Current detection device

Abstract

The current detection device of the present application has: a bus bar through which a measured current flows; a fastening member for fastening an external member to the bus bar; a frame that holds the bus bar and the fastening member in contact with each other; and a magnetic sensor disposed opposite the bus bar and capable of detecting a magnetic field generated by the measured current flowing through the bus bar. The bus bar has a fastening terminal portion at an end portion thereof that contacts the external member, and a connecting surface of the fastening terminal portion that contacts the external member is exposed from the frame. The fastening terminal portion has an anchoring portion having a surface different from the connecting surface and embedded in the frame, and thus has a frame integrated with the bus bar and the shield, so that the measurement accuracy is not easily reduced.

Description

Technical Field

[0001] This invention relates to a current detection device that measures the current based on the magnetic field generated by the current flowing in a busbar. Background Technology

[0002] From the viewpoint of improving the measurement accuracy of current detection devices, it is required to manage the positional relationship between the magnetic sensor and the shield and the busbar with high precision. As a current detection device that is integrally formed with the busbar and the shield and a frame made of resin, and in which the magnetic sensor is arranged inside the frame, a busbar module as described in Patent Document 1 has been proposed, for example.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-1168 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the busbar module described in Patent Document 1, during the molding of the frame, the busbar may deviate from its designed position due to the influence of flowing resin, or the resin may not be properly filled (short mold), or the bent busbar may deform due to springback. Such defects can cause the busbar, magnetic sensor, and shielding to deviate from their specified positional relationships, potentially affecting the measurement accuracy.

[0008] Therefore, the object of the present invention is to provide a current detection device having a frame integrated with the busbar and the shield, and whose measurement accuracy is not easily reduced.

[0009] The current detection device employs a structure in which a magnetic sensor is positioned opposite the busbar. Furthermore, the busbar has a fastening connection surface at its end, with a through hole for fastening an external terminal. This fastening connection surface is positioned overlapping the frame, and its back surface contacts a nut embedded in the frame. By inserting a bolt into the external terminal and screwing it into the through hole on the fastening connection surface with the nut, the busbar and the external terminal are securely connected.

[0010] In current sensing devices, a portion of the fastening connection surface of the busbar has a recess, and an extension of the recess is embedded in the resin of the frame. The fastening connection surface of the busbar protrudes more than the resin constituting the extension. By providing the extension, it is possible to prevent the busbar from floating relative to the nut due to springback. If the busbar floats, the amount by which the busbar is pressed up when the external terminal is fastened to the fastening connection surface with bolts can sometimes cause a deviation in the positional relationship between the busbar and the magnetic sensor. Therefore, the extension is an effective means of suppressing the reduction in measurement accuracy.

[0011] However, when the resin surface of the protrusion and the fastening connection surface are set to the same height, during the integral molding of the busbar and the frame, the resin forming the frame may flow to the fastening connection surface of the busbar due to deviations in molding conditions, etc. If the resin flows to the fastening connection surface and covers a part of the fastening connection surface, the electrical connection between the external terminal and the busbar will be damaged when the external terminal is fastened to the fastening connection surface.

[0012] Therefore, another object of the present invention is to provide a current detection device in which the electrical contact stability of the fastening connection surface is improved and the measurement accuracy is not easily reduced in a structure in which the recess of the fastening connection surface with the busbar is embedded in the resin of the frame.

[0013] In conventional current detection devices, locating pins are used to fix the shielding insert within the mold when it is formed into the frame. Therefore, a hole-like locating pin mark is formed at the location of the locating pin in the formed frame, and a portion of the shielding is exposed inside the hole. If the side of the shielding is used as the part that engages with the locating pin, this side is exposed in the hole. The shielding is manufactured by stamping a sheet metal to create its shape. That is, the side of the shielding is a fracture surface (cut surface) and is not surface-treated. Therefore, if the side of the shielding is exposed inside the hole, it may corrode from the side. If corrosion occurs, it will affect the magnetic properties of the shielding and may reduce the measurement accuracy.

[0014] Therefore, another object of the present invention is to provide a current detection device in which a shielding insert is formed in a frame structure, thereby suppressing corrosion by forming a structure that does not expose the side surface or fracture surface of the shielding, thus ensuring the measurement accuracy of the shielding.

[0015] Furthermore, in structures where the shielding insert is molded into the frame, the shielding material, made of metal, and the frame, made of resin, have different coefficients of thermal expansion. Metal has a higher coefficient of thermal expansion, so the shielding tends to expand more significantly when heated. Therefore, due to the larger expansion of the shielding, the portion of the frame in contact with the shielding (the molded resin portion) is stretched by more than the expansion amount of the molded resin portion in the direction of shielding expansion, thus applying stress to the molded resin portion. When a cross-section of the frame is cut along the stacking direction of the molded resin portion and the shielding, near the center of the shielding, the shielding and the molded resin portion form a layer, and the difference in their coefficients of thermal expansion has a significant impact, resulting in greater stress on the molded resin portion. When a locating pin is used to position the shielding during insert molding, the mark where the locating pin is located becomes an exposed hole after molding, and a weld line (a V-shaped groove formed during molding where the molding material flows around both sides of the locating pin converges) easily extends from this exposed hole. Since the weld line is often a fragile part, if the molded resin part is subjected to greater stress due to the difference in the coefficient of thermal expansion, cracks may occur along the weld line.

[0016] Therefore, the object of the present invention is to provide a current detection device in which a shielding insert is formed in a frame structure, and even if a fusion line is formed extending from the exposed hole, cracks can be suppressed along the fusion line.

[0017] Technical solutions to the problem

[0018] To solve the above problems, the current detection device of the first aspect of the present invention is characterized by comprising: a busbar through which the current to be measured flows; a fastening member for fastening an external member to the busbar; a frame for holding the busbar and the fastening member in contact with each other; and a magnetic sensor disposed opposite to the busbar and capable of detecting the magnetic field generated by the current to be measured flowing through the busbar, wherein the busbar has a fastening terminal portion at its end side that contacts the external member, the surface of the fastening terminal portion that contacts the external member, i.e., the connecting surface, is exposed from the frame, and the fastening terminal portion has an anchor portion having a surface different from the connecting surface and is embedded in the frame.

[0019] Therefore, the anchoring mechanism prevents the busbar from floating relative to the frame. By preventing floating, the positional relationship between the busbar and the magnetic sensor is prevented from deviating, thus maintaining good detection accuracy. Furthermore, the electrical connection is stable.

[0020] In the current detection device of the first aspect of the present invention, preferably, the connecting surface is exposed in a state that is more prominent than the portion of the frame covering the anchoring portion.

[0021] Therefore, when molding the frame and busbar insert, the resin film that seeps out from the part covering the anchor in the frame is less likely to be between the fastening terminal and the external component, thus ensuring a stable electrical connection between the fastening terminal and the external component.

[0022] In the current detection device of the first aspect of the present invention, preferably, the busbar has a curved portion between an end having a fastening terminal portion and an end on the opposite side of said end, and the magnetic sensor is configured to be positioned relative to the position between the curved portion and the fastening terminal portion in the busbar.

[0023] Therefore, the connection terminals to the external components are held in place by the anchoring part, so even if there is a springback force due to the bending part acting on the busbar, the connection terminals are less likely to float. Consequently, the positional relationship between the busbar and the magnetic sensor is less likely to deviate, contributing to improved measurement accuracy.

[0024] In the current detection device of the first aspect of the present invention, preferably, the anchoring part is embedded in a molded body of resin material having a frame.

[0025] Therefore, compared to cases where the busbar is pressed into the frame to form the anchoring part, it can be easily formed by insert molding, and it is also less likely to generate chips. The resin-based material includes monomeric synthetic resins, resins mixed with multiple synthetic resins, and resins mixed with fillers, etc.

[0026] The current detection device of the second aspect of the present invention comprises: a busbar through which the current to be measured flows; a magnetic sensor disposed opposite to the busbar and capable of detecting the magnetic field generated by the current to be measured flowing through the busbar; a pair of shielding members sandwiching the busbar and the magnetic sensor between the pair of shielding members; and a frame made of a resin-based material integrally formed with a first shielding member located near the busbar of the pair of shielding members, the first shielding member comprising: a substrate having a plate-like body of metal; and a protective portion made of a resin-based material covering at least a portion of the end face of the substrate.

