Current detector

Abstract

To provide a current detector where a sensor element can be arranged adjacent to an edge of a bus bar.SOLUTION: A current detector comprises a bus bar 30 through which current flows, and a package 22 including a sensor element 21 detecting a magnetic field generated around the bus bar. The bus bar includes a bent part 34. The bus bar also includes inflow-side portions 32, 832, and 932 linked to the bent part on the current inflow side rather than the bent part, and outflow-side potions 33 and 933 linked to the bent part on the current outflow side rather than the bent part. A package is provided in an adjacent position where at least the inflow-side portion or the outflow-side portion overlaps in one direction crossing both of a longitudinal direction of the inflow-side portion and an extension direction extending so as to be away from the bent part in the outflow-side portion.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The disclosure provided herein relates to a current detector. [Background technology]

[0002] Patent Document 1 describes a Hall sensor device in which conductor plates are arranged to surround a Hall sensor in a U-shape. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2002-516396 Summary of the Invention [Problem to be solved by the invention]

[0004] Since the Hall sensor is provided on the same plane as the conductor plate, a gap exists between the Hall sensor and the conductor plate. In Patent Document 1, it was difficult to arrange the Hall sensor close to the edge of the conductor plate.

[0005] An object of the present disclosure is to provide a current detector capable of improving the detection accuracy of a sensor element by disposing the sensor element close to an edge of a bus bar. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a current detector comprising: A busbar (30) through which current flows; and a package (22) including a sensor element (21) for detecting a magnetic field generated around the bus bar. The bus bar has a bent portion (34, 834, 934), the bus bar has an inflow side portion (32, 832, 932) connected to the bent portion on the current inflow side of the bent portion, and an outflow side portion (33, 933) connected to the bent portion on the current outflow side of the bent portion, A package is provided at a position overlapping and adjacent to at least one of the inlet side section and the outlet side section in a direction perpendicular to both the longitudinal direction of the inlet side section and the extension direction extending away from the bent portion in the outlet side section.

[0007] A magnetic flux is likely to be generated that runs through the edges of the inlet side portion and the outlet side portion in one direction. The magnetic flux density increases closer to the busbar. The package is provided at a position that overlaps at least one of the inlet side portion and the outlet side portion in one direction and is close to at least one of the portions. This makes it possible to arrange the sensor elements close together in a direction perpendicular to the one direction so that they overlap at least one edge. By arranging them close together, a strong magnetic field can be detected. The above means improves the sensor accuracy.

[0008] It should be noted that the reference numbers in parentheses above merely indicate the corresponding relationship with the configurations described in the embodiments described below, and do not in any way limit the technical scope. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is an electrical circuit diagram of the power conversion device. [Diagram 2] FIG. 1 is a perspective view of a current detector according to a first embodiment. [Diagram 3] 1 is a plan view of a current detector according to a first embodiment as viewed in a thickness direction. [Figure 4] 1 is a plan view of a current detector according to a first embodiment, as viewed in a width direction. [Diagram 5] 1 is a plan view of a current detector according to a first embodiment, as viewed in a width direction. [Figure 6] FIG. 11 is a plan view of a current detector according to a second embodiment, as viewed in a thickness direction. [Figure 7] FIG. 11 is a plan view of a current detector according to a third embodiment, as viewed in a thickness direction. [Figure 8] FIG. 13 is a plan view of a current detector according to a fourth embodiment, as viewed in the width direction. [Figure 9] FIG. 13 is a plan view of a current detector according to a fifth embodiment, as viewed in the width direction. [Figure 10] FIG. 13 is a plan view of a current detector according to a sixth embodiment, as viewed from the depth direction. [Figure 11] FIG. 13 is a plan view of a current detector according to a seventh embodiment, as viewed from the depth direction. [Figure 12] FIG. 13 is a plan view of a current detector according to an eighth embodiment, as viewed in a thickness direction. [Figure 13] FIG. 13 is a plan view of a current detector according to a ninth embodiment as viewed from the thickness direction. [Figure 14] FIG. 13 is a perspective view showing a modified example of the ninth embodiment. [Figure 15] FIG. 23 is a plan view of the current detector of the tenth embodiment as viewed in the thickness direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, the other embodiment described previously may be applied to the other parts of the configuration.

[0011] In addition to combinations of parts that are explicitly stated as possible in each embodiment, it is also possible to partially combine embodiments, embodiments and variations, and variations even if not explicitly stated, provided that there are no particular problems with the combination.

