Current sensor

Abstract

To provide a current sensor which can enhance positioning accuracy of a bus bar while reducing thermal stress.SOLUTION: A current sensor includes a bus bar 20, a resin member 30 for holding the bus bar, and a magnetoelectric transducer which is positioned to the resin member 30, and detects current flowing through the bus bar 20. The resin member 30 has a through hole 31. The bus bar 20 is inserted to the through hole 31. The bus bar 20 has: a body part 23 through which current flows, as a part arranged in the through hole 31; and at least one spring structure part 24 which is continuous to the body part 23, is brought into contact with a wall surface 33 of the through hole 31 in the resin member 30, and is spring-deformed in a plate width direction of the bus bar 20. The bus bar 20 is pressed in and fixed to the resin member 30.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The disclosure herein relates to current sensors. [Background technology]

[0002] Patent Document 1 discloses a current sensor. The contents of the prior art document are incorporated by reference as explanations of the technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-194650 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the bus bar is molded as an insert part integrally with the resin case. Because the bus bar is covered with resin, a large thermal stress occurs due to the difference in the linear expansion coefficient between the bus bar and the case. The thermal stress may cause, for example, cracks in the resin of the case or misalignment of the bus bar. To address this issue, a possible configuration is to provide a through hole in the resin case and pass the bus bar through the through hole. However, misalignment of the bus bar is likely to occur relative to the case, and ultimately relative to the magnetic flux density detection element positioned relative to the case. Misalignment may result in, for example, a decrease in current detection accuracy and a decrease in connectivity between the bus bar and other components. Further improvements to current sensors are desired in terms of the above and other aspects not mentioned.

[0005] One disclosed object is to provide a current sensor that can improve the positional accuracy of the bus bar while reducing thermal stress. [Means for solving the problem]

[0006] One aspect of the disclosure is A bus bar (20), a resin member (30) that holds the bus bar; a magnetoelectric conversion element (40) positioned relative to the resin member and configured to detect a current flowing through the bus bar; Equipped with The resin member has a through hole (31), The bus bar is inserted through the through hole, The bus bar has a main body portion (23) through which current flows, which is the portion that is placed within the through hole, and at least one spring structure portion (24) that is connected to the main body portion and comes into contact with the wall surface of the through hole in the resin member, thereby spring-deforming in the width direction of the bus bar, and is press-fitted and fixed into the resin member.

[0007] According to the disclosed current sensor, the bus bar is inserted through a through hole in the resin member, thereby reducing thermal stress. Furthermore, the bus bar has a spring structure, which improves the positional accuracy of the bus bar relative to the resin member and, ultimately, the magneto-electric conversion element. As a result, a current sensor can be provided that improves the positional accuracy of the bus bar while reducing thermal stress.

[0008] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims are intended to exemplarily indicate the corresponding parts of the embodiments described below, and are not intended to limit the technical scope. The objectives, features, and advantages disclosed in this specification will become more apparent by reference to the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of a power conversion device including a current sensor according to a first embodiment. [Figure 2] 2 is a cross-sectional view taken along line II-II in FIG. 1, showing the current sensor. [Figure 3] FIG. 2 is a plan view seen from the Y1 direction in FIG. [Figure 4]FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 10 is a cross-sectional view showing a current sensor according to a second embodiment. [Figure 6] FIG. 10 is a cross-sectional view showing a current sensor according to a third embodiment. [Figure 7] FIG. 10 is a cross-sectional view showing a current sensor according to a fourth embodiment. [Figure 8] FIG. 10 is a cross-sectional view showing a current sensor according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, several embodiments will be described with reference to the drawings. Note that in each embodiment, corresponding components are designated by the same reference numerals, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment previously described may be applied to the remaining portion of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of several embodiments may be partially combined together even if not explicitly stated, provided that there is no particular problem with the combination.

[0011] (First embodiment) Fig. 1 shows an example of the installation of the current sensor according to this embodiment, and shows a power conversion device including the current sensor according to this embodiment.

[0012] The power conversion device is applied to, for example, a mobile object powered by a rotating electric machine, such as an electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an aircraft such as an electric vertical take-off and landing aircraft or a drone, a ship, a construction machine, or an agricultural machine.

[0013] <Power conversion device> 1, the power conversion device 10 includes an inverter 11, an output terminal block 12, and a current sensor 13. The power conversion device 10 may include a housing (not shown) that houses other elements that configure the power conversion device 10.

