JP4818218B2 - Power supply for vehicle - Google Patents

Description

  The present invention relates to a power supply device for a vehicle that supplies electric power to a motor that is mounted on an electric vehicle and runs the vehicle.

  A power supply device for a vehicle has a battery in which a large number of batteries are connected in series to increase the output voltage, a contactor connected to the output side of the battery, and a load capacitor before switching the contactor on. A precharge circuit for charging, a current sensor for detecting a battery current, and a control circuit for detecting a signal from the current sensor and controlling the contactor on and off are provided. (See Patent Document 1)

  This power supply device accurately separates power components such as precharge resistors and precharge relays that realize heat generating components and precharge circuits, and control circuits that generate less heat while reducing the effects of noise. It is extremely difficult to detect battery current. Furthermore, this power supply device is required to dispose a high voltage circuit connected to a high voltage battery and a low voltage circuit driven by an in-vehicle battery of the vehicle, so as to be insulated from each other. This is because safety is enhanced by not connecting the high voltage circuit to the chassis ground. Since the ground line of the low voltage circuit is connected to the chassis ground of the vehicle, when the high voltage circuit is connected to the low voltage circuit, the high voltage circuit is connected to the chassis ground. In order to insulate the high voltage circuit from the chassis ground, the high voltage circuit and the low voltage circuit are insulated.

The power components of the high-voltage circuit connected to the battery are mounted on the power board that is a dedicated board, the control circuit that is the low-voltage circuit is mounted on the control board, and the power board and the control board are connected by a wire harness for control The high-voltage circuit and the low-voltage circuit are insulated and wired on the board, and the power board and control board are connected with a wire harness, and the power parts that are heat-generating parts are separated and arranged, and the high-voltage circuit And the low voltage circuit can be insulated from each other.
JP 2005-269742 A

  However, in the structure in which the power board is separated from the control board and the power board and the control board are connected by the wire harness, the signal transmitted from the power board to the control board is easily affected by noise. In particular, the wire harness is easily affected by induction noise, and the signal transmitted from the current sensor on the power board to the control board is easily affected by noise. If the wire harness connected to the current sensor is affected by noise, the current cannot be detected accurately. The control circuit detects the state of the battery with a signal from the current sensor. That is, the control circuit calculates the remaining capacity by integrating the battery current, and controls the current for charging / discharging the battery with the remaining capacity. If the current cannot be accurately detected due to noise, the state of the battery cannot be accurately determined, and the battery cannot be controlled in a normal state. In order to avoid this adverse effect, it is important for the control circuit to accurately detect the battery current. If the state of the battery cannot be accurately detected due to noise, the battery cannot be charged / discharged in an ideal state and the life is shortened. Furthermore, since the battery cannot be charged / discharged within a predetermined remaining capacity, the substantial capacity for charging / discharging the battery is reduced.

  Furthermore, since the wire harness is connected to the power board or the control board via the connector, contact failure of the connector or change in contact resistance causes detection accuracy to be lowered. In particular, signals that are signaled from the current sensor to the control circuit via the wire harness are susceptible to this effect. This is because the signal level is low, the S / N ratio is small, and the power level is low, so that a sufficient current cannot flow through the contacts of the connector.

  Further, the structure in which the power board and the control board are separately arranged and connected by the wire harness is calibrated by connecting the power board and the control board by the wire harness. This is to improve the measurement accuracy of the current sensor. Since calibration is performed in a state where a specific power board and a control board are connected by a wire harness, if the power board to be combined is different from the control board, the measurement accuracy is lowered. For this reason, when the power board and control board which are connected with a wire harness are changed, there also exists a fault to which a measurement precision falls.

  The present invention has been developed for the purpose of solving the above disadvantages of the conventional power supply apparatus. An important object of the present invention is to accurately transmit a current sensor signal from a power board to a control board while arranging power parts and parts such as a control circuit in an ideal state, and in a calibrated state. An object of the present invention is to provide a power supply device for a vehicle that can always detect current with high accuracy.