[0012] (First embodiment) 1 is an electrical circuit diagram of a power conversion device 1. The power conversion device 1 is mounted on a vehicle such as an electric vehicle or a hybrid vehicle. The power conversion device 1 performs power conversion between a battery 2 and a motor generator 3. The power conversion device 1, together with the battery 2 and the motor generator 3, constitutes a drive system for the vehicle.

[0013] The battery 2 is a chargeable and dischargeable secondary battery such as a lithium ion battery or a nickel metal hydride battery. The motor generator 3 is a three-phase AC rotating electric machine. The motor generator 3 may be called a multi-phase motor. The motor generator 3 functions as a drive source for the vehicle, that is, an electric motor. The motor generator 3 functions as a generator during regeneration.

[0014] The power conversion device 1 includes a capacitor 4, an inverter 5, a current sensor 20, an output bus bar 30, and a substrate 40. The capacitor 4 smoothes a direct current supplied from, for example, a battery 2. A positive terminal of the capacitor 4 is connected to a positive electrode, which is an electrode on the high potential side of the battery 2. A negative terminal of the capacitor 4 is connected to a negative electrode, which is an electrode on the low potential side of the battery 2.

[0015] The inverter 5 is a DC-AC converter that converts the supplied DC power into three-phase AC of a predetermined frequency. The inverter 5 outputs the power converted from DC power to AC power to the motor generator 3. The inverter 5 also converts AC power generated by the motor generator 3 into DC power.

[0016] The inverter 5 is configured with upper and lower arm circuits. The upper and lower arm circuits 6 are sometimes referred to as legs. The upper and lower arm circuits of each phase are configured by connecting an upper arm 6H and a lower arm 6L in series between a high potential power supply bus bar 11, which is a power supply line on the positive side, and a low potential power supply bus bar 12, which is a power supply line on the negative side.

[0017] The inverter 5 includes, as an example, a three-phase upper and lower arm circuit 6A. The three-phase upper and lower arm circuit 6A includes a U-phase upper and lower arm circuit, a V-phase upper and lower arm circuit, and a W-phase upper and lower arm circuit. The three-phase upper and lower arm circuits 6A are individually covered with a resin member to form a semiconductor module. The three-phase semiconductor module may be collectively referred to as a power module.

[0018] In this embodiment, as an example of the switching elements constituting each of the arms 6H and 6L, an n-channel type insulated gate bipolar transistor 7 (hereinafter, referred to as IGBT7) is used. A freewheeling diode FWD7D is connected in inverse parallel to each of the IGBT7. The upper and lower arm circuits 6A for one phase have two IGBT7s.

[0019] In the upper arm 6H, a first input terminal is connected to the collector of the IGBT 7. The high potential power supply bus bar 11 and the collector of the IGBT 7 are electrically connected via the first input terminal. In the lower arm 6L, a second input terminal is connected to the emitter of the IGBT 7. The low potential power supply bus bar 12 and the emitter of the IGBT 7 are electrically connected via the second input terminal. An output terminal is connected to the midpoint between the upper arm 6H and the lower arm 6L. The output terminal and the motor generator 3 are electrically connected via the output bus bar 30.

[0020] A gate terminal is connected to the gate of the IGBT 7 in the upper arm 6H. A gate terminal is connected to the gate of the IGBT 7 in the lower arm 6L. The gate terminal connected to the IGBT 7 in the upper arm 6H and the gate terminal connected to the IGBT 7 in the lower arm 6L are electrically connected to the substrate 40.

[0021] The substrate 40 is provided with a control circuit that controls the on / off of the IGBTs via the gate terminals. Therefore, the power conversion device 1 can supply three-phase AC currents with different periods to the motor generator 3 via the output bus bar 30 by controlling the on / off of the multiple IGBTs 7. The substrate 40 may also be provided with a drive circuit that drives the IGBTs 7 in addition to the control circuit. The drive circuit supplies a drive voltage to the gate of the IGBT 7 of the corresponding arm based on a drive command from the control circuit. The drive circuit drives the corresponding IGBT 7, i.e., drives it on and off, by applying the drive voltage. The drive circuit is sometimes called a driver.

[0022] The output bus bar 30 is connected to each phase of the motor generator 3. A current sensor 20 is provided on the output bus bar 30. The output bus bar 30 and the current sensor 20 may be collectively referred to as a current detector 50. It can also be said that the current detector 50 has the output bus bar 30 and the current sensor 20. It can also be said that the power conversion device 1 includes a capacitor 4, an inverter 5, a substrate 40, and a current detector 50.