[0014] The inverter 11 is a DC-AC conversion circuit. The inverter 11 converts a DC voltage into a three-phase AC voltage under switching control by a control unit (not shown) and outputs the voltage to the rotating electric machine. This drives the rotating electric machine to generate a predetermined torque. For example, during regenerative braking of a vehicle, the inverter 11 converts the three-phase AC voltage generated by the rotating electric machine in response to rotational force from the wheels into a DC voltage under switching control by the control unit. In this way, the inverter 11 performs bidirectional power conversion between a DC power source and the rotating electric machine.

[0015] The inverter 11 includes a plurality of semiconductor elements (not shown). The semiconductor elements are formed by forming switching elements such as MOSFETs and IGBTs on a semiconductor substrate (semiconductor chip). MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. The plurality of semiconductor elements configure upper and lower arm circuits for three phases.

[0016] The inverter 11 has output terminals 111 corresponding to the upper and lower arm circuits as external connection terminals. The illustrated inverter 11 has three output terminals 111. One of the output terminals 111 is electrically connected to a connection point between the upper arm and the lower arm of the U-phase upper and lower arm circuit. The other output terminal 111 is electrically connected to a connection point between the V-phase upper and lower arm circuits. The other output terminal 111 is electrically connected to a connection point between the W-phase upper and lower arm circuits. The inverter 11 has P-terminal and N-terminal (not shown) as external connection terminals. The P-terminal is electrically connected to a power supply line on the high potential side. The N-terminal is electrically connected to a power supply line on the low potential side.

[0017] The output terminal block 12 electrically connects the inverter 11 and the rotating electric machine. The output terminal block 12 includes bus bars 121 and a holding member for holding the bus bars 121. The bus bars 121 are plates made of a metal with good conductivity, such as Cu. The bus bars 121 may be a single plate, or may be formed by connecting a plurality of plates. The output terminal block 12 includes three-phase bus bars 121 for the inverter 11.

[0018] The illustrated output terminal block 12 is aligned with the inverter 11 in the Y direction. One end of the bus bar 121 protrudes from one surface of the holding member. The one end of the bus bar 121 is substantially L-shaped in the YZ plane and overlaps with the bus bar 20 of the current sensor 13 in the Z direction.

[0019] The current sensor 13 detects the phase current flowing in the winding of each phase of the rotating electric machine. The current sensor 13 includes a bus bar 20 through which the phase current flows. A large current flows through the bus bar 20. The current sensor 13 includes bus bars 20 for three phases. The illustrated current sensor 13 is arranged in the Y direction together with the inverter 11 and the output terminal block 12. The current sensor 13 is disposed between the inverter 11 and the output terminal block 12 in the Y direction.

[0020] One end of the bus bar 20 is connected to the output terminal 111 of the inverter 11, and the other end is connected to the bus bar 121 of the output terminal block 12. The illustrated bus bar 20 is connected to the output terminal 111 by welding, specifically laser welding. The bus bar 20 is connected to the bus bar 121 by fastening with bolts 14. The structure of the current sensor 13 will be described later.

[0021] The power conversion device 10 may include a capacitor device. The capacitor device provides a smoothing capacitor that smoothes the DC voltage supplied from the DC power source. The smoothing capacitor is disposed between the DC power source and the inverter 11.

[0022] The power conversion device 10 may include a converter. The converter is a DC-DC conversion circuit. The converter converts, for example, a DC voltage into a DC voltage of a different value in accordance with switching control by the control unit. The converter has a function of boosting the DC voltage supplied from the DC power source. The converter may also have a step-up / step-down function. When the power conversion device 10 includes a converter, the current sensor 13 may be arranged to detect a current flowing through a reactor of the converter.

[0023] The power conversion device 10 may include a control unit. The control unit has, for example, a drive command generation unit and a drive circuit unit. The drive command generation unit controls the inverter 11. The drive command generation unit generates a drive command (command signal) for controlling the on / off of the switching elements and outputs it to the drive circuit unit. The drive command generation unit generates the drive command based on a drive request for the rotating electric machine, such as a torque command value input from a higher-level ECU (not shown), and signals detected by various sensors. The various sensors may include a current sensor 13, a rotation angle sensor (not shown), and a voltage sensor. The rotation angle sensor detects the rotation angle of the rotor of the rotating electric machine. The voltage sensor detects the voltage across the smoothing capacitor. The drive circuit unit is sometimes referred to as a driver. The drive circuit unit can independently control the on / off of each switching element based on the drive command.

