Sensor wiring structure

Abstract

To provide a sensor wiring structure capable of suppressing a decrease in detection precision of a current sensor.SOLUTION: In a base section 51, a first bus-bar 61 and a second bus-bar 62 are disposed in parallel mutually. A magnetic field detection type current sensor 13 is connected to the first bus-bar 61. Each of the respective bus-bars 61, 62 is in a flexural shape having contact sections 61a, 62a extending along the base section 51 in a state abutting on the base section 51, separation sections 61b, 62b extending along the base section 51 in positions separated from the base section 51, and connection sections 61c, 62c for connecting the contact sections 61a, 62a and the separation sections 61b, 62b. In the first bus-bar 61 and the second bus-bar 62, the connection sections 61c, 62c of the respective bus-bars 61, 62 are provided in positions in which they are arranged side by side mutually as positions in extension directions of the bus-bars, and the directions of current flowing to the respective connection sections 61c, 62c are opposite mutually.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The disclosure in this specification relates to a sensor wiring structure to which a current sensor is connected.

Background Art

[0002] Conventionally, various techniques have been proposed for current sensors that detect the current flowing through a wiring section (see, for example, Patent Document 1). In addition, in an electric circuit including a current sensor, a plurality of electric components are arranged in proximity to each other due to requirements such as miniaturization.

[0003] On the other hand, for example, a configuration in which a bus bar is provided as a wiring section on a heat sink and an electric component such as a fuse is connected to the bus bar can be considered. Further, when a bus bar is provided on a heat sink, in order to avoid interference between the heat sink and the electric component, a configuration in which the bus bar is bent to form a part of the bus bar separated from the heat sink and the electric component is connected to the separated portion can be considered.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When arranging a plurality of electrical components in proximity, for example, when arranging two bus bars in parallel, a configuration is conceivable in which one bus bar is bent to avoid interference and a current sensor is provided on the other bus bar. In this case, when each bus bar is energized, there is concern that the detection accuracy of the current sensor may decrease due to the magnetic field generated in the standing portion of the bent bus bar. That is, in a configuration in which a part is separated from the heat sink due to bending in the bus bar, standing wall-like standing portions are formed on both sides with an electrical component such as a fuse interposed therebetween. Therefore, in one standing portion, a clockwise magnetic field is generated around the standing portion in plan view, and in the other standing portion, a counterclockwise magnetic field is generated around the standing portion in plan view. Therefore, a combined magnetic field is generated between the standing portions on both sides in a direction orthogonal to the bus bar, and there is concern that the detection accuracy of the current sensor provided on the adjacent bus bar may decrease due to the combined magnetic field.

[0006] In order to avoid the influence of the combined magnetic field generated in the adjacent bus bar in the current sensor, it is necessary to increase the separation distance between the bus bars or provide a shielding plate between the bus bars. Therefore, there is concern about an increase in size and an increase in the number of parts.

[0007] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a sensor wiring structure capable of suppressing a decrease in the detection accuracy of a current sensor.

Means for Solving the Problems

[0008] The present disclosure is a base portion, a first bus bar and a second bus bar arranged in parallel with each other in the base portion, and having, at least the first bus bar among the first bus bar and the second bus bar is a sensor wiring portion to which a magnetic field detection type current sensor is connected, each of the bus bars has a bent shape having a contact portion extending along the base portion in a state of being in contact with the base portion, a separation portion extending along the base portion at a position separated from the base portion, and a connecting portion connecting the contact portion and the separation portion. In the first bus bar and the second bus bar, the connecting portions of the respective bus bars are provided at positions side by side with respect to the positions in the extending direction of the respective bus bars, and the directions of the currents flowing through these connecting portions are opposite to each other.

[0009] When two bus bars are arranged in parallel on the base portion, it becomes possible to collectively arrange the electrical components connected to these bus bars. However, on the other hand, if one of the bus bars has a bent shape with respect to the base portion, there is a concern that the detection accuracy of the current sensor provided in the adjacent bus bar may decrease due to the magnetic field generated in the standing portion that stands up with respect to the base portion when the bus bar is energized.