[0023] The output busbar 30 is a conductive member made of a metal material such as copper having electrical conductivity. The output busbar 30 forms a current path through which a current flows. The output busbar 30 is plate-shaped and thin in the plate thickness direction. The output busbar 30 has a short side in one direction perpendicular to the plate thickness direction. The output busbar 30 has a long side in a direction perpendicular to the plate thickness direction and the short side direction. The output busbar 30 is elongated in the long direction. The output busbar 30 is formed by subjecting a metal member such as copper to punching, bending, or the like.

[0024] The output bus bar 30 is electrically connected to the inverter 5 and the motor generator 3. A current flows through the output bus bar 30 when current is passed from the inverter 5 to the motor generator 3. Alternatively, a current flows through the output bus bar 30 when current is passed from the motor generator 3 to the inverter 5. A specific form of the output bus bar 30 will be described later.

[0025] The current sensor 20 is provided on each of the three output bus bars 30. The current sensor 20 is a sensor that detects a current flowing between the inverter 5 and the motor generator 3.

[0026] In this embodiment, the current sensor 20 detects the current flowing through the output bus bar 30, and detects the magnetic field generated by the current flowing through the output bus bar 30. The current sensor 20 does not have a magnetic flux collecting core for converging the magnetic field, and is a coreless current sensor.

[0027] The current sensor 20 has a sensor element 21 and a package 22. The sensor element 21 is a magnetic sensor that detects a magnetic field. The sensor element 21 detects the magnetic flux of the magnetic field and outputs a detection signal according to the magnetic flux density. The sensor element 21 is an element that converts a magnetic signal into an electric signal, and is sometimes called a magnetoelectric conversion element. The sensor element 21 is, for example, a Hall element. The sensor element 21 has a predetermined detection direction. The sensor element 21 is capable of detecting magnetic flux passing in the detection direction. The predetermined detection direction corresponds to the thickness direction described below.

[0028] The detection signal of the sensor element 21 includes information about a component of the magnetic flux passing through the sensor element 21 that extends in the detection direction, but does not include information about a component perpendicular to the detection direction. That is, the sensor element 21 detects a component of the magnetic flux linking the sensor element 21 that extends in the detection direction, but does not detect a component perpendicular to the detection direction. One current sensor 20 may have one sensor element 21 or may have multiple sensor elements 21. Regardless of the number of sensor elements 21, the sensor elements 21 are sealed in one package 22 to form the current sensor 20.

[0029] The sensor element 21 is mainly made of semiconductor material. When the temperature of the sensor element 21 reaches or exceeds a certain level, it is no longer able to fully demonstrate its performance. The temperature limit at which the sensor element 21 can fully demonstrate its performance is sometimes referred to as the heat resistance temperature. In the current sensor 20, it is necessary to detect the magnetic field generated by the current flowing through the output bus bar 30, without exceeding the heat resistance temperature of the sensor element 21. For this reason, it is preferable not to provide a portion of the output bus bar 30 with high thermal resistance.

[0030] For example, it is desirable not to provide the output busbar 30 with a structure with a reduced cross-sectional area. The structure with a reduced cross-sectional area is, for example, a recess such as a notch, rolled, or dented. The presence of the recess increases the current density of the narrowed portion of the output busbar 30 adjacent to the recess. The magnetic flux density passing through the package 22 can be increased. However, the amount of heat generated increases in the narrowed portion. There is a concern that the sensor element 21 may not be able to fully perform its own performance due to the thermal effect of the narrowed portion. In view of this, in this embodiment, a structure with a reduced cross-sectional area is not formed in order to avoid the thermal effect on the sensor element 21. As an example, a structure in which the package 22 is provided at a position close to the recess in the thickness direction TD is not formed. As another example, a structure in which the package 22 is provided so that a part of the package 22 is accommodated in the recess is not formed.

[0031] The package 22 is formed in a thin rectangular parallelepiped shape from a resin material or the like. Hereinafter, the plate thickness direction of the package 22 may be referred to as the thickness direction TD. The thickness direction TD may be referred to as one direction perpendicular to the longitudinal direction of the output bus bar 30. The direction perpendicular to the thickness direction TD may be referred to as the width direction WD. The direction perpendicular to the thickness direction TD and the width direction WD may be referred to as the depth direction DP. The thickness direction TD, the width direction WD, and the depth direction DP are three directions perpendicular to each other.

