

[0026] The substrate 13 comprises an engagement section 131 that can engage with the projection 141 on a counter surface 13b opposite the magnetic shield 14A on the Z2 side, wherein the counter surface 13b is opposite the surface 13a on which the magnetic sensor 12 is mounted. The engagement section 131 only needs to be able to engage with the projection 141, so that, instead of a hole extending through in the Z direction, the engagement section 131 can, for example, also be designed as a recess not extending through in the Z direction, which corresponds to the shape of the projection 141.

[0027] The interlocking of the projection 141 of the magnetic shield 14A with the engagement section 131 of the substrate 13 facilitates the determination of the relative positional relationship between the magnetic shield 14A and the substrate 13. In particular, by fitting the projection 141 into the engagement section 131, the magnetic shield 14A and the substrate 13 can be easily aligned.

[0028] To ensure reliable and easy alignment, it is, as in Fig. As shown in Figure 2, it is advantageous that the current sensor 10 comprises a plurality of pairs of the projection 141 and the engagement section 131. By providing a plurality of pairs of the projection 141 and the engagement section 131 and the interlocking of the respective pairs, the positioning between the magnetic shield 14A and the substrate 13 is facilitated and the aligned state can be reliably maintained.

[0029] As a second reference section for positioning, the substrate 13 has a hole 132 that penetrates in the Z-direction and through which the mounting projection 152, described later, can be inserted. By engaging the projection 141 with the engagement section 131, the magnetic shield 14A is positioned at a predetermined location on the substrate 13, thereby aligning the hole 142 of the magnetic shield 14A with the hole 132 (substrate hole) of the substrate 13. In particular, viewed in the Z-direction, the hole 142 of the magnetic shield 14A and the hole 132 of the substrate 13 can be aligned to form a through hole.

[0030] The housing 15, made of resin and other materials, is integrally formed with the injection-molded busbar 11 and the injection-molded magnetic shield 14B. The housing 15 has a storage recess 151 opposite the substrate 13. Furthermore, a mounting projection 152 is provided within the storage recess 151, which projects forward as a third reference section for positioning in the Z2 direction.

[0031] By engaging the projection 141 with the engagement section 131, the hole 142 is aligned with the hole 132 when viewed in the Z direction. Therefore, the fastening projection 152 can easily be inserted into the hole 142 and the hole 132 as a third reference section.

[0032] The insertion of the mounting projection 152 defines the positional relationship between the magnetic shield 14A, the substrate 13, and the housing 15. In this state, the hole 142, the hole 132, and the mounting projection 152 are arranged along a straight line L parallel to the stacking direction (Z-direction) of the magnetic shield 14A, the substrate 13, and the housing 15.

[0033] In a state where the mounting projection 152 is inserted through the holes 142 and 132, the magnetic shield 14A and the substrate 13 are secured to the housing 15 by an anti-slip section 153 provided at the Z2-side end (distal end) of the mounting projection 152. The anti-slip section 153 is formed, for example, by hot-flashing the Z2-side end (distal end) of the mounting projection 152 after the mounting projection 152 has been inserted through the holes 142 and 132.

[0034] The anti-slip section 153 has an outer dimension that, viewed in the Z direction, is larger than the respective inner diameters of the hole 142 and the hole 132. Furthermore, the anti-slip section 153 is in close contact with a Z2-side surface 14Ab of the magnetic shield 14A. Therefore, the anti-slip section 153 acts as a retaining element that holds the magnetic shield 14A and the substrate 13 at a predetermined position within the housing 15.

[0035] The positional relationship between the magnetic shield 14A, the substrate 13 and the housing 15 is determined by the anti-slip section 153, wherein the magnetic sensor 12 is positioned on the substrate 13 at a position opposite the busbar 11 within the storage recess 151.