[0010] In consideration of this point, both the first bus bar and the second bus bar arranged in parallel with each other are formed into a bent shape having a contact portion, a separation portion, and a connecting portion. In the first bus bar and the second bus bar, the connecting portions of the respective bus bars are provided at positions side by side in the extending direction of the respective bus bars, and the directions of the currents flowing through these connecting portions are opposite to each other. In this case, in the connecting portion of the first bus bar, a magnetic field can be generated so as to reduce the magnetic field generated in the connecting portion of the second bus bar. Therefore, the influence of the magnetic field due to the energization of the second bus bar is reduced in the current sensor connected to the first bus bar. As a result, a decrease in the detection accuracy of the current sensor can be suppressed.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0012] Hereinafter, an embodiment in which the sensor wiring structure according to the present disclosure is embodied will be described with reference to the drawings. In this embodiment, a power supply circuit connected to a battery will be described. The power supply circuit is used in an electric vehicle including a battery and a driving motor, such as an electric vehicle or a hybrid vehicle. FIG. 1 is a diagram showing the configuration of the power supply circuit 10. The power supply circuit 10 is configured to selectively connect DC terminals on the positive and negative sides, INV terminals on the positive and negative sides, and AC terminals on the positive and negative sides to the battery 100. The power supply circuit 10 is provided in a junction box in the electric vehicle.

[0013] The power supply circuit 10 has a positive-side path 11 connected to the positive side of the battery 100 and a negative-side path 12 connected to the negative side of the battery 100. The battery 100 is a power storage device having a terminal voltage of, for example, several hundred V, and is, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery. An electric current sensor 13 and a fuse 14 are connected in series to the positive-side path 11, and an electric current sensor 15 is connected to the negative-side path 12.

[0014] The positive-side path 11 is branched into a positive-side first path 21 and a positive-side second path 22. A DC terminal (DC+) is connected to the positive-side first path 21 via an SMR (system main relay) 23 and a DC relay 24, and an INV terminal (INV+) is connected via the SMR 23. An AC terminal (AC+) is connected to the positive-side second path 22 via an AC relay 25.

[0015] The negative electrode side path 12 is branched into a negative electrode side first path 31 and a negative electrode side second path 32. A DC terminal (DC-) is connected to the negative electrode side first path 31 via an SMR (system main relay) 33 and a DC relay 34, and an INV terminal (INV-) is connected via the SMR 33. A series connection of a resistor 35 and a precharge relay 36 is connected in parallel with the SMR 33 to the negative electrode side first path 31. Also, an AC terminal (AC-) is connected to the negative electrode side second path 32 via an AC relay 37.

[0016] Although illustration is omitted, in-vehicle electrical loads are connected to the DC terminals (DC+, DC-), and an inverter for driving a rotating electric machine, which is a traveling motor, is connected to the INV terminals (INV+, INV-). Also, a charging device for charging the battery 100 is connected to the AC terminals (AC+, AC-). The charging device includes an AC-DC converter and charges the battery 100 with electric power supplied from an external charging facility such as a charging stand or a household power supply.

[0017] In the power supply circuit 10, when power supply to the electrical load or the inverter is started, the precharge relay 36 is turned on (closed), and power supply is performed via the resistor 35, thereby limiting the supply current from the battery 100 to the electrical load or the inverter. Note that the series connection of the resistor 35 and the precharge relay 36 may be provided on the positive electrode side.

[0018] In the power supply circuit 10, the energization state and the power-off state between the battery 100 and the electrical load or the inverter are switched by opening and closing the SMRs 23, 33 and the DC relays 24, 34. Also, the energization state and the power-off state between the battery 100 and the charging device are switched by opening and closing the AC relays 25, 37. Each of the above relays is opened and closed based on a command from the control device 40. Also, the detection currents detected by the current sensors 13, 15 are sequentially input to the control device 40. In the control device 40, for example, based on the detection currents of the current sensors 13, 15, it is determined whether an overcurrent has flowed through the positive electrode side path 11 or the negative electrode side path 12.