[0032] The package 22 houses the sensor element 21 in a covered state. The package 22 protects the sensor element 21 while allowing the sensor element 21 to detect a magnetic field. The above-mentioned substrate 40 is provided so as to overlap the package 22 in the thickness direction TD. The package 22 is fixed to the surface of the substrate 40 facing the package 22 in the thickness direction TD. As an example, the current sensor 20 has a plurality of conductive sensor terminals exposed from the package 22. The sensor terminals are electrically connected to the sensor element 21 inside the package 22. The package 22 is fixed to the substrate 40 by joining the sensor terminals to the substrate 40 via solder or the like. The current sensor 20 and the substrate 40 are electrically connected via solder.

[0033] <Specific form of output bus bar> FIG. 2 is a perspective view of the current detector 50. FIG. 3 is a plan view of the current detector 50 as viewed from the thickness direction TD. FIG. 4 is a plan view of the current detector 50 as viewed from one side in the width direction WD. FIG. 5 is a plan view of the current detector 50 of the first embodiment as viewed from the other side in the width direction WD. The output bus bar 30 in the first embodiment has a first extension portion 31, a second extension portion 32, and a third extension portion 33. The first extension portion 31, the second extension portion 32, and the third extension portion 33 are continuous in this order and made of the same material. Note that the form of the output bus bar 30 shown below is merely an example and is not limited thereto.

[0034] The output bus bar 30 is a conductive member that electrically connects the semiconductor module included in the inverter 5 to the motor generator 3. As an example, a semiconductor module is electrically connected to the end of the first extension 31 opposite to the end connected to the second extension 32. The inverter 5 has a three-phase semiconductor module. The semiconductor module has an output terminal connected to the midpoint of the upper and lower arm circuits 6A. A part of the output terminal is exposed from the resin member of the semiconductor module. The exposed output terminal and the end of the first extension 31 are connected by welding or the like.

[0035] The motor generator 3 is electrically connected to the end of the third extension 33 opposite to the end connected to the second extension 32. As an example, the motor generator 3 is electrically connected to the third extension 33 via a connector and a terminal block. The terminal block has a conductive member and a resin member. The third extension 33 is connected to one end of the conductive member. A connector is connected to the other end of the conductive member. The area between the one end and the other end of the conductive member is covered with the resin member. The end of the third extension 33 is fixed to the resin member via a bolt or the like so as to be electrically connected to the conductive member.

[0036] As shown in Figures 2 and 3, the output busbar 30 has a substantially Z-shape when viewed from the thickness direction TD. The symmetric angle between the first extension portion 31 and the second extension portion 32 when viewed from the thickness direction TD is a right angle. The symmetric angle is not limited to a right angle. The symmetric angle is less than 180 degrees. The angle between the second extension portion 32 and the third extension portion 33 when viewed from the thickness direction TD is a right angle. The angle between the second extension portion 32 and the third extension portion 33 when viewed from the thickness direction TD is not limited to a right angle. The angle between the second extension portion 32 and the third extension portion 33 when viewed from the thickness direction TD is less than 180 degrees.

[0037] The first extension portion 31 extends along the width direction WD. The longitudinal direction of the first extension portion 31 coincides with the width direction WD. The plate thickness direction of the first extension portion 31 coincides with the thickness direction TD. The short side direction of the first extension portion 31 coincides with the depth direction DP. Note that the output busbar 30 is not limited to a configuration having the first extension portion 31, the second extension portion 32, and the third extension portion 33. The output busbar 30 may be configured to have only the second extension portion 32 and the third extension portion 33.

[0038] The second extension portion 32 extends along the depth direction DP. The longitudinal direction of the second extension portion 32 coincides with the depth direction DP. The plate thickness direction of the second extension portion 32 coincides with the width direction WD. The short side direction of the second extension portion 32 coincides with the thickness direction TD.

[0039] The third extension portion 33 extends along the width direction WD. The longitudinal direction of the third extension portion 33 coincides with the width direction WD. In this embodiment, the longitudinal direction of the third extension portion 33 corresponds to the extension direction extending away from the bent portion 34. The plate thickness direction of the third extension portion 33 coincides with the thickness direction TD. The short side direction of the third extension portion coincides with the depth direction DP.

