JP4466327B2 - Vehicle power supply - Google Patents

Description

  The present invention relates to a vehicle power supply device, and more particularly to a vehicle power supply device for a vehicle that uses both a high-voltage power supply and a low-voltage power supply.

  Japanese Patent Laid-Open No. 11-185536 (Patent Document 1) discloses a shield material that is grounded to a power supply line in a remote control cable composed of a power supply line and a signal line for remotely operating a self-propelled aerial work platform. Techniques for coating are disclosed.

According to this technique, even if the cable is damaged due to changes over time or being crushed, the power supply line comes into contact with the shield covered by the power supply line, and the power supply current flows into the ground. When a current exceeding a specified value flows due to a short circuit, the current is interrupted by the blow of the fuse, so that a current does not accidentally flow from the power line to the signal line, and an ON signal does not flow.
JP-A-11-185536 JP-A-10-94101

  In recent years, electric vehicles equipped with a large-capacity battery having a power supply voltage of about several hundred volts and using a power stored in the battery to drive a driving motor and hybrid vehicles using a gasoline engine in combination with this have been put into practical use. .

  FIG. 6 is a circuit diagram showing a configuration of a vehicle power supply device 100 used in a conventional hybrid vehicle.

  Referring to FIG. 6, a vehicle power supply device 100 includes a high voltage battery 22 that outputs a high voltage, a vehicle load 12 that is driven by the high voltage battery 22, and a high voltage battery 22 and a vehicle load 12. System main relays 18 and 20 for connecting and disconnecting current supply paths.

  The vehicle load 12 is, for example, a drive system that drives wheels, and the drive system includes a motor and an inverter that drives the motor.

  Vehicle power supply device 100 further includes an ECU 116 that controls connection and disconnection of system main relays 18 and 20, wirings 134 and 138 that transmit control signals from ECU 116 to system main relays 18 and 20, and ECU 116. Wiring 32 for supplying battery potential + B.

  The high voltage battery 22 and the system main relays 18 and 20 are arranged in a trunk room 104 which is a rear region of the passenger seat in the vehicle. Further, the vehicle load 12 and the ECU 116 are arranged in the engine room 102 which is a front region of the passenger seat in the vehicle. In the case of a hybrid vehicle, the engine room 102 further stores an engine and a generator.

  The wires 134 and 138 and the wire 32 run in parallel between the engine room 102 and the trunk room 104.

  The vehicle power supply device 100 further includes a collision sensor 14 that detects a collision. ECU 116 includes a drive circuit 117 that drives the system main relay.

  The drive circuit 117 sets the levels of the wirings 134 and 138 to + B of the activation potential according to the state of a power switch (not shown) operated by the driver, and makes the system main relays 18 and 20 conductive. Further, the ECU sets the levels of the wirings 134 and 138 to the ground potential that is the inactivation potential in response to the collision sensor 14 detecting a collision, and interrupts the current supply path to the system main relays 18 and 20. Make it.

  Vehicle power supply device 100 further includes an auxiliary battery 24 that is arranged in trunk room 104 and supplies ECU 116 with power supply potential + B corresponding to the activation potential of the control signal. Wiring 32 connects auxiliary battery 24 and ECU 116 to provide power supply potential + B to ECU 116.

  As shown in FIG. 6, a relay called a system main relay is disposed between the large-capacity battery and a load circuit such as a motor. In the event of a vehicle collision, it is necessary to immediately open the system main relay and shut off the high voltage power supply to the power line.

Therefore, when the ECU 116 detects a collision, the ECU sets a control signal for controlling the system main relay to the inactive ground potential by using the drive circuit 117 to cut off the power supply.

  On the other hand, in the case of such a vehicle, in addition to the high voltage battery 22, a 12V auxiliary battery 24 for driving the ECU is often mounted.

  In the hybrid vehicle, since an inverter that generates an alternating current for driving the motor from a direct current from the high voltage battery 22 is mounted, it is difficult to secure a space in the engine room 2 in front of the passenger seat.

  For this reason, the high voltage battery 22 and the auxiliary battery 24 are installed in the trunk room 4 behind the passenger seat. Instead, control signal lines and power supply lines must be complicatedly arranged between the engine room and the trunk room.

