JP4985189B2 - Electric vehicle collision safety device - Google Patents

Description

  The present invention relates to a collision safety device provided in an electric vehicle.

2. Description of the Related Art Conventionally, in an electric vehicle equipped with a high-voltage traveling battery, one that opens a relay by cutting off an excitation line of a high-voltage relay and cutting off a relay driving current at the time of a collision is known (for example, Patent Document) 1).
JP 2004-159439 A

  However, when the high voltage system can be restarted at the time of a light collision, there is a problem that the high voltage relay cannot be restarted easily because the excitation line of the high voltage relay is disconnected.

  According to the electric vehicle collision safety device according to the present invention, the first protection means for preventing inflow of short-circuit current from the power supply unit different from the power supply unit for high power to the control means, and the first protection means is connected to the bus, Second protection means for supplying power to a predetermined power supply harness, and in the event of a vehicle collision, the second protection means is operated by a short circuit of the power supply harness, and the power supplied to the control means from another power supply unit is lowered. It is characterized by that.

  According to the present invention, in the event of a vehicle collision, the voltage supplied from the power source to the control means drops to open the relay, so that the restartability after the collision can be improved.

  Hereinafter, a collision safety device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram when a collision safety device according to the present invention is applied to a system of an electric vehicle that runs on a battery. In FIG. 1, a thick solid line indicates a DC high voltage, a thick broken line indicates an AC high voltage, and a thin broken line indicates a control signal line.

  The system shown in FIG. 1 includes a power supply circuit 10, a motor 2, an ECU (electronic control unit) 101, an IGN (ignition) switch 110, a weak battery 120, a DC / DC converter 121, a fuse box 122, and a separate fuse box 123. Is provided. Inside the separate fuse box 123, the ECU fuse 124 and the actuator fuse 125 are commonly connected via a specific bus. The actuator 126 is connected to the actuator fuse 125 in the separate fuse box 123 by the actuator power supply harness 129.

  The power supply circuit 10 includes a high voltage battery 1, system main relays 102 to 104, a precharge resistor 105, a smoothing capacitor 106 that stabilizes the voltage between terminals of the battery 1, an inverter 107, and a system voltage monitor 108 that detects the voltage of the smoothing capacitor 106. And a battery voltage monitor 109 for detecting the voltage of the high-voltage battery 1.

  The DC voltage of the high voltage battery 1 is converted into an AC voltage by the inverter 107 and supplied to the motor 2. The motor 2 is a drive motor for generating a drive torque of the vehicle. The inverter 107 also functions to convert generated power (AC voltage) when the motor 2 is regeneratively braked into DC voltage.

  System main relays 102 to 104 are turned on and off based on a control signal from ECU 101. When the vehicle travels, relay switches 103 and 104 are controlled to be on. A precharge resistor 105 is connected in series to the system main relay 102, and they are connected in parallel to the system main relay 103. The system main relay 102 and the precharge resistor 105 may be connected in parallel to the system main relay 104. These system main relays 102 to 104 and the precharge resistor 105 function as a safety device that connects and disconnects between the high voltage battery 1 and the inverter 107.

  The ECU 101 turns on and off the system main relays 102 to 104 and controls the motor system. The ECU 101 receives an ST signal 111 that instructs to start and stop the system. When the driver turns on the IGN switch 110, the ST signal 111 is turned on. When the driver turns off the IGN switch 110, the ST signal 111 is turned off. Further, the ECU 101 performs precharge control for precharging the smoothing capacitor 106 via the precharge resistor 105 when the system is started, and performs discharge control for the smoothing capacitor 106 when the system is stopped.

  The ECU 101 performs smoothing using the precharge resistor 105 when the difference between the voltage value Vb detected by the battery voltage monitor 109 and the voltage value Vc detected by the system voltage monitor 108 exceeds a predetermined value during the precharge control. The capacitor 106 is charged. As a result, the system main relays 103 and 104 are prevented from welding due to inrush current.

  The weak battery 120 provided separately from the high voltage battery 1 supplies electric power to the ECU 101 via the fuse box 122 and the separate fuse box 123 which are circuit protection devices. A DC / DC converter 121 is connected to the fuse box 122.

  In the separate fuse box 123, as described above, the ECU fuse 124 and the actuator fuse 125 are connected to a common bus. The ECU fuse 124 is connected to the ECU 101 to prevent the short-circuit current from flowing from the weak battery 120 to the ECU 101. The actuator fuse 125 is connected to the actuator 126 by an actuator power supply harness 129. The actuator power harness 129 is a conductive cable whose conductor is covered with a sheath or the like.

  FIG. 2 is a plan view showing a system layout of the vehicle in the present embodiment. As shown in FIG. 2, the actuator power supply harness 129 connected to the separate fuse box 123 passes through the front of the vehicle from the left side of the vehicle and is connected to the actuator 126 provided on the right side of the vehicle. On the front surface of the vehicle, the actuator power harness 129 is wired so as to pass through a space provided between the radiator fan shroud 127 and the engine 128.

  When the traveling vehicle collides and the front portion of the vehicle is deformed, the radiator fan shroud 127 and the engine 128 are engaged with the actuator power harness 129. At this time, the covering of the actuator power supply harness 129 is peeled off, and the internal power supply portion and the radiator fan shroud 127 or the engine 128 come into contact with each other, whereby the actuator power supply harness 129 is short-circuited. As a result, when the short-circuit current exceeds the rated value, the actuator fuse 125 is melted.