[0040] The second extension portion 32 has a first end surface 32A and a second end surface 32B separated in the width direction WD. The first end surface 32A is provided closer to the inverter 5 than the second end surface 32B. A first extension portion 31 is provided on the second extension portion 32 so as to be continuous with the first end surface 32A. The first extension portion 31 extends away from the first end surface 32A. A third extension portion 33 is provided on the second extension portion 32 so as to be continuous with the second end surface 32B. The third extension portion 33 extends away from the second end surface 32B.

[0041] The second extension portion 32 has a third end surface 32C and a fourth end surface 32D that are spaced apart in the depth direction DP. The first extension portion 31 and the third extension portion 33 are spaced apart in the depth direction DP. In FIG. 2, the third end surface 32C is provided closer to the front in the depth direction DP than the fourth end surface 32D. The first extension portion 31 is provided on the second extension portion 32 so as to be continuous with the third end surface 32C. The third extension portion 33 is provided on the second extension portion 32 so as to be continuous with the fourth end surface 32D.

[0042] The second extension portion 32 has a fifth end face 32E and a sixth end face 32F that are spaced apart in the thickness direction TD. The first extension portion 31 and the third extension portion 33 are spaced apart in the thickness direction TD. In FIG. 2, the fifth end face 32E is provided above the sixth end face 32F in the thickness direction TD. The third extension portion 33 is provided on the second extension portion 32 so as to be continuous with the fifth end face 32E. The first extension portion 31 is provided on the second extension portion 32 so as to be continuous with the sixth end face 32F.

[0043] The following description will be mainly focused on the current flowing through the output busbar 30 from the inverter 5 to the motor generator 3. In this case, the current flows from the first extension portion 31 to the third extension portion 33 along the longitudinal direction of the output busbar 30. The current flowing longitudinally through the output busbar 30 generates a magnetic field in the circumferential direction around the longitudinal direction. More specifically, the current flows in the width direction WD through the first extension portion 31, in the depth direction DP through the second extension portion 32, and in the width direction WD through the third extension portion 33. The current flowing in each direction through the first extension portion 31, the second extension portion 32, and the third extension portion 33 generates a magnetic field in the circumferential direction of each current direction.

[0044] The current sensor 20 detects a magnetic field generated by a current flowing through the second extension 32 and the third extension 33. The second extension 32 and the third extension 33 are target portions where a magnetic field is detected, and therefore may be referred to as detection target portions 32 and 33. The detection target portions 32 and 33 are L-shaped when viewed from the thickness direction TD. The detection target portions 32 and 33 have a bent portion 34 at a location where a seventh end face 33A, which is an end face in the depth direction of the third extension 33 on the first extension 31 side, meets with a second end face 32B. A magnetic field is generated in the circumferential direction around the longitudinal direction by a current flowing through the detection target portions 32 and 33. The second extension 32 is provided on the side where the current flows in relative to the bent portion 34, and therefore may be referred to as an inflow side portion. The third extension 33 is provided on the side where the current flows out relative to the bent portion 34, and therefore may be referred to as an outflow side portion.

[0045] Since this magnetic field is measured by the current sensor 20, it may be referred to as the measured magnetic field. The measured magnetic field occurs concentrically around the output busbar 30 in a plane defined by two directions perpendicular to the longitudinal direction. Since the measured magnetic field occurs in a ring shape around the output busbar 30, the rate of change of the magnetic field is greater in every direction toward the end face. The rate of change of the magnetic field can also be referred to as the rate of change of the inclination of the arrow that shows the magnetic field. In every direction, the magnetic flux density along the end face is greater the closer to the end face.

[0046] For example, a magnetic field along the thickness direction TD is generated in the vicinity of the second end face 32B, which is the end face in the width direction WD of the second extension portion 32. A magnetic field along the thickness direction TD is generated in the vicinity of the seventh end face 33A, which is the end face in the depth direction DP of the third extension portion 33. As described above, the current sensor 20 detects the component along the thickness direction TD in the measured magnetic field. By disposing the current sensor 20 in the vicinity of the second end face 32B and the seventh end face 33A, the magnetic flux density in the thickness direction TD penetrating the current sensor 20 can be increased. As the magnetic flux density penetrating the current sensor 20 increases, the signal-to-noise ratio improves, thereby improving the detection accuracy. In this embodiment, the positional relationship between the current sensor 20 and the output bus bar 30 is determined from this perspective.