[0036] As described above, the relative positions of the magnetic shield 14A, the substrate 13, and the housing 15 can be determined in the current sensor 10, with the magnetic shield 14A, the substrate 13, the busbar 11, and the magnetic shield 14B being stacked in that order in the direction from Z2 to Z1. By fixing the substrate 13 and the magnetic shield 14A in their predetermined positions with the housing 15 as a reference, misalignment of the positions of the busbar 11, the magnetic shield 14A, and the magnetic shield 14B relative to the magnetic sensor 12 provided on the substrate 13 can be prevented. This provides a current sensor 10 with excellent measurement accuracy, in which errors due to positional errors are suppressed. modification

[0037] Fig. 3 and Fig. Figure 4 shows a cross-sectional view and a top view, respectively, which schematically show the configuration of a current sensor 20, which is a modification of the current sensor 10. Fig. Figure 2 represents the current sensor 20 shown in these figures, which differs from the current sensor 10 shown in Figure 2. Fig. 2 by the fact that the current sensor 20 comprises magnetic shields 24A and 24B, each consisting of a plurality of identically shaped, stacked metal plate-like bodies, instead of magnetic shields 14A and 14B, each consisting of a single metal plate-like body.

[0038] Before the magnetic shield 24A of the current sensor 20 is described, the structure of a magnetic shield 114A with a typical stacked structure according to the state of the art is described. Fig. Figure 5 is an explanatory diagram of the structure of the magnetic shield 114A with a stacked structure according to the prior art. As in (a) of Fig. As shown in Figure 5, the magnetic shield 114A has a structure in which a large number of metal plates are stacked and crimped by punching from the top (Z2 side). (b) of Fig. Figure 5 shows the cross-sectional structure of the section along line BB in (a) of Fig. 5.

[0039] By simply stacking a large number of metal plates and crimping them together by punching, a shape such as the projection 141 of the magnetic shield 14A, shown in the first embodiment, is created. If there are deviations in the size of the projection or the shape of such sections, the problem can arise that the sections tilt even when arranged on a flat surface.

[0040] In the case of magnetic shielding 114A with a stacked structure according to the state of the art, as in (b) of Fig. As shown in Figure 5, a hole 1141 is provided in a metal plate 114A1 located on the underside (Z1 side). Viewed in the Z direction, the section overlapping the hole 1141 is punched out from an upper surface 114Ab, flanging the metal plates 114A1 to 114A4. At this point, the projection of the metal plate 114A2 adjacent to the metal plate 114A1 is pressed into the hole 1141. This prevents the formation of the projection that extends from a lower counter surface 114Aa of the magnetic shield 114A, as indicated by the single-dot line.

[0041] Fig. Figure 6 is an explanatory diagram of the structure of the magnetic shield 24A, which has the stacked structure of the current sensor 20. As shown in (a) of Fig. Figure 6 shows the magnetic shielding 24A combined with the magnetic shielding 114A according to the state of the art. Fig. 5 identical insofar as the magnetic shielding 24A is formed by stacking a large number of metal plates and crimping them by punching from the top (Z2 side).

[0042] However, as shown in the cross-sectional view of (b) in Fig. As shown in Figure 6, the lowest metal plate 24A1 in the magnetic shield 24A has no hole at the crimped point shown in (a) in Fig. 6 is marked with line BB. Therefore, on all metal plates 24A1 to 24A4, a recess is formed on the upper surface 24Ab of the flanged section, and a projection is formed on the counter surface 24Aa opposite the lower substrate 13. A press fit 241, which protrudes from the lower counter surface 24Aa (indicated by the single-dot line) and is formed during flange forming with a punch, is used to align the magnetic shield 24A with the substrate 13. In particular, the press fit 241 of the magnetic shield 24A, which is flanged in the stacking direction, is used as a projection to engage with the engagement section 131 of the substrate 13.

[0043] As described above, in the magnetic shield 24A, a portion of the press fit 241 required for processing is used as a projection that extends from the mating surface 24Aa opposite the substrate 13 of the magnetic shield 24B and engages with the engagement section 131 of the substrate 13. In this way, using the press fit 241 as a projection facilitates alignment between the magnetic shield 24A and the substrate 13, and it is possible to reduce the machining costs of the components and labor hours, thereby lowering the manufacturing costs of the magnetic shield 24A. Furthermore, the magnetic shield 24B can have a structure with a projection on one side, as in the magnetic shield 24A, or a structure without a projection, as in the prior art magnetic shield 114A.

