JP7119470B2 - current sensor - Google Patents

Description

The disclosure provided herein relates to a current sensor that detects a current to be measured.

2. Description of the Related Art As disclosed in Patent Document 1, a current detection system (current sensor) is known that detects current by converting a magnetic field generated by current flowing through a busbar into an electrical signal.

JP 2015-194472 A

As described in Patent Document 1, there is a problem in the technical field of current sensors that the detection accuracy of current (current to be measured) is degraded.

Therefore, an object of the disclosure described in this specification is to provide a current sensor in which deterioration in detection accuracy of the current to be measured is suppressed.

One disclosed is a conductive member (30) through which a current to be measured flows;
a wiring board (20) mounted with a magnetoelectric converter (25) for converting a magnetic field to be measured generated by the flow of a current to be measured into an electric signal;
an insulating sensor housing (50) housing a magnetoelectric conversion unit ;
a substrate adhesive (56e) for bonding the sensor housing and the wiring substrate,
The conductive member is provided in the sensor housing,
The sensor housing includes a substrate supporting portion (56a) that supports the wiring substrate, and a substrate bonding portion (56b) provided with a substrate adhesive,
The mounting surface (56d) of the substrate bonding portion on which the substrate adhesive is provided is further away from the wiring substrate than the supporting surface (56c) of the wiring substrate of the substrate supporting portion,
A wiring substrate is mounted on the supporting surface of the substrate supporting portion, a substrate adhesive is provided between the mounting surface of the substrate bonding portion and the wiring substrate, and the conductive member and the wiring substrate are arranged side by side in the sensor housing with a space therebetween. .

For example, when the wiring board is fixed and mounted on the sensor housing via a board adhesive, the cause of positional deviation of the wiring board (20) with respect to the conductive member (30) is the variation in the shape of the board adhesive (56e). and the manufacturing error of the sensor housing (50).

On the other hand, in the present disclosure, the wiring board (20) is mounted on the board supporting part (56a) and fixed to the board bonding part (56b) via the board adhesive (56e). According to this, the cause of the positional deviation of the wiring board (20) with respect to the conductive member (30) can be the manufacturing error of the sensor housing (50). As a result, relative displacement of the wiring board (20) with respect to the conductive member (30) is suppressed. As a result, fluctuations in the magnetic field to be measured passing through the magnetoelectric converter (25) mounted on the wiring board (20) are suppressed. A decrease in detection accuracy of the current to be measured is suppressed.

It should be noted that the reference numbers in parentheses above merely indicate the correspondence with the configurations described in the embodiments described later, and do not limit the technical scope in any way.

It is a block diagram for explaining an in-vehicle system. It is a perspective view showing a first current sensor. It is an exploded perspective view showing a 1st current sensor. FIG. 4 is a chart showing a first current sensor; FIG. FIG. 4 is a chart showing a first current sensor; FIG. 4 is a chart showing a wiring board; 4 is a block diagram for explaining a sensing unit; FIG. 4 is a diagram showing a conductive busbar; FIG. 4 is a chart showing a first shield; FIG. FIG. 11 is a chart showing a second shield; FIG. It is a chart showing a sensor housing. FIG. 4 is a chart for explaining substrate support pins and substrate bonding pins; FIG. FIG. 13 is a cross-sectional view taken along line XIII-XIII shown in column (b) of FIG. 12; FIG. 4 is a chart for explaining shield support pins and shield bonding pins; FIG. FIG. 15 is a cross-sectional view taken along line XV-XV shown in column (b) of FIG. 14; FIG. 3 is a perspective view showing two individual sensors; It is a perspective view which shows a wiring case. FIG. 10 is a perspective view for explaining how the individual sensor is attached to the wiring case; It is a perspective view which shows a 2nd current sensor. It is a chart which shows a wiring case. It is a chart which shows a wiring case. FIG. 4 is a chart showing a second current sensor; FIG. FIG. 4 is a chart showing a second current sensor; FIG. FIG. 4 is a chart for explaining magnetic saturation of the first shield; FIG. 4 is a chart showing simulation results of magnetic saturation; It is a chart for explaining the 2nd shield of a 2nd embodiment. FIG. 3 is a schematic diagram for explaining a magnetic field that penetrates a shield; It is a chart which shows the modification of a shield. It is a chart which shows the modification of a shield. It is a perspective view showing the 1st current sensor of a 3rd embodiment. 31 is a cross-sectional view taken along line XXXI-XXXI shown in FIG. 30; FIG. FIG. 4 is a chart for explaining a fixed form of the first current sensor; FIG. It is a chart which shows arrangement|positioning of the magnetoelectric conversion part of 4th Embodiment, and a conductive bus-bar. 4 is a chart for explaining output changes of a magnetoelectric conversion unit; FIG. 14 is a block diagram for explaining a sensing unit of the fourth embodiment; FIG. FIG. 3 is a block diagram for showing a differential circuit; FIG. It is a schematic diagram for demonstrating the shielding property of the shield of 5th Embodiment. FIG. 4 is a schematic diagram for explaining shielding properties of a shield; It is a chart which shows the modification of a shield. It is a chart which shows the modification of a shield. It is a perspective view which shows the modification of a 2nd current sensor. It is a chart which shows the modification of a 2nd current sensor. It is a chart which shows the modification of a 2nd current sensor. It is a perspective view which shows the assembly|attachment state to the wiring case of an individual sensor. FIG. 4 is a chart for explaining types of detection modes; FIG.

Embodiments will be described below with reference to the drawings.

(First embodiment)
<In-vehicle system>
First, an in-vehicle system 100 to which a current sensor is applied will be described. This in-vehicle system 100 constitutes a hybrid system. As shown in FIG. 1 , in-vehicle system 100 has battery 200 , power converter 300 , first motor 400 , second motor 500 , engine 600 , and power distribution mechanism 700 .

In-vehicle system 100 also has a plurality of ECUs. FIG. 1 shows a battery ECU 801 and an MGECU 802 as representatives of these multiple ECUs. These multiple ECUs mutually transmit and receive signals via bus wiring 800 to coordinately control the hybrid vehicle. Through this cooperative control, regeneration and power running of first motor 400, power generation of second motor 500, output of engine 600, and the like are controlled according to the SOC of battery 200. FIG. SOC is an abbreviation for state of charge. ECU is an abbreviation for electronic control unit.

The ECU has at least one arithmetic processing unit (CPU) and at least one memory device (MMR) as a storage medium for storing programs and data. The ECU is provided by a microcomputer having a computer readable storage medium. The storage medium is a non-transitional tangible storage medium that non-temporarily stores a computer-readable program. A storage medium may be provided by a semiconductor memory, a magnetic disk, or the like. The constituent elements of the in-vehicle system 100 are individually outlined below.

Battery 200 has a plurality of secondary batteries. These secondary batteries constitute a battery stack connected in series. A lithium-ion secondary battery, a nickel-hydrogen secondary battery, an organic radical battery, or the like can be used as the secondary battery.

A secondary battery generates an electromotive voltage through a chemical reaction. A secondary battery has a property that deterioration is accelerated when the amount of charge is too large or too small. In other words, the secondary battery has the property of accelerating deterioration when the SOC is overcharged or overdischarged.

The SOC of battery 200 corresponds to the SOC of the battery stack described above. The SOC of a battery stack is the sum of the SOCs of multiple secondary batteries. Overcharging and overdischarging of the SOC of the battery stack are avoided by the cooperative control described above. On the other hand, overcharging or overdischarging of the SOC of each of the plurality of secondary batteries is avoided by an equalization process that equalizes the SOC of each of the plurality of secondary batteries.

Equalization processing is accomplished by individually charging and discharging a plurality of secondary batteries. Battery 200 includes switches for individually charging and discharging a plurality of secondary batteries. Battery 200 also includes a voltage sensor, a temperature sensor, and the like for detecting the SOC of each of the plurality of secondary batteries. The battery ECU 801 controls the opening and closing of the switch based on the outputs of these sensors and a first current sensor 11, which will be described later. This equalizes the SOC of each of the plurality of secondary batteries.

The power conversion device 300 converts power between the battery 200 and the first motor 400 . The power conversion device 300 also performs power conversion between the battery 200 and the second motor 500 . The power conversion device 300 converts the DC power of the battery 200 into AC power having a voltage level suitable for powering the first motor 400 and the second motor 500 . The power conversion device 300 converts AC power generated by power generation by the first motor 400 and the second motor 500 into DC power having a voltage level suitable for charging the battery 200 . The power conversion device 300 will be described in detail later.

First motor 400 , second motor 500 and engine 600 are each connected to power distribution mechanism 700 . First motor 400 is directly connected to an output shaft of a hybrid vehicle (not shown). Rotational energy of the first motor 400 is transmitted to the running wheels via the output shaft. Conversely, the rotational energy of the running wheels is transmitted to the first motor 400 via the output shaft.

The first motor 400 is driven by AC power supplied from the power converter 300 . The rotational energy generated by this power running is distributed to the engine 600 and the output shaft of the hybrid vehicle by the power distribution mechanism 700 . As a result, cranking of the crankshaft and application of driving force to the running wheels are achieved. Also, the first motor 400 is regenerated by rotational energy transmitted from the running wheels. The AC power generated by this regeneration is converted into DC power and stepped down by the power conversion device 300 . This DC power is supplied to battery 200 . The DC power is also supplied to various electrical loads mounted on the hybrid vehicle.

The second motor 500 generates power using rotational energy supplied from the engine 600 . The AC power generated by this power generation is converted into DC power and stepped down by the power converter 300 . This DC power is supplied to the battery 200 and various electrical loads.

Engine 600 generates rotational energy by burning fuel. This rotational energy is distributed to the second motor 500 and the output shaft via the power distribution mechanism 700 . As a result, power generation by the second motor 500 and application of driving force to the running wheels are achieved.

Power distribution mechanism 700 has a planetary gear mechanism. Power distribution mechanism 700 has a ring gear, a planetary gear, a sun gear, and a planetary carrier.

The ring gear forms an annulus. A plurality of teeth are formed side by side in the circumferential direction on each of the outer peripheral surface and the inner peripheral surface of the ring gear.

Each of the planetary gear and the sun gear forms a disk shape. A plurality of teeth are arranged in the circumferential direction on the circumferential surfaces of the planetary gear and the sun gear.

The planetary carrier forms a ring. A plurality of planetary gears are connected to a flat surface that connects the outer peripheral surface and the inner peripheral surface of the planetary carrier. Flat surfaces of the planetary carrier and the planetary gear face each other.

A plurality of planetary gears are positioned on a circumference around the center of rotation of the planetary carrier. Adjacent intervals of these planetary gears are equal. In this embodiment, three planetary gears are arranged at intervals of 120°.

A sun gear is provided at the center of the ring gear. The inner peripheral surface of the ring gear and the outer peripheral surface of the sun gear face each other. Three planetary gears are provided between them. The teeth of each of the three planetary gears mesh with the teeth of each of the ring gear and sun gear. As a result, the rotations of the ring gear, the planetary gear, the sun gear, and the planetary carrier are mutually transmitted.

An output shaft of the first motor 400 is connected to the ring gear. A crankshaft of engine 600 is connected to the planetary carrier. An output shaft of the second motor 500 is connected to the sun gear. As a result, the rotational speeds of the first motor 400, the engine 600, and the second motor 500 are in a linear relationship in the alignment chart.

By supplying AC power from the power conversion device 300 to the first motor 400 and the second motor 500, torque is generated in the ring gear and the sun gear. Torque is generated in the planetary carrier by the combustion drive of the engine 600 . By doing so, the power running and regeneration of the first motor 400, the power generation of the second motor 500, and the application of the driving force to the running wheels are performed.

The behavior of each of first motor 400, second motor 500, and engine 600 is cooperatively controlled by a plurality of ECUs. For example, the MGECU 802 determines the target torques of the first motor 400 and the second motor 500 based on physical quantities detected by various sensors installed in the hybrid vehicle and vehicle information input from other ECUs. The MGECU 802 performs vector control so that the torque generated by each of the first motor 400 and the second motor 500 becomes the target torque.

<Power converter>
Next, the power conversion device 300 will be described. Power converter 300 includes converter 310 , first inverter 320 , and second inverter 330 . Converter 310 functions to step up or step down the voltage level of DC power. The first inverter 320 and the second inverter 330 function to convert DC power into AC power. The first inverter 320 and the second inverter 330 function to convert AC power into DC power.

In in-vehicle system 100 , converter 310 boosts the DC power of battery 200 to a voltage level suitable for powering first motor 400 and second motor 500 . First inverter 320 and second inverter 330 convert this DC power to AC power. This AC power is supplied to the first motor 400 and the second motor 500 . Also, the first inverter 320 and the second inverter 330 convert AC power generated by the first motor 400 and the second motor 500 into DC power. Converter 310 steps down this DC power to a voltage level suitable for charging battery 200 .

As shown in FIG. 1, converter 310 is electrically connected to battery 200 via first power line 301 and second power line 302 . Converter 310 is electrically connected to first inverter 320 and second inverter 330 via third power line 303 and fourth power line 304, respectively.

One end of first power line 301 is electrically connected to the positive electrode of battery 200 . One end of the second power line 302 is electrically connected to the negative electrode of the battery 200 . The other ends of first power line 301 and second power line 302 are electrically connected to converter 310 .

A first smoothing capacitor 305 is connected to the first power line 301 and the second power line 302 . One of the two electrodes of first smoothing capacitor 305 is connected to third power line 303 and the other is connected to fourth power line 304 .

Battery 200 has a system main relay (SMR) (not shown). The electrical connection between the battery stack of the battery 200 and the power converter 300 is controlled by opening and closing the system main relay. That is, continuation and interruption of power supply between the battery 200 and the power conversion device 300 are controlled by opening and closing the system main relay.

One end of the third power line 303 is electrically connected to a high side switch 311 of a converter 310 which will be described later. One end of the fourth power line 304 is electrically connected to the other end of the second power line 302 . The other ends of the third power line 303 and the fourth power line 304 are electrically connected to the first inverter 320 and the second inverter 330, respectively.

A second smoothing capacitor 306 is connected to the third power line 303 and the fourth power line 304 . One of the two electrodes of second smoothing capacitor 306 is connected to third power line 303 and the other is connected to fourth power line 304 .

First inverter 320 is electrically connected to first U-phase stator coil 401 through first W-phase stator coil 403 of first motor 400 via first conducting bus bar 341 through third conducting bus bar 343 . Second inverter 330 is electrically connected to second U-phase stator coil 501 through second W-phase stator coil 503 of second motor 500 via fourth conducting bus bar 344 through sixth conducting bus bar 346 .

<Converter>
Converter 310 has high side switch 311 , low side switch 312 , high side diode 311 a , low side diode 312 a and reactor 313 . As the high side switch 311 and low side switch 312, IGBT, power MOSFET, or the like can be adopted. In this embodiment, n-channel IGBTs are used as the high-side switch 311 and the low-side switch 312 .

When MOSFETs are used as the high-side switch 311 and the low-side switch 312, body diodes are formed in the MOSFETs. Therefore, the high side diode 311a and the low side diode 312a may be omitted. A semiconductor element that constitutes converter 310 can be manufactured from a semiconductor such as Si or a wide-gap semiconductor such as SiC.

The high side diode 311 a is connected in anti-parallel to the high side switch 311 . That is, the collector electrode of the high side switch 311 is connected to the cathode electrode of the high side diode 311a. The emitter electrode of the high side switch 311 is connected to the anode electrode of the high side diode 311a.

Similarly, a low-side diode 312 a is connected anti-parallel to the low-side switch 312 . A cathode electrode of a low-side diode 312 a is connected to the collector electrode of the low-side switch 312 . An anode electrode of a low-side diode 312 a is connected to the emitter electrode of the low-side switch 312 .

A third power line 303 is electrically connected to the collector electrode of the high-side switch 311 as shown in FIG. The emitter electrode of the high side switch 311 and the collector electrode of the low side switch 312 are connected. A second power line 302 and a fourth power line 304 are electrically connected to the emitter electrode of the low-side switch 312 . Thereby, the high side switch 311 and the low side switch 312 are connected in series from the third power line 303 to the second power line 302 in this order. In other words, the high-side switch 311 and the low-side switch 312 are connected in series from the third power line 303 to the fourth power line 304 in this order.

A middle point between the high-side switch 311 and the low-side switch 312 connected in series and one end of the reactor 313 are electrically connected via the conducting bus bar 307 . The other end of reactor 313 is electrically connected to the other end of first power line 301 .

As described above, DC power from the battery 200 is supplied to the middle point of the high-side switch 311 and the low-side switch 312 connected in series via the reactor 313 and the current bus bar 307 . The collector electrode of the high-side switch 311 is supplied with AC power of the motor converted into DC power by at least one of the first inverter 320 and the second inverter 330 . The AC power of the motor converted into DC power is supplied to battery 200 via high side switch 311 , current bus bar 307 and reactor 313 .

In this way, DC power for inputting/outputting battery 200 flows through conducting bus bar 307 . To limit the physical quantity that flows, a DC current that inputs and outputs the battery 200 flows through the conducting bus bar 307 .

High-side switch 311 and low-side switch 312 of converter 310 are controlled to be opened/closed by MGECU 802 . MGECU 802 generates a control signal and outputs it to gate driver 803 . The gate driver 803 amplifies the control signal and outputs it to the gate electrode of the switch. Thereby, MGECU 802 steps up or down the voltage level of the DC power input to converter 310 .

The MGECU 802 generates pulse signals as control signals. The MGECU 802 adjusts the step-up/step-down level of the DC power by adjusting the on-duty ratio and frequency of this pulse signal. The step-up/down level is determined according to the target torque and the SOC of battery 200 .

When boosting the DC power of battery 200 , MGECU 802 alternately opens and closes high-side switch 311 and low-side switch 312 . Therefore, the MGECU 802 inverts the voltage levels of the control signals output to the high side switch 311 and the low side switch 312 .

When a high level is input to the gate electrode of the high side switch 311 , a low level is input to the gate electrode of the low side switch 312 . In this case, DC power of battery 200 is supplied to first inverter 320 and second inverter 330 via reactor 313 and high-side switch 311 . At this time, electrical energy is accumulated in the reactor 313 due to the current flow. Also, electric charge is accumulated in the second smoothing capacitor 306 . The second smoothing capacitor 306 is charged.