[0047] <Positional relationship between current sensor and output bus bar> 2 to 4, current sensor 20 is shown in the shape of a rectangular parallelepiped with a thin plate thickness in the thickness direction TD. Package 22 of current sensor 20 corresponds to the rectangular parallelepiped shape. A portion of package 22 overlaps detection target portions 32, 33 in the thickness direction TD and is provided in a position close to the thickness direction TD. Package 22 overlaps bent portion 34 in the thickness direction TD and is provided in a position close to the thickness direction TD.

[0048] As described above, the detection targets 32 and 33 are L-shaped when viewed from the thickness direction TD. The detection targets 32 and 33 are adjacent to the overlapping region 35 where the projection region of the second extension 32 in the width direction WD and the projection region of the third extension 33 in the depth direction DP overlap. The overlapping region 35 is a gap. The overlapping region 35 may also be referred to as an enclosed region surrounded by the second extension 32 and the third extension 33. The package 22 is provided at a position close to the detection targets 32 and 33 and the overlapping region 35 in the thickness direction TD. The overlapping region 35 is sandwiched between both the second extension 32 and the third extension 33 and adjacent to both the second extension 32 and the third extension 33, and therefore may be referred to as an adjacent region.

[0049] The substrate 40 is provided on the opposite side of the package 22 from the detection targets 32, 33 in the thickness direction TD. The package 22 is fixed to the surface of the substrate 40 that faces the detection targets 32, 33 in the thickness direction TD. The substrate 40 is provided close to the detection targets 32, 33 to such an extent that a magnetic field in the thickness direction TD can pass through the package 22. This effectively prevents the increase in the size of the current detector 50 in the thickness direction TD.

[0050] A magnetic field along the thickness direction TD generated near the second end face 32B and a magnetic field along the thickness direction TD generated near the seventh end face 33A pass through the package 22. The direction of the magnetic field along the thickness direction TD generated near the second end face 32B coincides with the direction of the magnetic field along the thickness direction TD generated near the seventh end face 33A. The magnetic flux density of the magnetic field in the thickness direction TD passing through the package 22 increases. The detection accuracy of the current sensor 20 improves.

[0051] The package 22 overlaps the edges of the detection targets 32, 33 in the thickness direction TD. The edges of the detection targets 32, 33 that overlap with the package 22 may be referred to as overlapping edges 36. As an example, the sensor element 21 is provided in the package 22 so as to overlap the overlapping region 35. The sensor element 21 is provided so as to be positioned on the inside of the package 22, closer to the bent portion 34 than to the corners of the package 22. As another example, the sensor element 21 is provided in the package 22 so as to straddle at least a portion of the overlapping edges 36.

[0052] <Action and effect> The package 22 is provided at a position overlapping at least one of the second extension 32 and the third extension 33 in the thickness direction TD and adjacent to the thickness direction TD. This makes it possible to arrange the sensor element 21 close to the edge of the second extension 32 and the edge of the third extension 33 in a direction perpendicular to the thickness direction TD so that the sensor element 21 overlaps with the edge of the second extension 32 and the edge of the third extension 33. A magnetic field along the thickness direction TD is generated near the end face of the second extension 32. A magnetic field along the thickness direction TD is generated near the end face of the third extension 33. Accordingly, the magnetic field along the thickness direction TD generated near the end face of the second extension 32 and the magnetic field along the thickness direction TD generated near the end face of the third extension 33 overlap with each other, and the density of the magnetic flux penetrating the sensor element 21 increases. The detection accuracy of the sensor element is improved.

[0053] The package 22 has a rectangular parallelepiped shape with a small plate thickness in the thickness direction TD. The sensor element 21 is provided in the overlapping region 35 inside the package 22, and is provided closer to the bent portion 34 than the corner of the package 22. This increases the magnetic field in the thickness direction TD that passes through the sensor element 21. This improves the detection accuracy of the sensor element.

[0054] No recesses are formed in the detection target portions 32 and 33. This prevents an increase in the thermal resistance of the detection target portions 32 and 33. This makes it possible to improve the detection accuracy of the sensor element 21 while preventing an increase in thermal resistance.

[0055] The symmetric angle between the second extension portion 32 and the third extension portion 33 is less than 180 degrees. This allows the magnetic fields along the thickness direction TD to overlap in the overlap region 35, which increases the density of the magnetic flux penetrating the sensor element 21. This improves the detection accuracy of the sensor element 21.