[0019] Next, a specific wiring structure in the power supply circuit 10 will be described. FIG. 2 is a perspective view showing a wiring structure including a current sensor 13 and a fuse 14 in the power supply circuit 10. Further, FIG. 3 is a front view showing the mounting state of the current sensor 13 and the mounting state of the fuse 14 in the base portion 51, showing the mounting state of the current sensor 13 in the lower part and the mounting state of the fuse 14 in the upper part.

[0020] The base portion 51 is a plate-like laminate in which a cooling plate 52, a heat dissipation sheet 53, and an insulating sheet 54 are laminated. A first bus bar 61 and a second bus bar 62 are respectively fixed on the insulating sheet 54 of the base portion 51 (see FIG. 3). The cooling plate 52 has a cooling structure by air cooling or water cooling. By fixing each bus bar 61, 62 to the base portion 51, each bus bar 61, 62 is cooled when the bus bar is energized.

[0021] A current sensor 13 is connected to the first bus bar 61, and a fuse 14 is connected to the second bus bar 62. These bus bars 61, 62 are wiring members corresponding to the positive electrode side path 11 in FIG. 1 and are electrically connected in series with each other. The first bus bar 61 is a sensor wiring portion where the current sensor 13 is provided, and the second bus bar 62 is a fuse wiring portion where the fuse 14 is provided. The first bus bar 61 and the second bus bar 62 are fixed on the insulating sheet 54 in a state of being arranged in parallel with each other on the base portion 51.

[0022] The current sensor 13 is a magnetic field detection type current sensor having a detection element that outputs an electrical signal according to the magnetic flux density of a magnetic field. The detection element is a magnetoelectric conversion element such as a magnetoresistive element or a Hall element. When a current flows through the first bus bar 61, the magnitude of the current is measured by detecting the magnetic flux density of the magnetic field generated by the current with the magnetic detection element.

[0023] The first bus bar 61 has a bent shape and is fixed to the base portion 51 in a state where a part thereof is separated from the base portion 51. That is, the first bus bar 61 has a contact portion 61a that extends along the base portion 51 in a state of being in contact with the base portion 51, a separation portion 61b that extends along the base portion 51 at a position separated from the base portion 51, and a connecting portion 61c that connects the contact portion 61a and the separation portion 61b. The connecting portion 61c is a standing wall portion that stands up in a direction orthogonal to the base portion 51. The first bus bar 61 has a bent shape with two connecting portions 61c, and a current sensor 13 is connected to the separation portion 61b between the two connecting portions 61c.

[0024] Also, the second bus bar 62 has a bent shape similar to that of the first bus bar 61 and is fixed to the base portion 51 in a state where a part thereof is separated from the base portion 51. That is, the second bus bar 62 has a bent shape having a contact portion 62a that is in contact with the base portion 51, a separation portion 62b that is separated from the base portion 51, and a connecting portion 62c that connects the contact portion 62a and the separation portion 62b. The connecting portion 62c is a standing wall portion that stands up in a direction orthogonal to the base portion 51. The second bus bar 62 has a bent shape with two connecting portions 62c, and a fuse 14 is connected to the separation portion 62b between the two connecting portions 62c.

[0025] As shown in FIG. 2, the first bus bar 61 and the second bus bar 62 are arranged side by side such that the contact portions 61a and 62a and the separation portions 61b and 62b are adjacent to each other. In this case, when viewed in the arrangement direction of the bus bars 61 and 62 (direction A in FIG. 2), the connecting portions 61c and 62c of the bus bars 61 and 62 are provided at overlapping positions.

[0026] In FIG. 3, the distance dimension between two connection parts 61c in the first bus bar 61 is L1, the length dimension in the bus bar extending direction of each connection part 61c is L2, the distance dimension between two connection parts 62c in the second bus bar 62 is L3, and the length dimension of each connection part 62c is L4. Note that the length dimensions L2 and L4 of each connection part 61c and 62c correspond to the height dimensions from the base part 51 of each bus bar 61 and 62. In this case, in each of the bus bars 61 and 62, the distance dimensions L1 and L3 between the two connection parts 61c and 62c are such that L1 = L3. Also, in each of the bus bars 61 and 62, the length dimensions L2 and L4 of each connection part 61c and 62c are such that L2 = L4.