The power supply device for a vehicle according to claim 1 of the present invention includes a battery 1 for supplying electric power to a motor 23 for running the vehicle, a power component 4 connected to the battery 1 and a battery current sensor 5. A power board 2, a control board 3 on which a control circuit formed by connecting a current sensor 5 of the power board 2 is mounted , and a connecting rod 18 that connects the power board 2 and the control board 3 . The current sensor 5 of the power board 2 is connected to the control circuit via a hard wire 14 made of a metal rod. In this power supply device, the control board 3 and the power board 2 are connected in an integrated structure via the hard wire 14 and the connecting rod 18 .

  The power supply device for a vehicle according to claim 2 of the present invention connects the control board 3 in parallel with the power board 2 via the hard wire 14.

The power supply device for a vehicle according to claim 3 of the present invention includes a plurality of connecting rods 18 that connect the power board 2 and the control board 3 .

The power supply device for a vehicle according to claim 4 of the present invention connects the four corners of the control board 3 to the power board 2 via the connecting rod 18 .

  The power supply device of the present invention is characterized in that the signal of the current sensor can be accurately transmitted from the power board to the control board while arranging power parts and parts such as the control circuit in an ideal state. That is, the power supply device of the present invention mounts the power component connected to the battery and the current sensor of the battery on the power board, and the control circuit connecting the current sensor of the power board is mounted on the control board, This is because the control board is electrically connected to the power board directly through the hard wire or without the hard wire, and is physically connected to connect the power board and the control board into an integrated structure. .

  A hard wire made of a metal rod can reduce a noise level as compared with a wire harness and transmit a signal of a current sensor to a control circuit. In particular, the power supply device according to the first aspect of the present invention connects the power board to the control board via the hard wire, so that the power board and the control board can be arranged at optimum positions by using the hard wire as a short metal rod. In the conventional structure in which the power board and the control board are placed at predetermined positions and the wire harness is connected to these boards via the connector, the connector is detached and the force applied to the wire harness by the signal to be connected It is necessary to lengthen the wire harness so as not to act. In contrast, a power supply device that physically connects a power board and a control board via a hard wire made of a metal rod and physically connects the current sensor and the control circuit with a hard wire at the shortest distance. By connecting, the influence of inductive noise can be reduced. In addition, since the hard wire can be directly connected to the power board and the control board without going through the connector, there is no contact failure or contact resistance change due to the connector, and the battery state can be accurately detected over a long period of time. There is.

  In particular, the power supply device according to the third aspect of the present invention in which the control board is directly connected to the power board connects the control board directly to the power board without using a wire harness. There is a feature that the influence of inductive noise can be further reduced by connecting the circuit to the shortest distance.

  In the power supply device of the present invention, the power board and the control board are integrated with each other through a hard wire, or the control board is directly connected to the power board to form an integrated structure. Since the sensor can be calibrated, the power board and the control board are not exchanged in the calibrated state, and the power board and the control board can be used as a set of assemblies to always detect the current with high accuracy. Features are also realized.

  Embodiments of the present invention will be described below with reference to the drawings. However, the following embodiment exemplifies a power supply device for a vehicle for embodying the technical idea of the present invention, and the present invention does not specify the power supply device as follows.

  Further, in this specification, in order to facilitate understanding of the scope of claims, numbers corresponding to the members shown in the examples are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

  The power supply device for a vehicle shown in the exploded perspective views of FIGS. 1 and 3 includes a battery 1 that supplies electric power to a motor 23 that drives the vehicle, a power component 4 that is connected to the battery 1, and a current sensor 5 of the battery. Power boards 2 and 32, and control boards 3 and 33 on which a control circuit formed by connecting the current sensors 5 of the power boards 2 and 32 is mounted.

  The power boards 2 and 32 have the power component 4 fixed to the insulating plate 10. The insulating plate 10 fixes a conductive plate 11 obtained by cutting a metal plate having a thickness of 1 to 4 mm to a predetermined width on the surface of an insulating plate 12 made of an insulative heat conductive resin. A base plate 13 made of a metal plate is laminated. The insulating plate 10 has a feature that can efficiently dissipate heat generated by the power component 4. This is because the heat of the power component 4 is efficiently conducted to the base plate 13 on the back surface through the heat conductive resin and radiated from the base plate 13. In addition, the insulating plate 10 has a feature that the mechanical strength can be improved by reinforcing the back surface with the base plate 13. The conductive plate 11 is inserted and fixed to the surface in the step of forming the insulating plate 12, and is embedded in the insulating plate 12 while being insulated from the base plate 13.