[0056] Second embodiment 6 is a plan view of a current detector 50 according to the second embodiment as viewed from the thickness direction. The following mainly describes the configuration different from the first embodiment. In the second embodiment, the target angle is 90 degrees or more and less than 180 degrees. In the second embodiment, the magnetic field along the thickness direction TD is also increased.

[0057] Third embodiment 7 is a plan view of a current detector 50 of the third embodiment as viewed from the thickness direction. In the third embodiment, the target angle is equal to or greater than 0 degrees and less than 90 degrees. In this case, the distance between the detection targets 32, 33 is closer than when the target angle is 90 degrees or greater. The magnetic flux penetrating the sensor element 21 increases. In the third embodiment, the magnetic field along the thickness direction TD passing through the sensor element 21 also increases.

[0058] (Fourth embodiment) 8 is a plan view of a current detector 50 according to the fourth embodiment as viewed in the width direction WD. In the fourth embodiment, the angle between the seventh end surface 33A and the fifth end surface 32E as viewed in the width direction WD is greater than 90 degrees. The fourth embodiment also provides the same effects as the previous embodiments.

[0059] Fifth embodiment 9 is a plan view of a current detector 50 according to the fifth embodiment, as viewed in the width direction WD. In the fifth embodiment, the angle between the seventh end surface 33A and the fifth end surface 32E when viewed in the width direction WD is less than 90 degrees. The fifth embodiment also provides the same effects as the previous embodiments.

[0060] Sixth embodiment 10 is a plan view of a current detector 50 according to the sixth embodiment as viewed from the depth direction DP. In the sixth embodiment, the angle between the second extension 32 and the third extension 33 as viewed from the depth direction DP is greater than 90 degrees. The sixth embodiment also provides the same effects as the previous embodiments.

[0061] Seventh embodiment 11 is a plan view of a current detector 50 according to the seventh embodiment as viewed from the depth direction DP. In the seventh embodiment, the angle between the second extension 32 and the third extension 33 as viewed from the depth direction DP is less than 90 degrees. The seventh embodiment also provides the same effects as the previous embodiments.

[0062] Eighth embodiment FIG. 12 is a plan view of the current detector 50 of the eighth embodiment as viewed from the thickness direction TD. In the eighth embodiment, the second extension portion 832 and the third extension portion 33 may be collectively referred to as the detection target portions 832, 33. The second extension portion 832 may be referred to as the inflow side portion. In the eighth embodiment, the output bus bar 30 is substantially J-shaped as viewed from the thickness direction TD. The second extension portion 832 has a portion extending along the diagonal direction where the depth direction DP and the width direction WD intersect, and a portion extending along the depth direction DP. The portion extending along the diagonal direction where the depth direction DP and the width direction WD intersect may be referred to as the first portion 837. The portion extending along the depth direction DP may be referred to as the second portion 838. The first portion 837 is connected to the third extension portion 33. The second portion 838 is connected to an end portion of the first portion 837 opposite to the end portion connected to the third extension portion 33.

[0063] The second extension portion 832 has a second end surface 832B connected to the seventh end surface 33A. The second end surface 832B has a first partial end surface 837B of the first portion 837 and a second partial end surface 838B of the second portion 838. The first partial end surface 837B is continuous with the seventh end surface 33A on one side. The first partial end surface 837B is continuous with the second partial end surface 838B on the other side. The detection target portions 832 and 33 have bent portions 834 at two locations: a location where the first partial end surface 837B and the second partial end surface 838B collide with each other, and a location where the second partial end surface 838B and the seventh end surface 33A collide with each other. The bent portion 834 provided at the location where the first partial end surface 837B and the seventh end surface 33A collide with each other may be referred to as a first bent portion 834A. The bent portion 834 provided at the point where the first partial end surface 837B and the second partial end surface 838B meet is sometimes referred to as a second bent portion 834B.

[0064] The package 22 is provided at a position overlapping the second extension portion 832, the third extension portion 33, and the overlapping region 835 in the thickness direction TD and adjacent to the second extension portion 832, the third extension portion 33, and the overlapping region 835 in the thickness direction TD. The overlapping region 835 may be referred to as an enclosed region. The package 22 overlaps the ends of the detection objects 832 and 33 in the thickness direction TD. Since the overlapping edge portion 36 includes an edge portion of the first portion end face 837B extending obliquely, magnetic fields from three directions of the detection objects 33, 837, and the second portion 838 overlap. This increases the magnetic field along the thickness direction TD passing through the sensor element 21. The detection accuracy of the sensor element 21 is improved.