[0024] <Current sensor> Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 2 shows the structure of the current sensor.

[0025] As shown in FIGS. 1 and 2, the current sensor 13 includes at least the bus bar 20, the resin member 30, and the magnetoelectric conversion element 40 described above.

[0026] The bus bars 20 are plate materials made of a metal with good conductivity, such as Cu. The bus bars 20 include a U-phase bus bar 20U, a V-phase bus bar 20V, and a W-phase bus bar 20W. The illustrated bus bars 20 have their thickness direction in the Z direction and extend generally in the Y direction. The three bus bars 20 are arranged at approximately the same positions relative to each other in the Z direction and the Y direction. The three bus bars 20 are aligned in the X direction. The bus bars 20 are held in the resin member 30 by press-fitting.

[0027] The resin member 30 is formed using a resin material. Examples of the resin material include PBT and PPS. The example resin member 30 is PBT. The resin member 30 may be a single component or may be formed by assembling multiple components. The resin member 30 holds the bus bar 20. The resin member 30 has through holes 31 through which the bus bar 20 is inserted. The through holes 31 are provided individually for the bus bars 20. The resin member 30 has three through holes 31. The example through holes 31 extend in the Y direction. One end of the through hole 31 opens to one of the side surfaces of the resin member, and the other end of the through hole 31 opens to a side surface opposite in the Y direction from the side surface where the one end opens.

[0028] The magnetoelectric transducer 40 detects the current flowing through the bus bar 20. The magnetoelectric transducer 40 detects the magnetic flux density of the magnetic field generated when a current flows through the corresponding bus bar 20 and converts it into an electric signal. The magnetoelectric transducer 40 is positioned relative to the resin member 30 so as to be in a predetermined position relative to the bus bar 20. The magnetoelectric transducer 40 is, for example, a Hall element, a giant magnetoresistance element (GMR), an anisotropic magnetoresistance element (AMR), a tunnel magnetoresistance element (TMR), or the like.

[0029] The illustrated magnetoelectric conversion element 40 is a Hall element. The current sensor 13 includes three magnetoelectric conversion elements 40. The magnetoelectric conversion elements 40 are arranged on the corresponding bus bars 20 in the thickness direction (Z direction) of the bus bars 20. The three magnetoelectric conversion elements 40 are arranged at approximately the same positions as each other in the Z direction. The three magnetoelectric conversion elements 40 are lined up in the X direction.

[0030] The illustrated current sensor 13 further includes a core 50 and a substrate 60. The core 50 collects magnetic flux generated around the busbar 20 when a current flows through the busbar 20. The core 50 is sometimes referred to as a magnetic flux collecting core. The core 50 is held by the resin member 30. The periphery of the core 50 is covered by the resin member 30. The planar shape of the core 50 along the ZX plane is approximately C-shaped. The core 50 extends in the Y direction to cover the busbar 20. The core 50 has a gap 51. The core 50 is arranged so that the gap 51 faces the plate surface of the busbar 20. The core 50 is provided individually for the busbar 20. The current sensor 13 includes three cores 50. The three cores 50 are arranged at approximately the same positions as each other in the Z direction and the Y direction. The three cores 50 are lined up in the X direction.

[0031] The through holes 31 are provided individually for the cores 50. The through holes 31 are provided in the annular regions of the corresponding cores 50. The magnetoelectric conversion elements 40 (Hall elements) are disposed in the gaps 51 of the cores 50. The resin member 30 has recesses 32 in portions corresponding to the gaps 51. The recesses 32 open to the lower surface of the resin member 30. The magnetoelectric conversion elements 40 are disposed in the recesses 32 and are positioned in the gaps 51.

[0032] The substrate 60 is a printed circuit board. The magnetoelectric conversion element 40 is mounted on the substrate 60. The substrate 60 is fixed to the resin member 30 by heat caulking, fastening, or the like. The magnetoelectric conversion element 40 is positioned and fixed to the resin member 30 via the substrate 60. The illustrated substrate 60 is disposed on the lower surface side of the resin member 30.

[0033] <Busbar fixing structure> Fig. 3 is a plan view seen from the Y1 direction in Fig. 1. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3. Figs. 3 and 4 show a fixing structure of the bus bar in the current sensor.

[0034] 3 and 4 show only the U-phase bus bar 20U and the surrounding area of ​​the resin member 30 around the bus bar 20U for convenience, but the bus bars 20V and 20W have a similar structure. As described above, the bus bar 20 (20U) is inserted through the through hole 31 of the resin member 30. The bus bar 20 is held in the resin member 30 by press-fitting. The bus bar 20 has the welded portion 21 and the fastening portion 22 as portions that are disposed outside the resin member 30.