  On the other hand, when a vehicle collides, the vehicle body often deforms and is damaged. In such a case, there is a possibility that the conductive member bites into the control signal line or the power supply line and short-circuits. If the member is electrically connected to the grounded vehicle body, the control signal line is fixed to the ground potential even if the member is engaged with the control signal line, so that the system main relay does not become conductive.

  However, for example, a conductive member that is electrically separated from the grounded vehicle body such as a bracket may damage the signal line that controls the system main relay and the power supply line from the auxiliary battery due to deformation of the vehicle body at the time of a collision. The case of giving is also considered. As a result of the short circuit, the control signal line for controlling the system main relay may become the power supply potential. In such a case, there is a possibility that the system main relay once opened by the control of the ECU becomes conductive again.

  An object of the present invention is to provide a vehicle power supply device capable of reliably cutting off a power supply current.

  In summary, the present invention provides a power supply device for a vehicle, which connects and disconnects first and second power supplies, a load driven by the first power supply, and a current supply path between the first power supply and the load. An operating power supply potential supplied from a second power source, a control unit that outputs an activation potential different from the operating power supply potential, and outputs a control signal for controlling connection and disconnection of the connecting unit; A signal line for transmitting the control signal to the connection means, and a drive means for conducting the connection means when the control signal transmitted by the signal line becomes an activation potential.

  According to another aspect of the invention, there is provided a power supply device for a vehicle, the first and second power supplies, a load driven by the first power supply, and a connection of a current supply path between the first power supply and the load. And a connection means for cutting off, and a control unit that is supplied with an operating power supply potential from a second power supply and that has an activation potential and an inactivation potential and outputs a control signal for controlling connection and cutoff of the connection means; A signal line for transmitting a control signal from the control unit toward the connection means, and a predetermined signal including a pulse in which the control signal transmitted by the signal line is changed from an inactivation potential to an activation potential and further to an inactivation potential. Drive means for conducting the connection means at a certain time.

  Preferably, the first and second power sources, the driving means, and the connecting means are arranged in a rear region of the passenger seat in the vehicle, the load and the control unit are arranged in a front region of the passenger seat in the vehicle, and the signal line is , Disposed from the front region to the rear region.

  More preferably, a power supply wiring is further provided that extends from the front region to the rear region and supplies the operation power supply potential from the second power supply to the control unit.

  More preferably, the rear region is a trunk room and the front region is an engine room.

  Preferably, the apparatus further includes detection means for detecting a collision, and the control unit causes the drive means and the connection means to interrupt the current supply path using a control signal in response to the detection means detecting the collision.

  According to the present invention, since the system main relay is not turned on even if the signal line for controlling the system main relay is coupled to a fixed potential in the event of a collision, the power supply current can be cut off more reliably.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  FIG. 1 is a circuit diagram showing a configuration of a vehicle power supply device of the present invention.

  Referring to FIG. 1, a vehicle power supply device 1 includes a high voltage battery 22 that outputs a high voltage + HV, a vehicle load 12 that is driven by the high voltage battery 22, a high voltage battery 22, and a vehicle load 12. System main relays 18 and 20 for connecting and disconnecting current supply paths. The vehicle power supply device 1 can be applied to a hybrid vehicle, an electric vehicle, and the like.

  The high voltage battery 22 has a plurality of battery modules connected in series and outputs a high voltage + HV. For example, when 28 battery modules of 7.2V are connected in series, the high voltage + HV is 201.6V.

  The vehicle load 12 is, for example, a drive system that drives wheels, and the drive system includes a motor and an inverter that drives the motor.

  The vehicle power supply device 1 further includes an ECU 16 that controls connection and disconnection of the system main relays 18 and 20, a drive circuit 17 that performs relay driving for the system main relays 18 and 20, and a drive circuit 17 from the ECU 16 to the drive circuit 17. On the other hand, wirings 34 and 38 for transmitting a control signal and wiring 32 coupled to power supply potential + B running in parallel with wirings 34 and 38 are included.

  Unlike the conventional configuration shown in FIG. 6, the current flowing through the coil of the system main relay is supplied from the drive circuit 17. Since the wirings 34 and 38 may be signals for giving instructions to the drive circuit 17, the wirings can be made thinner than before. For example, in the past, it was necessary to pass a current of 0.4 A, but with the configuration shown in FIG. 1, the wires 34 and 38 may be thick enough to pass a current of 0.01 A.