When a low level is input to the gate electrode of the high side switch 311 , a high level is input to the gate electrode of the low side switch 312 . In this case, a closed loop passing through first smoothing capacitor 305, reactor 313, and low-side switch 312 is formed. Electric energy is accumulated in the reactor 313 as described above. Therefore, the reactor 313 tries to flow current. A current resulting from the electrical energy of this reactor 313 flows through the closed loop.

Further, in this case, the supply of DC power to the first inverter 320 and the second inverter 330 via the high-side switch 311 is interrupted. However, the second smoothing capacitor 306 is charged. Therefore, power is supplied from the second smoothing capacitor 306 to the first inverter 320 and the second inverter 330 . Power supply to the first inverter 320 and the second inverter 330 is continued.

After that, a high level is input to the high side switch 311 and a low level is input to the low side switch 312 . At this time, the DC power of battery 200 and the electrical energy accumulated in reactor 313 are supplied to first inverter 320 and second inverter 330 as DC power. As a result, the DC power of the battery 200 whose voltage is increased on a time-average basis is supplied to the first inverter 320 and the second inverter 330 . In addition, as the charge of the second smoothing capacitor 306 recovers, the amount of charge increases. As a result, the voltage level of the DC power supplied from the second smoothing capacitor 306 to the first inverter 320 and the second inverter 330 also rises.

When stepping down the DC power supplied from at least one of first inverter 320 and second inverter 330, MGECU 802 fixes the control signal output to low-side switch 312 at a low level. At the same time, the MGECU 802 sequentially switches the control signal output to the high-side switch 311 between high level and low level.

When a high level is input to the gate electrode of high-side switch 311 , DC power of at least one of first inverter 320 and second inverter 330 is supplied to battery 200 via high-side switch 311 and reactor 313 .

When a low level is input to the gate electrode of high-side switch 311 , DC power from at least one of first inverter 320 and second inverter 330 is not supplied to battery 200 . As a result, battery 200 is supplied with DC power whose voltage is stepped down on a time-average basis.

Strictly speaking, when a high level is input to the gate electrode of the high-side switch 311 as described above, the first smoothing capacitor 305 is charged. Electric energy is accumulated in the reactor 313 . After that, when a low level is input to the gate electrode of the high-side switch 311, if there is a difference between the output voltages and the time constants of the second smoothing capacitor 306 and the battery 200, Charging and discharging are performed. A diode (not shown) connects the first power line 301 and the second power line 302 . The diode has an anode electrode connected to the second power line 302 and a cathode electrode connected to the first power line 301 . Therefore, a closed loop passing through this diode, reactor 313 and first smoothing capacitor 305 is formed. A current resulting from the electrical energy of reactor 313 flows through this closed loop.

<Inverter>
The first inverter 320 has a first switch 321 to a sixth switch 326 and a first diode 321a to a sixth diode 326a. As the first switch 321 to the sixth switch 326, IGBTs, power MOSFETs, or the like can be used. In this embodiment, n-channel IGBTs are used as the first to sixth switches 321 to 326 . If MOSFETs are used as these switches, the above diodes may be omitted. A semiconductor element forming the first inverter 320 can be manufactured from a semiconductor such as Si or a wide-gap semiconductor such as SiC.

A first diode 321a to a sixth diode 326a corresponding to the first switch 321 to the sixth switch 326 are connected in anti-parallel. That is, if k is a natural number from 1 to 6, the cathode electrode of the kth diode is connected to the collector electrode of the kth switch. The anode electrode of the kth diode is connected to the emitter electrode of the kth switch.

The first switch 321 and the second switch 322 are serially connected in order from the third power line 303 toward the fourth power line 304 . A first U-phase leg is configured by the first switch 321 and the second switch 322 . One end of the first conducting bus bar 341 is connected to the midpoint between the first switch 321 and the second switch 322 . The other end of first conducting bus bar 341 is connected to first U-phase stator coil 401 of first motor 400 .

The third switch 323 and the fourth switch 324 are serially connected in order from the third power line 303 toward the fourth power line 304 . A first V-phase leg is configured by the third switch 323 and the fourth switch 324 . One end of the second conducting bus bar 342 is connected to the middle point between the third switch 323 and the fourth switch 324 . The other end of second conducting bus bar 342 is connected to first V-phase stator coil 402 of first motor 400 .

The fifth switch 325 and the sixth switch 326 are serially connected in order from the third power line 303 toward the fourth power line 304 . A first W-phase leg is configured by the fifth switch 325 and the sixth switch 326 . One end of the third conducting bus bar 343 is connected to the middle point between the fifth switch 325 and the sixth switch 326 . The other end of third conducting bus bar 343 is connected to first W-phase stator coil 403 of first motor 400 .

The second inverter 330 has the same configuration as the first inverter 320 . The second inverter 330 has seventh switches 331 to 12th switches 336 and seventh diodes 331a to 12th diodes 336a.

A seventh diode 331a to a twelfth diode 336a corresponding to the seventh switch 331 to the twelfth switch 336 are connected in antiparallel. If n is a natural number from 7 to 12, the collector electrode of the nth switch is connected to the cathode electrode of the nth diode. The anode electrode of the nth diode is connected to the emitter electrode of the nth switch.

A seventh switch 331 and an eighth switch 332 are connected in series between the third power line 303 and the fourth power line 304 to form a second U-phase leg. One end of the fourth conducting bus bar 344 is connected to the middle point between the seventh switch 331 and the eighth switch 332 . The other end of fourth conducting bus bar 344 is connected to second U-phase stator coil 501 of second motor 500 .

A ninth switch 333 and a tenth switch 334 are connected in series between the third power line 303 and the fourth power line 304 to form a second V-phase leg. One end of the fifth conducting bus bar 345 is connected to the middle point between the ninth switch 333 and the tenth switch 334 . The other end of fifth conducting bus bar 345 is connected to second V-phase stator coil 502 of second motor 500 .

The eleventh switch 335 and the twelfth switch 336 are connected in series between the third power line 303 and the fourth power line 304 to form a second W-phase leg. One end of the sixth conducting bus bar 346 is connected to the middle point between the eleventh switch 335 and the twelfth switch 336 . The other end of sixth conducting bus bar 346 is connected to second W-phase stator coil 503 of second motor 500 .

As described above, each of the first inverter 320 and the second inverter 330 has three-phase legs corresponding to the U-phase to W-phase stator coils of the motor. A control signal of the MGECU 802 amplified by the gate driver 803 is input to the gate electrodes of the switches that configure each of these three-phase legs.

When powering the motor, each switch is PWM-controlled by output of a control signal from the MGECU 802 . As a result, the inverter generates a three-phase alternating current. When the motor generates power, the MGECU 802 stops outputting the control signal, for example. AC power generated by the power generation of the motor thereby passes through the diode. As a result, AC power is converted to DC power.

The AC power input/output to/from first motor 400 described above flows through first conducting bus bar 341 to third conducting bus bar 343 that connect first inverter 320 and first motor 400 . Similarly, AC power input to and output from second motor 500 flows through fourth to sixth conducting bus bars 344 to 346 that connect second inverter 330 and second motor 500 .

In terms of the physical quantities that flow, the alternating current that inputs and outputs the first motor 400 flows through the first conducting bus bar 341 to the third conducting bus bar 343 . Alternating current to and from second motor 500 flows through fourth to sixth conducting bus bars 344 to 346 .

<Current sensor>
Next, a current sensor applied to the in-vehicle system 100 described so far will be described.

Current sensors include a first current sensor 11 , a second current sensor 12 and a third current sensor 13 . First current sensor 11 detects the current flowing through converter 310 . A second current sensor 12 detects the current flowing through the first motor 400 . A third current sensor 13 detects the current flowing through the second motor 500 .

The first current sensor 11 is provided on the conducting busbar 307 . As described above, the DC current that inputs and outputs the battery 200 flows through the conducting bus bar 307 . The first current sensor 11 detects this direct current.

A DC current detected by the first current sensor 11 is input to the battery ECU 801 . The battery ECU 801 monitors the SOC of the battery 200 based on the DC current detected by the first current sensor 11, the voltage of the battery stack detected by a voltage sensor (not shown), and the like.

The second current sensor 12 is provided on the first to third conducting busbars 341 to 343 . As described above, the alternating current for inputting and outputting the first motor 400 flows through the first to third conducting bus bars 341 to 343 . The second current sensor 12 detects this alternating current.

The alternating current detected by the second current sensor 12 is input to the MGECU 802 . The MGECU 802 vector-controls the first motor 400 based on the alternating current detected by the second current sensor 12 and the rotation angle of the first motor 400 detected by a rotation angle sensor (not shown).

The third current sensor 13 is provided on the fourth conducting bus bar 344 to the sixth conducting bus bar 346 . As described above, the alternating current for inputting and outputting the second motor 500 flows through the fourth conducting bus bar 344 to the sixth conducting bus bar 346 . The third current sensor 13 detects this alternating current.

The alternating current detected by the third current sensor 13 is input to the MGECU 802 . The MGECU 802 vector-controls the second motor 500 based on the alternating current detected by the third current sensor 13 and the rotation angle of the second motor 500 detected by a rotation angle sensor (not shown).

A first U-phase stator coil 401, a first V-phase stator coil 402, and a first W-phase stator coil 403 of the first motor 400 are star-connected. Similarly, the second U-phase stator coil 501, the second V-phase stator coil 502, and the second W-phase stator coil 503 of the second motor 500 are star-connected. Therefore, by detecting two phase currents out of the three phases of the stator coil, the remaining one phase current can be detected.

A configuration in which these three-phase stator coils are delta-connected can also be adopted. Also in this configuration, the current of the remaining one phase can be detected by detecting the current of the stator coil of two phases.

Second current sensor 12 is provided on two of first to third conducting bus bars 341 to 343 connected to first U-phase stator coil 401 to first W-phase stator coil 403 . More specifically, the second current sensor 12 is provided on the first conducting bus bar 341 and the second conducting bus bar 342 .

Therefore, the second current sensor 12 detects the current flowing through the first U-phase stator coil 401 and the current flowing through the first V-phase stator coil 402 . MGECU 802 detects the current flowing through first W-phase stator coil 403 based on the current flowing through first U-phase stator coil 401 and first V-phase stator coil 402 .

Similarly, third current sensor 13 is provided on two of fourth to sixth conducting bus bars 344 to 346 connected to second U-phase stator coil 501 to second W-phase stator coil 503 . More specifically, the third current sensor 13 is provided on the fourth conducting bus bar 344 and the fifth conducting bus bar 345 .

Therefore, the third current sensor 13 detects the current flowing through the second U-phase stator coil 501 and the current flowing through the second V-phase stator coil 502 . The MGECU 802 detects the current flowing through the second W-phase stator coil 503 based on the current flowing through the second U-phase stator coil 501 and the second V-phase stator coil 502 .

The DC current input/output to/from the battery 200 and the AC current input/output to/from the first motor 400 and the second motor 500 described above correspond to currents to be measured. The magnetic field generated by the flow of these currents corresponds to the magnetic field to be measured.

<First current sensor>
As described above, the first current sensor 11 is provided on the conducting bus bar 307 . The conducting bus bar 307 is divided between the reactor 313 side and the high side switch 311 (low side switch 312) side. The first current sensor 11 is provided on the conducting bus bar 307 so as to bridge the reactor 313 side and the high side switch 311 side of the separated conducting bus bar 307 . As a result, the current flowing through the conducting bus bar 307 , that is, the DC current inputting and outputting the battery 200 flows through the first current sensor 11 .

Of course, the configuration in which the conducting bus bar 307 is divided between the reactor 313 side and the high side switch 311 side is merely an example. For example, if the conducting bus bar 307 is not disconnected and is connected only to the high side switch 311 side, the first current sensor 11 bridges the reactor 313 and the conducting bus bar 307 .

As shown in FIGS. 2 to 5, first current sensor 11 has wiring board 20, conductive bus bar 30, shield 40, and sensor housing 50. As shown in FIGS. Conductive busbars 30 bridge the conducting busbars 307 described above. Therefore, a direct current flows through the conductive bus bar 30 . Conductive bus bar 30 corresponds to a conductive member.

Column (a) of FIG. 4 shows a top view of the first current sensor 11 . The (b) column of FIG. 4 shows a front view of the first current sensor. Column (c) of FIG. 4 shows a bottom view of the first current sensor. Section (a) of FIG. 5 shows a front view of the first current sensor 11 . Column (b) of FIG. 5 shows a side view of the first current sensor. Column (c) of FIG. 5 shows a rear view of the first current sensor. In addition, the same drawing is shown in the (b) column of FIG. 4 and the (a) column of FIG.

A portion of the conductive bus bar 30 is insert molded into the sensor housing 50 as clearly shown in these drawings. The wiring board 20 and the shield 40 are provided in the sensor housing 50 . The sensor housing 50 is made of an insulating resin material.

The wiring board 20 is fixed to the sensor housing 50 so as to face the part of the conductive bus bar 30 insert-molded in the sensor housing 50 . A later-described magnetoelectric conversion unit 25 is mounted on a portion of the wiring board 20 facing the conductive bus bar 30 . The magneto-electric converter 25 converts the magnetic field generated by the direct current flowing through the conductive bus bar 30 into an electric signal.

Shield 40 has a first shield 41 and a second shield 42 . The first shield 41 and the second shield 42 are fixed to the sensor housing 50 so as to be separated from each other. Between the first shield 41 and the second shield 42 are located portions of the wiring board 20 and the conductive bus bar 30 that face each other.

The first shield 41 and the second shield 42 are made of a material with higher magnetic permeability than the sensor housing 50 . Therefore, electromagnetic noise (external noise) trying to penetrate from the outside to the inside of the first current sensor 11 actively tries to pass through the first shield 41 and the second shield 42 . This suppresses the input of external noise to the magnetoelectric converter 25 .

A connection terminal 60 shown in FIG. 4 is insert-molded in the sensor housing 50 . The connection terminal 60 is electrically and mechanically connected to the wiring board 20 by solder 61 . The connection terminal 60 is electrically connected to the battery ECU 801 via a wire harness or the like. The electric signal converted by the magnetoelectric converter 25 is input to the battery ECU 801 via the connection terminal 60 and a wire harness (not shown).

Next, the constituent elements of the first current sensor 11 will be individually described in detail. Accordingly, the three directions that are orthogonal to each other are hereinafter referred to as the x-direction, the y-direction, and the z-direction. The x direction corresponds to the horizontal direction. The y direction corresponds to the extension direction.

<Wiring board>
As shown in FIG. 6, the wiring board 20 has a flat plate shape. The wiring board 20 has a flat shape with a thin thickness in the z direction. The wiring board 20 is formed by laminating a plurality of insulating resin layers and conductive metal layers in the z-direction. A facing surface 20a having the largest area of the wiring board 20 and a back surface 20b on the back side face the z-direction. Column (a) of FIG. 6 shows a top view of the wiring board. Column (b) of FIG. 6 shows a bottom view of the wiring board.

On the facing surface 20a of the wiring board 20, the first sensing section 21 and the second sensing section 22 shown in column (a) of FIG. 6 and FIG. 7 are mounted. Each of the first sensing section 21 and the second sensing section 22 has an ASIC 23 and a filter 24 . The ASIC 23 and the filter 24 are electrically connected via the wiring pattern of the wiring board 20 . A connection terminal 60 is electrically connected to this wiring pattern. ASIC is an abbreviation for application specific integrated circuit. A configuration in which the first sensing unit 21 and the second sensing unit 22 are mounted on the rear surface 20b can also be adopted.

<ASIC>
The ASIC 23 has a magnetoelectric conversion section 25 , a processing circuit 26 , connection pins 27 and a resin section 28 . The magnetoelectric converter 25 and the processing circuit 26 are electrically connected. One end of the connection pin 27 is electrically connected to the processing circuitry 26 . The other end of connection pin 27 is electrically and mechanically connected to wiring board 20 . One end side of the connection pin 27 , the processing circuit 26 , and the magnetoelectric conversion section 25 are covered with a resin section 28 . The other end side of the connection pin 27 is exposed from the resin portion 28 .

The magnetoelectric conversion unit 25 has a plurality of magnetoresistive effect elements whose resistance value varies according to the magnetic field (transmission magnetic field) passing through them. The magnetoresistive element changes its resistance value according to the magnetic field transmitted along the facing surface 20a. That is, the magnetoresistive element changes its resistance value according to the component along the x-direction and the component along the y-direction of the penetrating magnetic field.

On the other hand, the magnetoresistive element does not change its resistance value due to the transmitted magnetic field along the z direction. Therefore, even if external noise along the z-direction passes through the magnetoresistive element, it does not change the resistance value of the magnetoresistive element.

The magnetoresistive element has a pinned layer whose magnetization direction is fixed, a free layer whose magnetization direction changes according to the transmitted magnetic field, and a non-magnetic intermediate layer provided therebetween. When the intermediate layer has non-conductivity, the magnetoresistive element is a giant magnetoresistive element. When the intermediate layer has conductivity, the magnetoresistive element is a tunnel magnetoresistive element. The magnetoresistive element may be an anisotropic magnetoresistive element (AMR). Furthermore, the magnetoelectric conversion section 25 may have a Hall element instead of the magnetoresistive effect element.

The magnetoresistive element changes its resistance value depending on the angle formed by the magnetization directions of the pinned layer and the free layer. The magnetization direction of the pinned layer is along the facing surface 20a. The magnetization direction of the free layer is determined by the transmitted magnetic field along the facing surface 20a. The resistance value of the magnetoresistive element is the smallest when the magnetization directions of the free layer and fixed layer are parallel to each other. The resistance value of the magnetoresistive effect element is maximized when the magnetization directions of the free layer and the fixed layer are antiparallel.

The magnetoelectric conversion unit 25 has a first magnetoresistive effect element 25a and a second magnetoresistive effect element 25b as the magnetoresistive effect elements described above. The magnetization directions of the pinned layers of the first magnetoresistive element 25a and the second magnetoresistive element 25b are different by 90°. Therefore, the increase and decrease of the resistance values of the first magnetoresistive element 25a and the second magnetoresistive element 25b are reversed. When the resistance value of one of the first magnetoresistive element 25a and the second magnetoresistive element 25b decreases, the resistance value of the other element increases by the same amount.