[0027] Further, one end side of the first bus bar 61 and the second bus bar 62 in the extending direction of each bus bar 61 and 62 are electrically connected to each other. As a result, currents flow in opposite directions in the first bus bar 61 and the second bus bar 62.

[0028] FIG. 4 is a plan view showing the wiring structure in the present embodiment. Further, FIG. 5 is a plan view showing a wiring structure as a comparative example. In each of these figures, the magnetic fields generated around the standing parts (connection parts 61c, 62c, 71x) with respect to the base part 51 when each bus bar is energized are indicated by arrows.

[0029] In the wiring structure of FIG. 5 which is a comparative example, the bus bar 71 on the current sensor 13 side has a flat shape (a shape without bending) that is flat in the height direction which is the direction orthogonal to the paper surface of FIG. 5, while the bus bar 72 on the fuse 14 side has a bent shape with a step in the height direction. That is, similar to the second bus bar 62 shown in FIG. 2, the bus bar 72 is configured such that the contact part contacts the base part 51 for cooling the bus bar 72, and the separation part is separated from the base part 51 to avoid interference between the fuse 14 and the base part. Also, the connection part 72x between the contact part and the separation part is a standing part that stands up from the base part 51.

[0030] In this case, when the bus bar 72 on the fuse 14 side is energized, currents flow in the circumferential directions that are perpendicular to the plane of the paper and opposite to each other at the left and right connecting portions 72x. In FIG. 5, at the right connecting portion 72x, the current flows from the back side to the front side of the paper, and at the left connecting portion 72x, the current flows from the front side to the back side of the paper. Therefore, at the left and right connecting portions 72x (upright portions), magnetic fields M1 and M2 are generated in opposite circumferential directions, and a combined magnetic field M3 is generated between the left and right connecting portions 72x in the direction perpendicular to the bus bar 72 in plan view in the bus bar extending direction. And due to the combined magnetic field M3, there is a concern that the detection accuracy will decrease in the current sensor 13 provided in the adjacent bus bar 71.

[0031] On the other hand, in the wiring structure of FIG. 4, each of the bus bars 61 and 62 has a bent shape having a contact portion 61a, 62a, a separated portion 61b, 62b, and a connecting portion 61c, 62c. Further, the left and right connecting portions 61c of the first bus bar 61 and the left and right connecting portions 62c of the second bus bar 62 are provided at positions side by side with each other as positions in the bus bar extending direction (left - right direction in the figure). Furthermore, in the first bus bar 61 and the second bus bar 62, currents flow in opposite directions to each other in the bus bar extending direction. That is, in FIG. 4, a current flows in the right - hand direction in the figure in the first bus bar 61, while a current flows in the left - hand direction in the figure in the second bus bar 62. As a result, in the first bus bar 61 and the second bus bar 62, opposite - direction currents flow in the left - hand connecting portions 61c and 62c that are adjacent to each other side by side, and opposite - direction currents also flow in the right - hand connecting portions 61c and 62c that are adjacent to each other side by side.

[0032] In this case, when the first bus bar 61 is energized, magnetic fields M11 and M12 are generated in opposite circumferential directions at the left and right connecting portions 61c, and a combined magnetic field M13 is generated between the left and right connecting portions 61c in the direction perpendicular to the first bus bar 61 in the bus bar extending direction. Also, when the second bus bar 62 is energized, magnetic fields M21 and M22 are generated in opposite circumferential directions at the left and right connecting portions 62c, and a combined magnetic field M23 is generated between the left and right connecting portions 62c in the direction perpendicular to the second bus bar 62 in the bus bar extending direction.

[0033] Here, since the combined magnetic field M13 generated in the first bus bar 61 and the combined magnetic field M23 generated in the second bus bar 62 are in opposite directions to each other, the combined magnetic fields M13 and M23 cancel each other out. Therefore, in the current sensor 13, a decrease in the detection accuracy due to the combined magnetic field M23 on the second bus bar 62 side is suppressed.