  The high voltage battery 22, the system main relays 18 and 20, and the drive circuit 17 are disposed in the trunk room 4 that is a rear region of the passenger seat in the vehicle. Further, the vehicle load 12 and the ECU 16 are disposed in the engine room 2 which is a front region of the passenger seat in the vehicle. When the vehicle is a hybrid vehicle, the engine room 2 further stores an engine and a generator.

  The wires 34 and 38 and the wire 32 run in parallel between the engine room 2 and the trunk room 4.

  The vehicle power supply device 1 further includes a collision sensor 14 that detects a collision. The ECU 16 sets the levels of the wirings 34 and 38 to the activation potential according to the state of a power switch (not shown) operated by the driver, and causes the drive circuit 17 to conduct the system main relays 18 and 20. This activation potential is set to an intermediate potential lower than the power supply potential + B as will be described later with reference to FIG.

  Further, the ECU sets the levels of the wirings 34 and 38 to the ground potential that is the inactivation potential in response to the collision sensor 14 detecting a collision, and interrupts the current supply path to the system main relays 18 and 20. Make it.

  The collision sensor 14 may be a contact type collision sensor that is mechanically turned on / off or a semiconductor type collision sensor that has no contact point. Note that the output of the ECU that controls the airbag ignition may be used in addition to the collision sensor output, or may be used instead of the collision sensor output.

  The vehicular power supply device 1 is further connected to the auxiliary battery 24 that is arranged in the trunk room 4 and supplies the power supply potential + B corresponding to the activation potential of the control signal to the ECU 16, and the auxiliary battery 24 and the ECU 16 are connected to each other. And a wiring 32 for supplying a potential + B to the ECU 16. The power supply voltage + B is typically 12V, for example.

  Since an inverter is mounted in the engine room 2 in front of the passenger seat, it is difficult to secure a space. Therefore, the high voltage battery 22 and the auxiliary battery 24 are installed in the trunk room 4 behind the passenger seat.

  With this arrangement, the wires 34 and 38 and the wire 32 run in parallel between the engine room 2 and the trunk room 4.

  Here, the drive circuit 17 is disposed near the system main relays 18 and 20. The drive circuit 17 has a circuit configuration in which the system main relays 18 and 20 are turned on only when the potentials of the wirings 34 and 38 become an activation potential intermediate between the battery voltage + B and the ground potential.

  Then, a part of the vehicle body is deformed by the collision of the vehicle, and the conductive member electrically separated from the grounded vehicle body damages the wirings 32 to 38, and the wirings 34 and 38 are connected to the wiring 32. Even if the short circuit is caused and the levels of the wirings 34 and 38 become the power supply potential + B, the drive circuit 17 is not turned on, so that the system main relay does not become conductive again.

  Therefore, it is possible to reduce the probability that the system main relays 18 and 20 that are once controlled to be in an open state at the time of a collision will become conductive again after the collision.

  FIG. 2 is a circuit diagram showing a configuration of a drive circuit 17A which is an example of the drive circuit 17 in FIG.

  Referring to FIG. 2, drive circuit 17A receives a signal OUT1 output from ECU 16 in FIG. 1 at a negative input node and a comparison circuit 42 having a positive input node coupled to 5V and a signal OUT1 at a positive input node. Comparison circuit 44 having a negative input node coupled to 3V, AND circuit 46 that receives the outputs of comparison circuits 42 and 44 and outputs signal RON1, and receives the signal RON1 at the base and the collector is coupled to power supply potential + B and the emitter is the system And an NPN transistor 48 connected to the coil of the main relay SMR.

  Signal OUT1 corresponds to a signal transmitted through wirings 34 and 38 in FIG. 1, and system main relay SMR in FIG. 2 corresponds to system main relays 18 and 20 in FIG. The drive circuit 17 is provided with one system corresponding to each system main relay in the configuration shown in FIG.

  FIG. 3 is a diagram for explaining the operation of the drive circuit 17A.

  2 and 3, signal OUT1 sent from the ECU rises from 0V to the activation potential at time t1. This activation potential is an intermediate potential lower than the battery voltage + B and higher than the ground potential. For example, the activation potential is 4V. Then, the comparison circuit 42 outputs a high level (logic value “1”) because OUT1 is lower than 5V, and the comparison circuit 44 outputs a high level (logic value “1”) because OUT1 is higher than 3V. To do.