The magnetoelectric conversion unit 25 has two first magnetoresistance effect elements 25a and two second magnetoresistance effect elements 25b. The first magnetoresistive element 25a and the second magnetoresistive element 25b are connected in series from the power supply potential toward the reference potential to form a first half bridge circuit. A second half bridge circuit is configured by serially connecting the second magnetoresistive element 25b and the first magnetoresistive element 25a in order from the power supply potential to the reference potential.

Thus, in the two half-bridge circuits, the arrangement of the first magnetoresistive element 25a and the second magnetoresistive element 25b is reversed. Therefore, the midpoint potential of the two half-bridge circuits is configured such that when the potential of one decreases, the potential of the other increases. In the magnetoelectric converter 25, a full bridge circuit is configured by combining these two half bridge circuits.

The magnetoelectric conversion unit 25 has a differential amplifier 25c, a feedback coil 25d, and a shunt resistor 25e in addition to the magnetoresistive effect elements forming the full bridge circuit described above. The midpoint potential of the two half-bridge circuits is input to the inverting input terminal and the non-inverting input terminal of the differential amplifier 25c. A feedback coil 25d and a shunt resistor 25e are connected in series from the output terminal of the differential amplifier 25c toward the reference potential.

With the connection configuration described above, the output terminal of the differential amplifier 25c outputs an output corresponding to the variation in the resistance values of the first magnetoresistive element 25a and the second magnetoresistive element 25b that form the full bridge circuit. be. This change in resistance value is caused by the transmission of the magnetic field along the facing surface 20a through the magnetoresistive element. A magnetic field (magnetic field to be measured) generated by a current flowing through the conductive bus bar 30 is transmitted through the magnetoresistive element. Therefore, a current corresponding to the magnetic field to be measured flows through the input terminal of the differential amplifier 25c.

The input terminal and output terminal of the differential amplifier 25c are connected via a feedback circuit (not shown). Therefore, the differential amplifier 25c is virtual shorted. Therefore, the differential amplifier 25c operates so that the inverting input terminal and the non-inverting input terminal have the same potential. That is, the differential amplifier 25c operates so that the current flowing through the input terminal and the current flowing through the output terminal become zero. As a result, a current (feedback current) corresponding to the magnetic field to be measured flows from the output terminal of the differential amplifier 25c.

A feedback current flows between the output terminal of the differential amplifier 25c and the reference potential via the feedback coil 25d and the shunt resistor 25e. The flow of this feedback current generates a canceling magnetic field in the feedback coil 25d. This canceling magnetic field passes through the magnetoelectric conversion section 25 . As a result, the magnetic field to be measured that passes through the magnetoelectric converter 25 is canceled out. As described above, the magnetoelectric conversion unit 25 operates so that the magnetic field to be measured and the canceling magnetic field passing through itself are balanced.

A feedback voltage is generated at the midpoint between the feedback coil 25d and the shunt resistor 25e in accordance with the amount of the feedback current that generates the canceling magnetic field. This feedback voltage is output to the subsequent processing circuit 26 as an electrical signal that detects the current to be measured.

The processing circuit 26 has an adjustment amplifier 26a and a threshold power supply 26b. A midpoint between the feedback coil 25d and the shunt resistor 25e is connected to the non-inverting input terminal of the adjustment amplifier 26a. A threshold power supply 26b is connected to the inverting input terminal of the adjustment amplifier 26a. As a result, the differentially amplified feedback voltage is output from the adjustment amplifier 26a.

The resistance value of each of the first magnetoresistive element 25a and the second magnetoresistive element 25b that constitute the full bridge circuit has the property of being dependent on temperature. Therefore, the output of the adjustment amplifier 26a fluctuates due to temperature changes. Therefore, the processing circuit 26 has a temperature detection element (not shown) and a non-volatile memory that stores the relationship between the temperature and the resistance value of the magnetoresistive effect element. This nonvolatile memory is electrically rewritable. By rewriting the values stored in the nonvolatile memory, the gain and offset of the adjustment amplifier 26a are adjusted. As a result, fluctuations in the output of the adjustment amplifier 26a due to temperature changes are canceled.

<Filter>
Filter 24 has a resistor 24a and a capacitor 24b. As shown in FIG. 7, the wiring board 20 is provided with a power wiring 20c, a first output wiring 20d, a second output wiring 20e, and a ground wiring 20f as wiring patterns.

The ASIC 23 of the first sensing section 21 is connected to the power wiring 20c, the first output wiring 20d, and the ground wiring 20f. The output terminal of the adjustment amplifier 26a of the ASIC 23 of the first sensing section 21 is connected to the first output wiring 20d.

The resistor 24a of the filter 24 of the first sensing section 21 is provided on the first output wiring 20d. The capacitor 24b connects the first output wiring 20d and the ground wiring 20f. Thus, the filter 24 of the first sensing section 21 forms a low-pass filter with the resistor 24a and the capacitor 24b. The output of the ASIC 23 of the first sensing section 21 is output to the battery ECU 801 via this low-pass filter. As a result, the output of first sensing section 21 from which high-frequency noise has been removed is input to battery ECU 801 .

The ASIC 23 of the second sensing section 22 is connected to the power wiring 20c, the second output wiring 20e, and the ground wiring 20f. The output terminal of the adjustment amplifier 26a of the ASIC 23 of the first sensing section 21 is connected to the second output wiring 20e.

The resistor 24a of the filter 24 of the second sensing section 22 is provided on the second output wiring 20e. The capacitor 24b connects the second output wiring 20e and the ground wiring 20f. Thus, the filter 24 of the second sensing section 22 forms a low-pass filter with the resistor 24a and the capacitor 24b. The output of the ASIC 23 of the second sensing section 22 is output to the battery ECU 801 via this low-pass filter. As a result, the output of the second sensing section 22 from which high-frequency noise has been removed is input to the battery ECU 801 .

As described above, the first sensing section 21 and the second sensing section 22 of this embodiment have the same configuration. The magnetoelectric conversion portions 25 of the first sensing portion 21 and the second sensing portion 22 are arranged in the y direction. As will be described in detail later, the same magnetic field is transmitted through the magnetoelectric conversion section 25 of each of the first sensing section 21 and the second sensing section 22 .

Therefore, the electrical signal input from the first sensing unit 21 to the battery ECU 801 and the electrical signal input from the second sensing unit 22 to the battery ECU 801 are the same. Battery ECU 801 compares these two input electrical signals to determine whether or not one of first sensing unit 21 and second sensing unit 22 is abnormal. Thus, the first current sensor 11 according to this embodiment has redundancy.

The shunt resistor 25e may be provided inside the resin portion 28, or may be provided outside. When provided outside the resin portion 28 , the shunt resistor 25 e is mounted on the wiring board 20 . The shunt resistor 25e is externally attached to the ASIC23.

Also, each of the four resistors forming the full bridge circuit may not be a magnetoresistive element. At least one of these four resistances should be a magnetoresistive element. Only one half-bridge circuit may be configured instead of the full-bridge circuit.

If the redundancy described above does not have to be provided, the first current sensor 11 may have one of the first sensing section 21 and the second sensing section 22 .

<Conductive busbar>
Conductive busbar 30 is made of a conductive material such as copper, brass and aluminum. The conductive bus bar 30 can be manufactured, for example, by the methods enumerated below. The conductive bus bar 30 can be manufactured by pressing a flat plate. The conductive bus bar 30 can be manufactured by integrally connecting a plurality of flat plates. Conductive busbar 30 can be manufactured by welding a plurality of flat plates. Conductive busbar 30 can be manufactured by pouring molten conductive material into a mold. A method for manufacturing the conductive bus bar 30 is not particularly limited.

As shown in FIG. 8, the conductive bus bar 30 has a flat shape with a thin thickness in the z direction. A front surface 30a and a back surface 30b thereof of the conductive bus bar 30 each face the z-direction. Column (a) of FIG. 8 shows a top view of the conductive bus bar. Column (b) of FIG. 8 shows a side view of the conductive bus bar.

Conductive busbar 30 extends in the y direction. As shown separated by two dashed lines in FIG. 8, the conductive bus bar 30 has a covering portion 31 covered by the sensor housing 50, and a first exposed portion 32 and a second exposed portion 33 exposed from the sensor housing 50. have The first exposed portion 32 and the second exposed portion 33 are arranged in the y direction with the covering portion 31 interposed therebetween. The first exposed portion 32 and the second exposed portion 33 are integrally connected via the covering portion 31 .

As shown in column (b) of FIG. 8, the lengths (thicknesses) in the z direction of the covering portion 31, the first exposed portion 32, and the second exposed portion 33 are equal. That is, the z-direction separation distances between the front surface 30a and the rear surface 30b of the covering portion 31, the first exposed portion 32, and the second exposed portion 33 are equal.

A bolt hole 30c is formed in each of the first exposed portion 32 and the second exposed portion 33 for electrical and mechanical connection with the conducting bus bar 307 through a bolt. The bolt hole 30c penetrates the front surface 30a and the rear surface 30b.

As described above, the conducting bus bar 307 is divided between the reactor 313 side and the high side switch 311 side. Mounting holes corresponding to the bolt holes 30c are formed on the reactor 313 side and the high side switch 311 side of the conducting bus bar 307, respectively.

The reactor 313 side mounting hole of the conducting bus bar 307 and the bolt hole 30c of the first exposed portion 32 are aligned in the z direction. The mounting hole of the conducting bus bar 307 on the side of the high side switch 311 and the bolt hole 30c of the second exposed portion 33 are aligned in the z direction. In this state, the shaft of the bolt is passed through the bolt hole 30c and the mounting hole. Then, the nut is tightened from the tip of the shank of the bolt toward the head. Conductive bus bar 307 and conductive bus bar 30 are sandwiched between the head of the bolt and the nut. As a result, the conducting bus bar 307 and the conducting bus bar 30 are brought into contact with each other and electrically and mechanically connected. As described above, the electrically conductive bus bar 30 bridges the reactor 313 side and the high side switch 311 side of the electrically conductive bus bar 307 . A common current flows through the conducting bus bar 307 and the conducting bus bar 30 .

As shown in column (a) of FIG. 8, the covering portion 31 is formed with a narrowed portion 31a having a locally short length in the x direction. The length in the x direction of the constricted portion 31a of this embodiment is gradually shortened. The narrowed portion 31a has a length in the x direction that decreases in two stages from the first exposed portion 32 side of the covering portion 31 toward the central point CP of the covering portion 31 in the y direction. Similarly, the constricted portion 31a has a length in the x direction that decreases in two stages from the second exposed portion 33 side of the covering portion 31 toward the central point CP of the covering portion 31 in the y direction. The length of the constricted portion 31a in the x direction may be shortened in multiple stages, or may be shortened continuously.

The above center point CP is equivalent to the center of gravity of the covering portion 31 . The covering portion 31 and the constricting portion 31a are symmetrical with respect to a center line passing through the center point CP in the z direction as an axis of symmetry AS.

The narrowed portion 31 a is shorter in the x direction than the first exposed portion 32 and the second exposed portion 33 . Therefore, the density of the current flowing through the constricted portion 31 a is higher than the density of the current flowing through the first exposed portion 32 and the second exposed portion 33 . As a result, the intensity of the magnetic field to be measured generated from the current flowing through the narrowed portion 31a is increased.

8, the magnetoelectric conversion units 25 of the first sensing unit 21 and the second sensing unit 22 are schematically enclosed by dashed lines in columns (a) and (b) of FIG. 8, respectively. The sensing portion 22 is arranged to face the constricted portion 31a with a space therebetween in the z-direction. Therefore, a high-strength magnetic field to be measured generated from the current flowing through the constricted portion 31a passes through each of the first sensing portion 21 and the second sensing portion 22 .

As described above, the conductive busbars 30 extend in the y direction. Therefore, current flows in the y direction in the conductive bus bar 30 . This current flow in the y-direction generates a magnetic field to be measured in the circumferential direction around the y-direction in accordance with Ampere's law. The magnetic field to be measured flows circularly around the conductive busbar 30 in a plane defined by the x-direction and the z-direction. The first sensing section 21 and the second sensing section 22 detect the component along the x direction of the magnetic field to be measured.

As indicated by broken lines in FIG. 8, the magnetoelectric conversion portions 25 of the first sensing portion 21 and the second sensing portion 22 are arranged in the y direction. These two magnetoelectric converters 25 are arranged symmetrically with respect to an axis of symmetry AS. The x-direction position of the two magnetoelectric conversion portions 25 and the x-direction position of the axis of symmetry AS (center point CP) are the same. Therefore, the two magnetoelectric converters 25 are arranged in the y direction via the center point CP.

Also, the distance in the z direction between the two magnetoelectric conversion portions 25 and the covering portion 31 is the same. As described above, the covering portion 31 and the constricted portion 31a are symmetrical with respect to the axis of symmetry AS. As described above, the magnetic fields to be measured having the same components in the x direction are transmitted through the two magnetoelectric conversion units 25 .

The conductive bus bar 30 of this embodiment is manufactured by pressing a conductive flat plate. This pressing involves placing a flat plate in a die and bringing a punch close to the die to apply a pulling force to the flat plate. This separates the flat plate into the conductive busbars 30 and the chips to produce the conductive busbars 30 .

When the conductive bus bar 30 is manufactured by the above press working, the conductive bus bar 30 is formed with a sheared surface. Sagging occurs on the sheared surface of the conductive bus bar 30 on the side of the first contact with the punch. This may impair the perpendicularity of the shear plane. As a result, the distribution of the magnetic field to be measured generated by the current flowing through the conductive bus bar 30 may deviate from the design.

The conductive bus bar 30 of this embodiment has a surface on the side of the wiring substrate 20 that is finally separated by the punch, rather than a surface that comes into contact with the punch first. That is, the surface that first comes into contact with the punch is the back surface 30b, and the surface that is finally separated by the punch is the front surface 30a. The shear plane corresponds to the side surface between the surface 30a and the back surface 30b. Therefore, the perpendicularity of the side surface of the conductive bus bar 30 on the side of the surface 30a is less likely to be impaired. A surface 30 a of the conductive bus bar 30 faces the wiring board 20 . Therefore, the distribution of the magnetic field to be measured passing through the first sensing section 21 and the second sensing section 22 mounted on the wiring board 20 is suppressed from deviating from the design.

After the conductive bus bar 30 is manufactured by press working as described above, it is necessary to distinguish which side surface 30a side or rear surface 30b side the sagging occurs. A notch 33a for distinguishing this is formed in the second exposed portion 33 of the conductive bus bar 30 as a mark. The notch 33a of this embodiment has a semicircular shape.

<Shield>
Shield 40 has a first shield 41 and a second shield 42 as described above. As shown in FIGS. 9 and 10, each of the first shield 41 and the second shield 42 has a plate shape with a thin thickness in the z direction. One surface 41a with the largest area of the first shield 41 and its back surface 41b each face the z-direction. The largest surface 42a of the second shield 42 and its rear surface 42b face the z-direction.

As shown in FIGS. 2 and 3, the first shield 41 and the second shield 42 are provided on the sensor housing 50 such that the one surface 41a and the one surface 42a face each other in the z direction. The rear surface 41 b of the first shield 41 and the rear surface 42 b of the second shield 42 are exposed outside the sensor housing 50 . The back surface 41b and the back surface 42b constitute part of the outermost surface of the first current sensor 11, respectively.

Column (a) of FIG. 9 shows a top view of the first shield. Column (b) of FIG. 9 shows a bottom view of the first shield. Column (a) of FIG. 10 shows a top view of the second shield. Column (b) of FIG. 10 shows a bottom view of the second shield.

These first shield 41 and second shield 42 can be manufactured by pressing a plurality of flat plates made of a soft magnetic material with high magnetic permeability such as permalloy. Alternatively, the first shield 41 and the second shield 42 can be manufactured by rolling electromagnetic steel.

Each of the first shield 41 and the second shield 42 of this embodiment is manufactured by pressing a plurality of flat plates made of a soft magnetic material. Each of the plurality of flat plates is formed with four protrusions protruding from the main surface toward the back surface. Accordingly, each of the plurality of flat plates is formed with four recesses that are recessed from the back surface toward the main surface. Each of the plurality of flat plates is arranged such that the main surface and the back surface are opposed to each other. Then, a plurality of flat plates are stacked so that the convex portion of one of the two opposing flat plates fits into the concave portion of the other. A plurality of flat plates are crimped in this stacked state. Thus, the first shield 41 and the second shield 42 are manufactured.

When manufacturing the first shield 41 and the second shield 42 by rolling the electromagnetic steel, the direction in which the electromagnetic steel is extended by the rolling is, for example, the x-direction. This aligns the atomic arrangement (crystal) of the electrical steel in the x direction. As a result, the magnetic permeability is higher in the x direction than in the y direction. By specifying the rolling direction of the electromagnetic steel in this way, the magnetic permeability of the shield can be made anisotropic.

<First shield>
The planar shape of the first shield 41 is a rectangle whose longitudinal direction is the x direction, as shown in FIG. Notches 41c are formed in the four corners of the first shield 41 of this embodiment. In FIG. 9, the first shield 41 is provided with two broken lines extending in the x direction in order to clarify the boundary between the center and both ends of the first shield 41 in the y direction. Hereinafter, the center of the first shield 41 in the y direction is referred to as a first central portion 41d. Both ends of the first shield 41 in the y direction are indicated as first end portions 41e. The first center portion 41d is located between the two ends of the first end portions 41e in the y direction.

As clearly indicated by the dashed lines, the first end portions 41e are shorter in the x direction than the first central portion 41d. Therefore, the first end portions 41e have a lower magnetic permeability in the x direction than the first central portion 41d. It is difficult for a magnetic field to enter the first end portions 41e. Therefore, the magnetic field is generated from one of the two ends of the first both ends 41e to the other through the parts (parallel parts) that are directly connected to the first both ends 41e of the first central part 41d and arranged in the y direction. Permeation is suppressed. It is difficult for the magnetic field to pass through the parallel portions of the first central portion 41d. As a result, the parallel portion of the first central portion 41d is difficult to be magnetically saturated.

The parallel portion of the first central portion 41d in which magnetic saturation is suppressed, the first sensing portion 21 and the second sensing portion 22 mounted on the wiring board 20 are arranged in the z direction. The magnetoelectric conversion portions 25 of the first sensing portion 21 and the second sensing portion 22 are positioned between the first central portion 41d and the constricted portion 31a.