[0034] Also, in the wiring structure of FIG. 4, since the first bus bar 61 and the second bus bar 62 are connected in series, the magnitudes of the currents flowing through the connecting portions 61c and 62c are the same. In addition, in the first bus bar 61 and the second bus bar 62, the distance dimensions L1 and L3 between the two connecting portions 61c and 62c are L1 = L3, and the length dimensions L2 and L4 of the connecting portions 61c and 62c are L2 = L4. According to these configurations, the magnitude of the combined magnetic field M13 generated in the first bus bar 61 and the magnitude of the combined magnetic field M23 generated in the second bus bar 62 are the same. Therefore, the effect of reducing the magnetic field that causes interference during current detection by the current sensor 13 is enhanced.

[0035] Instead of the configuration of FIG. 2, the configuration of FIG. 6 is also possible. FIG. 6 is a front view schematically showing the wiring structure.

[0036] In the wiring structure of FIG. 6, the first bus bar 61 has a bent shape having a contact portion 61a, a spaced portion 61b, and a connecting portion 61c, similar to the wiring structure of FIG. 3. However, in the wiring structure of FIG. 6, as a difference from FIG. 3, in the first bus bar 61, the portion between the two connecting portions 61c is the contact portion 61a, and the current sensor 13 is connected to the contact portion 61a. On the other hand, the second bus bar 62 has the same configuration as the wiring structure of FIG. 3.

[0037] That is, the first bus bar 61 and the second bus bar 62 are arranged side by side such that the contact portion 61a of the first bus bar 61 and the separated portion 62b of the second bus bar 62 are adjacent to each other, and the separated portion 61b of the first bus bar 61 and the contact portion 62a of the second bus bar 62 are adjacent to each other. As a result, the first bus bar 61 and the second bus bar 62 are arranged side by side such that their respective contact portions 61a, 62a and separated portions 61b, 62b are staggered in the bus bar extending direction. In the arrangement direction of each bus bar 61, 62, the connecting portions 61c, 62c of each bus bar 61, 62 are provided at overlapping positions.

[0038] Also, in the first bus bar 61 and the second bus bar 62, the directions of the currents in the bus bar extending direction are the same as each other. That is, the directions of the currents in each bus bar 61, 62 are each rightward in FIG. 6. In this case, since the contact portions 61a, 62a and the separated portions 61b, 62b of each bus bar 61, 62 are staggered, and the directions of the currents in the bus bar extending direction are the same as each other, the directions of the currents are opposite to each other at the connecting portions 61c, 62c of the first bus bar 61 and the second bus bar 62. Therefore, similar to FIG. 4 described above, the direction of the synthetic magnetic field M13 generated in the first bus bar 61 and the direction of the synthetic magnetic field M23 generated in the second bus bar 62 are opposite to each other, and the synthetic magnetic fields M13, M23 cancel each other out. Accordingly, in the current sensor 13, a decrease in the detection accuracy due to the synthetic magnetic field M23 on the second bus bar 62 side is suppressed.

[0039] Also in the configuration of FIG. 6, similar to the configuration of FIG. 3, it is preferable that the distance dimensions L1, L3 between the two connecting portions 61c, 62c in each bus bar 61, 62 are L1 = L3, and the length dimensions L2, L4 of each connecting portion 61c, 62c are L2 = L4.

[0040] In addition, in the wiring structures of FIGS. 3 and 6, in addition to the configuration in which the current sensor 13 is connected to the first bus bar 61 and the fuse 14 is connected to the second bus bar 62, a configuration in which the current sensor 13 is connected to both of the bus bars 61 and 62 may be employed. That is, both the first bus bar 61 and the second bus bar 62 may be sensor wiring portions provided with the current sensor 13.

[0041] According to the present embodiment described in detail above, the following excellent effects can be obtained.