[0035] The welded portion 21 is a portion of the bus bar 20 that is welded to the output terminal 111 of the inverter 11. The welded portion 21 overlaps the output terminal 111 so that the plate surfaces face each other. The illustrated bus bar 20 is connected to the output terminal 111 by laser welding as described above. The welded portion 21 and the output terminal 111 overlap in the Z direction.

[0036] Fastening portion 22 is a connection portion of busbar 20 with busbar 121 of output terminal block 12. Fastening portion 22 overlaps busbar 121 so that the plate surfaces face each other. Fastening portion 22 is formed with holes 221 through which bolts 14 are inserted. In the illustrated busbar 20, welded portion 21 and output terminal 111 overlap in the Z direction.

[0037] The bus bar 20 has a main body portion 23 and a spring structure portion 24 as portions disposed within the through hole 31. The main body portion 23 is a portion through which current flows. In the illustrated bus bar 20, the weld portion 21 is connected to one end of the main body portion 23, and the fastening portion 22 is connected to the other end of the main body portion 23. The weld portion 21, the main body portion 23, and the fastening portion 22 provide a current path through which current flows. The main body portion 23 extends generally in the Y direction.

[0038] The spring structure 24 is connected to the main body 23. The spring structure 24 is provided so as to be capable of spring deformation. The spring structure 24 comes into contact with the wall surface 33 of the through hole 31 in the resin member 30, and spring-deforms in the width direction of the bus bar 20, i.e., the X direction. The bus bar 20 has at least one spring structure 24. The illustrated bus bar 20 has two (multiple) spring structures 24. The spring structure 24 is provided at each end of the bus bar 20 in the X direction. The two spring structures 24 are provided at approximately the same position as each other in the Y direction. The spring structure 24 has an approximately constant width along its longitudinal direction.

[0039] Busbar 20 has a notch 25. Notch 25 separates main body portion 23 from spring structure portion 24. By providing notch 25 in the metal plate material, spring structure portion 24 that is capable of spring deformation is provided. At least a portion of notch 25 is disposed within through hole 31.

[0040] In the illustrated busbar 20, the notches 25 extend in the X direction from the end of the metal plate material. Two notches 25 are provided adjacent to each spring structure 24. The two notches 25 are provided so as to sandwich the spring structure 24 in the Y direction. All of the notches 25 are disposed within the through holes 31. The width of the main body 23 is narrower at the positions where the spring structures 24 are connected and at the positions adjacent to the notches 25 in the X direction than at other portions. The main body 23 has a structure in which narrow width portions are disposed between wide width portions.

[0041] The resin member 30 has a protrusion 34. The protrusion 34 is a portion that protrudes from the wall surface 33 of the through hole 31 beyond the surrounding area of ​​the protrusion 34. The protrusion 34 is in contact with the bus bar 20. The protrusion 34 is in contact with the bus bar 20 and elastically deforms. The example protrusion 34 includes a plate surface protrusion 341 and a side surface protrusion 342.

[0042] The plate surface protrusion 341 comes into contact with the plate surface 201 of the busbar 20. The plate surface protrusion 341 protrudes from the surface of the wall surface 33 that faces the plate surface 201. The plate surface protrusion 341 only needs to come into contact with at least one of the plate surfaces 201. The plate surface protrusion 341 may come into contact with the main body portion 23 or the spring structure portion 24. Preferably, a plurality of plate surface protrusions 341 are provided so as to come into contact with both of the plate surfaces 201. Preferably, a plurality of plate surface protrusions 341 are provided so as to come into contact with a plurality of points in the plate width direction of the busbar 20.

[0043] The illustrated resin member 30 has a plate surface protrusion 341 that contacts the upper surface and a plate surface protrusion 341 that contacts the lower surface. The plate surface protrusion 341 that contacts the upper surface and the plate surface protrusion 341 that contacts the lower surface are provided so as to overlap each other in a plan view in the Z direction. The plate surface protrusions 341 are provided near both ends of the bus bar 20 in the plate width direction. The plate surface protrusions 341 contact the plate surface 201 of the spring structure 24.