  The power component 4 is fixed on the upper surface of the insulating plate 10. The power component 4 detects a current flowing through the battery 1 and a precharge relay 7 and a precharge resistor 8 that realize a precharge circuit that charges a pair of contactors 6 and a capacitor 21 connected in parallel to the load 20. The current detection resistor 9 is the current sensor 5. These power components 4 are fixed to the conductive plate 12 by spot welding.

  The contactor 6 is connected to the positive and negative output terminals of the battery 1. The contactor 6 is switched to an on state in a state where the ignition switch of the vehicle is turned on, and connects the battery 1 to the load 20. When the ignition switch is turned off, the contactor 6 is also turned off, so that the battery 1 is not connected to the load 20. The contactor 6 is turned on and off by controlling energization of the exciting coil. Therefore, the exciting coil of the contactor 6 fixed to the power board 2 shown in FIG. 1 is connected to the control circuit of the control board 3 via the hard wire 14. The control circuit controls the energization of the exciting coil via the hard wire 14 to turn the contactor 6 on and off.

  The vehicle power supply device is connected to the motor 23 and the generator 24 via the inverter 22. The inverter 22 has a large capacity capacitor 21 connected in parallel to the battery 1 side. The large-capacitance capacitor 21 causes a large current to flow when the contactor 6 is switched on, and causes the contact of the contactor 6 to be welded. In order to prevent this problem, a precharge circuit is provided. The precharge circuit includes a series circuit of a precharge resistor 6 and a precharge relay 7 and is mounted on the power boards 2 and 32.

  The current sensor 5 includes a current detection resistor 9 connected in series with the battery 1 and an amplifier 19 that amplifies the voltage across the current detection resistor 9. The current detection resistor 9 generates a voltage proportional to the current flowing through the battery 1. The current detection resistor 9 is a resistor having an electric resistance as low as possible. This is because power consumption increases in proportion to electrical resistance. This is because the power consumption of the current detection resistor 9 generates heat and makes it impossible to efficiently supply the power of the battery 1 to the load 20. In the current detection resistor 9, a voltage proportional to the current is generated at both ends. That is, the voltage across the current detection resistor 9 is proportional to the electrical resistance and the current. The voltage at both ends of the low-resistance current detection resistor 9 is low. Since the current cannot be detected with high accuracy at a low voltage, the voltage across the current detection resistor 9 is amplified by the amplifier 19. The amplified both-end voltage is converted into a digital signal by an A / D converter. The control circuit calculates the current signal converted into the digital signal and calculates the remaining capacity of the battery 1.

  Since the voltage across the current detection resistor 9 is a weak voltage, it is easily affected by inductive noise. Further, the output of the amplifier 19 is also easily affected by inductive noise. This is because the power consumption of the amplifier 19 is limited, so that the output impedance cannot be lowered sufficiently. For this reason, it is important for the current sensor 5 to reduce the influence of inductive noise and input a current signal to the control circuit.

  In the power supply device, a current detection resistor 9 that is a part of the current sensor 5 is mounted on the power boards 2 and 32, and an amplifier 19 is mounted on the control boards 3 and 33. However, both the current detection resistor and the amplifier can be mounted on the power board. A power supply device in which the current detection resistor 9, which is a part of the current sensor 5, is mounted on the power boards 2 and 32 and the amplifier 19 is mounted on the control boards 3 and 33, detects the current of the power board 2 via the hard wire 14. The resistor 9 is connected to the amplifier 19 of the control board 3, or the control board 33 is directly connected to the power board 32, and the current detection resistor 9 is connected to the amplifier 19. In this power supply apparatus, the amplifier 19 is separated from the power component 4 that is a heat generating component and mounted on the control boards 3 and 33. Therefore, the current caused by the heat of the amplifier 19, for example, the influence of temperature drift can be reduced and the current can be detected stably. . The power supply device can mount both the current detection resistor and the amplifier on the power board, but this device connects the output of the amplifier to the control board via hard wires, or directly connects the control board to the power board. Connect the amplifier output to the control board. Since this power supply device outputs the signal amplified by the amplifier to the control board, the influence of inductive noise can be further reduced.