[0044] Fig. Figure 7 is a schematic cross-sectional view of the current sensor 30 as a further modification of the current sensor 20. Fig. 3. The current sensor 30 differs from the current sensor 10 in that the current sensor 30 includes a mounting screw 31 and the housing 15 has a screw hole 154 as a third reference section that can engage with the mounting screw 31. Furthermore, viewed in the Z direction, the inner diameters of a hole 242 (first shielding hole) and of the hole 132 are larger than the threaded section of the mounting screw 31 and smaller than the outer diameter of the screw head 32.

[0045] In the current sensor 30, the magnetic shield 24A and the substrate 13 are attached to the housing 15 by the screw head 32 of the fastening screw 31, the fastening screw 31 being inserted through the hole 242 and the hole 132. This allows the magnetic shield 24A, the substrate 13, and the housing 15 to be attached in a stacked state at a predetermined location, with the fastening screw 31 serving as a retaining element.

[0046] Fig. 8 and Fig. Figure 9 shows a cross-sectional view or a top view, schematically illustrating the appearance of the current sensor 35 as a further modification of the current sensor 20. Fig. 3 show. 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 fastened with two mounting projections 152 and two mounting screws 31.

[0047] As with the current sensor 35, other fasteners can also be used to secure the magnetic shield 24A, the substrate 13, and the housing 15. The various fasteners can be arranged in combinations and configurations that differ from those shown in Fig. The configurations shown in Figure 9 differ. For example, one fastening projection 152 can be combined with three fastening screws 31, or three fastening projections 152 can be combined with one fastening screw 31. Alternatively, the configuration can include the anti-slip section 153, which is provided at the distal ends of all or some of the fastening projections 152. Fig. Figure 9 shows an example where the magnetic shield 24A has four fasteners, but the number of fasteners is not limited to four, but can be, for example, two, three or five or more. Second embodiment

[0048] Fig. 10 and Fig. Figure 11 shows a cross-sectional view and a top view, respectively, schematically illustrating the configuration of a current sensor 40 of the present embodiment. As shown in Fig. 10 and Fig. As shown in Figure 11, the current sensor 40 differs from the current sensor 20. Fig. 3 by the fact that the current sensor 40 includes a magnetic shield 44A instead of the magnetic shield 24A.

[0049] The magnetic shield 44A has a hole 442 as a first reference section, which is provided only in a thin plate element 44A1 (first thin plate element) adjacent to the substrate 13, among the plurality of thin plate elements 44A1, 44A2, 44A3 and 44A4 of the magnetic shield 44A.

[0050] In other words, when a plurality of thin plate elements 44A1, 44A2, 44A3, and 44A4 are viewed from the Z2 side, the thin plate element 44A1 has an exposed section 444 that projects beyond the thin plate elements 44A2, 44A3, and 44A4, and has the hole 442 in the exposed section 444. Furthermore, when the Z2 side is viewed as the top, the exposed section 444 is located below (the Z1 side) the top of the thin plate element 44A4 and forms a step section 445.

[0051] By forming the hole 442 in the exposed section 444 of the thin plate element 44A1, the anti-slip section 153 can be positioned on the stepped section 445. This allows the projection of the anti-slip section 153 relative to the top of the thin plate element 44A4 to be reduced compared to the case where the anti-slip section 153 is positioned on the top of the thin plate element 44A4. That is, miniaturization and a reduction in height in the Z-direction can be achieved.

[0052] Furthermore, the formation of the hole 442 in the exposed section 444 of the thin plate element 44A1 reduces the depth of the hole 442 in the stacking direction. This makes it easier to fit the mounting projection 152 into the hole 442. Additionally, the length of the mounting projection 152 is shorter in the Z-direction, thus improving its strength. By fitting the mounting projection 152 of the housing 15 into the hole 442 of the magnetic shield 44A and the hole 132 of the substrate 13, and subsequently securing the magnetic shield 44A and the substrate 13, the magnetic shield 44A and the substrate 13 can therefore be more securely attached to the housing 15.