[0044] The side protrusions 342 contact the side surfaces 202 of the busbar 20. The side protrusions 342 contact the side surfaces 202 at the spring structure 24. The side protrusions 342 protrude from the surface of the wall surface 33 that faces the side surfaces 202. The side protrusions 342 only need to contact at least one of the side surfaces 202. Preferably, multiple side protrusions 342 are provided so as to contact both of the side surfaces 202 in the plate width direction. The illustrated side protrusions 342 contact each of the spring structure 24. Four plate surface protrusions 341 and two side surface protrusions 342 are provided at predetermined positions in the Y direction, for example, at the center position of the through hole 31.

[0045] <Summary of the First Embodiment> The current sensor 13 of this embodiment includes a busbar 20, a resin member 30, and a magnetoelectric conversion element 40 positioned relative to the resin member 30. The resin member 30 has a through hole 31. The busbar 20 passes through the through hole 31. The busbar 20 has, as a portion disposed within the through hole 31, a main body portion 23 through which a current flows, and at least one spring structure portion 24 that is connected to the main body portion 23 and comes into contact with a wall surface 33 of the through hole 31 in the resin member 30 to spring deform in the plate width direction of the busbar 20. The busbar 20 is press-fitted and fixed into the resin member 30.

[0046] In this manner, the busbar 20 is configured to pass through the through-hole 31 of the resin member 30. Therefore, compared to a configuration in which the busbar 20 is inserted into the resin member 30, the thermal stress caused by the difference in linear expansion coefficient between the busbar 20 and the resin member 30 can be reduced. Furthermore, since the busbar 20 is provided with the spring structure 24, the spring structure 24 can alleviate the thermal stress. Furthermore, the reaction force of the spring deformation of the spring structure 24 can position the busbar 20 at a predetermined position. This can improve the positional accuracy of the busbar 20 relative to the resin member 30 and, ultimately, the magneto-electric conversion element 40. As described above, the positional accuracy of the busbar 20 can be improved while reducing thermal stress.

[0047] Thermal stress may cause, for example, resin cracking in the resin member or misalignment of the bus bar. Misalignment may cause a decrease in current detection accuracy and a decrease in connectivity with other members. Current sensor 13 of this embodiment can, for example, suppress a decrease in connectivity with other members. Misalignment of bus bar 20 can be suppressed, making it easier to weld it to output terminal 111. It can also make it easier to fasten it to bus bar 121. Current sensor 13 of this embodiment can, for example, suppress a decrease in current detection accuracy. Current sensor 13 of this embodiment can, for example, increase the positional accuracy of bus bar 20 while suppressing resin cracking.

[0048] Furthermore, a large current flows through the bus bar 20. Since the bus bar 20 is configured to be in contact with the resin member 30 by the spring structure 24, the heat generated by the large current flowing through the bus bar 20 is less likely to be transmitted to the resin member 30. In other words, the influence of heat on the resin member 30 can be reduced.

[0049] As shown in the example, multiple spring structures 24 may be provided on the bus bar 20. This increases the number of contact points with the wall surface 33 of the resin member 30, thereby further improving the positional accuracy of the bus bar 20. For example, the spring structures 24 may be provided at both ends in the plate width direction. This further improves the positional accuracy of the bus bar 20 in the plate width direction.

[0050] As illustrated, the bus bar 20 may be provided with a notch 25 that separates the main body portion 23 from the spring structure portion 24. The notch 25 can narrow the heat transfer path, thereby making it difficult for heat to be transferred to the resin member 30.

[0051] As illustrated, the bus bar 20 may be connected to the main body 23 to form a current path together with the main body 23, and may have a welded portion 21 to which a metal member is welded outside the through hole 31. In the illustrated power conversion device 10, the output terminal 111 corresponds to the metal member. As described above, the notch 25 restricts the heat transfer path, and therefore, transfer of heat from the welded portion 21 to the resin member 30 during welding can be effectively suppressed.

[0052] As illustrated, resin member 30 may have protrusions 34 that protrude from wall surfaces 33 of through holes 31 and come into contact with bus bars 20. Protrusions 34 come into contact with bus bars 20 and are elastically deformed. This, together with the effect of spring structure 24, can further improve the positional accuracy of bus bars 20.

[0053] As illustrated, the protrusion 34 may include a side protrusion 342 that contacts the side surface 202 of the busbar 20 in the spring structure 24. By providing the side protrusion 342, the spring structure 24 can be brought into contact with the wall surface 33 at a predetermined position. This can further improve the positional accuracy in the plate width direction.