<Second shield>
The planar shape of the second shield 42 is a rectangle whose longitudinal direction is the x direction, as shown in FIG. In FIG. 10, the second shield 42 is provided with two dashed lines extending in the x direction in order to clarify the boundary between the center and both ends of the second shield 42 in the y direction. Hereinafter, the center of the second shield 42 in the y direction will be referred to as a second central portion 42d. Both ends of the second shield 42 in the y direction are indicated as second end portions 42e. The second center portion 42d is located between the two ends of the second end portions 42e in the y direction.

The second shield 42 has two edges 42f aligned in the x direction. Extension portions 42c extending in the z-direction are formed on the second central portion 42d sides of these two end sides 42f. These two extending portions 42c extend in the z-direction from the back surface 42b toward the one surface 42a. The extending portion 42c has a rectangular parallelepiped shape whose longitudinal direction is the y direction. The extended portion 42c is formed by crimping a plurality of flat plates made of a soft magnetic material and then bending them when manufacturing the second shield 42, as described above.

As described above, the first shield 41 and the second shield 42 are provided in the sensor housing 50 such that the one surface 41a of the first shield 41 and the one surface 42a of the second shield 42 face each other in the z direction. The extended portion 42 c extends toward the first shield 41 while being provided in the sensor housing 50 . The end surface of the extending portion 42c and the one surface 41a of the first central portion 41d of the first shield 41 face each other in the z direction.

As a result, the distance between the first center portion 41d of the first shield 41 and the extension portion 42c of the second shield 42 is greater than the z-direction separation distance between the one surface 41a of the first shield 41 and the one surface 42a of the second shield 42. The separation distance in the z direction is shorter. Therefore, the magnetic field entering the first shield 41 is easily transmitted to the second shield 42 via the extension 42c.

As described above, the extended portion 42c extends in the z-direction from the second central portion 42d side of the edge 42f. The extended portion 42c is not formed on the second end portion 42e side of the edge 42f. Therefore, the magnetic field that has entered the first shield 41 is easily transmitted to the second central portion 42d of the second shield 42 via the extended portion 42c.

The second central portion 42d, the first sensing portion 21 and the second sensing portion 22 mounted on the wiring board 20 face each other in the z direction. Between the first central portion 41d and the second central portion 42d, the magnetoelectric conversion portion 25 and the constriction portion 31a of each of the first sensing portion 21 and the second sensing portion 22 are positioned.

In addition, the position of the magnetoelectric conversion portion 25 in the x direction is between two extending portions 42c formed on each of the two end sides 42f. Therefore, when external noise along the x direction tries to pass through the region between the one surface 41a of the first shield 41 where the magnetoelectric conversion unit 25 is located and the one surface 42a of the second shield 42, the external noise is transferred to the magnetoelectric conversion unit. It tries to enter the extension 42c instead of 25. The direction of transmission of the external noise entering the extended portion 42c is bent so as to pass through the second shield 42 . As a result, transmission of external noise through the magnetoelectric converter 25 is suppressed.

<Sensor case>
As shown in FIGS. 3 and 11, the conductive bus bar 30 and the connection terminals 60 are insert-molded in the sensor housing 50 . The wiring board 20 and the shield 40 are provided in the sensor housing 50 . Conductive bus bar 30, wiring board 20, and shield 40 are spaced apart in the z-direction. Column (a) of FIG. 11 shows a top view of the sensor housing. Column (b) of FIG. 11 shows a bottom view of the sensor housing.

As shown in FIGS. 5 and 11 , the sensor housing 50 has a base portion 51 , an insulating portion 52 , a first enclosing portion 53 , a second enclosing portion 54 and a connector portion 55 .

The base 51 forms a rectangular parallelepiped with the x direction as its longitudinal direction. Therefore, the base 51 has six faces. The base 51 has a left surface 51a and a right surface 51b facing in the y-direction. The base 51 has an upper surface 51c and a lower surface 51d facing in the x-direction. The base 51 has an upper end surface 51e and a lower end surface 51f facing in the z direction.

As shown in columns (a) and (c) of FIG. 5 , the insulating portion 52 is formed on a portion of each of the left surface 51 a and the right surface 51 b of the base portion 51 . These two insulating portions 52 extend in the y-direction away from the base portion 51 . The two insulating portions 52 are arranged in the y direction with the base portion 51 interposed therebetween. The covering portion 31 of the conductive bus bar 30 is covered with the two insulating portions 52 and the base portion 51 respectively.

Roughly speaking, the two insulating portions 52 cover the first exposed portion 32 side and the second exposed portion 33 side of the covering portion 31 . The narrowed portion 31 a of the covering portion 31 is covered with the base portion 51 . Therefore, the constricted portion 31a is positioned between the upper end surface 51e and the lower end surface 51f of the base portion 51 in the z-direction. An insulating resin material forming the base portion 51 is positioned between the narrowed portion 31a and the upper end surface 51e and between the narrowed portion 31a and the lower end surface 51f.

As shown in column (a) of FIG. 11 , the first enclosing portion 53 is formed on the upper end surface 51 e of the base portion 51 . The first enclosing portion 53 has a left wall 53a and a right wall 53b aligned in the y direction. The first enclosing portion 53 has an upper wall 53c and a lower wall 53d aligned in the x direction.

The walls forming the first surrounding portion 53 are formed along the edge of the upper end surface 51e. The left wall 53a, the upper wall 53c, the right wall 53b, and the lower wall 53d are connected in order in the circumferential direction around the z direction. As a result, the first enclosing portion 53 has an annular shape that opens in the z direction. The upper end surface 51 e is surrounded by the first surrounding portion 53 . The wiring substrate 20 and the first shield 41 are provided in the first storage space defined by the first enclosing portion 53 and the upper end surface 51e.

As shown in column (b) of FIG. 11 , the second enclosing portion 54 is formed on the lower end surface 51 f of the base portion 51 . The second enclosing portion 54 has a left wall 54a and a right wall 54b aligned in the y direction. The second enclosing portion 54 has an upper wall 54c and a lower wall 54d aligned in the x direction.

The walls forming the second enclosing portion 54 are formed around a portion of the lower end surface 51f that is aligned with the constricted portion 31a of the base portion 51 in the z direction. The left wall 54a, the upper wall 54c, the right wall 54b, and the lower wall 54d are connected in order in the circumferential direction around the z-direction. Thereby, the second surrounding portion 54 has an annular shape that opens in the z direction. A portion of the lower end surface 51f is surrounded by the second surrounding portion 54 . The second shield 42 is provided in the second housing space defined by the second enclosing portion 54 and the lower end surface 51f.

The second storage space is smaller than the first storage space in a plane perpendicular to the z-direction. The second storage space is aligned with part of the first storage space in the z-direction. A portion of the first storage space that is not aligned with the second storage space in the z direction and the connector portion 55 are aligned in the z direction.

As shown in column (b) of FIG. 5 and column (b) of FIG. The connector portion 55 extends in the z-direction away from a portion of the lower end surface 51f that is not surrounded by the second surrounding portion 54 (non-surrounding portion). The connector portion 55 forms part of the lower wall 54d.

The connector portion 55 has a column portion 55a extending in the z-direction from the lower end surface 51f, and an enclosing portion 55c surrounding the tip end surface 55b of the column portion 55a in the z-direction. The connection terminal 60 extends in the z direction. The connection terminal 60 is covered with the column portion 55a and portions of the base portion 51 that are aligned with the column portion 55a in the z-direction.

One end of the connection terminal 60 is exposed outside the column portion 55a from the tip surface 55b. One end of the connection terminal 60 exposed from the tip surface 55b is surrounded by the surrounding portion 55c. Thus, the enclosing portion 55c and one end of the connection terminal 60 constitute a connector. A connector such as a wire harness is connected to this connector.

The other end of the connection terminal 60 is exposed outside the base portion 51 from the upper end surface 51e. The other end of the connection terminal 60 is provided in the first housing space. The connection terminal 60 is separated from the portion (constricted portion 31a) of the conductive bus bar 30 covered by the base portion 51 in the x direction. The other end of the connection terminal 60 in the x direction is positioned on the lower wall 53d side. The narrowed portion 31a is located on the upper wall 53c side. An insulating resin material forming the base portion 51 is positioned between the portions of the connection terminal 60 and the narrowed portion 31a that are insert-molded in the sensor housing 50 .

As described above, a DC current flows through the conductive bus bar 30 to and from the battery 200 . An electrical signal having a smaller amount of current than a direct current flows through the connection terminal 60 between the wiring board 20 and the battery ECU 801 . If the creepage distance between the conductive bus bar 30 and the connection terminal 60 is short, there is a risk that the two will be electrically connected and short-circuited.

A rib 52a is formed on the insulating portion 52 to prevent such a problem from occurring. The rib 52a protrudes from the insulating portion 52 in the z direction. The rib 52a extends in the x direction. The length of the rib 52a in the x direction is longer than the length of each of the first exposed portion 32 and the second exposed portion 33 in the x direction.

Rib 52a is located between first exposed portion 32 and second exposed portion 33 of conductive bus bar 30 located outside insulating portion 52 and the other end of connection terminal 60 exposed outside from upper end surface 51e. The ribs 52 a increase the creeping distance between the conductive bus bars 30 and the connection terminals 60 on the surface of the sensor housing 50 . This suppresses a short circuit between the conductive bus bar 30 and the connection terminal 60 .

Further, rib 52 a is located between first exposed portion 32 and second exposed portion 33 and first shield 41 and second shield 42 . As a result, a short circuit between the conductive bus bar 30 and the shield 40 is also suppressed.

The extension of the creepage distance by the ribs 52a allows the length of the insulating portion 52 in the y direction to be shortened. The length of the insulating portion 52 in the y direction can be shortened by approximately 85%. This suppresses an increase in the physical size of the first current sensor 11 .

<Fixation form of the wiring board to the sensor housing>
As shown in columns (a) of FIG. 11 and (a) of FIG. 12, the upper end surface 51e of the base portion 51 is formed with substrate support pins 56a and substrate bonding pins 56b that locally extend in the z-direction. . A plurality of substrate support pins 56a and substrate bonding pins 56b are formed on the upper end surface 51e. Column (a) of FIG. 12 shows a perspective view of the sensor housing. Column (b) of FIG. 12 shows a perspective view of a sensor housing provided with a wiring board. Some reference numerals are omitted in FIG. 12 in order to explain these pins.

Each of the plurality of substrate support pins 56a has a tip surface 56c facing in the z direction. The positions in the z-direction of the plurality of tip surfaces 56c are the same. Similarly, each of the substrate bonding pins 56b has a leading end face 56d facing in the z direction. The positions in the z-direction of the plurality of tip surfaces 56d are the same.

As shown in FIG. 13, the length in the z direction between the tip surface 56c of the substrate support pin 56a and the upper end surface 51e is L1. The length in the z direction between the tip surface 56d of the board bonding pin 56b and the upper end surface 51e is L2. As clearly shown in the drawing, length L1 is longer than length L2.

Therefore, the tip end face 56c of the substrate support pin 56a is farther from the upper end face 51e in the z-direction than the tip end face 56d of the substrate bonding pin 56b. The wiring board 20 is mounted on the sensor housing 50 in such a manner that the facing surface 20a contacts the tip surface 56c of the board support pin 56a. The board support pins 56a correspond to the board support portion. The tip surface 56c corresponds to the support surface.

In the state of being mounted on the tip surface 56c of the substrate support pin 56a, the facing surface 20a of the wiring substrate 20 and the tip surface 56d of the substrate bonding pin 56b are separated in the z direction. A substrate adhesive 56e is provided between the wiring substrate 20 and the substrate bonding pins 56b to bond and fix the two. The substrate bonding pin 56b corresponds to the substrate bonding portion. The tip surface 56d corresponds to the mounting surface.

When the wiring substrate 20 and the sensor housing 50 are fixed by the substrate adhesive 56e, the temperature of the substrate adhesive 56e is set higher than the environmental temperature in which the first current sensor 11 is provided. The temperature of the substrate adhesive 56e at this time can be set to about 150° C., for example. At this temperature, the substrate adhesive 56e has fluidity. A silicon-based adhesive can be used as the substrate adhesive 56e.

A substrate adhesive 56e having a fluidity of about 150° C. is applied to the tip surface 56d of the substrate bonding pin 56b. Then, the wiring board 20 is provided in the sensor housing 50 so that the tip surfaces 56c of the board support pins 56a and the board adhesive 56e are in contact with the facing surface 20a of the wiring board 20, respectively. Thereafter, the substrate adhesive 56e is cooled to room temperature and solidified.

As a result, a residual stress that condenses to the center of the substrate adhesive 56e is generated at the ambient temperature where the first current sensor 11 is provided. This residual stress causes the wiring board 20 and the board bonding pins 56b to approach each other. The contact state between the facing surface 20a of the wiring board 20 and the tip surface 56c of the board support pin 56a is maintained.

As a result, the positional deviation of the wiring board 20 with respect to the sensor housing 50 does not depend on the variation in the shape of the substrate adhesive 56e having fluidity when the wiring board 20 is fixed. A positional deviation of the wiring board 20 with respect to the sensor housing 50 becomes a manufacturing error of the sensor housing 50 . In other words, a positional deviation of the wiring board 20 with respect to the conductive bus bar 30 insert-molded in the sensor housing 50 results in a manufacturing error of the sensor housing 50 .

In this embodiment, three substrate support pins 56a are formed on the upper end surface 51e. Two of these three substrate support pins 56a are spaced apart in the y direction. The remaining one board support pin 56a is spaced in the x direction from the midpoint between two board support pins 56a aligned in the y direction. The end faces 56c of the three substrate support pins 56a form vertices of an isosceles triangle. The constricted portion 31a of the conductive bus bar 30 is located between the two board support pins 56a arranged in the y-direction and the remaining one board support pin 56a.

In this embodiment, three substrate bonding pins 56b are formed on the upper end surface 51e. Two of these three substrate bonding pins 56b are spaced apart in the y direction. The remaining substrate bonding pin 56b is spaced in the x direction from the midpoint between the two substrate support pins 56a aligned in the y direction. The end faces 56d of the three substrate bonding pins 56b form vertices of an isosceles triangle.

The other ends of the plurality of connection terminals 60 are arranged between two board support pins 56a arranged in the y direction. The remaining one board support pin 56a is positioned at the midpoint between the two board bonding pins 56b aligned in the y direction. This remaining substrate support pin 56a is therefore aligned with the remaining substrate bonding pin 56b in the x-direction. The center point CP of the constricted portion 31a is located between the remaining one board support pin 56a and the remaining one board bonding pin 56b in the x direction.

With the above configuration, the isosceles triangle formed by connecting the tip surfaces 56c of the three substrate support pins 56a and the isosceles triangle formed by connecting the tip surfaces 56d of the three substrate bonding pins 56b overlap in the z direction. there is The central point CP of the constricted portion 31a is located in the region where these two isosceles triangles overlap in the z direction.

The wiring board 20 is provided on the sensor housing 50 so as to face each of these two isosceles triangles in the z direction. A portion of the wiring substrate 20 facing the two isosceles triangles faces the two isosceles triangles for contact with the substrate support pins 56a and connection with the substrate bonding pins 56b via the substrate adhesive 56e. The connection with the sensor housing 50 is more stable than that of the portion that does not. The first sensing section 21 and the second sensing section 22 are mounted on the portion of the wiring board 20 where the connection with the sensor housing 50 is stabilized.

In a state in which the wiring board 20 is mounted on the board support pins 56a and fixed to the board bonding pins 56b via the board adhesive 56e, the facing surface 20a of the wiring board 20 and the upper end surface 51e of the base 51 are aligned in the z direction. They are separated and opposed to each other. If there is no manufacturing error or the like, the separation distance between the facing surface 20a and the upper end surface 51e is constant over the entire surface, and the two are in a parallel relationship.

As described above, the constricted portion 31a of the conductive bus bar 30 is insert-molded in the base portion 51. As shown in FIG. If there is no manufacturing error or the like, the distance between the surface 30a of the constricted portion 31a and the upper end surface 51e of the base portion 51 is constant over the entire surface, and the two are in a parallel relationship.

Due to the above-described parallel relationship, when there is no manufacturing error, the distance between the facing surface 20a of the wiring board 20 and the surface 30a of the constricted portion 31a is constant over the entire surface, and both are in a parallel relationship. .

By the way, as described above, the wiring board 20 is formed by laminating a plurality of resin layers and metal layers in the z-direction. Therefore, the manufacturing error of the thickness of the wiring board 20 in the z direction is large. Manufacturing errors in the z-direction thickness of the wiring board 20 include manufacturing errors in the z-direction position due to insert molding of the conductive bus bars 30 into the sensor housing 50 and placement errors in the z-direction of the wiring board 20 with respect to the sensor housing 50. is about twice as much as

On the other hand, the first sensing portion 21 and the second sensing portion 22 are provided on the surface 20a of the wiring board 20 facing the conductive bus bar 30 as described above. Therefore, the distance in the z direction between the conductive busbars 30 of the first sensing portion 21 and the second sensing portion 22 does not depend on the thickness of the wiring board 20 in the z direction. Variation in the z-direction separation distance between the first sensing portion 21 and the second sensing portion 22 and the conductive bus bar 30 due to a manufacturing error in the z-direction thickness of the wiring board 20 is suppressed.

The number of substrate support pins 56a and substrate bonding pins 56b is not limited to three. Four or more substrate support pins 56a may be employed. The number of substrate bonding pins 56b may be one, two, or four or more.

When the number of each of the substrate support pins 56a and the substrate bonding pins 56b is three or more, a polygon formed by connecting the tip surfaces 56c of the three or more substrate support pins 56a and the three or more substrate bonding pins 56b. A configuration in which the polygon formed by connecting the tip surface 56d overlaps in the z direction is preferable. In this configuration, it is preferable to mount the first sensing section 21 and the second sensing section 22 in regions facing the two polygons in the z direction on the wiring board 20 . This suppresses positional deviation of the first sensing unit 21 and the second sensing unit 22 with respect to the sensor housing 50 .

An example is shown in which the substrate support pins 56a and the substrate bonding pins 56b are columnar extending in the z-direction. However, these shapes are not limited to columnar shapes. The tip surface 56c of the substrate support pin 56a may be further away from the upper end surface 51e than the tip surface 56d of the substrate bonding pin 56b, and the shape is not particularly limited.