[0053] The in Fig. Figure 10 shows a magnetic shield 44A with a cut-out section 443 that extends continuously from the thin plate element 44A4 (second thin plate element) furthest from the substrate 13 in the stacking direction (Z-direction) to the thin plate element 44A2 (third thin plate element), which adjoins the thin plate element 44A1, beneath the thin plate elements 44A1 to 44A4. Specifically, the thin plate elements 44A2 to 44A4, with the exception of the thin plate element 44A1, have the cut-out section 443, and, viewed from the surface 44Ab (second surface) of the magnetic shield 44A, the exposed section 444 of the thin plate element 44A1 has the holes 442.

[0054] As described above, the magnetic shield 44A has the hole or cut-out section 443, which is formed continuously from the thin plate element 44A4 to the thin plate element 44A2 along the stacking direction (Z-direction) under the thin plate elements 44A2 and 44A3 (third thin plate element), which are arranged between the thin plate element 44A1 (first thin plate element) and the thin plate element 44A4 (second thin plate element). Viewed from the Z2 to Z1 direction, the area 44Ab exposed by the cut-out section 443 is the exposed section 444.

[0055] In the magnetic shield 44A, only the thin plate element 44A1, which serves as the first thin plate element, has the hole 442 as the first reference section, and the step section 445 is formed by the exposed section 444 of the thin plate element 44A1 and the end faces in the Y direction of the thin plate elements 44A2 to 44A4. In particular, a section of the step section 445 is formed by the exposed section 444.

[0056] As in Fig. As shown in Figure 11, the anti-slip section 153, viewed in the Z-direction, touches the exposed section 444, which is exposed, and the anti-slip section 153 holds the magnetic shield 44A and the substrate 13 with the exposed section 444 as a holding surface. In this way, the magnetic shield 44A can be fixed in the predetermined position within the housing 15.

[0057] In the Fig. 10 and Fig. In the current sensor 40 shown in Figure 11, viewed in the stacking direction of the magnetic shield 44A, the thin plate element 44A1, which is in contact with the substrate 13, is larger than the other thin plate elements 44A2 to 44A4. And the hole 442 (shield hole), as the first reference section, is formed in the exposed section 444 of the thin plate element 44A1, which projects beyond the other thin plate elements 44A2 to 44A4.

[0058] In Fig. 10. The thin plate elements 44A2 to 44A4 have the same shape and size and are each formed with a shape that differs from that of the thin plate element 44A1. However, this is not limited to this configuration. For example, the thin plate element 44A2 may have the same shape and size as the thin plate element 44A1, while the thin plate elements 44A3 to 44A4 may have shapes that differ from those of the thin plate element 44A1. Now, looking from the direction Z2 to Z1, a section projecting beyond the thin plate elements 44A3 to 44A4 on the surface on the Z2 side of the thin plate element 44A2 may be the exposed section 444, and the hole 442 may penetrate the thin plate elements 44A2 and 44A1.

[0059] That is, if a plurality of thin plate elements (large plate elements), including the thin plate element 44A1, of identical shape and size are continuously stacked and have a section extending beyond the remaining thin plate elements (small plate elements), including the thin plate element 44A4, the thin plate elements may have the exposed section 444 on the surface on the Z2 side of the large plate element furthest from the substrate 13, and the exposed section 444 may have the hole 442 penetrating all the large plate elements.

[0060] According to this configuration, each of the thin plate elements 44A1 to 44A3 is exposed beneath the thin plate elements 44A1 to 44A4 when viewed in the stacking direction. Specifically, one thin plate element other than thin plate element 44A4, which is furthest from the substrate 13 in the stacking direction, has the exposed section 444, which is exposed at surface 44Ab on the opposite side of a counter surface 44Aa facing the substrate 13. The magnetic shield 44A, the substrate 13, and the housing 15 are fixed when the anti-slip section 153 contacts the exposed section 444.

[0061] Furthermore, the hole 442 is short compared to the case where the thin plate element 44A4 has the exposed section 444. Therefore, the mounting projection 152 can easily be fitted into the hole 442. Additionally, the mounting projection 152 is shorter, and the strength of the current sensor 40 is improved.