  When the actuator fuse 125 is blown, a large current flows into the actuator fuse 125 and at the same time, the bus voltage drops. As a result, the current value flowing into the ECU fuse 124 connected to the common bus with the actuator fuse 125 decreases, and the control voltage of the ECU 101 decreases. When the control voltage of the ECU 101 decreases and falls below a predetermined voltage value, the ECU 101 turns off the system main relays 103 and 104 and disconnects the connection between the high voltage battery 1 and the inverter 107.

  Even after the vehicle has collided as described above, even if the driver turns on the IGN switch 110 and instructs the system to restart, the actuator fuse 125 is blown. Is supplied to the ECU 101. As a result, the system can be turned on even when restarting.

According to the embodiment described above, the following operational effects can be obtained.
(1) The ECU fuse 124 connected to the ECU 101 and the actuator fuse 125 connected to the actuator power supply harness 129 are commonly connected to the bus, and the actuator power supply harness 129 is short-circuited in the event of a vehicle collision. The control voltage was reduced. Therefore, when the control voltage falls below a predetermined voltage value, the ECU 101 turns off the system main relays 103 and 104 and disconnects the connection between the high voltage battery 1 and the inverter 107, so that the system cannot be started every time a collision occurs. This will improve the restartability.

  In a conventional electric vehicle, a collision ECU (for an airbag) detects a collision, notifies the ECU of collision information, and cuts off the high voltage. As shown in the timing chart of FIG. 3A, the collision determination (time t3) is made from the occurrence of the collision (time t1), and the high voltage is cut off at the time t4. In particular, when a high-voltage part is damaged, the high-voltage components included in the high-voltage part may be damaged. In contrast, since the present embodiment has the above-described configuration, as shown in the timing chart of FIG. 3B, the high voltage can be cut off at time t2 after the occurrence of the collision (time t1). . Therefore, the time from the collision to the high voltage cut-off is shortened, and it is possible to prevent the high voltage component from being damaged due to the time taken from the collision to the cut-off.

(2) The ECU fuse 124 and the actuator fuse 125 are stored in a separate fuse box 123, and the fuse box 122 is connected to the low-power battery 120 and the DC / DC converter 121. Therefore, since the separate fuse box 123 is not directly connected to the low-power battery 120 and the DC / DC converter 121, the voltage drop characteristic of the ECU 101 is improved in the event of a vehicle collision, that is, when the fuse 125 for the actuator is blown. Can prevent damage.

(3) The wiring path of the actuator power supply harness 129 is between the radiator fan shroud 127 and the engine 128. As a result, it is possible to secure a high possibility that the actuator power supply harness 129 is short-circuited in the event of a vehicle collision. Therefore, the connection between the high-voltage battery 1 and the inverter 107 at the time of the collision is reliably cut off, and the system can be restarted. Can be maintained.

The embodiment described above can be modified as follows.
The wiring path of the actuator power harness 129 is not limited between the radiator fan shroud 127 and the engine 128. For example, the actuator power harness 129 may be wired between the radiator fan shroud 127 and the transmission as long as it is possible to ensure a high possibility that the actuator power harness 129 is short-circuited in the event of a vehicle collision.

  Correspondence between the constituent elements of the claims and the constituent elements of the embodiment is as follows. That is, the ECU 101 is the control means, the ECU fuse 124 is the first protection means, the actuator fuse 125 is the second protection means, the separate fuse box 123 is the first protection means storage portion, and the fuse box 122 is the second protection means. Each of the protection means storage units is configured. In addition, the above description is an example to the last, and when interpreting invention, it is not limited to the correspondence of the component of said embodiment and this invention at all.

It is a figure explaining the structure of the system in embodiment of this invention. It is a figure explaining the layout of the system in embodiment of this invention. It is a time chart explaining from the time of a vehicle collision to a high voltage interruption | blocking, (a) shows the time chart in embodiment of this invention, (b) shows the time chart in the conventional vehicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... High voltage battery, 101 ... ECU, 120 ... Low electric battery,
122 ... fuse box, 123 ... separate fuse box,
124 ... Fuse for ECU, 125 ... Fuse for actuator,
129 ... Power supply harness for actuator

Claims (3)

Control means for controlling the driving of the relay provided in the power unit for high power, and turning off the relay when the control voltage falls below a predetermined voltage value ;
First protective means for preventing inflow of short-circuit current from another power supply section provided separately from the power supply section for high power to the control means;
A second protection means connected to the first protection means by a bus and supplying power to a predetermined power harness;
Due to a short circuit of the power harness at the time of a vehicle collision, a large current flows into the second protection means and the current of the first protection means decreases, so that the control voltage is greater than the predetermined voltage value. An electric vehicle collision safety device characterized by being lowered . The electric vehicle collision safety device according to claim 1,
A first protection means storage section and a second protection means storage section different from the first protection means storage section;
The electric vehicle collision safety apparatus according to claim 1, wherein the first protection means and the second protection means are stored in the first protection means storage section, and the second protection means storage section is connected to the separate power supply section. In the electric vehicle collision safety device according to claim 1 or 2,
The electric vehicle collision safety apparatus according to claim 1, wherein a wiring path of the power supply harness is either between a radiator shroud and an engine or between a radiator shroud and a transmission.

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