  The control boards 3 and 33 are printed boards, and are mounted with a microcomputer 15 that realizes a control circuit. Furthermore, the control circuit of the figure fixes the connector 16 which connects the wire harness for connecting with the control circuit of the vehicle side on the upper surface. The microcomputer 15 calculates the current signal input from the current sensor 5 and calculates the remaining capacity of the battery 1. The remaining capacity is calculated by adding the integrated value of charging current and subtracting the integrated value of discharging current. Further, the control circuit controls the current of the battery 1 based on the calculated remaining capacity. For example, the control circuit limits or stops the charging current when the remaining capacity of the battery 1 reaches the maximum value, and conversely stops or stops the discharging current when the remaining capacity reaches the minimum value, thereby determining the predetermined remaining capacity of the battery 1. The battery is charged and discharged while being kept in the range of

  The power boards 2 and 32 and the control boards 3 and 33 are electrically connected via signal lines. The signal line connects the current sensors 5 of the power boards 2 and 32 to the control circuit. The signal line connects the control circuit to the contactor 6 and the precharge relay 7 to switch the contactor 6 and the precharge relay 7 on and off. Further, the signal line is connected to a circuit that transmits an electrical signal transmitted between the power boards 2 and 32 and the control boards 3 and 33.

  1 and 2 uses a hard wire 14 for connecting the power board 2 and the control board 3 together as a signal line. In other words, the signal line is used in combination with the rod connecting the power board 2 and the control board 3. In this power supply device, the power board 2 and the control board 3 are connected by a plurality of hard wires 14 made of metal rods. The hard wire 14 has a lower end fixed to the insulating plate 10. The hard wire 14 of FIGS. 1 and 2 has a lower end fixed to the insulating plate 10 in a vertical posture. Since the hard wire 14 connects the power board 2 to the control board 3 and physically connects it, the lower end is electrically connected to the power component 4 and is fixed to the insulating plate 10. The hard wire 14 is connected to the power component 4 via the conductive plate 11 provided on the surface of the insulating plate 10. A pair of hard wires 14 that connect the current sensor 5 to the control circuit have lower ends connected to the current sensor 5.

  The hard wire 14 is fixed to the power substrate 2 with its lower end embedded in the insulating plate 10, or fixed to the conductive plate 11 fixed to the insulating plate 10 by soldering or welding. Further, the upper end of the hard wire 14 is inserted into a through hole 17 provided in the control board 3 and fixed to the control board 3, and soldered to a conductive portion of the control board 3 to be electrically connected. In the power supply device of FIG. 1, a plurality of hard wires 14 are arranged on the same surface in parallel postures at predetermined intervals, and are connected to the power board 2 and the control board 3. The power supply device of FIG. 1 connects the power board 2 and the control board 3 via a plurality of hard wires 14, and further connects the power board 2 and the control board 3 via a connecting rod 18. In the illustrated power supply device, the four corners of the control board 3 are connected to the power board 2 via a connecting rod 18. In this power supply device, the control board 3 can be firmly and firmly connected to the power board 2 by both the hard wire 14 and the connecting rod 18.

  In the power supply apparatus of FIGS. 3 and 4, the control board 33 is directly connected to the power board 32. This power supply device includes a contactor 6, a precharge resistor 8, a precharge relay 7, and a current detection resistor 9 that is a current sensor 5 mounted on a power board 32, and an amplifier 19 that amplifies the voltage of the current detection resistor 9. A control circuit is mounted on the control board 33. However, both the current detection resistor and the amplifier can be mounted on the power board.