[0054] As illustrated, the protrusion 34 may include a plate surface protrusion 341 that contacts the plate surface 201 of the bus bar 20. This can improve the positional accuracy in the plate thickness direction.

[0055] (Second embodiment) This embodiment is a modification of the preceding embodiment as a basic form, and the description of the preceding embodiment can be used. In the preceding embodiment, the spring structure portion is provided at one location in the Y direction. Instead of this, the spring structure portion may be provided at multiple locations in the Y direction.

[0056] Fig. 5 is a cross-sectional view showing the current sensor according to this embodiment, which corresponds to Fig. 4. Fig. 5 shows a fixing structure of the bus bar in the current sensor.

[0057] The bus bar 20 has four spring structures 24. Two of the spring structures 24 are provided near the open ends of the through holes 31 on the inverter 11 side. The two spring structures 24 are provided at both ends of the bus bar 20 in the X direction. The other two spring structures 24 are provided near the open ends of the through holes 31 on the output terminal block 12 side. The two spring structures 24 are provided at both ends of the bus bar 20 in the X direction. The illustrated spring structures 24 are substantially L-shaped in a plan view in the Z direction.

[0058] The cutout 25 includes cutouts 251 and 252. The cutout 251 separates the welded portion 21, the main body 23, and the spring structure 24 on the welded portion 21 side. The cutout 251 is provided adjacent to the welded portion 21, the main body 23, and the spring structure 24 on the welded portion 21 side. The cutout 252 separates the fastening portion 22, the main body 23, and the spring structure 24 on the fastening portion 22 side. The cutouts 251 and 252 shown in the example are substantially L-shaped when viewed in a plane in the Z direction.

[0059] The resin member 30 has four plate surface protrusions 341 and two side surface protrusions 342 at positions corresponding to the spring structure 24 on the welding portion 21 side. The resin member 30 has four plate surface protrusions 341 and two side surface protrusions 342 at positions corresponding to the spring structure 24 on the fastening portion 22 side. The other configurations are the same as those described in the preceding embodiment.

[0060] <Summary of the second embodiment> As shown in the example, spring structures 24 may be spaced apart in the Y direction, which is the extension direction of the through holes. This makes it possible to prevent busbar 20 from tilting in the width direction (X direction) or thickness direction (Z direction) along the length of busbar 20. In other words, the positional accuracy of busbar 20 can be further improved.

[0061] The positions of the spring structures 24 are not limited to the above example, and may be any positions spaced apart in the Y direction.

[0062] (Third embodiment) This embodiment is a modification of the preceding embodiment, and the description of the preceding embodiment can be used. In the preceding embodiment, the bus bar is provided with a spring structure. In addition to this, the bus bar may be provided with a stopper portion.

[0063] Fig. 6 is a cross-sectional view showing the current sensor according to this embodiment, which corresponds to Fig. 5. Fig. 6 shows a fixing structure of the bus bar in the current sensor.

[0064] The bus bar 20 has four spring structures 24, similar to the configuration shown in Fig. 5. The resin member 30 has four plate surface protrusions 341 and two side surface protrusions 342 at positions corresponding to the spring structures 24 on the welded portion 21 side, similar to the configuration shown in Fig. 5. The resin member 30 has four plate surface protrusions 341 and two side surface protrusions 342 at positions corresponding to the spring structures 24 on the fastening portion 22 side.

[0065] The bus bar 20 has a stopper portion 26. The stopper portion 26 comes into contact with the periphery of one of the opening ends of the through hole 31 in the resin member 30. The stopper portion 26 comes into contact with the periphery of the opening end on the entry side in the press-fitting direction PD of the bus bar 20 into the resin member 30. The stopper portion 26 coming into contact with the periphery of the opening end restricts further insertion of the bus bar 20. The stopper portion 26 may be provided contiguous to the fastening portion 22, or may also serve as part of the fastening portion 22.

[0066] In the illustrated busbar 20, a part of the fastening portion 22 also serves as the stopper portion 26. In the busbar 20, the width of the stopper portion 26 (fastening portion 22) is longer than the maximum diameter portion of the through-hole 31. The stopper portion 26 comes into contact with the periphery of the open end on the fastening portion 22 side. The other configurations are the same as those described in the preceding embodiment.

[0067] <Summary of the third embodiment> As illustrated, busbar 20 may be provided with stopper 26 that contacts the periphery of one of the opening ends of through-hole 31 in resin member 30. When busbar 20 is press-fitted, stopper 26 comes into contact with the periphery of the opening end, thereby restricting further insertion of busbar 20. This improves the positional accuracy of busbar 20 in the penetration direction (press-fitting direction) of through-hole 31, i.e., in the Y direction.