[0042] Both the first bus bar 61 and the second bus bar 62 arranged in parallel with each other are formed in a bent shape having connecting portions 61c and 62c standing up from the base portion 51. The connecting portions 61c and 62c of the bus bars 61 and 62 in the bus bar extending direction are provided at positions side by side, and the directions of the currents flowing through the connecting portions 61c and 62c are opposite to each other. In this case, in the connecting portion 61c of the first bus bar 61, a magnetic field can be generated so as to reduce the magnetic field generated in the connecting portion 62c of the second bus bar 62. Therefore, the influence of the magnetic field due to the energization of the second bus bar 62 on the current sensor 13 connected to the first bus bar 61 is reduced. As a result, a decrease in the detection accuracy of the current sensor 13 can be suppressed.

[0043] The first bus bar 61 and the second bus bar 62 are arranged side by side in a state where the contact portions 61a and 62a and the spaced portions 61b and 62b are adjacent to each other (see FIGS. 2 and 3). In this case, by making the directions of the currents in the bus bar extending direction in each of the bus bars 61 and 62 opposite to each other, the directions of the currents in the connecting portions 61c and 62c side by side with each other become opposite to each other. Thereby, in the current sensor 13 provided in the first bus bar 61, the influence due to the energization of the second bus bar 62 can be reduced.

[0044] The first bus bar 61 and the second bus bar 62 are arranged side by side such that the contact portions 61a, 62a and the spaced portions 61b, 62b are staggered in the bus bar extending direction (see FIG. 6). In this case, in each of the bus bars 61, 62, by making the directions of the currents in the bus bar extending direction the same as each other, the directions of the currents become opposite to each other at the connecting portions 61c, 62c of the first bus bar 61 and the second bus bar 62. Thereby, in the current sensor 13 provided in the first bus bar 61, the influence due to the energization of the second bus bar 62 can be reduced.

[0045] In the first bus bar 61 and the second bus bar 62 connected in series, the directions of the currents flowing through the connecting portions 61c, 62c which are side by side are made opposite to each other. In this case, the magnitudes of the currents flowing through the connecting portions 61c, 62c are the same, and the magnetic field generated at the connecting portion 61c of the first bus bar 61 and the magnetic field generated at the connecting portion 62c of the second bus bar 62 can be preferably canceled out.

[0046] In the first bus bar 61 and the second bus bar 62, the distance dimensions L1, L3 between the two connecting portions 61c, 62c are set to L1 = L3, and the length dimensions L2, L4 of the connecting portions 61c, 62c are set to L2 = L4. In this case, the magnitudes of the magnetic fields generated at the connecting portion 61c of the first bus bar 61 and the connecting portion 62c of the second bus bar 62 become the same, and the effect of reducing the magnetic field that becomes a disturbance when detecting the current by the current sensor 13 can be enhanced.

[0047] <Other Embodiments> The above embodiment may be modified as follows, for example.

[0048] · The first bus bar 61 and the second bus bar 62 each have a bent shape with two bent portions, and in a configuration where the current sensor 13 is connected to the first bus bar 61 among the first bus bar 61 and the second bus bar 62, it is conceivable that the synthetic magnetic field generated by the connection portion 61c of the first bus bar 61 on the current sensor side, that is, the synthetic magnetic field generated by the standing portion of the first bus bar 61 on its own side, affects the detection accuracy of the current sensor 13. Therefore, from the perspective of the first bus bar 61 on the current sensor side, it is desirable that the synthetic magnetic field generated on its own side be appropriately attenuated by the synthetic magnetic field on the second bus bar 62 side.

[0049] In this case, in the first bus bar 61, the synthetic magnetic field (first synthetic magnetic field) generated by the magnetic fields generated at each connection portion 61c at the midpoint (bisection point) between the two connection portions 61c is compared with the synthetic magnetic field (second synthetic magnetic field) generated by the magnetic fields generated at each connection portion 62c at the midpoint between the two connection portions 62c in the second bus bar 62. Considering the positional relationship with the current sensor 13, it is considered that the former synthetic magnetic field (first synthetic magnetic field) has a greater influence on the current sensor 13. Therefore, considering this point, it is advisable to determine the strength of the synthetic magnetic field on each of the bus bar 61 and 62 sides. Note that the midpoint between the two connection portions 61c in the first bus bar 61 is the position of the detection element in the current sensor 13.