[0062] It should be noted that the Fig. 10 and Fig. Figure 11 shows an aspect where the fastening is carried out using the anti-slip section 153, but the screw head 32 can be used instead of part or all of the anti-slip section 153. If the fastening screw 31 is used instead of the fastening projection 152, by providing the hole 442 in one or a plurality of thin plate elements 44A1 to 44A3, which are not the thin plate element 44A4, the length of the hole 442 in the Z-direction is shortened, so that it is possible to reduce the load when fastening the magnetic shield 44A and the substrate 13 to the housing 15 and to improve the fastening strength.

[0063] Furthermore, in Fig. 10 and Fig. 11. The cut-out section 443 extends over the entire length of both ends in the Y-direction, but can also be formed only around the first reference section (hole 442). Reducing the cut-out area can prevent a deterioration in shielding performance. modification

[0064] Fig. 12 and Fig. Figure 13 shows a cross-sectional view or a top view, which schematically illustrates the configuration of a current sensor 50 as a modification of the current sensor 40. Fig.Figure 10 shows the magnetic shield 44A of the current sensor 50 shown in these figures. The magnetic shield 44A of the current sensor 50 shown in these figures differs from that of the current sensor 40 in that the thin plate elements 44A2 to 44A4 have a hole 446 instead of the cut-out section 443. Viewed from direction Z2 towards Z1, the current sensor 50 has a recessed section 447 defined by the exposed section 444 of the thin plate element 44A1, the exposed section 444 being exposed by the hole 446 and the end faces of the thin plate elements 44A2 to 44A4 in the Y direction.

[0065] The magnetic shield 44A of the current sensor 50 has the hole 446, which is formed continuously along the stacking direction from the thin plate element 44A4 to the thin plate element 44A2. The magnetic shield 44A and the substrate 13 are attached to the housing 15 by the anti-slip section 153 being in contact with the exposed section 444 of the thin plate element 44A4, the exposed section 444 protruding from the hole 446.

[0066] As in the case where the thin plate elements 44A2 to 44A4 have the cut-out section 443, if the thin plate elements 44A2 to 44A4 have the hole 446, the surface on the Z2 side of the large plate element furthest from the substrate 13 can have the exposed section 444, and the exposed section 444 can have the hole 442 that penetrates all the large plate elements. This configuration results in a shorter length of the hole 442 in the stacking direction formed in the exposed section 444, compared to the case where the thin plate element 44A4 has the exposed section 444. Therefore, the mounting projection 152 can be easily fitted into the hole 442, thereby increasing the strength of the current sensor 50. Industrial applicability

[0067] The present invention is useful as a current sensor for measuring the measured current flowing through devices, for example to control the power supply system of vehicles and the like, which comprise various devices. Reference symbol list 10 Current sensor 11 Busbar 12 Magnetic sensor 13 Substrat 13a Area 13b Opposite surface 131 Intervention section 132 holes 14A magnetic shielding 14Aa Opposite surface 14Ab area 14B magnetic shielding 141 lead 142 holes 15 cases 151 Storage recess 152 Mounting projection 153 Anti-slip section 154 screw holes 20 Current sensor 24A magnetic shielding 24A1 to 24A4 metal plates 24Aa Counter surface 24Ab area 24B magnetic shielding 241 Press connection 242 holes 30 Current sensor 31 Mounting screw 32 screw head 35 Current sensor 40 Current sensor 44A magnetic shielding 44A1 to 44A4 thin plate elements 44Aa Opposite surface 44Ab area 442 holes 443 cut-out section 444 exposed section 445 Step section 446 holes 447 Recess section 50 current sensor 100 current sensor 101 Busbar 102 Magnetic sensor 103 Substrat 104A, 104B magnetic shielding 105 cases 106 Coverage 110 Current sensor 114A magnetic shielding 114A1, 114A2 Metal plate 114Aa Counter surface 114Ab area 1141 holes L straight line QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2018

[0002] JP 96793

[0002]