[0027] Therefore, the end face of the substrate of the first shielding member is covered by the protective portion. Thus, by positioning the first shielding member within the mold by having the support pin abut against the location of the protective portion during the integral molding of the first shielding member and the frame, even if the inner surface of the hole formed at the location of the support pin in the frame exposes the first shielding member, the substrate will not be exposed. Therefore, it is less likely that the exposed substrate will be corroded, adversely affecting the operation of the current sensor.

[0028] In the current detection device of the second aspect of the present invention, preferably, the first shielding member has an exposed portion at the part opposite to the busbar that exposes the substrate.

[0029] Therefore, by having an exposed portion, the gap between the first shielding member and the busbar can be increased by the amount of thickness of the protective portion, thereby allowing the resin material to flow smoothly into the gap when the first shielding member is inserted into the frame, thereby stabilizing the current detection function.

[0030] In the current detection device of the second aspect of the present invention, preferably, when the exposed portion is viewed from the busbar side, the exposed portion has a widened portion on the outside of the portion overlapping with the busbar, which exposes the substrate.

[0031] By having a widened section, resin-based material can be easily supplied to the gap between the busbar and the shielding member.

[0032] In the current detection device of the second aspect of the present invention, preferably, the substrate has an expansion portion connected to the exposed portion and exposing the substrate, and the protective portion covers the end face of the substrate in such a way that at least the exposed portion and the expansion portion are exposed.

[0033] By providing an expansion section, similar to a widening section, the supply of resin-based materials is facilitated.

[0034] In the current detection device of the second aspect of the present invention, preferably, the first shielding member is a member inserted into the interior of a frame having a hole that exposes a portion of the expansion portion.

[0035] By configuring the locating pin of the first shielding member to engage with the expansion portion during insert molding, the locating pin will not obstruct the supply of resin-based material to the gap between the busbar and the shielding member, and the placement accuracy of the first shielding member within the mold can be improved. This improved placement accuracy enhances the accuracy of current measurement.

[0036] The third-party current detection device of the present invention is characterized in that the current detection device has a sensor unit, the sensor unit having: a plate-shaped busbar through which the current to be measured flows; a magnetic sensor disposed opposite to the plate surface of the busbar; a pair of shielding members disposed on both sides of the busbar and the magnetic sensor sandwiching the busbar and the magnetic sensor from the stacking direction; and a frame body made of a resin-based material, wherein the first shielding member of the pair of shielding members located on the side closer to the busbar is an insert formed inside the frame body and is made of a plate-shaped body that is polygonal in plan view, having cutouts at at least two corners of the polygon; the frame body has at least one through hole portion that is partially connected to an end face formed by the cutout portion and extending along the stacking direction.

[0037] Therefore, the contact area between the support pin of the first shielding member and the first shielding member can be reduced during insert molding. Thus, even if the first shielding member has a metal plate and the end face of the metal plate is exposed on the inner surface of the hole of the current sensor, the exposed area of ​​the end face is small. Therefore, it is not easy for the end face to be corroded, which would have an adverse effect on the operation of the current sensor.

[0038] In the third-party current detection device of the present invention, preferably, in a cross-section cut with a plane parallel to the plate surface of the first shielding member, the outline of the through hole and the cut portion are in point contact with each other.

[0039] By using point contact, the exposed end face can be reduced.

[0040] In the third-party current detection device of the present invention, preferably, in a cross-section cut with a plane parallel to the plate surface of the first shielding member, even if cut at any position in the stacking direction, the outline of the through hole and the cut portion are in point contact with each other at the same position.

[0041] Therefore, the contact is made along the stacking direction, thus reducing the exposure of the end face.

[0042] In the third-party current detection device of the present invention, preferably, the cut portion forms multiple end faces, and in the cross-section when cut with a plane parallel to the plate surface of the first shielding member, the outline of the through hole portion makes point contact with the multiple end faces respectively.

[0043] By setting multiple end faces, even if there are two cutouts, the first shielding member can be stably supported in the mold during insert molding, thereby reducing the exposure of the end faces.

[0044] In the third-party current detection device of the present invention, preferably, the cut portion is formed to have at least two end faces, and the through hole portion is partially connected to two or more end faces of the end face forming the cut portion.

[0045] By setting multiple end faces, even if there are two cutouts, the first shielding member can be stably supported in the mold during insert molding, thereby reducing the exposure of the end faces.

[0046] In the third-party current detection device of the present invention, preferably, the cut portion is formed having two end faces, and the through hole portion is partially connected to the two end faces forming the cut portion.

[0047] By setting two end faces, even with two cutouts, the first shielding member can be stably supported within the mold during insert molding, thereby reducing the exposure of the end faces.

[0048] In the third-party current detection device of the present invention, preferably, the cross-sectional shape when the through hole is cut with a surface parallel to the plate surface of the first shielding member is circular.

[0049] With a circular through-hole and a cylindrical support pin, the contact between the support pin and the first shielding member during insert molding is easily stabilized. Therefore, the configuration accuracy of the first shielding member in the current sensor is increased, thereby improving the accuracy of current measurement.

[0050] In the third-party current detection device of the present invention, preferably, the first shielding member is rectangular in top view and has cutouts at a pair of diagonal positions, and the frame has through holes corresponding to the cutouts.

[0051] As a result, the size management of the first shielding component becomes easier, thereby making it easier to improve the accuracy of current measurement.

[0052] In the third-party current detection device of the present invention, preferably, the first shielding member is rectangular in top view, with cutouts at two pairs of diagonal positions, and the frame has through holes corresponding to the cutouts.

[0053] Therefore, it is easy to improve the configuration accuracy of the first shielding component, thereby making it easier to improve the measurement accuracy of the current.

[0054] The fourth aspect of the current detection device of the present invention is characterized in that the current detection device has a sensor unit, the sensor unit having: a plate-shaped busbar through which the current to be measured flows; a magnetic sensor disposed opposite to the plate surface of the busbar; a pair of shielding members disposed on both sides of the busbar and the magnetic sensor sandwiching the busbar and the magnetic sensor from the stacking direction of the busbar and the magnetic sensor; and a frame body made of a resin-based material, wherein the first shielding member located near the busbar is a plate-shaped body inserted into the interior of the frame body, and a plurality of sensor units are arranged in the frame body along a first direction parallel to the plate surface of the first shielding member, and the frame body has an exposure hole that exposes the plate surface of the first shielding member, the exposure hole being formed such that the plate surface located at the end of the first shielding member is exposed in a second direction orthogonal to the first direction and parallel to the plate surface of the first shielding member.

[0055] Therefore, it is less likely that cracks will form along the weld line due to thermal stress. Furthermore, in areas formed solely by the molded resin portion without a shielding member immediately adjacent to the end of the shielding member, the resin material flows better compared to areas with a shielding member. Therefore, even when a locating pin is placed near the end of the shielding member, the resin material is adequately filled around it, thus reducing the likelihood of weak weld lines. Additionally, during insert molding, when the resin material flows along the first direction in the gap between the first shielding member and the busbar, the flow is not obstructed or interrupted, facilitating the appropriate placement of the resin material within the gap.

[0056] In the current detection device of the fourth aspect of the present invention, preferably, the first direction is orthogonal to the extension direction of the busbar.

[0057] Therefore, it is easy to set the first direction as the length direction of the frame.

[0058] In the current detection device of the fourth aspect of the present invention, preferably, the long side of the rectangular part of the first shielding member is arranged along the first direction, and one or more exposed holes are arranged along the long side.

[0059] Therefore, during insert molding, it is easy to use locating pins to support the first shielding component.

[0060] In the current detection device of the fourth aspect of the present invention, preferably, the frame has: a housing, an insert formed with a first shielding member; and a cover, holding the other of the pair of shielding members, namely the second shielding member, and a substrate on which a magnetic sensor is mounted is fixed to the housing.

[0061] Therefore, it is easy to locate a pair of shielding plates, thus enabling the manufacture of a device with stable detection accuracy.

[0062] In any of the second, third, and fourth embodiments of the present invention, the current detection device preferably has a fastening member for fastening an external component to the busbar, the frame holds the busbar and the fastening member in contact with each other, the busbar has a fastening terminal portion at its end side that contacts the external component, the connection surface of the fastening terminal portion that contacts the external component is exposed from the frame, the fastening terminal portion has an anchoring portion that has a surface different from the connection surface and is embedded in the frame.