[0050] In terms of the wiring structure shown in FIG. 4, the synthetic magnetic field M13 on the first bus bar 61 side corresponds to the first synthetic magnetic field, and the synthetic magnetic field M23 on the second bus bar 62 side corresponds to the second synthetic magnetic field. In this case, it is preferable that the directions of the synthetic magnetic field M13 and the synthetic magnetic field M23 are opposite to each other, and the synthetic magnetic field M13 is weaker than the synthetic magnetic field M23.

[0051] Specifically, it is preferable that each of the bus bars 61 and 62 has the configuration shown in FIG. 7. FIG. 7 is a front view schematically showing a wiring structure. In FIG. 7, the distance dimension L1 on the side of the first bus bar 61 and the distance dimension L3 on the side of the second bus bar 62 satisfy L1 > L3. Also, the length dimensions L2 and L4 of each of the bus bars 61 and 62 are such that L2 = L4. The first bus bar 61 and the second bus bar 62 are connected in series. In this case, the direction of the combined magnetic field M13 on the side of the first bus bar 61 and the direction of the combined magnetic field M23 on the side of the second bus bar 62 are opposite to each other, and the combined magnetic field M13 is weaker than the combined magnetic field M23.

[0052] According to the above configuration, in the first bus bar 61 on the current sensor side, since the combined magnetic field generated on its own side becomes relatively weak, the mutual magnetic fields in each of the bus bars 61 and 62 can be more appropriately canceled out.

[0053] In addition to the configuration of FIG. 7, a configuration may be adopted in which the distance dimensions L1 and L3 of each of the bus bars 61 and 62 are set such that L1 = L3, and the length dimensions L2 and L4 of each of the bus bars 61 and 62 are set such that L2 < L4. In any case, a configuration in which the directions of the combined magnetic fields M13 and M23 are opposite to each other and the combined magnetic field M13 on the side of the first bus bar 61 is weaker than the combined magnetic field M23 on the side of the second bus bar 62 is sufficient.

[0054] Incidentally, in a configuration in which the current sensor 13 is connected to both the first bus bar 61 and the second bus bar 62, it is preferable that the combined magnetic field M13 and the combined magnetic field M23 have opposite directions and the same strength.

[0055] ·In the above embodiment, in each of the bus bars 61 and 62, the connecting portions 61c and 62c are configured to stand up in a direction orthogonal to the base portion 51, but this may be changed. For example, as shown in FIG. 8, in each of the bus bars 61 and 62, the connecting portions 61c and 62c may be configured to stand up in a direction obliquely intersecting the base portion 51.

[0056] ·It is also possible to adopt the wiring structure shown in FIG. 9. In FIG. 9, the first bus bar 61 has a configuration in which only one bent portion is provided. That is, in the first bus bar 61, one side of both sides of the current sensor 13 has a bent shape having a contact portion 61a, a spaced portion 61b, and a connecting portion 61c, and the other side has a configuration having only the spaced portion 61b. The current sensor 13 is connected to the spaced portion 61b. On the other hand, the second bus bar 62 has the same configuration as the wiring structure of FIG. 2.

[0057] Even in the configuration of FIG. 9, at the connecting portion 61c of the first bus bar 61, a magnetic field can be generated so as to reduce the magnetic field generated at the connecting portion 62c of the second bus bar 62. Therefore, the influence of energization of the second bus bar 62 on the current sensor 13 connected to the first bus bar 61 is reduced.

[0058] In the configuration of FIG. 9, in the first bus bar 61, a configuration is adopted in which a magnetic field that counteracts the combined magnetic field M23 on the second bus bar 62 side is generated at one connecting portion 61c. Therefore, on the first bus bar 61 side, it is preferable to adopt a configuration in which the magnetic field generated at the connecting portion 61c is increased, that is, a configuration in which the magnetic field that counteracts the combined magnetic field M23 is increased. For example, in the first bus bar 61, the distance dimension L31 between the center position (detection element position) of the current sensor 13 and the connecting portion 61c in the bus bar extending direction may be shorter than the distance dimension L32 between the center position (midpoint position between the two connecting portions 62c) of the fuse 14 and the connecting portion 62c in the bus bar extending direction in the second bus bar 62.