[0068] The arrangement of the spring structure 24 is not limited to the above example. For example, the spring structure 24 may be arranged as shown in FIG.

[0069] (Fourth embodiment) This embodiment is a modification of the preceding embodiment, and the description of the preceding embodiment can be used. In the preceding embodiment, the bus bar is provided with a stopper portion. In addition to this, the stopper portion may be provided to be spring-deformable.

[0070] Fig. 7 is a cross-sectional view showing the current sensor according to this embodiment. Fig. 7 corresponds to Fig. 6. Fig. 7 shows a fixing structure of the bus bar in the current sensor.

[0071] 6, the busbar 20 has four spring structures 24. The resin member 30 has four plate surface protrusions 341 and two side surface protrusions 342 at positions corresponding to the spring structures 24 on the welding portion 21 side. The resin member 30 has four plate surface protrusions 341 and two side surface protrusions 342 at positions corresponding to the spring structures 24 on the fastening portion 22 side.

[0072] The busbar 20 has a stopper portion 26. The stopper portion 26 is provided adjacent to the fastening portion 22. In other words, the stopper portion 26 is provided in the vicinity of the fastening portion 22. The width of the fastening portion 22 in the busbar 20 is longer than the maximum diameter portion of the through hole 31. The stopper portion 26 is provided so as to be spring deformable in the Y direction. The stopper portion 26 extends in the Y direction from the fastening portion 22. The tip of the stopper portion 26 comes into contact with the periphery of the opening end on the fastening portion 22 side, thereby restricting further insertion of the busbar 20. The other configurations are the same as those described in the preceding embodiment.

[0073] <Summary of the Fourth Embodiment> As illustrated, abutment stopper 26 may be provided near fastening portion 22. Abutment stopper 26 may be provided to be spring deformable. Even though abutment stopper 26 is configured to contact resin member 30, the spring deformation can alleviate stress that occurs when fastening portion 22 and bus bar 121 of output terminal block 12 are fastened together. For example, it is possible to prevent abutment stopper 26 from strongly hitting resin member 30 and causing resin cracks.

[0074] (Fifth embodiment) This embodiment is a modification of the previous embodiment, and the description of the previous embodiment can be used. In the previous embodiment, the width of the spring structure is constant. Instead, the width of the spring structure may be varied in parts.

[0075] Fig. 8 is a cross-sectional view showing the current sensor according to this embodiment, which corresponds to Fig. 4. Fig. 8 shows a fixing structure of the bus bar in the current sensor.

[0076] 4, busbar 20 has two spring structures 24. Resin member 30 has four plate surface protrusions 341 and two side surface protrusions 342 at positions corresponding to spring structures 24.

[0077] The spring structure portion 24 has a root portion 241 and a tip portion 242. The root portion 241 is the portion from the boundary with the main body portion 23 to a predetermined position. The tip portion 242 is the portion that continues to the root portion 241. The tip portion 242 is the portion from the predetermined position to the tip of the spring structure portion 24. The tip portion 242 is in contact with the wall surface 33, for example, the side protrusion portion 342. The width of the root portion 241 is narrower than the width of the tip portion 242. The root portion 241 is a narrow portion, and the tip portion 242 is a wide portion. The other configurations are the same as those described in the preceding embodiment.

[0078] <Summary of the Fourth Embodiment> As shown in the example, in the spring structure 24, the width of the root portion 241 from the boundary with the main body portion 23 to a predetermined position may be narrower than the width of the tip portion 242 connected to the root portion 241. In this way, the root portion 241 of the spring structure 24 mainly undergoes spring deformation. The tip portion 242 that comes into contact with the wall surface 33 has a stable shape. This makes it easier for the spring structure 24 to undergo spring deformation, making it easier to achieve the above-mentioned effects.

[0079] Although an example in which the spring structure 24 having a narrow base portion 241 is applied to the configuration shown in Fig. 4 has been shown, the present invention is not limited to this. The spring structure 24 having a narrow base portion 241 may also be applied to the configurations shown in Figs. 5, 6, and 7.

[0080] (Other embodiments) The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and modifications thereto by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and / or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses the omission of parts and / or elements from the embodiments. The disclosure encompasses the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are defined by the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the claims.

[0081] The disclosure in the specification, drawings, etc. is not limited by the claims. The disclosure in the specification, drawings, etc. encompasses the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification, drawings, etc. without being bound by the claims.