<Fixation form of the first shield to the sensor housing>
As shown in columns (a) of FIG. 11 and (a) of FIG. 14, the upper end surface 51e of the base portion 51 is formed with shield support pins 57a and shield bonding pins 57b that locally extend in the z-direction. . A plurality of shield support pins 57a and shield bonding pins 57b are formed on the upper end surface 51e. Column (a) of FIG. 14 shows a perspective view of a sensor housing provided with a wiring board. Column (b) of FIG. 14 shows a perspective view of a sensor housing provided with a wiring board and a shield. In FIG. 14, some reference numerals are omitted in order to explain these pins.

Each of the plurality of shield support pins 57a has a tip surface 57c facing in the z direction. The positions in the z-direction of the plurality of tip surfaces 57c are the same. Similarly, each of the plurality of shield bonding pins 57b has a leading end surface 57d facing in the z direction. The z-direction positions of the plurality of tip surfaces 57d are the same.

As shown in FIG. 15, each of the shield support pins 57a and the shield bonding pins 57b is longer in the z-direction than the substrate support pin 56a. More specifically, each of the shield support pins 57a and the shield bonding pins 57b is longer than the board support pin 56a in the z direction by at least the thickness of the wiring board 20 in the z direction. Therefore, in the state where the wiring board 20 is mounted on the sensor housing 50 as described above, the tip end surface 57c of the shield support pin 57a and the tip end surface 57d of the shield bonding pin 57b are higher than the rear surface 20b of the wiring board 20. 51e in the z-direction. A configuration in which the difference in length in the z direction between the shield bonding pin 57b and the board support pin 56a is shorter than the thickness of the wiring board 20 in the z direction can also be adopted.

As shown in FIG. 15, the length in the z direction between the tip surface 57c of the shield support pin 57a and the upper end surface 51e is L3. The length in the z direction between the tip surface 57d of the shield bonding pin 57b and the upper end surface 51e is L4. As clearly shown in the drawing, length L3 is longer than length L4.

For this reason, the tip end face 57c of the shield support pin 57a is farther from the upper end face 51e in the z-direction than the tip end face 57d of the shield bonding pin 57b. The first shield 41 is mounted on the sensor housing 50 in such a manner that the one surface 41a contacts the tip surface 57c of the shield support pin 57a. The shield support pin 57a corresponds to the shield support portion. The tip surface 57c corresponds to the contact surface.

When mounted on the tip surface 57c of the shield support pin 57a, the one surface 41a of the first shield 41 and the tip surface 57d of the shield bonding pin 57b are separated in the z direction. A substrate adhesive 56e is provided between the first shield 41 and the shield bonding pin 57b to bond and fix them. The shield bonding pin 57b corresponds to the shield bonding portion. The tip surface 57d corresponds to the installation surface.

When bonding and fixing the first shield 41 and the sensor housing 50 with the shield adhesive 57e, the temperature of the shield adhesive 57e is set higher than the environmental temperature in which the first current sensor 11 is provided. The temperature of the shield adhesive 57e at this time can also be set to about 150.degree. At this temperature, the shield adhesive 57e has fluidity. A silicone-based adhesive can be used as the shield adhesive 57e.

A shield adhesive 57e having a fluidity of about 150° C. is applied to the tip surface 57d of the shield adhesive pin 57b. The first shield 41 is provided on the sensor housing 50 so that the tip surface 57c of the shield support pin 57a and the shield adhesive 57e are in contact with the one surface 41a of the first shield 41, respectively. After that, the shield adhesive 57e is cooled to room temperature and solidified.

As a result, a residual stress is generated in the shield adhesive 57e that condenses to its center at the ambient temperature where the first current sensor 11 is provided. This residual stress causes the first shield 41 and the shield bonding pin 57b to approach each other. The contact state between the one surface 41a of the first shield 41 and the tip surface 57c of the shield support pin 57a is maintained.

As a result, the positional deviation of the first shield 41 with respect to the sensor housing 50 does not depend on the variation in the shape of the shield adhesive 57e having fluidity when fixed by adhesion. A positional deviation of the first shield 41 with respect to the sensor housing 50 becomes a manufacturing error of the sensor housing 50 . In other words, the displacement of the first shield 41 with respect to the wiring board 20 fixed to the sensor housing 50 results in manufacturing error of the sensor housing 50 .

In this embodiment, three shield support pins 57a are formed on the upper end surface 51e. One of the three shield support pins 57a is integrally connected with the left wall 53a. One of the remaining two shield support pins 57a is integrally connected to the right wall 53b. The remaining one shield support pin 57a is integrally connected with the upper wall 53c. As a result, the tip surfaces 57c of the three shield support pins 57a form the vertices of a triangle.

A shield support pin 57a integrally connected to the left wall 53a and a shield support pin 57a integrally connected to the right wall 53b are arranged in the y direction. The space between these two shield support pins 57a and the shield support pin 57a integrally connected to the upper wall 53c are spaced apart in the x direction. The first sensing portion 21 and the second sensing portion 22 of the wiring board 20 are positioned in a triangular region formed by connecting the tip surfaces 57c of the three shield support pins 57a.

In this embodiment, three shield bonding pins 57b are formed on the upper end surface 51e. One of these three shield bonding pins 57b is integrally connected to the left wall 53a. One of the remaining two shield bonding pins 57b is integrally connected to the right wall 53b. The remaining one shield adhesive pin 57b is integrally connected with the upper wall 53c. As a result, the tip surfaces 57d of the three shield bonding pins 57b form vertices of a triangle.

The shield bonding pin 57b integrally connected with the left wall 53a and the shield bonding pin 57b integrally connected with the right wall 53b are arranged in the y direction. The space between these two shield bonding pins 57b and the shield bonding pin 57b integrally connected to the upper wall 53c are spaced apart in the x direction. A triangular area formed by connecting tip surfaces 57d of these three shield bonding pins 57b, the first sensing section 21 and the second sensing section 22 are arranged in the z direction.

One shield support pin 57a and one shield bonding pin 57b are arranged on each of the left wall 53a and the right wall 53b. One shield supporting pin 57a and one shield bonding pin 57b are arranged on the upper wall 53c. A triangle formed by connecting tip surfaces 57c of three shield support pins 57a and a triangle formed by connecting tip surfaces 57d of three shield bonding pins 57b overlap in the z direction. The overlapping region in the z-direction and the center point CP of the constricted portion 31a are aligned in the z-direction.

A first shield 41 is provided on the sensor housing 50 in a manner facing each of these two triangles in the z-direction. The portion of the first shield 41 that faces the two triangles is in contact with the shield support pin 57a and is connected to the shield bonding pin 57b via the shield adhesive 57e, so the portion that does not face the two triangles is Also, the connection with the sensor housing 50 is stabilized.

The portion of the first shield 41 where the connection with the sensor housing 50 is stabilized is aligned with the first sensing portion 21 and the second sensing portion 22 of the wiring board 20 in the z direction. Specifically, the first central portion 41d of the first shield 41 is aligned with the first sensing portion 21 and the second sensing portion 22 in the z-direction.

In a state in which the first shield 41 is mounted on the shield support pins 57a and fixed to the shield bonding pins 57b via the shield adhesive 57e, the one surface 41a of the first shield 41 and the rear surface 20b of the wiring board 20 are aligned in the z direction. are spaced apart from each other. If there is no manufacturing error or the like, the distance between the one surface 41a and the rear surface 20b is constant over the entire surface, and the two are parallel to each other. Therefore, the distance between the opposing surface 20a of the wiring board 20 and the one surface 41a of the first shield 41 is constant over the entire surface, and the two are in a parallel relationship.

6 and 14, at the end of the wiring board 20, notches 20g are provided for passing the shield support pins 57a and the shield bonding pins 57b above the wiring board 20, respectively. is formed. The wiring board 20 is formed with a plurality of through holes 20h for passing the other ends of the connection terminals 60 therethrough.

As shown in FIG. 6, the plurality of through holes 20h are arranged in the y direction. The portion of the wiring board 20 where the plurality of through holes 20h are formed and the portion where the first sensing portion 21 and the second sensing portion 22 are mounted are arranged in the x direction. Between these two parts of the wiring board 20 aligned in the x direction, there is a first guide for guiding the position of the wiring board 20 in the x direction with respect to the sensor housing 50 when the wiring board 20 is provided in the sensor housing 50 . A notch 20i is formed. In addition, when the wiring board 20 is installed in the sensor housing 50 , the position of the wiring board 20 in the y direction with respect to the sensor housing 50 is provided at the portion where the first sensing unit 21 and the second sensing unit 22 are mounted on the wiring board 20 . A second notch 20j is formed for guiding the .

Correspondingly, the left wall 53a and the right wall 53b of the sensor housing 50 are inserted into the first notches 20i as shown in columns (a) of FIG. 11 and (b) of FIG. A first convex portion 53e is formed. The left wall 53a and the right wall 53b are each provided with a second protrusion 53f that faces the second notch 20j in the y direction. The first notch 20i and the first protrusion 53e have similar shapes and extend in the y direction. The second notch 20j and the second protrusion 53f have similar shapes and extend in the x direction.

The numbers of the shield support pins 57a and the shield bonding pins 57b are not limited to the above example. Four or more can be employed as the number of shield support pins 57a. The number of shield bonding pins 57b may be one, two, or four or more.

When the number of each of the shield supporting pins 57a and the shield bonding pins 57b is three or more, a polygon formed by connecting the tip surfaces 57c of the three or more shield supporting pins 57a and the tip surfaces of the three or more shield bonding pins 57b. A configuration in which the polygon formed by connecting 57d overlaps in the z direction is preferable. In this configuration, the regions facing the two polygons in the first shield 41 in the z direction should be aligned with the first sensing portion 21 and the second sensing portion 22 of the wiring board 20 in the z direction. This suppresses displacement of the first shield 41 with respect to each of the first sensing portion 21 and the second sensing portion 22 .

As indicated by the names of the shield supporting pin 57a and the shield bonding pin 57b, an example is shown in which these are columnar extending in the z-direction. However, these shapes are not limited to columnar shapes. The tip surface 57c of the shield support pin 57a may be further away from the upper end surface 51e than the tip surface 57d of the shield bonding pin 57b, and the shape is not particularly limited.

<Fixation form of the second shield to the sensor housing>
As shown in column (b) of FIG. 11 and FIG. 15, a plurality of shield support pins 57a are also formed on the lower end surface 51f of the base portion 51. As shown in FIG.

Unlike the first shield 41 , the wiring board 20 is not provided between the sensor housing 50 and the second shield 42 . Therefore, the shield support pins 57a formed on the lower end surface 51f are shorter in the z direction than the shield support pins 57a formed on the upper end surface 51e. The positions of the tips of the plurality of substrate support pins 56a in the z-direction are the same. The second shield 42 is mounted on the sensor housing 50 in such a manner that the one surface 42a is in contact with the tip surface 57c of the shield support pin 57a.

When mounted on the tip surface 57c of the shield support pin 57a, the one surface 42a of the second shield 42 is separated from the lower end surface 51f in the z direction. A shield adhesive 57e is provided between the second shield 42 and the lower end surface 51f.

When the second shield 42 and the sensor housing 50 are adhered and fixed by the shield adhesive 57e, the temperature of the shield adhesive 57e is also set higher than the environmental temperature in which the first current sensor 11 is provided.

A fluid shield adhesive 57e is applied to the lower end surface 51f. The second shield 42 is provided on the sensor housing 50 so that the tip surface 57c of the shield support pin 57a and the shield adhesive 57e are in contact with the one surface 42a of the second shield 42, respectively. After that, the shield adhesive 57e is cooled to room temperature and solidified.

As a result, the shield adhesive 57e provided on the lower end surface 51f also has a residual stress that condenses toward its center at the ambient temperature where the first current sensor 11 is provided. This residual stress causes the second shield 42 and the shield bonding pin 57b to approach each other. The contact state between the one surface 42a of the second shield 42 and the tip surface 57c of the shield support pin 57a is maintained.

As a result, the positional deviation of the second shield 42 with respect to the sensor housing 50 does not depend on the variation in the shape of the shield adhesive 57e that has fluidity when fixed by adhesion. A positional deviation of the second shield 42 with respect to the sensor housing 50 becomes a manufacturing error of the sensor housing 50 . In other words, the positional deviation of the second shield 42 with respect to the wiring board 20 fixed to the sensor housing 50 becomes a manufacturing error of the sensor housing 50 .

In this embodiment, four shield support pins 57a are formed on the lower end surface 51f. Tip faces 57c of the four shield support pins 57a form vertices of a quadrangle. A quadrangle formed by connecting the end faces 57c of these four shield support pins 57a and the central point CP of the constricted portion 31a are aligned in the z direction. The shield adhesive 57e is applied to a region of the lower end surface 51f facing this square.

The second shield 42 is provided on the sensor housing 50 so as to face the square in the z direction. The portion of the second shield 42 that faces the quadrangle is in contact with the shield support pin 57a and is connected to the lower end surface 51f via the shield adhesive 57e. The connection with 50 is stable.

The portion of the second shield 42 where the connection with the sensor housing 50 is stabilized is aligned with the first sensing portion 21 and the second sensing portion 22 of the wiring board 20 in the z direction. Specifically, the second central portion 42d of the second shield 42 is aligned with the first sensing portion 21 and the second sensing portion 22 in the z-direction.

The number of shield support pins 57a formed on the lower end surface 51f is not limited to four. Three or more shield support pins 57a may be employed as appropriate.

When the number of the shield support pins 57a is three or more, the area facing the polygon formed by connecting the tip surfaces 57c of the three or more shield support pins 57a in the second shield 42 in the z direction is the first sensing section. 21 and the second sensing unit 22 are preferably aligned in the z-direction. This suppresses positional deviation of the second shield 42 with respect to each of the first sensing portion 21 and the second sensing portion 22 .

As described above, the two end sides 42f of the second shield 42 aligned in the x-direction are formed with the extended portions 42c extending in the z-direction. Two groove portions 51g for providing the extension portion 42c are formed in the lower end surface 51f.

As shown in column (b) of FIG. 11 and FIG. 13, the two grooves 51g are arranged in the x direction between the upper wall 54c and the lower wall 54d. The two grooves 51g are formed in the z-direction from the lower end surface 51f toward the upper end surface 51e. A part of one of the two grooves 51g is formed by the upper wall 54c. A portion of the remaining one groove portion 51g is constituted by the lower wall 54d. The covering portion 31 is positioned between these two groove portions 51g. Therefore, the covering portion 31 is positioned between the two extending portions 42c of the second shield 42. As shown in FIG.

<Length of support pin and adhesive pin>
The upper end surface 51e of the base portion 51 is divided into a portion where the other ends of the connection terminals 60 arranged in the x direction are exposed and a portion covering the constricted portion 31a, with the first convex portion 53e as a boundary in the y direction. can be done. The portion of the upper end surface 51e where the other end of the connection terminal 60 is exposed is located closer to the lower end surface 51f in the z direction than the portion covering the constricted portion 31a. Therefore, the distance in the z direction between the portion of the upper end surface 51e where the other end of the connection terminal 60 is exposed and the opposing surface 20a of the wiring board 20 is It is longer than the separation distance in the z direction from the surface 20a. This is to ensure a distance for inserting the other end of the connection terminal 60 into the through hole 20 h of the wiring board 20 .

As described above, the exposed portion of the other end of the connection terminal 60 on the upper end surface 51e and the portion covering the constricted portion 31a have different positions in the z direction. A board support pin 56a is formed in each of these two parts. Although the z-direction positions of the upper end faces 51e thus formed are different, in this embodiment, the z-direction positions of the tip faces 56c of the plurality of substrate support pins 56a are the same. Therefore, the substrate support pins 56a have different lengths in the z direction.

The z-direction lengths of the plurality of substrate support pins 56a are not uniformly equal to the length L1 shown in FIG. This length L1 indicates the length in the z direction of the substrate support pin 56a formed at the portion covering the constricted portion 31a on the upper end surface 51e. The length in the z direction of the substrate support pins 56a formed at the exposed portions of the other ends of the connection terminals 60 on the upper end surface 51e is longer than the length L1 is longer by the difference in the positions of

As described above, the length of the support pin in the z direction may differ depending on the position of the surface to be formed in the z direction. The z-direction positions of the tip surfaces 56c of the plurality of substrate support pins 56a may be the same. The same applies to the plurality of shield support pins 57a.

When the wiring board 20 is mounted on the sensor housing 50, a fluid board adhesive 56e is applied to the end surfaces 56d of the board bonding pins 56b. The substrate adhesive 56e is variable in z-direction shape due to its fluidity. Therefore, the z-direction positions of the tip surfaces 56d of the plurality of board bonding pins 56b may be different. This also applies to the plurality of shield bonding pins 57b.

<Second Current Sensor and Third Current Sensor>
Next, the second current sensor 12 will be explained in detail. The second current sensor 12 and the third current sensor 13 have substantially the same configuration. Therefore, description of the third current sensor 13 is omitted.

Also, the second current sensor 12 has components in common with the first current sensor 11 . Therefore, the description of the same points as those of the first current sensor 11 will be omitted below, and the different points will be mainly described.

As described above, the second current sensor 12 is provided on the first conducting bus bar 341 and the second conducting bus bar 342 . The second current sensor 12 has two individual sensors 71 having the same function as the first current sensor 11 in order to detect currents in the first current bus bar 341 and the second current bus bar 342 . The second current sensor 12 also has a wiring case 72 that accommodates these two individual sensors 71 .

One of the two individual sensors 71 detects the magnetic field generated from the alternating current flowing through the first conducting busbar 341 . The other of the two individual sensors 71 detects the magnetic field generated from the alternating current flowing through the second current bus bar 342 .

Two individual sensors 71 are shown in FIG. Thus, the two individual sensors 71 have the same shape. Structural differences between the individual sensor 71 and the first current sensor 11 are the connecting portion of the conductive bus bar 30 to the conducting bus bar, the shape of the connector portion 55 covering the connection terminal 60, and the like. That is, the shape of the first exposed portion 32 and the second exposed portion 33 of the conductive bus bar 30, the disappearance of the enclosing portion 55c, and the like.