[0063] Therefore, in the second, third, or fourth type of current detection device, the anchoring part can prevent the busbar from floating relative to the frame. By preventing floating, the positional relationship between the busbar and the magnetic sensor is prevented from deviating, thereby maintaining good detection accuracy and ensuring a stable electrical connection.

[0064] Invention Effects

[0065] According to the present invention, the reduction in measurement accuracy of a current detection device having a frame integral with the busbar and shield can be suppressed, even if the measurement accuracy is not easily reduced. Furthermore, in a structure where the recess of the fastening connection surface of the busbar is embedded in the resin of the protruding portion of the frame, the electrical contact stability of the fastening connection surface can be improved, thereby providing a current detection device whose measurement accuracy is not easily reduced. Moreover, a current detection device can be provided in a structure where the shield insert is molded into the frame, and corrosion is suppressed by forming a structure that minimizes the exposure of the side surface, i.e., the cross-section, of the shield, ensuring the measurement accuracy of the shield. Additionally, a current detection device can be provided in a structure where the shield insert is molded into the frame, and even if a fusion line is formed extending from the exposed hole, cracking along the fusion line can be suppressed. Attached Figure Description

[0066] Figure 1 (a) Figure 1 (b) is a perspective view showing the structure of the current detection device according to the first embodiment of the present invention.

[0067] Figure 2 (a) is Figure 1 (a) is a sectional view of line A-A'. Figure 2 (b) is Figure 2 (a) is a magnified view of a portion of the image.

[0068] Figure 3 yes Figure 1 (a) Sectional view of line B-B'.

[0069] Figure 4 (a) Figure 4 (b) is a diagram showing the relationship between the busbar of the first embodiment and the corresponding first shielding member.

[0070] Figure 5 (a) is a perspective view showing the structure of the first shielding member according to the first embodiment. Figure 5 (b) shows Figure 5 (a) is a perspective view of the structure of the substrate of the first shielding member.

[0071] Figure 6 yes Figure 1 (a) Sectional view of line C-C'.

[0072] Figure 7 (a) Figure 7 (b) Figure 7 (c) Figure 7 (d) Figure 7 (e) is a diagram showing the structure of the fastening terminal and the anchoring portion in a modified example of the first embodiment.

[0073] Figure 8 (a) is a bottom view showing the structure of the housing according to the second embodiment. Figure 8 (b) shows Figure 8 (a) A bottom view of the structure of the shielding member built into the shell.

[0074] Figure 9 It is shown in magnification Figure 8 (b) is a bottom view of the shielding member on the left.

[0075] Figure 10 It is shown Figure 8 (a) is a diagram showing the thermal stress distribution of the shell.

[0076] Figure 11 (a) Figure 11 (b) Figure 11 (c) Figure 11 (d) is a diagram showing the relationship between the cutout portion of the substrate of the shielding member in a modified example of the second embodiment and the positioning pin. Detailed Implementation

[0077] Hereinafter, a current detection device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In each figure, the XYZ coordinates are shown as reference coordinates. In the following description, the Z1-Z2 direction is referred to as the vertical direction, the X1-X2 direction as the horizontal direction, and the Y1-Y2 direction as the front-back direction. The X1-X2 direction and the Y1-Y2 direction are perpendicular to each other, and the XY plane including these is perpendicular to the Z1-Z2 direction. In addition, the state of viewing the lower side (Z2 side) from the upper side (Z1 side) is sometimes referred to as a top view.

[0078] <First Implementation>

[0079] Figure 1 (a) Figure 1 (b) are perspective views showing the structure of the current detection device 10 according to the first embodiment. Figure 1 (a) is a view taken from the top (Z1 side). Figure 1 (b) is a view from the bottom (Z2 side). Figure 2 (a) is Figure 1 (a) is a sectional view of line A-A'. Figure 2 (b) is Figure 2 (a) is a magnified view of a portion of the image. Figure 3 yes Figure 1 (a) A cross-sectional view along line B-B' also shows bolts 34 for electrically connecting the external component M to the busbar 21. Figure 4 (a) Figure 4 (b) are diagrams showing the relationship between the busbar 21 and the corresponding first shielding member 61 in the first embodiment. Figure 4 (a) is a 3D diagram. Figure 4 (b) is a top view. Figure 5 (a) is a perspective view showing the structure of the first shielding member 61 according to the first embodiment. Figure 5 (b) shows Figure 5 (a) is a perspective view of the structure of the base material 161 of the first shielding member 61. Figure 6 yes Figure 1 (a) Sectional view of line C-C'.

[0080] like Figure 1 (a) Figure 1 (b) or Figure 2 As shown in (a), the current detection device 10 of the first embodiment includes: busbars 21, 22, and 23 through which the current to be measured flows; a frame 40 housing and holding a portion of the busbars 21, 22, and 23; magnetic sensors 51, 52, and 53 respectively disposed opposite to the plate surfaces of the plate-shaped busbars 21, 22, and 23; and three pairs of shielding members (first shielding members 61, 62, and 63, and second shielding members 71, 72, and 73), which are separated from the busbars 21, 22, and 23 and the magnetic sensors 51, 52, and 53 respectively. That is, the busbars and magnetic sensors are disposed between the first shielding member and the second shielding member constituting the pair of shielding members. The busbars 21, 22, and 23 are disposed at equal intervals in the left-right direction (X1-X2 direction), and the magnetic sensors 51, 52, and 53 respectively disposed opposite to the busbars 21, 22, and 23 are also disposed at equal intervals. Furthermore, the configuration of busbars 21, 22, and 23 in the left-right direction (X1-X2 direction) may not be equally spaced.

[0081] The aforementioned shielding components consist of first shielding components 61, 62, and 63 located near the busbars 21, 22, and 23, respectively, and second shielding components 71, 72, and 73 located closer to the magnetic sensors 51, 52, and 53 than the busbars 21, 22, and 23, respectively. The first shielding components 61, 62, and 63... Figure 2 (a) The first shielding members 61, 62, and 63 are arranged in the order of first shielding members 61, 62, and 63 from left to right (from X1 to X2). The second shielding members 71, 72, and 73 are also arranged in the same order as the first shielding members. Figure 2 (a) is arranged from left to right (from X1 side to X2 side) in the order of second shielding members 71, 72, and 73. First shielding member 61 and second shielding member 71 form a first pair, with a magnetic sensor 51 and a busbar 21 sandwiched between them. Similarly, first shielding member 62 and second shielding member 72 form a second pair, with a magnetic sensor 52 and a busbar 22 sandwiched between them. Furthermore, first shielding member 63 and second shielding member 73 form a third pair, with a magnetic sensor 53 and a busbar 23 sandwiched between them.

[0082] The first sensor unit is composed of two shielding members 61 and 71 forming a first pair, and the magnetic sensor 51 and busbar 21 sandwiched between them. Similarly, the second sensor unit is composed of two shielding members 62 and 72 forming a second pair, and the magnetic sensor 52 and busbar 22 sandwiched between them. Likewise, the third sensor unit is composed of two shielding members 63 and 73 forming a third pair, and the magnetic sensor 53 and busbar 23 sandwiched between them.

[0083] The frame 40 is formed by molding a non-magnetic and insulating resin-based material, and has a housing 45 and a cover 44 that covers the upper part of the housing 45. Figure 2 (a) Figure 2 (b) Figure 3 As shown, the second shielding components 71, 72, and 73 are held in the cover 44 by insert molding, and the first shielding components 61, 62, and 63 are held in the housing 45 by insert molding.

[0084] A base plate 50 is fixed to the housing 45, and magnetic sensors 51, 52, and 53 are mounted on the base plate 50 in a manner opposite to busbars 21, 22, and 23, respectively. Thus, the magnetic field generated by the measured current flowing in the busbars 21, 22, and 23 opposite to each magnetic sensor 51, 52, and 53 can be detected by each magnetic sensor 51, 52, and 53.

[0085] Here, busbars 21, 22, and 23 have the same shape as each other. Figure 2 (b) Figure 3 , Figure 4 (a) Figure 4 (b) Figure 6 In this example, busbar 21 is used as an example, but other busbars 22 and 23 also have the same structure. In addition, busbars 21, 22, and 23 can also have different shapes from each other.

[0086] like Figure 3 As shown, the busbar 21 has a structure in which a plate-shaped metal component is bent along the thickness direction. The upright part 21u extends from the bent part 21f formed by the bending process along the vertical direction (Z1-Z2 direction), and the extension part 21v (outer extension) extends along the front-back direction (Y1-Y2 direction).