Claims

A current sensor comprising: a busbar through which a measured current flows; a magnetic sensor arranged to face the busbar in order to detect a magnetic field generated by the busbar; a substrate on which the magnetic sensor is mounted; a pair of a flat-plate-like first magnetic shield and a flat-plate-like second magnetic shield, the pair enclosing the busbar, the magnetic sensor and the substrate;and a housing in which the busbar and the second magnetic shield are provided, wherein the first magnetic shield, the substrate and the housing are stacked in this order, wherein the first magnetic shield has a projection extending from a first surface opposite the substrate and a first reference section for positioning, wherein the substrate has an engagement section that can be engaged with the projection and a second reference section for positioning, wherein the housing has a third reference section for positioning, and wherein, in a state in which the projection and the engagement section are engaged with each other, the first reference section, the second reference section and the third reference section are aligned in a straight line parallel to a stacking direction of the first magnetic shield, the substrate and the housing. The current sensor according to claim 1, wherein the first magnetic shield comprises a plurality of thin plate elements stacked on top of each other, and wherein the projection is a press fit in which the plurality of thin plate elements are crimped in a stacking direction. The current sensor according to claim 2, wherein a first thin plate element of the plurality of thin plate elements contained in the first magnetic shield, wherein the first thin plate element adjoins the substrate, has the first reference section. The current sensor according to claim 1, wherein the projection and the engagement section are provided in a plurality of pairs. The current sensor according to claim 1, wherein the first reference section is a shielding hole penetrating the first magnetic shield, wherein the second reference section is a substrate hole penetrating the substrate, wherein the third reference section is a mounting projection, wherein the mounting projection has an anti-slip section at a distal end of the mounting projection, and wherein, in a state in which the mounting projection is inserted through the shielding hole and the substrate hole, the first magnetic shield and the substrate are secured to the housing by the anti-slip section. The current sensor according to claim 5, wherein the first magnetic shield comprises a plurality of thin plate elements stacked on top of each other, and wherein the anti-slip section touches an exposed section of a thin plate element of the plurality of thin plate elements, wherein the thin plate element is other than a second thin plate element having the greatest distance from the substrate in the stacking direction, wherein the exposed section has a first surface facing the substrate and a second surface on the opposite side of the first surface, the second surface being exposed. The current sensor according to claim 6, wherein, if a thin plate element arranged between a first thin plate element adjacent to the substrate and the second thin plate element is designated as a third thin plate element, the first magnetic shield has a hole or a cut-out section formed continuously along the stacking direction from the second thin plate element to the third thin plate element, and the second surface exposed by the hole or cut-out section is the exposed section. The current sensor according to claim 1, further comprising: a fastening screw, wherein the first reference section is a shielding hole penetrating the first magnetic shield, wherein the second reference section is a substrate hole penetrating the substrate, wherein the third reference section is a screw hole that can be threaded to engage with the fastening screw, and wherein, in a state in which the fastening screw is inserted through the shielding hole and the substrate hole, the first magnetic shield and the substrate are fastened to the housing by a screw head of the fastening screw. The current sensor according to claim 8, wherein the first magnetic shield comprises a plurality of thin plate elements stacked on top of each other, and wherein the screw head contacts an exposed section of a thin plate element of the plurality of thin plate elements, wherein the thin plate element is other than a second thin plate element having the greatest distance from the substrate in the stacking direction, wherein the exposed section has a first surface facing the substrate and a second surface on the opposite side of the first surface, the second surface being exposed. The current sensor according to claim 9, wherein, if a thin plate element arranged between a first thin plate element adjacent to the substrate and the second thin plate element is designated as a third thin plate element, the first magnetic shield has a hole or a cut-out section formed continuously along the stacking direction from the second thin plate element to the third thin plate element, and the second surface exposed by the hole or cut-out section is the exposed section. The current sensor according to claim 7 or 10, wherein the first magnetic shield comprises a plurality of thin plate elements stacked on top of each other, and a first thin plate element of the plurality of thin plate elements contained in the first magnetic shield, wherein the first thin plate element adjoins the substrate, has an exposed section with a first surface facing the substrate and a second surface on the opposite side of the first surface, wherein the second surface is exposed, and wherein the exposed section forms part of a step section or a recess section.

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