The reason why the individual sensor 71 and the first current sensor 11 are different in structure is that they are connected to different objects. This is because first current sensor 11 is connected to conducting bus bar 307 of converter 310 . This is because the second current sensor 12 is connected to the first conducting bus bar 341 and the second conducting bus bar 342 of the first inverter 320 . However, the internal structures of the individual sensor 71 and the first current sensor 11 are the same. Therefore, the individual sensor 71 has the same effects as the first current sensor 11 .

A plurality of individual sensors 71 are housed in a wiring case 72 shown in FIG. As shown in FIG. 18, a plurality of individual sensors can be accommodated collectively in the wiring case 72 . As shown in FIG. 19 , the second current sensor 12 is configured by housing a plurality of individual sensors in the wiring case 72 .

In this arrangement, the first shields 41 and the second shields 42 of the individual sensors 71 are alternately arranged in the x direction. The detection directions of the magnetic field of the magnetoelectric conversion unit 25 of the individual sensor 71 are the z direction and the y direction.

Six individual sensors 71 are housed in each of the wiring cases 72 shown in FIGS. The number of individual sensors 71 housed in this wiring case 72 is merely an example. It is sufficient that the wiring case 72 can accommodate at least two individual sensors 71 .

Also, the wiring case 72 of the second current sensor 12 may house a current sensor that detects the current of other vehicle-mounted equipment. Further, the second current sensor 12 and the third current sensor 13 have a common wiring case 72, and the common wiring case 72 includes the individual sensors of the second current sensor 12 and the third current sensor 13. A configuration in which 71 is housed can also be adopted.

<Wiring case>
As shown in FIG. 17 , the wiring case 72 has an integrated housing 73 , terminal housings 74 and conducting terminals 75 . The integrated housing 73 and the terminal housing 74 are made of an insulating resin material. The integrated housing 73 and the terminal housing 74 are integrally connected. As shown in FIGS. 18 and 19, an integrated housing 73 houses a plurality of individual sensors 71 . Therefore, the integrated housing 73 is larger than the sensor housing 50 of the individual sensor 71 . A plurality of conducting terminals 75 are insert-molded in the terminal housing 74 . As shown in FIGS. 20 to 23, one end and the other end of each of the plurality of conducting terminals 75 are exposed outside the terminal housing 74 .

Column (a) of FIG. 20 shows a rear view of the wiring case. Column (b) of FIG. 20 shows a top view of the wiring case. Column (c) of FIG. 20 shows a bottom view of the wiring case. Column (a) of FIG. 21 shows a left side view of the wiring case. Column (b) of FIG. 21 shows a top view of the wiring case. Column (c) of FIG. 21 shows a right side view of the wiring case. In addition, the same drawing is shown in the (b) column of FIG. 20 and the (b) column of FIG.

Column (a) of FIG. 22 shows a front view of the second current sensor. Column (b) of FIG. 22 shows a top view of the second current sensor. Column (c) of FIG. 22 shows a bottom view of the second current sensor. Column (a) of FIG. 23 shows a side view of the second current sensor. Column (b) of FIG. 23 shows a top view of the second current sensor. In addition, the same drawing is shown in the (b) column of FIG. 22 and the (b) column of FIG.

As shown in column (c) of each of FIGS. 20 and 22, wiring case 72 has integrated wiring board 76 . One ends of the connection terminals 60 of the individual sensors 71 are connected to the integrated wiring board 76 . One end of the conducting terminal 75 is connected to the integrated wiring board 76 . Thereby, the individual sensors 71 and the conducting terminals 75 are electrically connected via the wiring pattern of the integrated wiring board 76 . The other end of the conducting terminal 75 is electrically connected to the MGECU 802 via a wire harness or the like. As described above, the output of the individual sensor 71 is input to the MGECU 802 via the integrated wiring board 76, the conducting terminal 75, and the wire harness. The integrated wiring board 76 and the conducting terminals 75 correspond to input/output wiring.

As described above, the second current sensor 12 is provided on the first conducting bus bar 341 and the second conducting bus bar 342 . These conducting bus bars are divided between the first inverter 320 side and the first motor 400 side. The conducting bus bar has a portion connecting first inverter 320 and second current sensor 12 and a portion connecting second current sensor 12 and first motor 400 .

A portion connecting the first inverter 320 and the second current sensor 12 in the current-carrying bus bar of the present embodiment is a conductive plate made of a metal material. A portion of the conducting bus bar that connects the second current sensor 12 and the first motor 400 is a wire. In the following description, the portion of the conducting bus bar that connects first inverter 320 and second current sensor 12 is simply referred to as a conductive plate. A portion of the conducting bus bar that connects the second current sensor 12 and the first motor 400 is simply indicated as a wire.

The form of the current-carrying bus bar can be appropriately changed according to the respective forms of the inverter and the motor, and the mounting form of these on the vehicle. Therefore, the specific form of the current-carrying bus bar is not limited to the above example. The forms of the wiring case 72 and the conductive bus bars 30 of the individual sensors 71 can be appropriately changed according to the forms of these conducting bus bars. In particular, the shape of the conductive bus bar 30 of the individual sensor 71 can be accommodated only by changing the shapes of the first exposed portion 32 and the second exposed portion 33 . Therefore, the internal shape of the individual sensor 71 does not need to be changed. This eliminates the need to change the manufacturing line of the individual sensor 71 .

The integrated housing 73 has a bottom wall 77 and a peripheral wall 78 as shown in FIGS. The bottom wall 77 faces the z-direction. The planar shape of the bottom wall 77 is a rectangle whose longitudinal direction is the x direction.

The peripheral wall 78 rises in the z-direction from the inner bottom surface 77a of the bottom wall 77 facing the z-direction. The peripheral wall 78 has a left wall 78a and a right wall 78b aligned in the x direction. The peripheral wall 78 has an upper wall 78c and a lower wall 78d arranged in the y direction. The left wall 78a, the upper wall 78c, the right wall 78b, and the lower wall 78d are connected in order in the circumferential direction around the z direction. As a result, the peripheral wall 78 has a tubular shape opening in the z direction. A plurality of individual sensors 71 can be stored in the storage space formed by the bottom wall 77 and the peripheral wall 78 .

As shown in FIG. 18, the individual sensor 71 is inserted into the storage space of the integrated housing 73 from the z direction. As shown in FIG. 19, a plurality of individual sensors 71 are arranged side by side in the x direction in the storage space.

The plurality of individual sensors 71 has a first shield 41 and a second shield 42 similar to the first current sensor 11 . The first shield 41 and the second shield 42 face each other while being spaced apart in the x direction. Therefore, in the storage space, the first shields 41 and the second shields 42 of the individual sensors are arranged alternately.

As shown in FIG. 16, from the sensor housing 50 of the individual sensor 71, the first exposed portion 32 and the second exposed portion 33 extend in the y direction. A slit 78e is formed in the upper wall 78c of the integrated housing 73 for arranging the tip of the first exposed portion 32 outside the housing space while housing the sensor housing 50 of the individual sensor 71 in the housing space. there is The slit 78e is formed along the z-direction from the tip surface of the upper wall 78c toward the bottom wall 77. As shown in FIG.

When the individual sensor 71 is stored in the integrated housing 73, the tip of the first exposed portion 32 of the individual sensor 71 is positioned outside the storage space through the slit 78e. The tip of the first exposed portion 32 is electrically connected to the conductive plate by laser welding or the like.

A conductive terminal 79 is insert-molded on the bottom wall 77 of the integrated housing 73 . 20 and 21, part of the conductive terminal 79 is exposed from the inner bottom surface 77a of the bottom wall 77. As shown in FIG.

When the individual sensor 71 is accommodated in the integrated housing 73 , the second exposed portion 33 of the individual sensor 71 is arranged to face the portion of the conductive terminal 79 exposed from the inner bottom surface 77 a. The second exposed portion 33 and the conductive terminal 79 are electrically connected by laser welding or the like.

The integrated housing 73 also has a terminal block 80 for supporting a plurality of conductive terminals 79 . The terminal block 80 is integrally formed on the bottom wall 77 side of the bottom wall 78d. The terminal block 80 has a rectangular parallelepiped shape extending in the x direction. A plurality of conductive terminals 79 are also insert-molded in this terminal block 80 . A portion of the plurality of conductive terminals 79 are exposed from this terminal block 80 . A portion of the conductive terminal 79 exposed from the terminal block 80 extends in the z-direction away from the terminal block 80 . A portion of the conductive terminal 79 exposed from the terminal block 80 faces the lower wall 78d in the y direction. Portions of the plurality of conductive terminals 79 exposed from the terminal block 80 are spaced apart in the x direction.

A portion of the conductive terminal 79 exposed from the terminal block 80 has a flat shape with a thin thickness in the y direction. A portion of the conductive terminal 79 exposed from the terminal block 80 has a conducting surface 79a facing in the y direction and a back surface 79b thereof. The conductive terminal 79 is formed with a bolt hole 79c penetrating the conductive surface 79a and the back surface 79b in the y direction.

A nut 81 opening in the y direction is provided on the rear surface 79b of the conductive terminal 79. As shown in FIG. The opening of the nut 81 and the opening of the bolt hole 79c are aligned in the y direction.

A wire terminal is provided on the conducting surface 79 a of the conducting terminal 79 . A bolt hole penetrating in the y direction is also formed in the terminal of this wire. The surface of the wire terminal through which the bolt hole penetrates is opposed to the conducting surface 79 a of the conductive terminal 79 . In this manner, the shanks of bolts (not shown) are passed through both bolt holes. Then, the tip of the shank of this bolt is fastened to the nut 81 . A bolt is fastened to the nut 81 so as to go from the tip of the shaft of the bolt toward the head. The conductive terminal 79 and the wire terminal are sandwiched between the head of the bolt and the nut 81 . This brings the terminal of the wire into contact with the conductive terminal 79, electrically and mechanically connecting the two. As described above, the second exposed portion 33 of the individual sensor 71 and the wire terminal are electrically connected via the conductive terminal 79 .

A connection terminal 60 extends in the z-direction from the sensor housing 50 of the individual sensor 71 . A bottom wall 77 of the integrated housing 73 is formed with an insertion hole for arranging one end of the connection terminal 60 outside the storage space. This insertion hole penetrates an inner bottom surface 77a of the bottom wall 77 and an outer bottom surface 77b on the back side thereof. One end of the connection terminal 60 protrudes outside the storage space through the insertion hole in a manner away from the outer bottom surface 77b. Note that the insertion hole is minute. The through holes are therefore not shown in the drawing.

The terminal housing 74 is aligned with the integrated housing 73 in the x direction. The terminal housing 74 is integrally connected with the left wall 78 a of the integrated housing 73 . Terminal housing 74 extends in the z-direction. The terminal housing 74 has an upper surface 74a and a lower surface 74b aligned in the z-direction.

A plurality of conducting terminals 75 insert-molded in the terminal housing 74 extend in the z-direction. One end of the conducting terminal 75 protrudes from the lower surface 74b of the terminal housing 74. As shown in FIG. The other end of the conducting terminal 75 protrudes from the upper surface 74 a of the terminal housing 74 .

As shown in columns (a) and (c) of FIG. 20, the outer bottom surface 77b of the bottom wall 77 of the integrated housing 73 and the bottom surface 74b of the terminal housing 74 are continuously connected in the x direction and the y direction. An integrated wiring board 76 is provided on the continuously connected outer bottom surface 77b and lower surface 74b.

The integrated wiring board 76 has a flat shape with a thin thickness in the z direction. The integrated wiring board 76 has a mounting surface 76a and a back surface 76b facing in the z direction. The integrated wiring board 76 is fixed to the integrated housing 73 and the terminal housing 74 in such a manner that the mounting surface 76a faces the outer bottom surface 77b and the lower surface 74b in the z-direction.

As described above, one end of the conducting terminal 75 protrudes from the lower surface 74b. One end of the connection terminal 60 protrudes from the outer bottom surface 77b. On the other hand, the integrated wiring board 76 is formed with a first through hole 76c into which one end of the conducting terminal 75 is inserted. A second through hole 76 d into which one end of the connection terminal 60 is inserted is formed in the integrated wiring board 76 . These first through-holes 76c and second through-holes 76d respectively penetrate the mounting surface 76a and the back surface 76b of the integrated wiring board 76 in the z-direction. A wiring pattern is formed in the integrated wiring board 76 to electrically connect the first through holes 76c and the second through holes 76d.

An integrated wiring board 76 is provided on the outer bottom surface 77b and the bottom surface 74b so that one end of the conducting terminal 75 is inserted into the first through hole 76c. Then, the first through hole 76c and the conducting terminal 75 are electrically connected via solder or the like.

The individual sensor 71 is provided in the storage space so that one end of the connection terminal 60 is inserted into the insertion hole of the bottom wall 77 and the second through hole 76d. Then, the second through hole 76d and the connection terminal 60 are electrically connected via solder or the like. As described above, the connection terminals 60 of the individual sensors 71 are electrically connected to the conducting terminals 75 via the second through holes 76d, the wiring pattern of the integrated wiring board 76, and the first through holes 76c.

The wiring case 72 has a plurality of flanges 82 for mounting on the vehicle. Each of the plurality of flanges 82 is formed with a bolt hole 82a for bolting the second current sensor 12 to the vehicle.

The wiring case 72 of this embodiment has three flanges 82 . One of the three flanges 82 is formed on the bottom wall 77 on the right wall 78b side. One of the remaining two flanges 82 is formed on the lower wall 78 d side of the terminal housing 74 . This flange 82 is integrally connected with the terminal block 80 . The remaining one flange 82 is formed on the side of the terminal housing 74 opposite to the connecting portion with the integrated housing 73 .

As described above, two of the three flanges 82 are arranged in the x direction via the integrated housing 73 and the terminal housing 74 . A remaining flange 82 is spaced apart in the y-direction from the two flanges 82 aligned in the x-direction. The three flanges 82 thus form the vertices of a triangle.

As described above, one end of the connection terminal 60 protrudes from the outer bottom surface 77b, and one end of the conducting terminal 75 protrudes from the lower surface 74b. An integrated wiring board 76 is provided on the outer bottom surface 77b and the lower surface 74b. Each of the three flanges 82 has a leg portion 83 extending in the z-direction in order to avoid contact between one end of the connecting terminal 60, one end of the energizing terminal 75, and the integrated wiring board 76 with the vehicle. The legs 83 separate one end of the connection terminal 60, one end of the current-carrying terminal 75, and the integrated wiring board 76 from the vehicle in the z direction when the second current sensor 12 is mounted on the vehicle.

<Action and effect of the current sensor>
Next, the effects of the current sensor according to this embodiment will be described. As described above, the first current sensor 11 and the individual sensors 71 of the second current sensor 12 and the third current sensor 13 have the same configuration. Therefore, the same action and effect are obtained. Therefore, in order to avoid complication, the first current sensor 11 and the individual sensor 71 are simply referred to as current sensors hereinafter without distinguishing between them. Due to various effects described below, deterioration in detection accuracy of the current to be measured is suppressed.

<Magnetic saturation of shield>
As described above, the first end portions 41e of the first shield 41 are shorter in the x direction than the first central portion 41d. Therefore, it is difficult for the magnetic field to enter the first end portions 41e. A magnetic field can be transmitted from one of the two ends of the first both ends 41e to the other through a portion (parallel portion) that is directly connected to the first both ends 41e of the first central portion 41d and aligned in the y direction. suppressed. As a result, the magnetic saturation of the parallel portion of the first central portion 41d is suppressed. Leakage of electromagnetic noise from the first central portion 41d is suppressed.

FIG. 24 schematically shows hatched areas of the first shield 41 that are likely to be magnetically saturated due to the transmission of the magnetic field. Column (a) of FIG. 24 is a schematic diagram showing magnetic saturation occurring in a first shield having no notch as a comparative configuration. Column (b) of FIG. 24 is a schematic diagram showing a magnetically saturated region of the first shield 41 of the present embodiment. Thick solid arrows shown in FIG. 24 indicate the current flowing through the conductive bus bar 30 .

As shown in this schematic diagram, the first shield without a notch tends to be uniformly magnetically saturated. On the other hand, in the first shield 41 having the notch 41c, even if magnetic saturation occurs in a region other than the parallel portion of the first central portion 41d, magnetic saturation is suppressed in the parallel portion.

FIG. 25 shows simulation results of the magnetic field distribution passing through the shield. Column (a) of FIG. 25 shows the magnetic field distribution of the cross section along line XXVa-XXVa shown in FIG. Column (b) of FIG. 25 shows the magnetic field distribution of the cross section along line XXVb--XXVb shown in FIG.

However, column (a) in FIG. 25 shows the simulation results when each of the first shield 41 and the second shield 42 is rectangular. Column (b) of FIG. 25 shows simulation results when the notches 41c are formed in the first shield 41 and the second shield 42, respectively. The strength of the magnetic field is indicated by hatching density. The coarser the hatching, the weaker the magnetic field strength, and the denser the hatching, the higher the magnetic field strength.

As is clear from this simulation result, the magnetic field distribution of each of the first shield and the second shield is uniform when there is no notch 41c. Then, the strength of the entire magnetic field of each of the first shield and the second shield increases. On the other hand, if the notch 41c is formed, the strength of the entire magnetic field of each of the first shield and the second shield is lowered. In particular, the strength of the magnetic field distribution at the parallel portions of the first central portion 41d and the second central portion 42d is low. Therefore, leakage of electromagnetic noise from the first central portion 41d and the second central portion 42d due to magnetic saturation is suppressed.

As shown in FIG. 25, the magnetic field distribution strengths of the first shield 41 and the second shield 42 are different. This difference is due to the difference in distance between the first shield 41 and the second shield 42 and the respective conductive busbars 30 . In both magnetic field distributions, the strength is low in the parallel portions and the strength is high in regions other than the parallel portions.

The parallel portion of the first central portion 41d in which magnetic saturation is suppressed, the first sensing portion 21 and the second sensing portion 22 mounted on the wiring board 20 are arranged in the z direction. Therefore, electromagnetic noise leaked by magnetic saturation of the first central portion 41 d is suppressed from being input to the magnetoelectric conversion portions 25 of the first sensing portion 21 and the second sensing portion 22 .

<Misalignment of the shield>
The first shield 41 is mounted on shield support pins 57a and fixed to shield bonding pins 57b via shield adhesive 57e. The second shield 42 is mounted on shield support pins 57a and fixed to the base 51 via a shield adhesive 57e.