[0087] A fastening terminal portion 21a is provided at the front end (Y1 side) of the extension portion 21v. A through hole portion 21h is formed in the fastening terminal portion 21a, penetrating the busbar 21 in the thickness direction (Z1-Z2 direction). The cross-sectional shape of the through hole portion 21h, orthogonal to its axial direction, is circular. Here, a curved portion 21f is provided in the busbar 21 between the end where the fastening terminal portion 21a is provided and the end on the opposite side in the length direction of the busbar 21 (the upper end of the erected portion 21u).

[0088] Here, the magnetic sensor 51 is positioned relative to the bend 21f and the fastening terminal 21a of the busbar 21. With this configuration, even if the bend 21f springs back, it is held in place by the extension 21v embedded in the frame 40, thus maintaining the positional relationship with the magnetic sensor 51, thereby ensuring detection accuracy, and the electrical connection between the fastening terminal 21a and the fastening member 31 is also stably maintained.

[0089] In the extension 21v, at the position corresponding to the first shielding member 61 when the busbar 21 is fixed to the housing 45, a narrow portion 21g is provided to shorten the width in the left and right directions.

[0090] like Figure 1 As shown in (a), fastening terminal portions 22a and 23a are also provided on the other busbars 22 and 23, and through holes 22h and 23h are provided in the same manner as the through hole portion 21h. The cross-sectional shape of the through hole portions 22h and 23h orthogonal to their axial direction is also circular.

[0091] like Figure 1 (a) Figure 1 As shown in (b), the housing 45 has three protrusions 41, 42, and 43 extending in a plate-like shape in the forward direction. The protrusions 41, 42, and 43 are equally spaced in the left-right direction, corresponding to the busbars 21, 22, and 23. The fastening terminals 21a, 22a, and 23a of the busbars 21, 22, and 23 are respectively fixed to the upper parts of the protrusions 41, 42, and 43. Fastening members 31, 32, and 33 are provided on the protrusions 41, 42, and 43 for fastening bolts 34 to the busbars 21, 22, and 23 respectively. The bolts 34 are used to electrically connect the external component M to the busbars 21, 22, and 23 (see reference). Figure 3 ).

[0092] like Figure 3As shown, the fastening member 31 is a nut disposed within the protrusion 41, having an inner surface 31h with threads corresponding to the bolt 34. The fastening member 31 is formed to penetrate the protrusion 41 in the vertical direction, and its central axis is also in the vertical direction. Furthermore, the central axis of the fastening member 31 and the central axis of the through hole 21h of the fastening terminal portion 21a of the busbar 21 fixed to the protrusion 41 are aligned in the XY plane, thereby connecting the through hole 21h and the inner surface 31h to form a hole extending vertically. When the bolt 34 is inserted into the through hole 21h and screwed into the inner surface 31h until the bolt 34 contacts the surface of the fastening terminal portion 21a, i.e., the connecting surface 21b (fastening connection surface), the connection is fastened in such a way that the fastening terminal portion 21a of the busbar 21 and the fastening member 31 are in contact with each other.

[0093] like Figure 4 (a) Figure 4 As shown in (b), an anchoring portion 21e is formed in the fastening terminal portion 21a of the busbar 21. In the area corresponding to the fastening member 31 when viewed from above, the anchoring portion 21e has a step formed between the upper and lower surface sides on the front end face and the two side end faces. More specifically, an upper step portion 21c is formed on the front end face that displaces the lower step portion 21d on the upper surface side relative to the lower surface side in the rearward direction, and an upper step portion 21c is formed on the side end face that displaces the upper surface side relative to the lower step portion 21d on the lower surface side, which has the same left-right width as the other extensions 21v on the lower surface side, inwardly in the left-right direction. A surface is formed that is a distance lower than the upper surface by stamping or other processes at the end of the upper surface. Therefore, when viewed from above, the upper step portion 21c has a smaller area inside the lower step portion 21d.

[0094] The surface of the upper stepped portion 21c is coplanar with the connecting surface 21b of the fastening terminal portion 21a, and the surface of the lower stepped portion 21d is configured as a different surface that is offset from the connecting surface 21b in the vertical direction.

[0095] like Figure 6As shown, the fastening terminal portion 21a is embedded in the housing 45 of the frame 40 with the connecting surface 21b protruding upwards from the surface 41a of the frame 40. Furthermore, the upper surface of the step (lower step portion 21d) of the anchor portion 21e is embedded in the housing 45 of the frame 40. In other words, the lower step portion 21d of the anchor portion 21e and a portion of the upper step portion 21c are entirely covered by the housing 45, with the upper part of the upper step portion 21c protruding upwards from the surface 41a of the housing 45. Additionally, the busbar 21 is integrally formed with the frame 40, which is a resin-based molded body, via insert molding. Therefore, a structure covering the anchor portion 21e can be easily formed, and by providing a step at the boundary between the connecting surface 21b and the surface 41a of the frame 40, it is possible to prevent resin coverage, thereby enabling reliable electrical connection with external components. Furthermore, by embedding the lower stepped portion 21d of the anchoring portion 21e entirely within the frame 40, even if the busbar 21 rebounds, it is possible to prevent the busbar 21 from floating relative to the fastening member 31. By preventing floating, the positional variation of the busbar 21 relative to the magnetic sensor 51 can be suppressed, thereby achieving stable measurement accuracy. In contrast, assuming that the connecting surface 21b and the surface 41a of the frame 40 are formed as a continuous plane, due to deviations in molding conditions, resin-based material from the frame 40 may sometimes seep into the connecting surface 21b and cover the surface with resin coating. Since resin-based materials are insulating, if resin coating occurs, electrical conduction cannot be achieved when connecting external components and the busbar 21.

[0096] By configuring and fixing the anchoring part 21e in this way, even if the size of the current detection device 10 is reduced, or the size of the busbar 21 or the interval with the adjacent busbars 22 and 23 is reduced, the fastening terminal part 21a of the busbar 21 is reliably held in the frame 40. Therefore, the fastening terminal part 21a is difficult to deform, thereby maintaining the positional relationship between the fastening terminal part 21a and the fastening member 31, and the position of the busbar 21 relative to the magnetic sensor 51 does not change, enabling high-precision detection.

[0097] like Figure 1 As shown in (a), the cover 44 has a through hole 44a in the thickness direction (vertical direction). In top view, there are four holes 44a relative to each of the second shielding members 71, 72, 73, and they are symmetrical front and back and left and right, so that a portion of the expansion portion (described later) of each of the second shielding members 71, 72, 73 disposed in the cover 44 is exposed.

[0098] Figure 1As shown in (b), the housing 45 has a through hole 45a extending in the thickness direction (vertical direction). Viewed from the bottom (Z2 side), the through hole 45a has four portions relative to each of the first shielding members 61, 62, and 63, and is symmetrical front-to-back and left-to-right, so that the expansion portions of each of the first shielding members 61, 62, and 63 disposed within the housing 45, such as a portion of the expansion portion 161c of the first shielding member 61, are exposed. Furthermore, the number and arrangement of the through holes 45a relative to each of the first shielding members 61, 62, and 63 may differ from the structure described above.

[0099] The hole 44a of the cover 44 is formed by removing the locating pins used to position the second shielding members 71, 72, and 73 during insert molding, and the hole 45a of the housing 45 is formed after removing the locating pins used to position the first shielding members 61, 62, and 63. By molding using locating pins in this way, the configuration accuracy of the first shielding members 61, 62, and 63 and the second shielding members 71, 72, and 73 within the mold can be improved, thereby improving the accuracy of current measurement.

[0100] The first shielding members 61, 62, and 63, and the second shielding members 71, 72, and 73, have the same shape as each other. Figure 5 (a) Figure 5 In (b), the first shielding member 61 is used as an example for explanation, but the other first shielding members 62, 63 and second shielding members 71, 72, 73 also have the same structure.

[0101] like Figure 5 As shown in (a), the first shielding member 61 has a base material 161 and a protective portion 261. Figure 2 As shown in (b), similar to the first shielding member 61, the second shielding member 71 has a base material 171 and a protective part 271.