[0065] Ninth embodiment FIG. 13 is a plan view of the current detector 50 of the ninth embodiment as viewed from the thickness direction TD. In the ninth embodiment, the second extension portion 932 and the third extension portion 933 may be collectively referred to as the detection target portions 932 and 933. The second extension portion 932 may be referred to as the inflow side portion. The third extension portion 933 may be referred to as the outflow side portion. In the ninth embodiment, the output bus bar 30 is substantially U-shaped as viewed from the thickness direction TD. In the ninth embodiment, the bent portion 934 is curved so as to be folded back. The ninth embodiment also has the same effects as the previous embodiments. In addition, as shown in FIG. 14, the output bus bar 930 may have a spiral shape. In this case, as long as the package 22 is provided in a position overlapping and adjacent to the detection target portions 932 and 933 and the overlapping region 935 in the thickness direction TD, the same effects as the previous embodiments are achieved. The overlapping region 935 may also be referred to as an enclosed region.

[0066] Tenth embodiment In the embodiments described so far, a configuration has been described in which a part of the package 22 overlaps both the second extension 32, 832, 932 and the third extension 33, 933 in the thickness direction TD and is adjacent to the thickness direction TD. However, the arrangement of the package 22 is not limited to this. It is sufficient that a part of the package 22 is provided at a position overlapping at least one of the second extension 32, 832, 932 and the third extension 33, 933 in the thickness direction TD and adjacent to the thickness direction TD. The tenth embodiment can be combined with each of the embodiments described so far. FIG. 15 is a plan view of the current detector 50 of the tenth embodiment as seen from the thickness direction. The drawing shows, as an example, a configuration in which the package 22 is provided at a position overlapping the second extension 32 in the thickness direction TD and adjacent to the thickness direction TD. The drawing shows a configuration in which the package 22 is provided at a position adjacent to the third extension 33 in the thickness direction TD without overlapping with the third extension 33 in the thickness direction TD. [Explanation of symbols]

[0067] 21 sensor element, 22 package, 30 bus bar, 32 inlet side portion, 33 outlet side portion, 34 bend portion, 35 adjacent area, 40 substrate, 832 inlet side portion, 834 bend portion, 834A first bend portion, 834B second bend portion, 835 adjacent area, 837 first portion, 838 second portion, 932 inlet side portion, 933 outlet side portion, 934 bend portion, 935 adjacent area.

Claims

1. A bus bar (30) through which a current flows; a package (22) including a sensor element (21) for detecting a magnetic field generated around the bus bar; The bus bar has a bend (34, 834, 934); The bus bar has an inflow side portion (32, 832, 932) connected to the bent portion on the inflow side of the current relative to the bent portion, and an outflow side portion (33, 933) connected to the bent portion on the outflow side of the current relative to the bent portion, A current detector in which the package is provided at a position overlapping and close to at least one of the inlet side portion and the outlet side portion in a direction perpendicular to both the longitudinal direction of the inlet side portion and the extension direction extending away from the bend in the outlet side portion.

2. 2. The current detector of claim 1, wherein the angle formed between the inlet side portion and the outlet side portion in an adjacent region (35, 835, 935) that is sandwiched between both the inlet side portion and the outlet side portion and adjacent to both the inlet side portion and the outlet side portion is less than 180 degrees.

3. The sensor element is fixed to a substrate (40); 3. The current detector according to claim 2, wherein the substrate is provided close to the bus bar to an extent that the magnetic field in the one direction can pass through the sensor element.

4. 3. The current detector according to claim 1, wherein the bus bar extends so as to be curved and folded back at the bent portion.

5. 4. The current detector according to claim 2, wherein an angle between the inflow side portion and the outflow side portion on the adjacent region side is less than 90 degrees.

6. The inlet side portion has a first portion (837) connected to the outlet side portion and a second portion (838) connected to an end portion of the first portion opposite to the end portion connected to the outlet side portion, The bent portion has a first bent portion (834A) provided between the first portion and the outflow side portion, and a second bent portion (834B) provided between the first portion and the second portion, The current detector according to claim 5 , wherein the package is provided at a position adjacent to the outflow side portion, the first portion, and the second portion in the one direction.

7. The package has a rectangular parallelepiped shape with a thin plate thickness in the one direction, 4. The current detector according to claim 2, wherein the sensor element is provided in the adjacent region inside the package and is provided closer to the bent portion than to a corner of the package.

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