As a result, the displacement of the first shield 41 and the second shield 42 with respect to the sensor housing 50 does not depend on the variation in the shape of the fluid shield adhesive 57e when fixed. A positional deviation of the first shield 41 and the second shield 42 with respect to the sensor housing 50 results in a manufacturing error of the sensor housing 50 . A manufacturing error of the sensor housing 50 can be the cause of the displacement of the first shield 41 and the second shield 42 with respect to the wiring substrate 20 fixed to the sensor housing 50 . As a result, deterioration in the suppression of electromagnetic noise input to the magnetoelectric converter 25 by the first shield 41 and the second shield 42 is suppressed.

The temperature of the shield adhesive 57e when bonding and fixing the first shield 41 and the second shield 42 to the sensor housing 50 is set higher than the environmental temperature in which the current sensor is provided. The shield adhesive 57e is cooled to room temperature and solidified. For this reason, the shield adhesive 57e has a residual stress that condenses to its center at the environmental temperature where the current sensor is installed. This residual stress maintains the contact state between the first shield 41 and the shield support pin 57a and the contact state between the second shield 42 and the shield support pin 57a.

This suppresses displacement of the first shield 41 and the second shield 42 in the z direction with respect to the sensor housing 50 . In other words, the z-direction displacement of the first shield 41 and the second shield 42 with respect to the wiring board 20 fixed to the sensor housing 50 is suppressed. As a result, deterioration in the suppression of input of electromagnetic noise to the magnetoelectric converter 25 by the first shield 41 and the second shield 42 is suppressed.

<Displacement of wiring board>
The wiring board 20 is mounted on board support pins 56a and fixed to board bonding pins 56b via a board adhesive 56e.

As a result, the positional deviation of the wiring board 20 with respect to the sensor housing 50 does not depend on the variation in the shape of the substrate adhesive 56e having fluidity when the wiring board 20 is fixed. A positional deviation of the wiring board 20 with respect to the sensor housing 50 becomes a manufacturing error of the sensor housing 50 . A manufacturing error of the sensor housing 50 can be the cause of the displacement of the wiring board 20 with respect to the conductive bus bar 30 fixed to the sensor housing 50 . As a result, variation in the magnetic field to be measured that passes through the magnetoelectric converter 25 mounted on the wiring board 20 is suppressed.

The temperature of the substrate adhesive 56e when bonding and fixing the wiring substrate 20 to the sensor housing 50 is set higher than the environmental temperature in which the current sensor is provided. The substrate adhesive 56e is cooled to room temperature and solidified. Therefore, the substrate adhesive 56e has a residual stress that condenses to its center at the environmental temperature where the current sensor is installed. This residual stress maintains the contact state between the wiring board 20 and the board support pins 56a.

This suppresses displacement of the wiring board 20 in the z direction with respect to the sensor housing 50 . In other words, the z-direction displacement of the wiring board 20 with respect to the conductive bus bar 30 fixed to the sensor housing 50 is suppressed. This suppresses fluctuations in the magnetic field to be measured that passes through the magnetoelectric converter 25 mounted on the wiring board 20 .

<Manufacturing Error of Wiring Board>
A first sensing portion 21 and a second sensing portion 22 are provided on a surface 20 a of the wiring board 20 facing the conductive bus bar 30 . As a result, the distance in the z direction between the conductive busbars 30 of the first sensing portion 21 and the second sensing portion 22 does not depend on the thickness of the wiring board 20 in the z direction. Variation in the z-direction separation distance between these sensing portions and the conductive bus bar 30 due to manufacturing errors in the z-direction thickness of the wiring board 20 is suppressed.

<Separation of wiring case and individual sensor>
When a conductive bus bar is fixed to a housing made of an insulating resin material, the conductive bus bar is misaligned with respect to the housing due to manufacturing errors of the housing and aged deterioration such as creep. The positional deviation increases as the size of the housing increases.

On the other hand, as described above, the second current sensor 12 and the third current sensor 13 have the integrated housing 73 larger in size than the sensor housing 50 of the current sensor (individual sensor 71). A current sensor is housed in this integrated housing 73 . The conductive bus bar 30 is fixed to the sensor housing 50 instead of the large integrated housing 73 . The magnetoelectric converter 25 detects the current flowing through the conductive bus bar 30 .

According to this, the occurrence of relative positional deviation between the conductive bus bar 30 and the magnetoelectric conversion unit 25 due to manufacturing errors of the housing and aged deterioration such as creep is suppressed.

(Second embodiment)
Next, a second embodiment will be described with reference to FIGS. 26 and 27. FIG. The current sensors according to the respective embodiments described below have many points in common with those according to the above-described embodiments. Therefore, the description of the common parts will be omitted, and the different parts will be mainly described below. Also, hereinafter, the same reference numerals are given to the same elements as those shown in the above-described embodiment.

<Extension on both ends>
In the first embodiment, an example is shown in which the extended portions 42c extending in the z-direction are formed on the second central portion 42d sides of the two edge sides 42f of the second shield 42 arranged in the x-direction. On the other hand, in this embodiment, as shown in FIG. 26, extension portions 42c are formed on the two end sides 42f of the second shield 42 on the side of the second end portions 42e. Column (a) of FIG. 26 is a perspective view for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive busbar. The (b) column of FIG. 26 is a side view for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive busbar.

With this configuration, the magnetic field that has entered the second shield 42 is easily transmitted to the first shield 41 via the extended portions 42c formed on the side of the second end portions 42e. The transmission path of this magnetic field is on the side of the first end portions 41e in the first shield 41, as schematically shown in FIG. Similarly, the transmission path of the magnetic field is on the second end 42 e side of the second shield 42 .

27 indicates the current flowing through the conductive bus bar 30. As shown in FIG. A solid arrow indicates a magnetic field that passes through the first shield 41 . A dashed arrow indicates a magnetic field that penetrates the second shield 42 . A symbol with a dot in the center of a circle indicates a magnetic field directed from the second shield 42 to the first shield 41 in the z-direction. A crossed symbol in a circle indicates a magnetic field directed from the first shield 41 to the second shield 42 in the z-direction.

Therefore, it becomes difficult for the electromagnetic noise that has entered the second shield 42 to flow to the first shield 41 via the second central portion 42d. Similarly, electromagnetic noise that enters the first shield 41 is less likely to pass through the second shield 42 via the first central portion 41d.

Therefore, the second central portion 42d and the first central portion 41d are difficult to be magnetically saturated. As a result, magnetic field leakage due to magnetic saturation is suppressed from each of the second central portion 42d and the first central portion 41d.

Further, as clearly shown in column (b) of FIG. 26 , the magnetoelectric conversion portion 25 of each of the first sensing portion 21 and the second sensing portion 22 is positioned between the two extending portions 42c in the y direction. That is, the magnetoelectric conversion portion 25 is positioned between the second central portion 42d and the first central portion 41d in the z direction. Therefore, the input of the magnetic field leaked by the magnetic saturation of the second central portion 42d and the first central portion 41d to the magnetoelectric conversion portion 25 is suppressed. As a result, deterioration in detection accuracy of the current to be measured is suppressed.

In this embodiment, an example in which the extending portions 42c are formed on the two end sides 42f of the second shield 42 on the second end portion 42e side is shown. However, for example, as shown in column (a) of FIG. 28, a configuration in which extension portions 42c are also formed in the second central portions 42d of the two end sides 42f of the second shield 42 can also be adopted. However, the extending portion 42c formed in the second central portion 42d is shorter in the z direction than the extending portions 42c formed in the second end portions 42e. As a result, the magnetic field penetrating the shield 40 is more likely to pass through the edges than through the center.

Further, as shown in the column (b) of FIG. 28, the extending portion 42c is formed on the second end portion 42e side of one of the two end sides 42f, and the other second end portion 42e and the second central portion are formed. A configuration in which an extension portion 42c is formed in each of 42d can also be adopted. However, the lengths in the z-direction of the extending portions 42c formed at the other second end portions 42e and the second center portion 42d of the two end sides 42f are the same. This also makes it easier for the magnetic field that has entered the shield 40 to pass through the edges rather than the center. Each of columns (a) and (b) in FIG. 28 is a perspective view for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive busbar.

Furthermore, as shown in column (a) of FIG. 29, one side of the two ends of the second end 42e of the two ends 42f and the two ends of the other second end 42e It is also possible to employ a configuration in which extension portions 42c are formed on the other side of each of the two ends. The extension 42c formed on one of the two edges 42f and the extension 42c formed on the other are separated in the y direction and the x direction.

A configuration in which the extended portion 42c is formed not only on the second shield 42 but also on the first shield 41 can be adopted. The first shield 41 has two opposing sides 41f aligned in the x direction. For example, as shown in column (b) of FIG. 29, a configuration in which extension portions 42c are formed on the first end portions 41e of the two opposing sides 41f of the first shield 41 can be employed. Each of columns (a) and (b) in FIG. 29 is a perspective view for explaining the arrangement of the shield, magnetoelectric converter, and conductive bus bar.

The form of the extension part 42c that can be formed in the first shield 41 can employ a form equivalent to the form of the extension part 42c that is formed in the second shield 42 described above. The extended portion 42c formed on the first shield 41 corresponds to the extended portion.

It should be noted that current sensors according to the present embodiment and the embodiments described below include components equivalent to those of the current sensor described in the first embodiment. Therefore, it goes without saying that the same effect can be obtained.

(Third Embodiment)
Next, a third embodiment will be described with reference to FIGS. 30 to 32. FIG.

<Stress relaxation part>
In this embodiment, the conductive bus bar 30 of the first current sensor 11 is formed with a stress relief portion 34 . The stress relief portions 34 are formed on the first exposed portion 32 and the second exposed portion 33 of the conductive bus bar 30, respectively.

As described above, the conductive bus bar 30 has the covering portion 31 covered by the sensor housing 50 . The first exposed portion 32 and the second exposed portion 33 are each exposed from the sensor housing 50 and integrally connected to the covering portion 31 . A bolt hole 30c is formed in each of the first exposed portion 32 and the second exposed portion 33 for electrical and mechanical connection with the conducting bus bar 307 through a bolt. The stress relieving portion 34 is formed between the portion of each of the first exposed portion 32 and the second exposed portion 33 connected to the covering portion 31 and the portion where the bolt hole 30c is formed.

As shown in FIG. 31, the stress relieving portion 34 is locally curved from the rear surface 30b of the conductive bus bar 30 toward the front surface 30a. Due to this bending, the stress relief portion 34 is bent and elastically deformable against the force applied to the conductive bus bar 30 in the z direction. In FIG. 31, the stress relief portion 34 is curved so as to undulate once, but the number of undulations and the curved form are not limited to the above example.

Conductive busbar 30 is bolted to current-carrying busbar 307 as described above. The conducting bus bar 307 of this embodiment corresponds to the first terminal block 307a and the second terminal block 307b shown in FIG. The conductive bus bar 30 is bolted to the first terminal block 307a and the second terminal block 307b. As a result, the first terminal block 307 a and the second terminal block 307 b are bridged by the conducting bus bar 307 . The first terminal block 307a and the second terminal block 307b are electrically connected via the conducting bus bar 307 . In the following, as shown in FIG. 32, bolts that are passed through the bolt holes 30c of the conductive bus bar 30 are denoted by 307c. The first terminal block 307a and the second terminal block 307b correspond to an external power supply section.

The first terminal block 307a has a first mounting surface 307d facing in the z direction. Similarly, the second terminal block 307b has a second mounting surface 307e facing in the z direction. A fastening hole 307f for fastening the shaft portion of the bolt 307c is formed in the first mounting surface 307d and the second mounting surface 307e. The fastening holes 307f are open to the first mounting surface 307d and the second mounting surface 307e. The fastening hole 307f extends in the z direction. Column (a) of FIG. 32 shows a case where the positions of the first placement surface and the second placement surface in the z direction match. Column (b) in FIG. 32 shows a case where the positions of the first mounting surface and the second mounting surface in the z direction do not match.

The rear surface 30b of the first exposed portion 32 faces the first mounting surface 307d in the z direction. The rear surface 30b of the second exposed portion 33 faces the second mounting surface 307e in the z direction. In this manner, the first current sensor 11 is provided on the first terminal block 307a and the second terminal block 307b.

When the positions of the first mounting surface 307d and the second mounting surface 307e in the z-direction match as shown in column (a) of FIG. 30b are brought into contact with each other, and the rear surface 30b of the second exposed portion 33 is brought into contact with the second placement surface 307e. In this contact state, the tip of the shaft portion of the bolt 307c is inserted into the bolt hole 30c of the conductive bus bar 30 and the fastening hole 307f of the terminal block from the z direction. Then, the bolt 307c is fastened to the terminal block so that the head of the bolt 307c approaches the first mounting surface 307d (second mounting surface 307e). The first exposed portion 32 and the second exposed portion 33 are sandwiched between the head of the bolt 307c and the terminal block. This mechanically and electrically connects the first current sensor 11 to the terminal block.

On the other hand, when the positions of the first mounting surface 307d and the second mounting surface 307e in the z-direction do not match as shown in column (b) of FIG. When the rear surface 30b of the exposed portion 32 contacts, the rear surface 30b of the second exposed portion 33 does not contact the second mounting surface 307e. The second placement surface 307e and the back surface 30b of the second exposed portion 33 are spaced apart in the z direction to form a gap therebetween.

In this separated state, the shaft portion of the bolt 307c is passed through the bolt hole 30c and the fastening hole 307f, and when the head portion of the bolt 307c contacts the surface 30a of the second exposed portion 33, a force acts on the second exposed portion 33 in the z direction. works.

As described above, in order to increase the intensity of the magnetic field to be measured that passes through the magnetoelectric conversion section 25, the covering section 31 is locally formed with the constriction section 31a having a short length in the x direction. Since the narrowed portion 31a is short in the x-direction, its rigidity is lower than that of other portions. Therefore, the narrowed portion 31a is easily deformed.

Therefore, when the force directed in the z-direction when the bolt 307c is tightened acts on the second exposed portion 33 as described above, the constricted portion 31a may be deformed. The position of the constricted portion 31a within the sensor housing 50 may be displaced. Of course, even if the narrowed portion 31 a is not formed in the covering portion 31 , the position of the covering portion 31 within the sensor housing 50 may be displaced. As a result, the distribution of the magnetic field to be measured passing through the magnetoelectric converter 25 may change.

On the other hand, as described above, the stress relief portion 34 is formed in each of the first exposed portion 32 and the second exposed portion 33 . Therefore, even if there is a gap between the second mounting surface 307e and the rear surface 30b of the second exposed portion 33 due to the difference in the z-direction positions of the first mounting surface 307d and the second mounting surface 307e, , the stress relief portion 34 is elastically deformed according to the force of the bolt 307c directed in the z direction. This suppresses deformation of the constricted portion 31a. Displacement of the position of the constricted portion 31a within the sensor housing 50 is suppressed. As a result, change in the distribution of the magnetic field to be measured that passes through the magnetoelectric converter 25 is suppressed. A decrease in detection accuracy of the current to be measured is suppressed.

The length (thickness) between the front surface 30a and the back surface 30b of the stress relaxation portion 34 is equal to the thickness of each of the covering portion 31, the first exposed portion 32, and the second exposed portion 33. . As a result, unlike a configuration in which the thickness of the stress relaxation portion is locally thinner than that of the covered portion or the exposed portion, for example, local heat generation in the stress relaxation portion 34 due to the application of current is suppressed. As a result, the reduction in the life of the conductive bus bar 30 is suppressed.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIGS. 33 to 35. FIG. Column (a) of FIG. 33 shows a top view of the conductive bus bar. Column (b) of FIG. 33 shows a side view of the conductive bus bar. Column (a) of FIG. 34 shows the positions of the wiring board 20 and the conductive bus bar 30 on which the magnetoelectric conversion units 25 of the first sensing unit 21 and the second sensing unit 22 are mounted. Column (b) of FIG. 34 shows the displacement of the wiring board 20 with respect to the conductive bus bar 30 . Column (c) of FIG. 34 shows the magnetic fields that pass through the magnetoelectric conversion portions 25 of the first sensing portion 21 and the second sensing portion 22, respectively.

<Difference cancellation>
In the first embodiment, an example in which the magnetoelectric conversion portions 25 of the first sensing portion 21 and the second sensing portion 22 are arranged in the y direction is shown. On the other hand, in the present embodiment, the magnetoelectric conversion portions 25 of the first sensing portion 21 and the second sensing portion 22 are arranged in the x direction as indicated by broken lines in FIG. The magnetoelectric conversion section 25 of the first sensing section 21 corresponds to the first magnetoelectric conversion section. The magnetoelectric conversion section 25 of the second sensing section 22 corresponds to the second magnetoelectric conversion section.

The two magnetoelectric converters 25 are arranged symmetrically with respect to the axis of symmetry AS. The y-direction positions of the two magnetoelectric conversion portions 25 and the y-direction position of the axis of symmetry AS (center point CP) are the same. Therefore, the two magnetoelectric converters 25 are arranged in the x direction via the center point CP.

Also, the distance in the z direction between the two magnetoelectric conversion portions 25 and the covering portion 31 is the same. The covering portion 31 and the constricted portion 31a are symmetrical with respect to the axis of symmetry AS. As described above, although the components in the z-direction are different, magnetic fields to be measured that have the same components in the x-direction pass through the two magneto-electric converters 25 . Therefore, the absolute values of the electrical signals output from the two magnetoelectric conversion units 25 are equal.

As described above, the covering portion 31 is covered with the base portion 51 of the sensor housing 50 . The wiring board 20 on which the two magnetoelectric conversion units 25 are mounted is mounted on board support pins 56 a formed on the sensor housing 50 . Therefore, the displacement of the wiring board 20 in the z direction is restricted by the board support pins 56a.

However, the wiring board 20 is fixed to the board bonding pins 56b via the board adhesive 56e. The substrate adhesive 56e expands due to changes in the environmental temperature and deteriorates over time such as creep. For this reason, the wiring substrate 20 may be displaced relative to the covering portion 31 in the x direction and the y direction.