[0059] As a modification of FIG. 9, when the current sensor 13 is connected to the contact portion 61a in the first bus bar 61, one side of both sides of the current sensor 13 may be the first bus bar 61 having a bent shape having a contact portion 61a, a spaced portion 61b, and a connecting portion 61c, and the other side may be the first bus bar 61 having only the contact portion 61a.

[0060] · The wiring structures of the above embodiments are applicable not only to the power supply circuit 10 of the electric vehicle. For example, it can also be used as a wiring structure for connecting a plurality of current sensors that each detect a polyphase (e.g., three-phase) phase current in a rotating electrical machine.

Description of Reference Numerals

[0061] 13... Current sensor, 51... Base portion, 61... First bus bar, 62... Second bus bar, 61a, 62a... Contact portion, 61b, 62b... Separation portion, 61c, 62c... Connecting portion.

Claims

1. a base portion (51); a first bus bar (61) and a second bus bar (62) arranged in parallel with each other in the base portion; and at least the first bus bar of the first bus bar and the second bus bar is a sensor wiring structure that is a sensor wiring portion to which a magnetic field detection type current sensor (13) is connected, each of the bus bars has a bent shape having a contact portion (61a, 62a) extending along the base portion in a state of being in contact with the base portion, a separation portion (61b, 62b) extending along the base portion at a position separated from the base portion, and a connecting portion (61c, 62c) connecting the contact portion and the separation portion; a sensor wiring structure in which, in the first bus bar and the second bus bar, the connecting portions of the respective bus bars are provided at positions side by side with each other as positions in the extending direction of the respective bus bars, and the directions of the currents flowing through the respective connecting portions are opposite to each other.

2. The first bus bar and the second bus bar are arranged side by side such that the contact portions and the separation portions are adjacent to each other, By making the directions of the currents in the extending direction of the first bus bar and the second bus bar opposite to each other, the directions of the currents flowing through the connecting portions in the respective bus bars are opposite to each other. The sensor wiring structure according to claim 1.

3. The first bus bar and the second bus bar are arranged side by side such that the contact portion of one bus bar and the separation portion of the other bus bar are adjacent to each other, By making the directions of the currents in the extending direction of the first bus bar and the second bus bar the same as each other, the directions of the currents flowing through the connecting portions in the respective bus bars are opposite to each other. The sensor wiring structure according to claim 1.

4. The first bus bar and the second bus bar are connected in series by connecting one ends of both ends of each of the bus bars to each other. The sensor wiring structure according to claim 2 or 3.

5. The first bus bar and the second bus bar each have a bent shape having two connecting portions. In the first bus bar, when the distance dimension between the two connection portions is L1 and the length dimension of each of these connection portions in the bus bar extending direction is L2, and in the second bus bar, when the distance dimension between the two connection portions is L3 and the length dimension of each of these connection portions in the bus bar extending direction is L4, the sensor wiring structure according to claim 1, wherein L1 = L3 and L2 = L4.

6. The first bus bar and the second bus bar each have a bent shape having two connection portions, and are connected in series with each other. Only the first bus bar among the first bus bar and the second bus bar is the wiring portion for the sensor. When energizing the first bus bar and the second bus bar, the combined magnetic field generated by the magnetic fields generated at the two connection portions at the midpoint between the two connection portions on the first bus bar side is the first combined magnetic field, and the combined magnetic field generated by the magnetic fields generated at the two connection portions at the midpoint between the two connection portions on the second bus bar side is the second combined magnetic field. In this case, the first combined magnetic field and the second combined magnetic field are opposite in direction, and the first combined magnetic field is weaker than the second combined magnetic field. The sensor wiring structure according to claim 1.

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