  In the illustrated power board 32, a connector 34 for connecting the control board 33 is fixed to the upper surface. The control board 33 is inserted into the connector 34, and the control board 33 is connected to the power board 32. The control board 33 is provided with a connection terminal 35 at an insertion portion to be inserted into the connector 34. The connector 34 has a holding recess 34A into which the insertion portion 33A of the control board 33 is inserted. The holding recess 34A elastically sandwiches the insertion portion 33A of the control board 33 inserted therein from both sides, and holds the control board 33 in a predetermined posture, and in a posture perpendicular to the power board 32 in FIG. To do. Furthermore, the holding recess 34 </ b> A of the connector 34 is provided with a contact 36 at a position where it contacts the connection terminal 35 of the insertion portion 33 </ b> A inserted here.

  This power supply device inserts the insertion portion 33 </ b> A of the control board 33 into the holding recess 34 </ b> A of the connector 34 and electrically connects the connection terminal 35 to the contact 36. Further, the insertion portion 33 </ b> A of the control board 33 is inserted into the holding recess 34 </ b> A of the connector 34 and connected in a posture perpendicular to the power board 32. In the illustrated power supply apparatus, a connector 34 is fixed to a power board 32, and an insertion portion 33 </ b> A of a control board 33 is inserted into the connector 34 and connected thereto. The power supply device having this structure can be connected to the power board 32 so that the control board 33 can be easily attached and detached. However, the power supply device of the present invention can connect the control board to the power board via a connector without using a connector, and can electrically connect the power board and the control board with a lead wire or a lead board.

It is a disassembled perspective view of the power supply device for vehicles concerning one example of the present invention. FIG. 2 is a vertical sectional view of the vehicle power supply device shown in FIG. 1. It is a disassembled perspective view of the power supply device for vehicles concerning the other Example of this invention. FIG. 4 is a vertical sectional view of the vehicle power supply device shown in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery 2 ... Power board 3 ... Control board 4 ... Power component 5 ... Current sensor 6 ... Contactor 7 ... Precharge relay 8 ... Precharge resistor 9 ... Current detection resistor 10 ... Insulating plate 11 ... Conductive plate 12 ... Insulating plate 13 ... Base plate 14 ... Hard wire 15 ... Microcomputer 16 ... Connector 17 ... Through hole 18 ... Connecting rod 19 ... Amplifier 20 ... Load 21 ... Condenser 22 ... Inverter 23 ... Motor 24 ... Generator 32 ... Power board 33 ... Control board 33A ... Insert Portion 34 ... Connector 34A ... Holding recess 35 ... Connection terminal 36 ... Contact

Claims (8)

A battery (1) for supplying power to a motor (23) for running the vehicle, a power component (4) connected to the battery (1), and a power board (5) mounted with a battery current sensor (5) 2) and a control board (3) for mounting a control circuit formed by connecting the current sensor (5) of the power board (2), and a power supply device for a vehicle,
A connecting rod (18) for connecting the power board (2) and the control board (3);
The current sensor (5) of the power board (2) is connected to the control circuit via a hard wire (14) made of a metal rod, and via the hard wire (14) and the connecting rod (18). A power supply device for a vehicle in which a control board (3) and a power board (2) are connected in an integrated structure.   The vehicle power supply device according to claim 1, wherein the control board (3) is connected in parallel to the power board (2) via a hard wire (14). The vehicle power supply device according to claim 1 or 2, wherein a plurality of the connecting rods (18) are provided. The power supply device for a vehicle according to claim 3, wherein the connecting rod (18) is provided at four corners of the control board (3).   The current sensor (5) includes a current detection resistor (9) connected in series with the battery (1), and an amplifier (19) that amplifies the voltage across the current detection resistor (9). The vehicle power supply device according to claim 1, wherein 9) is mounted on the power boards (2) and (32), and the amplifier (19) is mounted on the control boards (3) and (33).   The current detection resistor includes a current detection resistor connected in series with the battery and an amplifier that amplifies the voltage across the current detection resistor, and the current detection resistor and the amplifier are mounted on a power board. A power supply device for a vehicle.   The power supply device for a vehicle according to claim 1, wherein the power boards (2), (32) are formed by fixing a conductive plate (11) to an insulating heat conductive resin.   The power supply device for a vehicle according to claim 7, wherein the power boards (2), (32) have a base plate (13) made of a metal plate laminated on a back surface of a heat conductive resin.

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