When the wiring board 20 is displaced in the y-direction, the x-direction component of the magnetic field to be measured that passes through the two magnetoelectric transducers 25 does not change due to the symmetrical arrangement in the x-direction. However, when the wiring board 20 is displaced in the x-direction as shown in FIG. 34, the x-direction component of the magnetic field to be measured that passes through both changes. As a result, the absolute values of the electrical signals output from the two magnetoelectric conversion units 25 are no longer equal.

The dashed lines shown in FIG. 34 indicate the arrangement positions of the two magnetoelectric converters 25 with respect to the conductive bus bar 30 . A dashed-dotted line indicates the axis of symmetry AS passing through the center point CP of the conductive bus bar 30 . A two-dot chain line indicates the position where the two magnetoelectric conversion portions 25 are displaced with respect to the conductive bus bar 30 . The white arrow indicates the direction of displacement of the wiring board 20 on which the two magnetoelectric transducers 25 are mounted with respect to the conductive bus bar 30 by the board adhesive 56e. Solid line arrows shown in columns (a) and (b) of FIG. Solid arrows shown in column (c) of FIG.

However, both the two magnetoelectric conversion units 25 are mounted on the wiring board 20 as described above. Therefore, even if the relative position in the x direction between the wiring board 20 and the covering portion 31 changes due to the deformation of the substrate adhesive 56e as described above, the relative distance between the two magnetoelectric conversion portions 25 mounted on the wiring board 20 remains unchanged. does not change. Therefore, when the relative position between the wiring board 20 and the covering portion 31 changes in the x direction due to the deformation of the substrate adhesive 56e, one of the two magnetoelectric converting portions 25 approaches the axis of symmetry AS, and the other moves away from the axis of symmetry AS. . The near and far distances are equal. In the column (b) of FIG. 34, this near and far distance is indicated by Δ.

Therefore, as shown in column (c) of FIG. 34, the magnetic field to be measured that passes through one of the two magnetoelectric conversion portions 25 decreases, and the magnetic field to be measured that passes through the other increases. It is expected that the amount of decrease and the amount of increase of the magnetic field to be measured that passes through the two magnetoelectric converters 25 will be the same. In column (b) of FIG. 34, the amount of change in the magnetic field to be measured is indicated by ΔB.

Therefore, in this embodiment, the polarities of the electrical signals output from the two magnetoelectric conversion units 25 are inverted. In order to invert the polarity in this way, for example, as shown in FIG. Alternatively, more simply, the polarities of the two electrical signals are reversed by reversing the inverting input terminal and the non-inverting input terminal of the differential amplifier 25c shown in FIG. 7 between the first sensing section 21 and the second sensing section 22. be able to.

As described above, the two magnetoelectric conversion units 25 output electric signals having the same absolute value of the amount of increase and the amount of decrease and having different polarities. Two electric signals generated by the first current sensor 11 are input to the battery ECU 801 . Two electrical signals generated by the second current sensor 12 and the third current sensor 13 are input to the MGECU 802 .

Battery ECU 801 and MGECU 802 take the difference between the two electric signals. This difference processing is B+ΔB−(−(B− ΔB))=2B. Alternatively, it can be expressed as B−ΔB−(−(B+ΔB))=2B. Plus corresponds to one of the first and second polarities, and minus corresponds to the other of the first and second polarities.

By performing the difference processing in this way, the decrease and increase of the electric signal due to the change in the relative position between the wiring board 20 and the covering portion 31 caused by the deformation of the substrate adhesive 56e are cancelled. The battery ECU 801 and the MGECU 802 correspond to the difference section.

For example, as shown in FIG. 36, a configuration in which a difference circuit 29 for obtaining a difference between the outputs of the two magnetoelectric converters 25 is mounted on the wiring substrate 20 can also be adopted. A first output wiring 20d and a second output wiring 20e are connected to the inverting input terminal and the non-inverting input terminal of the differential circuit 29, respectively. In this case, the differential circuit 29 corresponds to the differential section.

The change in the relative position in the x direction between the wiring board 20 and the covering portion 31 is caused not only by the deformation of the board adhesive 56e, but also by external stress acting on the vehicle and vibration caused by driving the engine 600, for example. obtain. However, even if the relative position in the x direction between the wiring board 20 and the covering portion 31 changes due to these, the difference between the two electric signals output from the two magnetoelectric conversion portions 25 is obtained as described above. By doing so, the decrease and increase of the electric signal due to the change in the relative position between the wiring board 20 and the covering portion 31 are cancelled. As described above, deterioration in detection accuracy of the magnetic field to be measured is suppressed.

(Fifth embodiment)
Next, a fifth embodiment will be described with reference to FIGS. 37 and 38. FIG.

<Anisotropy of magnetic permeability>
In the first embodiment, an example is shown in which the first shield 41 and the second shield 42 are each manufactured by pressing a plurality of flat plates made of a soft magnetic material. On the other hand, in this embodiment, the first shield 41 and the second shield 42 are each manufactured by rolling electromagnetic steel.

By specifying the rolling direction of the electromagnetic steel as described in the first embodiment, the magnetic permeability of the shield can be made anisotropic. In this embodiment, the rolling direction of the first shield 41 and the second shield 42 is along the z direction. As a result, the magnetic permeability of the first shield 41 and the second shield 42 is anisotropic. The method of manufacturing the first shield 41 and the second shield 42 is not limited to the above example, and they may be manufactured using a material having anisotropic magnetic permeability. Alternatively, one of the first shield 41 and the second shield 42 may have magnetic permeability anisotropy.

As shown in FIG. 37, in each of the second current sensor 12 and the third current sensor 13, individual sensors 71 are arranged side by side in the x direction. The first shields 41 and the second shields 42 of the individual sensors 71 are arranged alternately in the x direction. In this configuration, the detection directions of the magnetic field of the magnetoelectric converter 25 of the individual sensor 71 are the z direction and the y direction. In this configuration, it is also possible to adopt a configuration in which the first shield 41 of one of the two individual sensors 71 arranged in the x direction and the second shield 42 of the other are integrated.

In such a configuration in which a plurality of individual sensors 71 are arranged in the x direction, the magnetic field to be measured emitted from the conductive bus bar 30 of one individual sensor 71 becomes external noise for the other individual sensors 71 . This external noise is annularly formed on a plane defined by the x-direction and the z-direction with the conductive bus bar 30 as the center. External noise therefore has components along the x and z directions. In this way, the environment is such that the external noise along the x-direction and the z-direction easily penetrates the individual sensor 71 .

In FIG. 37 two individual sensors 71 are shown. A current to be measured flows through the conductive bus bar 30 of the two individual sensors 71 indicated by a cross in a circle. The magnetic field to be measured is emitted from here. For the adjacent individual sensor 71, the magnetic field to be measured emitted from the conductive bus bar 30 marked with a cross in this circle is electromagnetic noise. In FIG. 37, magnetic fields are indicated by arrows.

As described above, each of the first shield 41 and the second shield 42 has anisotropy in the z direction. Therefore, components of the external noise along the z-direction tend to enter the first shield 41 and the second shield 42, respectively. On the other hand, the component of the external noise along the x direction does not depend on the anisotropy of the first shield 41 and the second shield 42 . Therefore, the component along the x direction tends to pass through the magnetoelectric conversion section 25 .

For example, when the magnetic field indicated by the dashed arrow in FIG. 37 tries to pass through the magnetoelectric converter 25, the component along the z direction of this magnetic field positively tries to pass through the first shield 41 and the second shield 42, respectively. However, some x-direction component of this magnetic field remains. Therefore, the component of the magnetic field in the x direction tries to pass through the magnetoelectric converter 25 .

On the other hand, the detection directions of the magnetic field to be measured by the magnetoelectric converter 25 are the z-direction and the y-direction. The magnetoelectric converter 25 does not detect a magnetic field in the x direction. Therefore, even if the x-direction component of the electromagnetic noise is transmitted through the magnetoelectric conversion section 25, it is possible to prevent the detection accuracy of the magnetic field to be measured from deteriorating.

The arrangement configuration of the individual sensors 71 is not limited to the above example. For example, as shown in FIG. 38, a configuration in which individual sensors 71 are arranged side by side in the x direction is also conceivable. In this configuration, the first shields 41 of the individual sensors 71, the second shields 42, and the magnetoelectric converters 25 are arranged in the x direction. The magnetic field detection directions of the magnetoelectric converter 25 of the individual sensor 71 are the x direction and the y direction. In this configuration, it is also possible to employ a configuration in which the first shields 41 of the plurality of individual sensors 71 arranged in the x direction are integrated. Similarly, a configuration in which the second shields 42 of the plurality of individual sensors 71 are integrated into one may be adopted.

FIG. 38 also shows two individual sensors 71 . Of the two individual sensors 71, the current to be measured flows through the conductive bus bar 30 marked with a cross in a circle. The magnetic fields are indicated by arrows in FIG. 38 as well. The magnetic field has components along the x and z directions. Therefore, the environment is such that external noise along the x-direction and z-direction easily penetrates the individual sensor 71 .

In this configuration, the magnetic permeability of the first shield 41 and the second shield 42 is higher in the x direction than in the y direction. Therefore, the x-direction component of the external noise tends to enter the first shield 41 and the second shield 42 . On the other hand, the component of the external noise along the z-direction does not depend on the anisotropy of the first shield 41 and the second shield 42 . Therefore, the component along the z direction tends to pass through the magnetoelectric conversion section 25 .

For example, when the magnetic field indicated by the broken arrow in FIG. However, some z-direction component of this magnetic field remains. Therefore, the component of this magnetic field in the z direction tends to pass through the magnetoelectric conversion section 25 .

On the other hand, the detection directions of the magnetic field to be measured by the magnetoelectric converter 25 are the x direction and the y direction. The magnetoelectric converter 25 does not detect a magnetic field in the z direction. Therefore, even if the component of the electromagnetic noise in the z-direction passes through the magnetoelectric conversion section 25, the detection accuracy of the magnetic field to be measured is prevented from deteriorating.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present disclosure. is.

(First modification)
In the first embodiment, an example in which the notches 41c are formed at the four corners of the first shield 41 is shown. As a result, the first end portions 41e of the first shield 41 are shorter in the x direction than the first center portion 41d. An example in which the extension portion 42c is formed on the second shield 42 is shown.

On the other hand, as shown in FIG. 39, it is also possible to employ a configuration in which notches 41c are formed at the four corners of the first shield 41 and the second shield 42, respectively. As a result, the length in the x direction of the second end portions 42e is shorter than that of the second central portion 42d. As shown in column (b) of FIG. 39, the magnetoelectric conversion portions 25 of the first sensing portion 21 and the second sensing portion 22 mounted on the wiring substrate 20 are placed between the first central portion 41d and the second central portion 42d. is located. Column (a) of FIG. 39 is a perspective view for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive busbar. The (b) column of FIG. 39 is a side view for explaining the arrangement of the shield, the magnetoelectric transducer, and the conductive busbar.

Further, as shown in column (a) of FIG. 40, the second shield 42 does not have to have the extended portion 42c and the notch 41c. As shown in column (b) of FIG. 40, a configuration in which notches 41c are formed in two of the four corners of the first shield 41 can also be adopted. In addition, two notches 41c are located in a line with the x direction in the (b) column of FIG. Each of columns (a) and (b) in FIG. 40 is a perspective view for explaining the arrangement of the shield, the magnetoelectric converter, and the conductive bus bar. As described above, it is sufficient that the first end portions 41e of the first shield 41 are shorter in the x direction than the first center portion 41d, and the formation position of the notch 41c is not particularly limited.

(Second modification)
In the first embodiment, the integrated housing 73 has the bottom wall 77 and the peripheral wall 78, and a plurality of individual sensors 71 are stored in the storage space formed by these walls. However, as shown in FIGS. 41-43, the integrated housing 73 does not have to have the peripheral wall 78 . In this case, the individual sensor 71 is provided rotated by 90° with respect to the bottom wall 77 . Thereby, each of the front surface 30a and the back surface 30b of the conductive busbar 30 of the individual sensor 71 faces the z-direction. One surface 41a and a back surface 41b of the first shield 41 each face the z direction. Similarly, one surface 42a and a back surface 42b of the second shield 42 also face the z-direction. The detection directions of the magnetoelectric conversion portion 25 of the individual sensor 71 are the x direction and the y direction.

As a result, as shown in FIG. 38, the first shields 41 of the individual sensors 71 are aligned in the x direction. The second shields 42 of the individual sensors 71 are arranged in the x direction. The magnetoelectric converters 25 of the individual sensors 71 are arranged in the x direction.

Note that column (a) of FIG. 42 shows a top view of the second current sensor. Column (b) of FIG. 42 shows a front view of the second current sensor. Column (c) of FIG. 42 shows a bottom view of the second current sensor. Column (a) of FIG. 43 shows a side view of the second current sensor. Column (b) of FIG. 43 shows a front view of the second current sensor. The same drawing is shown in the (b) column of FIG. 42 and the (b) column of FIG.

In this modified example, the same number of bolt holes along the z direction as the individual sensors 71 are formed in the terminal block 80 . A bolt hole 30 c is formed in the second exposed portion 33 of the individual sensor 71 . A bolt is passed through the bolt hole of the terminal block 80, the bolt hole 30c of the second exposed portion 33, and the bolt hole formed in the wire terminal. A nut is fastened to the tip of the bolt. A nut is fastened to the bolt from the tip of the shank of the bolt toward the head. The second exposed portion 33 and the wire terminal are sandwiched between the head of the bolt and the terminal block 80 . As a result, the second exposed portion 33 and the terminal of the wire come into contact with each other and are electrically and mechanically connected.

(Third modification)
The rib 52a is formed in the sensor housing 50 of the first current sensor 11 as shown in the first embodiment. Similarly, a rib 52a may be formed on the sensor housing 50 of the individual sensor 71 as shown in FIG. A guide portion 72 a for inserting the individual sensor 71 into the wiring case 72 may be formed on the bottom wall 77 of the integrated housing 73 . The guide portion 72a constitutes a hollow groove having a shape similar to that of the rib 52a. The guide portion 72a is open in the z direction. Through this opening, the rib 52a is passed through the hollow of the guide portion 72a. This facilitates assembly of the individual sensor 71 to the integrated housing 73 . In the modification shown in FIG. 44, a groove 77c is formed in the bottom wall 77 for providing a projecting end of the tip of the connection terminal 60 of the individual sensor 71. As shown in FIG.

(Fourth modification)
As schematically shown in column (a) of FIG. 45, each embodiment has shown an example in which individual sensors 71 are provided for the U-phase stator coil and the V-phase stator coil of the motor. An example in which these individual sensors 71 have the first sensing section 21 and the second sensing section 22 is shown.

However, as schematically shown in column (b) of FIG. 45, a configuration in which individual sensors 71 are provided for each of the U-phase stator coil, the V-phase stator coil, and the W-phase stator coil of the motor can also be adopted. . These individual sensors 71 can employ a configuration having only the first sensing section 21 .

As described above, the remaining one current can be detected based on the currents flowing through two of the three-phase stator coils. Therefore, the current of the remaining one stator coil can be detected based on two outputs of the first sensing units 21 of the three individual sensors 71 provided for the three-phase stator coils. Also, the current of the remaining one stator coil can be detected by the first sensing section 21 of the individual sensor 71 provided for the remaining one stator coil. By comparing these two detected currents, it is possible to determine whether or not there is an abnormality in one of them.

(Other modifications)
Each embodiment has shown an example in which a current sensor is applied to the vehicle-mounted system 100 that constitutes a hybrid system. However, the vehicle-mounted system to which the current sensor is applied is not limited to the above example. For example, the current sensor may be applied to an in-vehicle system of an electric vehicle or an engine vehicle. The system to which the current sensor is applied is not particularly limited.

DESCRIPTION OF SYMBOLS 11... 1st current sensor, 12... 2nd current sensor, 13... 3rd current sensor, 20... Wiring board, 20a... Opposing surface, 20b... Back surface, 21... First sensing part, 22... Second sensing part, 25 Magnetoelectric converter 29 Differential circuit 30 Conductive busbar 30a Front surface 30b Back surface 30c Bolt hole 31 Covering portion 31a Narrowing portion 32 First exposure portion 33 Second exposure Part, 34... Stress relief part, 40... Shield, 41... First shield, 41a... One surface, 41c... Notch, 41d... First central part, 41e... First both ends, 41f... Opposite sides, 42... Second Shield 42a...One surface 42c...Extended part 42d...Second central part 42e...Second both ends 42f...End side 50...Sensor housing 51...Base part 51f...Lower end face 56a...Substrate support Pin 56b... Board adhesion pin 56c... Tip end face 56d... Tip face 56e... Board adhesive 57a... Shield support pin 57b... Shield adhesion pin 57c... Tip face 57d... Tip face 57e... Shield adhesion Agent 71 Individual sensor 72 Wiring case 73 Integrated housing 75 Energizing terminal 76 Integrated wiring board 100 In-vehicle system 307 Energizing bus bar 307 a First terminal block 307 b Second Terminal block 341 First conducting bus bar 342 Second conducting bus bar 343 Third conducting bus bar 344 Fourth conducting bus bar 345 Fifth conducting bus bar 346 Sixth conducting bus bar 801 Battery ECU 802... MGECU, AS... axis of symmetry, CP... center point

Claims (2)

a conductive member (30) through which the current to be measured flows;
a wiring board (20) mounted with a magnetoelectric converter (25) for converting a magnetic field to be measured generated by the flow of the current to be measured into an electric signal;
an insulating sensor housing (50) that houses the magnetoelectric conversion unit ;
a substrate adhesive (56e) for bonding the sensor housing and the wiring substrate,
The conductive member is provided in the sensor housing,
The sensor housing includes a substrate supporting portion (56a) that supports the wiring substrate, and a substrate bonding portion (56b) on which the substrate adhesive is provided,
A mounting surface (56d) of the substrate bonding portion on which the substrate adhesive is provided is spaced further from the wiring substrate than a supporting surface (56c) of the wiring substrate of the substrate supporting portion,
The wiring substrate is mounted on the supporting surface of the substrate supporting portion, the substrate adhesive is provided between the mounting surface of the substrate bonding portion and the wiring substrate, and the conductive member and the conductive member are provided in the sensor housing. A current sensor that is spaced apart from the wiring board. 2. The current sensor according to claim 1, wherein the magnetoelectric conversion portion is mounted on the facing surface (20a) of the wiring substrate on the side of the conductive member.

Images