[0102] like Figure 5 As shown in (b), the substrate 161 has a structure in which multiple metal plates of the same shape are overlapped, and the four corners, which are rectangular in top view, are cut out to form cutouts 161t. Figure 5As shown in (a), the protective portion 261 is made of a resin-based material and is configured to cover the end face of the cut-out portion 161t in the end face 161s of the substrate 161 and the end face near it. The protective portion 261 also covers a portion of the upper surface and the bottom surface connected to the end face 161s of the substrate 161, and its thickness in the vertical direction is greater than that of the substrate 161. Here, by setting the substrate 161 to a rectangular shape in plan view, dimensional management becomes easier, and the accuracy of current measurement can be improved. In addition, by cutting off the corners of the substrate 161 in a rectangular shape, the management of the cutting process becomes easier, and point contact with the positioning pin can be easily achieved. Therefore, both end face exposure can be suppressed, and high-precision positioning can be achieved.

[0103] like Figure 5 As shown in (a), in a top view, the central portion of the substrate 161 in the X1-X2 direction is not covered by the protective portion 261 and becomes the exposed portion 161a. Figure 4 (a) Figure 4 As shown in (b), in the first shielding member 61, the exposed portion 161a is opposite to the extension portion 21v of the busbar 21.

[0104] like Figure 4 (b) and Figure 5 As shown in (a), the widened portion 161b, which widens in the left-right direction (X1-X2 direction), is connected to the approximately central portion of the exposed portion 161a in the front-back direction. The widened portion 161b is formed such that its width in the left-right direction is wider than the opposing busbar 21, and it is not covered by the busbar 21 when viewed from above, thus remaining exposed. That is, when viewing the exposed portion 161a from the side of the busbar 21, the widened portion 161b is formed such that the substrate 161 is exposed on the outer side of the portion overlapping with the busbar 21.

[0105] like Figure 4 (b) and Figure 5 As shown in (a), the expansion portion 161c, which extends along the front-back direction (Y1-Y2 direction), is connected to the approximately central portion of the exposed portion 161a in the left-right direction. The expansion portion 161c is opposite to the busbar 21.

[0106] Since the first shielding member 61 covers a portion of the end face 161s, i.e., the cutout 161t, of the substrate 161 through the protective portion 261, when the first shielding member 61 is integrally formed with the frame 40 (insert molding), the support pin used to define the position of the first shielding member 61 abuts against the position where the protective portion 261 exists. Even if the inner surface of the hole formed at the location with the support pin in the molded frame 40 exposes the first shielding member 61, the substrate 161 will not be exposed. Therefore, it is less likely that the exposed substrate 161 will be corroded, adversely affecting the operation of the current detection device 10. Furthermore, when the protective portion 261 is formed around the substrate 161 by injection molding, the end face (fracture surface) of the substrate 161 is exposed from the protective portion 261 at the location where the support pin abuts at the designated position for holding the substrate 161 in the mold. However, by insert molding the first shielding member 61 into the frame 40, the exposed portion of the end face (fracture surface) of the substrate 161 is covered by the resin material of the frame 40. Therefore, it is less likely that the exposed substrate 161 will be corroded, thus adversely affecting the operation of the current detection device 10.

[0107] Furthermore, since an exposed portion 161a with a thickness smaller than that of the protective portion 261 is arranged at a position opposite to the busbar 21, the gap S between the first shielding member 61 and the busbar 21 (see reference) can be made larger. Figure 2 (b) is relatively large. Therefore, the resin material for insert molding can easily flow into the gap S, and thus, the resin material can be appropriately and completely arranged at a specified thickness. As a result, the current detection function can be stabilized. Moreover, since the first shielding member 61 is provided with a widened portion 161b that is not covered by the busbar 21 and an expansion portion 161c that extends to the end of the substrate 161, the resin material can be supplied to the gap S between the first shielding member 61 and the busbar 21 more stably.

[0108] Hereinafter, a variation of the first embodiment will be described.

[0109] Figure 7 (a) Figure 7 (b) Figure 7 (c) Figure 7 (d) Figure 7 (e) are diagrams showing the structures of the fastening terminal portions 101a, 111a, 121a, 131a, 141a and the anchoring portions 101e, 111e, 121e, 131e, 141e in the modified examples of the first embodiment. Figure 7 (a) is a cross-sectional view showing the fastening terminal portion 101a and the anchoring portion 101e of modified example 1. Figure 7 (b) is a perspective view showing the fastening terminal portion 111a and the anchoring portion 111e of modified example 2. Figure 7(c) is a perspective view showing the fastening terminal portion 121a and the anchoring portion 121e of modified example 3. Figure 7 (d) is a perspective view showing the fastening terminal portion 131a and the anchoring portion 131e of modified example 4. Figure 7 (e) is a perspective view showing the fastening terminal portion 141a and the anchoring portion 141e of modified example 5. Figure 7 (a) is a cross-section orthogonal to the front-back direction (Y1-Y2 direction). Furthermore, in Figure 7 (b) ~ Figure 7 In (e), the through hole that runs through the manifold in the thickness direction is omitted.

[0110] like Figure 4 (a) Figure 4 (b) Figure 6 As shown, the surfaces of the upper stepped portion 21c and the lower stepped portion 21d of the anchoring portion 21e in the first embodiment extend along the XY plane, respectively, and the side of the upper stepped portion 21c extends along the vertical direction.

[0111] In contrast, Figure 7 (a) The fastening terminal portion 101a shown has a through hole 101h that passes through the busbar in the thickness direction (vertical direction), and an anchoring portion 101e is formed by an upper stepped portion 101c and a lower stepped portion 101d. The side of the upper stepped portion 101c has a tapered shape that widens outward as it gets closer to the lower stepped portion 101d. In this anchoring portion 101e, similar to the anchoring portion 21e in the first embodiment, the surface of the upper stepped portion 101c, i.e., the connecting surface 101b, protrudes upward more than the surface 41a of the frame 40 and is embedded in the housing 45 of the frame 40, thereby achieving the same effect as in the first embodiment.

[0112] exist Figure 7 (b) In the fastening terminal portion 111a shown, the surface of the busbar, i.e., the connecting surface 111b, is quadrilateral when viewed from above. The side surfaces extending from the front side and the left and right sides of the four sides of the connecting surface 111b, i.e., the anchoring portions 111e, are formed as conical surfaces that widen towards the lower side and outwards. In this anchoring portion 111e, the lower part is embedded in the frame 40, and the connecting surface 111b is embedded in the housing 45 of the frame 40 in a state that protrudes upwards more than the surface 41a of the frame 40.

[0113] exist Figure 7In the fastening terminal portion 121a shown in (c), the surface of the busbar, i.e., the connecting surface 121b, is approximately quadrilateral when viewed from above, and a portion of the upper part of the side surface 121c connected to the left and right sides is formed into a recess 121d by extrusion processing. The recess 121d and the two side surfaces 121c on which the recess 121d is provided constitute the anchor portion 121e. In this anchor portion 121e, the area of ​​the lower side of the side surface 121c, including a portion of the lower side of the recess 121d, is embedded in the frame 40, and the connecting surface 121b is embedded in the housing 45 of the frame 40 in a state that protrudes upwards more than the surface 41a of the frame 40.

[0114] exist Figure 7 In the fastening terminal portion 131a shown in (d), the surface of the busbar, i.e., the connecting surface 131b, is approximately quadrilateral when viewed from above, and a portion of the upper part of the side surface 131c connected to the front side is formed into a recess 131d by extrusion processing. The recess 131d and the side surface 131c with the recess 131d constitute an anchoring portion 131e. In this anchoring portion 131e, the area of ​​the lower side of the side surface 131c, including a portion of the lower side of the recess 131d, is embedded in the frame 40, and the connecting surface 121b is embedded in the housing 45 of the frame 40 in a state that protrudes upwards more than the surface 41a of the frame 40.

[0115] exist Figure 7 In the fastening terminal portion 141a shown in (e), similar to the side end face of the fastening terminal portion 21a in the first embodiment, a step is formed between the upper surface side and the lower surface side of the two side end faces, thereby forming an upper step portion 141c that displaces the lower step portion 141d of the upper surface side in the left-right direction inward. The upper step portion 141c and the lower step portion 141d form an anchoring portion 141e. In this anchoring portion 141e, the surface of the upper step portion 141c, i.e., the connecting surface 141b, is embedded in the housing 45 of the frame 40 in a state that protrudes upward more than the surface 41a of the frame 40.