  The AND circuit 46 outputs a high level as the signal RON1 because the two inputs are both at a high level (logic value “1”). Then, the transistor 48 is turned on, a current flows through the coil of the system main relay SMR, and the system main relay SMR is turned on.

  Subsequently, at time t2, it is assumed that the vehicle collides with something due to an accident or the like. Then, the collision sensor 14 in FIG. 1 detects the collision, and in response to this, the ECU 16 once deactivates the signal OUT1 to 0V. In the drive circuit 17A, the comparison circuit 42 outputs a high level (logic value “1”) because OUT1 is lower than 5V, but the comparison circuit 44 has a low level (logic value “0”) because OUT1 is lower than 3V. Is output.

  The AND circuit 46 outputs a low level as the signal RON1 because one of the inputs becomes a low level (logical value “0”). Then, system main relay SMR is turned off.

  Further, at time t3, it is assumed that the vehicle body is damaged due to the impact of the collision, and as a result, the wiring 34 or 38 in FIG. The signal OUT1 applied to the drive circuit 17A is pulled up to the power supply potential + B, for example, 12V.

  However, in the drive circuit 17A, since the comparison circuit 44 outputs a high level (logic value “1”) because OUT1 is higher than 3V, the comparison circuit 42 outputs a low level (logic value “0” because OUT1 is higher than 5V). ”) Is output.

  Also at this time, the AND circuit 46 outputs a low level as the signal RON1 because one of the inputs becomes a low level (logical value “0”). Then, system main relay SMR remains off.

  Note that although the intermediate activation potential is determined using two comparison circuits in FIG. 2, it may be determined whether the digital value captured by the A / D converter is within a predetermined range, for example. .

  As described above, since the activation level of the input of the drive circuit 17A is set to an intermediate potential between the power supply potential and the ground potential as shown in FIG. 2, the signal line for controlling the power supply wiring relay is short-circuited in the event of a collision. However, it is possible to avoid the system main relay that has been shut off once being turned on again.

[Modification]
FIG. 4 is a circuit diagram showing a modification of the drive circuit 17 of FIG.

  Referring to FIG. 4, drive circuit 17B includes a delay circuit 52 that receives signal OUT2 output from ECU 16 in FIG. 1, and an exclusive OR circuit that receives signal OUT2 and the output of delay circuit 52 and outputs signal RON2. 54, and an NPN transistor 56 having a base receiving signal RON2 and a collector coupled to power supply potential + B and an emitter connected to a coil of system main relay SMR.

  Signal OUT2 corresponds to a signal transmitted through wirings 34 and 38 in FIG. 1, and system main relay SMR in FIG. 4 corresponds to system main relays 18 and 20 in FIG. The drive circuit 17 is provided with one system corresponding to each system main relay in the configuration shown in FIG.

  FIG. 5 is a diagram for explaining the operation of the drive circuit 17B.

  4 and 5, the ECU receives the start command and vibrates the signal OUT2 so as to repeat the high level and the low level for each period T. This period T is a delay time of the delay circuit 52.

  Then, if one of the two inputs of the exclusive OR circuit 54 is at a high level, the other is at a low level. Therefore, the signal RON2 output from the exclusive OR circuit 54 is at a high level. As a result, the transistor 56 is turned on, a current flows through the coil of the system main relay SMR, and the system main relay SMR is turned on. In this example, the ECU vibrates the signal OUT2 while maintaining the system main relay SMR in the conductive state.

  Subsequently, at time t2, it is assumed that the vehicle collides with something due to an accident or the like. Then, the collision sensor 14 in FIG. 1 detects the collision, and in response to this, the signal OUT2 that has been vibrated by the ECU 16 is temporarily fixed to 0 V and deactivated. The two inputs of the exclusive OR circuit 54 both become low level, the signal RON2 is also deactivated to low level, and the system main relay SMR is turned off.

  Further, at time t3, it is assumed that the vehicle body is damaged due to the impact of the collision, and as a result, the wiring 34 or 38 in FIG. Signal OUT2 applied to drive circuit 17B is pulled up to the power supply potential + B, for example, 12V.

  As a result, the signal RON2 once becomes high level from time t3 to t4, but again becomes low level after time t4, so that the system main relay is not left in the conductive state after the collision.

  As another modification, a relay is turned on / off with a one-shot pulse from the ECU, and a latch circuit is provided in the drive circuit 17 to retain this information and turn on / off the relay drive current for each pulse input. Switching is conceivable. As yet another modification, the relay is turned on / off by a command based on a combination of predetermined pulses from the ECU using serial communication, and a decoder is provided in the drive circuit 17 to switch the relay drive current on / off. It is also possible.