[0082] When an element or layer is referred to as being "on," "coupled," "connected," or "bonded," it may be directly coupled, connected, or bonded to another element or layer, and intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly coupled," "directly connected," or "directly bonded" to another element or layer, no intervening elements or layers are present. Other terms used to describe relationships between elements should be construed in a similar manner (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used in this specification, the term "and / or" includes any and all combinations of the associated listed item or items. That is, reference to A and / or B means at least one of A and B, and can include A only, B only, or both A and B.

[0083] Spatially relative terms such as "inside," "outside," "back," "below," "low," "top," "top," and the like are used herein to facilitate the description of one element or feature's relationship to other elements or features, as illustrated. Spatially relative terms may be intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures were turned over, elements described as "below" or "directly below" other elements or features would then be oriented "above" the other elements or features. Thus, the term "bottom" can encompass both an orientation of top and bottom. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used in this specification would be interpreted accordingly.

[0084] Although an example in which the current sensor 13 includes the core 50 has been described, the present invention is not limited to this. The present invention can also be applied to a current sensor 13 that does not include the core 50, that is, a coreless current sensor.

[0085] In the example shown, busbar 20 has welded portion 21 connected to one end of main body portion 23 and fastened portion 22 connected to the other end, but this is not limiting. Both end portions connected to main body portion 23 and connected to other members (metal members) may be welded portions or fastened portions. The inverter 11 side may be the fastened portion, and the output terminal block 12 side may be welded portion. The connection method is also not limited to welding or fastening. [Explanation of symbols]

[0086] 10...power conversion device, 11...inverter, 111...output terminal, 12...output terminal block, 121...bus bar, 13...current sensor, 14...volt, 20, 20U, 20V, 20W...bus bar, 201...plate surface, 202...side surface, 21...welded portion, 22...fastening portion, 221...hole, 23...main body portion, 24...spring structure portion, 241...root portion, 242...tip portion, 25, 251, 252...notch, 26...stopping portion, 30...resin member, 31...through hole, 32...recess, 33...wall surface, 34...projection portion, 341...plate surface projection portion, 342...side projection portion, 40...magnetoelectric conversion element, 50...core, 51...gap, 60...substrate

Claims

1. A bus bar (20); a resin member (30) for holding the bus bar; a magnetoelectric conversion element (40) positioned relative to the resin member and detecting a current flowing through the bus bar; Equipped with The resin member has a through hole (31), The bus bar is inserted through the through hole, The bus bar has, as a portion disposed within the through hole, a main body portion (23) through which the current flows, and at least one spring structure portion (24) connected to the main body portion and contacting the wall surface of the through hole in the resin member to spring deform in the plate width direction of the bus bar, and is press-fitted and fixed into the resin member.

2. The current sensor according to claim 1 , wherein the bus bar includes a plurality of the spring structures.

3. The current sensor according to claim 2 , wherein the spring structure is provided at each end position in the plate width direction.

4. The current sensor according to claim 2 , wherein the spring structures are spaced apart in the extending direction of the through hole.

5. A current sensor as described in any one of claims 1 to 4, wherein in the spring structure, the width of the root portion (241) from the boundary with the main body portion to a predetermined position is narrower than the width of the tip portion (242) connected to the root portion.

6. The current sensor according to any one of claims 1 to 4, wherein the bus bar has a notch (25) that separates the main body portion from the spring structure portion.

7. The current sensor according to claim 6, wherein the bus bar is connected to the main body portion to form a current path together with the main body portion, and has a welded portion (21) to which a metal member is welded outside the through hole.

8. The current sensor according to any one of claims 1 to 4, wherein the resin member has a protrusion (34) that protrudes from a wall surface of the through hole and comes into contact with the bus bar.

9. The current sensor of claim 8 , wherein the protrusions include side protrusions (342) that contact the sides of the bus bar at the spring structure.

10. The current sensor according to claim 8, wherein the protrusion includes a plate surface protrusion (341) that contacts the plate surface of the bus bar.

11. The current sensor according to any one of claims 1 to 4, wherein the bus bar has an abutment stopper portion (26) that contacts a periphery of one of the open ends of the through hole in the resin member.

12. the bus bar is connected to the main body portion, forms a current path together with the main body portion, and has a fastening portion (22) provided in the vicinity of the stopper portion; The current sensor according to claim 11, wherein the abutment stopper is provided so as to be capable of being spring-deformed.

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