[0116] In the first embodiment, the substrate 161 is set to a planar shape that is rectangular when viewed from above, but the planar shape can also be a polygonal shape other than a rectangle. In this structure, by providing a notch at the corner and making the positioning pin point-contact with the end face of the notch, insert molding can be performed with high precision in configuring the shielding member.

[0117] In the first embodiment, cutouts 161t are provided at the four corners of the substrate 161, i.e., at two pairs of diagonal positions. However, it is also possible to provide cutouts at one pair of diagonal positions or three corners instead. In addition, when the planar shape of the substrate 161 is set to a polygonal shape other than a rectangle, the number of cutouts can be two or more, as long as the substrate can be accurately aligned.

[0118] <Second Implementation>

[0119] Figure 8 (a) is a bottom view showing the structure of the housing 340 according to the second embodiment. Figure 8 (b) shows Figure 8 (a) A bottom view of the structure of the base materials 361, 362, 363 of the shielding members built into the housing 340. Figure 9 It is shown in magnification Figure 8 (b) Bottom view of the base material 361 of the shielding member. Figure 10 It is shown Figure 8 (a) is a diagram showing the thermal stress distribution of the shell 340. Figure 8 (b) and Figure 9 The image also shows support pins 301, 302, and 303 for horizontal positioning and positioning pins 311, 312, and 313 for vertical positioning.

[0120] Similar to the housing 45 (frame 40) of the first embodiment, Figure 8 (a) The housing 340 shown as a frame has a structure in which the shielding members are embedded in the substrates 361, 362, and 363 by insert molding. The structure, manufacturing process, and function of the housing 340 described below can also be applied to the housing 45 and cover 44 of the first embodiment. Thus, similar to the first embodiment, by using a pair of shielding members arranged at the position where the busbar and the magnetic sensor are sandwiched along the stacking direction, namely the shielding member in the cover 44 and the shielding member in the housing 45, three sensor units arranged along the length direction of the housing 340, i.e., the first direction D1, can be formed. In this configuration, the extension direction of the busbar is the same as in the first embodiment, which is a direction orthogonal to the first direction D1. Furthermore, even if the number of sensor units is two or four or more, the structure, function, and effect of the second embodiment can be obtained.

[0121] and Figure 5 Similarly, the substrate 161 of the first embodiment shown in (b) is also... Figure 8 (b) The base materials 361, 362, and 363 of the shielding member shown have a structure in which multiple metal plates of the same shape are overlapped, and the four corners, which appear as quadrilaterals when viewed from above, are rectangularly cut out to form cutouts 361t. Therefore, the cutouts 361t have an end face 361t1 extending along a first direction D1 and an end face 361t2 extending along a second direction D2 (the width direction of the housing 340) orthogonal to the first direction D1 (see reference). Figure 9 ).

[0122] In the insert molding of the substrates 361, 362, and 363 of the shielding member in the housing 340, in order to include the in-plane direction of the surface including the first direction D1 and the second direction D2 ( Figure 8 (a) Figure 8 (b) The orientation of the paper, i.e., the horizontal direction when the bottom surface of the housing 340 is arranged in a horizontal direction, is determined using cylindrical support pins 301, 302, and 303. Specifically, for Figure 8 (b) On the left side of the shielding member, the base material 361 has four support pins 301 that abut against two end faces 361t1 and 361t2 of the four cutouts 361t. Since the two end faces 361t1 and 361t2 of the cutouts 361t extend along the first direction D1 and the second direction D2, respectively, in a top view, the cylindrical support pins 301 make point contact with point P1 of one end face 361t1 and point P2 of the other end face 361t2. This point contact is also the same in a cross-section cut with a plane parallel to the plate surface of the base material 361, and the point contact is at the same position at any position in the stacking direction. Furthermore, in the thickness direction of the base material 361 of the shielding member, which is orthogonal to the first direction D1 and the second direction D2, the end faces 361t1 and 361t2 of the cutouts 361t make contact with lines extending the aforementioned points P1 and P2 in the vertical direction (thickness direction). Four support pins 302 and 303 are also provided for the central substrate 362 and the right substrate 363, respectively. When viewed from above, they make point contact with the two end faces of the cut-out portions 362t and 363t, respectively, and make line contact in the thickness direction of the substrates 362 and 363.

[0123] exist Figure 8 In the insert molding of the housing 340 shown in (a), a molding material made of resin-based material is supplied from the left side to the right side of the paper along the first direction D1.

[0124] like Figure 8 As shown in (a), in the housing 340, hollow cylindrical through holes 341a, 342a, and 343a are formed at the positions where the inserts are configured with support pins 301, 302, and 303, extending to the bottom surface. The cross-sectional shape of the through holes 341a, 342a, and 343a orthogonal to their axial direction is circular.

[0125] The through holes 341a, 342a, and 343a are formed with corresponding outlines at positions corresponding to the support pins 301, 302, and 303. Therefore, similar to the support pins 301, 302, and 303, in a cross-section cut with a plane parallel to the plate surface of the substrates 361, 362, and 363 of the shielding member, the aforementioned outlines make point contact with two end faces of the respective cut portions 361t, 362t, and 363t of the substrates 361, 362, and 363 of the shielding member, and make line contact in the thickness direction of the substrates 361, 362, and 363 of the shielding member. Therefore, the contact area between the substrates 361, 362, and 363 of the shielding components and the support pins 301, 302, and 303 during insert molding can be reduced. Thus, even if the end faces of the metal substrates 361, 362, and 363 are exposed on the inner surfaces of the through holes 341a, 342a, and 343a, the exposed area of ​​the end faces of the cut portions 361t, 362t, and 363t of the substrates 361, 362, and 363 can be reduced. Therefore, it is less likely that the end faces of the cut portions 361t, 362t, and 363t will be corroded, which would adversely affect the operation of the current detection device. Furthermore, when the injection pressure for filling the mold with resin-based material during insert molding is within an appropriate range and processed at a higher level, the resin material may enter between the substrates 361, 362, 363 and the support pins 301, 302, 303. Normally, after molding, the exposed portions of substrates 361, 362, 363 in a linear fashion are sometimes covered by the resin material. Without causing defects due to this, the end faces of the cut portions 361t, 362t, 363t become more difficult to corrode; therefore, even if the exposed portions are covered by the resin material, there is no problem.

[0126] In addition, by providing four cutouts 361t, 362t, and 363 in each substrate 361, 362, and 363, the substrates 361, 362, and 363 can be stably supported during insert molding, thereby reducing the exposure of the end faces of the substrates 361, 362, and 363.

[0127] In the insert molding of the shielding member in the housing 340, in order to achieve a direction perpendicular to the first direction D1 and the second direction D2 (and... Figure 8 (a) Figure 8 (b) Positioning in the direction perpendicular to the paper surface, i.e., the plumb direction when the bottom surface of the housing 340 is arranged in the horizontal direction, is achieved using cylindrical positioning pins 311, 312, and 313.

[0128] like Figure 8As shown in (b), the long sides 361a, 362a, and 363a of each substrate 361, 362, and 363, which are rectangular in top view, are arranged along the first direction D1. Regarding the left substrate 361, two cylindrical locating pins 311 abut against the two ends of its surface 361b in the second direction D2. The locating pins 311 are arranged symmetrically in the first direction D1 and the second direction D2. For the substrate 362 of the central shielding member and the substrate 363 of the right shielding member, four locating pins 312 and 313 are arranged, similar to the arrangement of locating pins 311 relative to the left substrate 361. By arranging the locating pins in this way, when the forming material is supplied along the first direction D1, there are no locating pins on the center line of the supply path in the second direction D2. Therefore, the flow of the forming material is not obstructed or cut off, and the forming material can easily flow into the gap between the shielding member and the busbar, i.e., with... Figure 2 (b) has the same gap as the gap S.

[0129] like Figure 8 As shown in (a), in the housing 340, hollow cylindrical exposed holes 341b, 342b, and 343b are formed at the positions where the inserts are configured with locating pins 311, 312, and 313, extending to the bottom surface, so that the plate surfaces 361b, 362b, and 363 at the ends of the substrates 361, 362, and 363 in the stacking direction are exposed. The cross-sectional shape of the exposed holes 341b, 342b, and 343b orthogonal to their axial direction is circular.