  In other words, an instruction to turn on the relay may be sent to the drive circuit 17 by a signal whose level changes at least once in the order of low level, high level, and low level. Even in such a case, a part of the vehicle body is deformed by the collision of the vehicle, and the conductive member electrically separated from the grounded vehicle body damages the wiring and transmits the instruction to the power supply level or the ground level. Even if it is fixed to the relay, the relay will not be accidentally turned on again.

  Therefore, it is possible to reduce the probability that the system main relays 18 and 20 that are once controlled to be in an open state at the time of a collision will become conductive again after the collision.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a circuit diagram which shows the structure of the power supply device for vehicles of this invention. FIG. 2 is a circuit diagram illustrating a configuration of a drive circuit 17A that is an example of the drive circuit 17 in FIG. 1. It is a diagram for explaining the operation of the drive circuit 17A. FIG. 6 is a circuit diagram illustrating a modification of the drive circuit 17 in FIG. 1. It is a figure for demonstrating operation | movement of the drive circuit 17B. It is a circuit diagram which shows the structure of the vehicle power supply device 100 used for the conventional hybrid vehicle.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Vehicle power supply device, 2 Engine room, 4 Trunk room, 12 Vehicle load, 14 Collision sensor, 17, 17A, 17B Drive circuit, 18, 20, SMR System main relay, 22 High voltage battery, 24 Auxiliary battery, 32 ~ 38 wiring, 42, 44 comparison circuit, 46 AND circuit, 48, 56 transistor, 52 delay circuit, 54 exclusive OR circuit.

Claims (6)

First and second power sources;
And connecting means for connection and disconnection of the previous SL current supply path from the first power source to the load,
Operating power supply potential from the second power is supplied, and a control unit for outputting a control signal for controlling the connection and disconnection of the previous SL connecting means,
A signal line for transmitting the control signal from the control unit toward the connection means;
It said connecting means is conductive when the control signal transmitted by the signal line becomes the activity of potential, and driving means for Ru is blocking the connection means when said control signal becomes inactive potential Prepared ,
The activation potential is an intermediate potential between the operating power supply potential and the ground potential,
The deactivation potential is located on both the ground potential side of the activation potential and the operation power supply potential side of the activation potential,
The first power source, the driving means and the connecting means are arranged in a first region in the vehicle,
The load and the control unit are arranged in a second region separated from the first region in the vehicle,
The vehicle power supply device , wherein the signal line is disposed from the first region to the second region . First and second power sources;
And connecting means for connection and disconnection of the previous SL current supply path from the first power source to the load,
A control unit that is supplied with an operating power supply potential from the second power supply and that has an activation potential and a deactivation potential and outputs a control signal for controlling connection and disconnection of the connection means;
A signal line for transmitting the control signal from the control unit toward the connection means;
Said control signal transmitted by the signal line so that conduct the connecting means when the a signal that repeats a change between a non-activated potential and the activation potential, the control signal is the deactivation potential or when secured to the activation potential and drive means for Ru is blocking the connection means,
The first power source, the driving means and the connecting means are arranged in a first region in the vehicle,
The load and the control unit are arranged in a second region separated from the first region in the vehicle,
The vehicle power supply device , wherein the signal line is disposed from the first region to the second region . The first region is disposed in a rear region of a passenger seat in the vehicle;
The second region is disposed in a front region of the passenger seat in the vehicle,
The vehicle power supply device according to claim 1, wherein the signal line is disposed from the front region to the rear region. The second power source is disposed in the first region;
4. The vehicle power supply device according to claim 3, further comprising a power supply wiring disposed from the front region to the rear region and configured to supply the operation power supply potential from the second power supply to the control unit. The rear region is a trunk room;
The front area is, Ri Oh in the engine room,
The load includes a drive system for driving wheels,
The first power source is a main battery for driving the drive system;
The second power supply, the Ru lower auxiliary battery der in voltage than the main battery, the vehicle power supply device according to claim 3 or 4. It further comprises detection means for detecting a collision,
6. The control unit according to claim 1, wherein the control unit causes the drive unit and the connection unit to block the current supply path using the control signal in response to the detection unit detecting a collision. The vehicle power supply device according to Item.

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