[0130] exist Figure 10 In the diagram, areas with high thermal stress intensity are represented by white. As the thermal stress intensity decreases, the concentration of white decreases, and the color concentration gradually changes from gray to black. The area with the lowest thermal stress intensity is represented by black. Figure 10 As can be seen, the regions corresponding to the metal substrates 361, 362, and 363 exhibit high thermal stress intensity and are indicated in white. Conversely, regions consisting solely of resin-based materials without substrates 361, 362, and 363 are indicated in black, indicating low thermal stress intensity. Furthermore, in the regions corresponding to substrates 361, 362, and 363, the areas around the through-holes exhibit a higher degree of blackness compared to the central region, indicating low thermal stress intensity. Therefore, even if fusion lines extending downstream from the exposed holes 341b, 342b, and 343b in the flow direction of the molding material are formed, the low thermal stress intensity makes it less prone to cracking along the fusion lines.

[0131] The metal substrates 361, 362, and 363 and the shell 340 (frame) made of resin material have different coefficients of thermal expansion. Therefore, when heat is applied to the shell 340, the substrates 361, 362, and 363 expand more than the shell 340. Consequently, the areas in the shell 340 without the embedded substrates 361, 362, and 363, i.e., the areas made of molded resin material, are less susceptible to stress. When a cross-section of the shell 340 is observed cut along the stacking direction (thickness direction) of the substrates 361, 362, and 363, near the center of the substrates 361, 362, and 363, the molded resin portion forms layers on the upper and lower surfaces of the substrates 361, 362, and 363. Therefore, the difference in the coefficients of thermal expansion has a significant impact, resulting in greater stress on the molded resin portion.

[0132] Furthermore, from a top view, the peripheral regions at the ends of the substrates 361, 362, and 363, such as the area between substrates 361, 362, and 363, are composed solely of the molding resin portion. Therefore, the effect of differences in the coefficients of thermal expansion is mitigated. Consequently, the stress applied to the molding resin portion is less compared to the central portion of substrates 361, 362, and 363. Therefore, it can be understood that even if fusion lines extending from the exposed holes 341b, 342b, and 343b along the supply direction of the molding material, i.e., the first direction D1, are formed, it is less likely that cracks will occur along the fusion lines due to thermal stress.

[0133] Furthermore, in the peripheral regions of the ends of the substrates 361, 362, and 363 viewed from above, compared to the regions where the substrates 361, 362, and 363 are embedded, the resin material used for molding flows more easily because the substrates 361, 362, and 363 are not present. Therefore, even if locating pins 311, 312, and 313 are provided at both ends on the second direction D2 of the substrates 361, 362, and 363, weld lines are less likely to form because the resin material is fully filled around them.

[0134] Hereinafter, a variation of the second embodiment will be described.

[0135] In the second embodiment, the substrates 361, 362, and 363 are shaped as rectangles when viewed from above, but the planar shape can also be a polygonal shape other than a rectangle. Even in this structure, by providing cutouts at the corners and making the through holes 341a, 342a, and 343a partially contact the end faces of the cutouts, high-precision positioning can be achieved, and the exposure of the end faces can be minimized.

[0136] In the second embodiment, two exposed holes 341b, 342b, and 343b are provided along the long sides 361a, 362a, and 363a of each substrate 361, 362, and 363, respectively, but the number of them may be one or more.

[0137] Figure 11 (a) Figure 11 (b) Figure 11 (c) Figure 11 (d) is a diagram showing the relationship between the cutouts 461t, 561t and the positioning pins 401, 501 of the respective substrates 461, 561 of the shielding member in the modified examples (modifications 6, 7) of the second embodiment. Figure 10 (a) is a top view showing the relationship between the cutout 461t of the substrate 461 and the locating pin 401 in Modified Example 6. Figure 10 (b) shows Figure 10 (a) A sectional view of line D-D'. Figure 10 (c) is a top view showing the relationship between the cutout 561t of the substrate 561 and the locating pin 501 in Modified Example 7. Figure 10 (d) is Figure 10 (c) Sectional view of line E-E'.

[0138] exist Figure 11 (a) Figure 11 In variation 6 shown in (b), similar to the substrates 361, 362, and 363 of the second embodiment, a rectangular cutout 461t is provided at the corner of the substrate 461, which is rectangular in top view. Figure 11 As shown in (b), the cut portion 461t has two end faces that are wedge-shaped and become thinner towards the top. Ridge portions 461t1 and 461t2 are formed at the front end of the wedge shape of each of the two end faces.

[0139] For the cutout portion 461t in this structure, the cylindrical positioning pin 401 makes line contact with the ridge portions 461t1 and 461t2, respectively. After the substrate 461 insert is formed, similar to the second embodiment, a through hole is formed at the position corresponding to the positioning pin 401. However, since the outer line of the through hole makes point contact with the cutout portion 461t, the exposure of the cutout portion 461t can be suppressed at the ridge portions 461t1 and 461t2.

[0140] exist Figure 11 (c) Figure 11 In variation 7 shown in (d), similar to the substrates 361, 362, and 363 of the second embodiment, a rectangular cutout 561t is provided at the corner of the substrate 561, which is rectangular in top view. The cutout 461t has an end face 561t1 extending along the first direction D1 and an end face 561t2 extending along the second direction D2.

[0141] In variation 7, a truncated cone-shaped locating pin 501 is used, the central axis of which is along the thickness direction of the substrate 561. Figure 11 (d) Vertical orientation) configuration. In this configuration, the outline of the through hole formed at the position corresponding to the locating pin 501 makes point contact with one end face 561t1 along a line along the first direction D1, and makes point contact with the other end face 561t2 along a line along the second direction D2. Thus, exposure of the cutout portion 561t can be suppressed in this part.

[0142] Furthermore, in the description of the second embodiment, it is explained that the support pins 301, 302, and 303 are cylindrical. In fact, since the support pins 301, 302, and 303 need to be pulled out from the molded resin part after molding, they are processed so that, although small, their diameter tapers towards the top to facilitate removal.

[0143] The present invention has been described with reference to the above embodiments, but the present invention is not limited to the above embodiments. Improvements or modifications can be made within the scope of the ideas of the present invention for the purpose of improvement.

[0144] Explanation of reference numerals in the attached figures: 10: Current detection device 21, 22, 23: Busbars 21a, 22a, 23a: Fastening terminal section 21b: Connecting surface 21c: Upper stepped section 21d: Lower step section 21e: Anchoring section 21f: Curved section 21g: Narrow section 21h, 22h, 23h: Through-hole section 21u: Establishment Department 21v: Extension 31, 32, 33: Fastening components 31h: Inner surface 34: Bolt 40: Frame 41, 42, 43: Protrusions 41a: Surface 44: Cover 44a: Hole 45: Casing 45a: Hole 50: Substrate 51, 52, 53: Magnetic sensors 61, 62, 63: First shielding component 71, 72, 73: Second shielding components 101a, 111a, 121a, 131a, 141a: Fastening terminal section 101b, 111b, 121b, 131b, 141b: Connecting surfaces 101c, 141c: Upper stepped section 101d, 141d: Lower step section 101e, 111e, 121e, 131e, 141e: Anchoring section 101h: Through hole 121c, 131c: Side view 121d, 131d: concave part 161, 171: Substrate 161a: Exposed area 161b: Widening section 161c: Expanding part 161s: End face 161t: Incision site 261, 271: Protection Department 301, 302, 303: Support pins 311, 312, 313: Positioning pins 340: Housing 341a, 342a, 343a: Through holes 341b, 342b, 343b: Exposed hole portion 361, 362, 363: Substrate 361a, 362a, 363a: Long side 361b, 362b, 363b: Surface 361t, 362t, 363t: Incision site 361t1, 361t2: End face 401, 501: Positioning pins 461, 561: Substrate 461t, 561t: Incision site 461t1, 461t2: Ridge section 561t1, 561t2: End face D1: First Direction D2: Second Direction M: External components P1, P2: Points of contact S: Gap

Claims

1. A current detection device, characterized in that, have: Busbar, through which the current to be measured flows; Fastening components are used to securely connect external components to the busbar; The frame holds the busbar and the fastening member in contact with each other. as well as A magnetic sensor, configured opposite to the busbar, is capable of detecting the magnetic field generated by the measured current flowing through the busbar. The busbar has a fastening terminal portion at its end side that contacts the external component. The surface of the fastening terminal that contacts the external component, i.e., the connecting surface, is exposed from the frame. The fastening terminal portion has an anchoring portion, which has a surface different from the connecting surface and is embedded in the frame. The connecting surface is exposed in a manner that is more prominent than the portion of the frame that covers the anchor portion.

2. The current detection device according to claim 1, wherein, The busbar has a curved portion between the end having the fastening terminal and the end opposite to the end. The magnetic sensor is configured to be positioned relative to the bend and the fastening terminal portion in the busbar.

3. The current detection device according to claim 1 or 2, wherein, The anchoring portion is embedded in a molded body of resin-based material in the frame.

4. A current detection device, characterized in that, have: Busbar, through which the current to be measured flows; A magnetic sensor, configured opposite to the busbar, is capable of detecting the magnetic field generated by the measured current flowing through the busbar; A pair of shielding members sandwich the busbar and the magnetic sensor between the pair of shielding members; as well as The frame, made of resin-based material, is integrally formed with the first shielding member of the pair of shielding members located near the busbar. The first shielding member has: Substrate, having a plate-like shape of metal; and The protective part, made of resin-based material, covers at least the portion of the molded die that abuts against the end face of the substrate.

5. The current detection device according to claim 4, wherein, The first shielding member has an exposed portion at the location opposite to the busbar, which exposes the substrate.

6. The current detection device according to claim 5, wherein, When the exposed portion is viewed from the busbar side, the exposed portion has a widened portion on the outside of the portion overlapping with the busbar, which exposes the substrate.

7. The current detection device according to claim 5, wherein, The substrate has an expansion portion that is connected to and exposes the exposed portion. The protective portion covers the end face of the substrate in such a way that at least the exposed portion and the expanded portion are exposed.

8. The current detection device according to claim 6, wherein, The substrate has an expansion portion that is connected to and exposes the exposed portion. The protective portion covers the end face of the substrate in such a way that at least the exposed portion and the expanded portion are exposed.

9. The current detection device according to claim 7, wherein, The first shielding member is an insert formed inside the frame. The frame has a hole that exposes a portion of the expansion portion.

10. The current detection device according to claim 8, wherein, The first shielding member is an insert formed inside the frame. The frame has a hole that exposes a portion of the expansion portion.

11. The current detection device according to any one of claims 4 to 10, wherein, The frame has: The housing, with the first shielding member molded as an insert; and The cover holds the other of the pair of shielding members, namely the second shielding member. The substrate on which the magnetic sensor is mounted is fixed to the housing.

12. The current detection device according to any one of claims 4 to 10, wherein, It has fastening members for securely connecting external components to the busbar. The frame holds the busbar and the fastening member in contact with each other. The busbar has a fastening terminal portion at its end side that contacts the external component. The connection surface of the fastening terminal that contacts the external component is exposed from the frame. The fastening terminal portion has an anchoring portion, which has a surface different from the connecting surface and is embedded in the frame.

13. The current detection device according to claim 11, wherein, It has fastening members for securely connecting external components to the busbar. The frame holds the busbar and the fastening member in contact with each other. The busbar has a fastening terminal portion at its end side that contacts the external component. The connection surface of the fastening terminal that contacts the external component is exposed from the frame. The fastening terminal portion has an anchoring portion, which has a surface different from the connecting surface and is embedded in the frame.

14. A current detection device, characterized in that, The current detection device has a sensor unit. The sensor unit has: A plate-shaped busbar through which the current to be measured flows; A magnetic sensor is configured opposite to the surface of the busbar. A pair of shielding members are positioned at a location that sandwiches the busbar and the magnetic sensor from both sides in the stacking direction of the busbar and the magnetic sensor; and The frame is constructed from a molded body made of resin-based material. The first shielding member, located near the busbar, is an insert formed inside the frame and is composed of a polygonal plate-like body in plan view, with cutouts at at least two corners of the polygon. The frame has at least one through hole, which is partially connected to an end face formed by the cutout and extending along the stacking direction.

15. The current detection device according to claim 14, wherein, In a cross-section cut with a plane parallel to the plate surface of the first shielding member, the outline of the through hole and the cut portion are in point contact with each other.

16. The current detection device according to claim 15, wherein, In a cross-section cut with a plane parallel to the plate surface of the first shielding member, even if cut at any position in the stacking direction, the outline of the through hole and the cut portion are in point contact with each other at the same position.

17. The current detection device according to claim 14, wherein, The cut portion forms multiple end faces, and in a cross-section cut with a plane parallel to the plate surface of the first shielding member, the outline of the through hole portion makes point contact with the multiple end faces respectively.

18. The current detection device according to claim 14, wherein, The cut portion is formed to have at least two end faces. The through hole portion is partially connected to two or more end faces that form the cut portion.

19. The current detection device according to claim 14, wherein, The cut portion is formed having two end faces. The through hole is partially connected to the two end faces that form the cut.

20. The current detection device according to claim 14, wherein, The cross-sectional shape of the through hole is circular when cut with a plane parallel to the plate surface of the first shielding member.

21. The current detection device according to claim 14, wherein, The first shielding member is rectangular when viewed from above, and has cutouts at a pair of diagonal positions. The frame has through holes that correspond to the cutouts.

22. The current detection device according to claim 14, wherein, The first shielding member is rectangular in top view and has the cutouts at two pairs of diagonal positions. The frame has through holes that correspond to the cutouts.

23. The current detection device according to any one of claims 14 to 22, wherein, The frame has: The housing, with the first shielding member molded as an insert; and The cover holds the other of the pair of shielding members, namely the second shielding member. The substrate on which the magnetic sensor is mounted is fixed to the housing.

24. The current detection device according to any one of claims 14 to 22, wherein, It has fastening members for securely connecting external components to the busbar. The frame holds the busbar and the fastening member in contact with each other. The busbar has a fastening terminal portion at its end side that contacts the external component. The connection surface of the fastening terminal that contacts the external component is exposed from the frame. The fastening terminal portion has an anchoring portion, which has a surface different from the connecting surface and is embedded in the frame.

25. The current detection device according to claim 23, wherein, It has fastening members for securely connecting external components to the busbar. The frame holds the busbar and the fastening member in contact with each other. The busbar has a fastening terminal portion at its end side that contacts the external component. The connection surface of the fastening terminal that contacts the external component is exposed from the frame. The fastening terminal portion has an anchoring portion, which has a surface different from the connecting surface and is embedded in the frame.

26. A current detection device, characterized in that, The current detection device has a sensor unit. The sensor unit has: A plate-shaped busbar through which the current to be measured flows; A magnetic sensor is configured opposite to the surface of the busbar. A pair of shielding members are positioned at a location that sandwiches the busbar and the magnetic sensor from both sides in the stacking direction of the busbar and the magnetic sensor; and The frame is constructed from a molded body made of resin-based material. Of the pair of shielding members, the first shielding member located near the busbar is a plate-like body embedded inside the frame. Within the frame, a plurality of sensor units are arranged along a first direction parallel to the surface of the first shielding member. The frame has an exposed hole that exposes the plate surface of the first shielding member. The exposed hole is formed such that the plate surface located at the end of the first shielding member is exposed in a second direction orthogonal to the first direction and parallel to the plate surface of the first shielding member.

27. The current detection device according to claim 26, wherein, The first direction is orthogonal to the extension direction of the busbar.

28. The current detection device according to claim 26, wherein, The first shielding member has a rectangular long side arranged along the first direction when viewed from above, and one or more exposed holes are arranged along the long side.

29. The current detection device according to any one of claims 26 to 28, wherein, The frame has: The housing, with the first shielding member molded as an insert; and The cover holds the other of the pair of shielding members, namely the second shielding member. The substrate on which the magnetic sensor is mounted is fixed to the housing.

30. The current detection device according to any one of claims 26 to 28, wherein, It has fastening members for securely connecting external components to the busbar. The frame holds the busbar and the fastening member in contact with each other. The busbar has a fastening terminal portion at its end side that contacts the external component. The connection surface of the fastening terminal that contacts the external component is exposed from the frame. The fastening terminal portion has an anchoring portion, which has a surface different from the connecting surface and is embedded in the frame.

31. The current detection device according to claim 29, wherein, It has fastening members for securely connecting external components to the busbar. The frame holds the busbar and the fastening member in contact with each other. The busbar has a fastening terminal portion at its end side that contacts the external component. The connection surface of the fastening terminal that contacts the external component is exposed from the frame. The fastening terminal portion has an anchoring portion, which has a surface different from the connecting surface and is embedded in the frame.

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