JP7675356B2 - Vehicle power cutoff system - Google Patents

Description

The present invention relates to a vehicle power cutoff system used in various battery-powered vehicles.

A conventional cutoff device will be described below. A conventional cutoff device is provided between the propulsion drive power storage device and the propulsion drive load. The power required for the cutoff device to operate is supplied from a storage battery. When the vehicle is damaged in a collision or the like, the cutoff device immediately cuts off the power supply from the propulsion drive power storage device to the propulsion drive load, preventing the vehicle and passengers from falling into a more dangerous situation due to a current leakage from the propulsion drive power storage device.

Note that, for example, Patent Document 1 is known as prior art literature related to the invention of this application.

JP 2011-25912 A

However, with conventional circuit breakers, there was a risk that the circuit breaker would not function properly if the power supply from the storage battery became unstable.

The present invention aims to improve the reliability of power cutoff operations.

To achieve this objective, the present disclosure is characterized by comprising a backup unit having a first power terminal and a second power terminal that receive an operating voltage from an auxiliary battery, a cutoff control unit connected to the first power terminal, and a pyrotechnic cutoff unit connected to the second power terminal and controlled by the cutoff control unit, the cutoff unit being capable of cutting off the power supply from the vehicle propulsion drive storage unit to the vehicle propulsion drive load, a storage unit, a first discharge circuit connected to the first power terminal and capable of outputting the power stored in the storage unit to the cutoff control unit at a first voltage, a second discharge circuit connected to the second power terminal and capable of outputting the power stored in the storage unit to the pyrotechnic cutoff unit at a second voltage higher than the first voltage when the first discharge circuit outputs the first voltage to the cutoff control unit, and a power supply control unit that controls the operation of the first discharge circuit and the second discharge circuit.

According to the present invention, the cutoff control unit and the pyrotechnic cutoff unit are capable of receiving power from both the auxiliary battery and the power storage unit. Therefore, even if the auxiliary battery voltage becomes temporarily unstable or the vehicle is involved in an accident causing a failure of the auxiliary battery, a stable power supply from the backup unit to the cutoff control unit required for cutting off power from the vehicle propulsion drive power storage unit to the vehicle propulsion drive load is possible. Furthermore, it becomes possible to supply a sufficiently high voltage from the backup unit to the pyrotechnic cutoff unit. This stabilizes the operation of the cutoff control unit and enables the pyrotechnic cutoff unit to operate at high speed, improving the reliability of the power cutoff operation by the cutoff control unit and the pyrotechnic cutoff unit.

FIG. 1 is a first circuit block diagram showing a configuration of a vehicle power cutoff system according to an embodiment of the present disclosure; FIG. 2 is a second circuit block diagram showing the configuration of a vehicle power cutoff system according to an embodiment of the present disclosure; FIG. 3 is a third circuit block diagram showing the configuration of a vehicle power cutoff system according to an embodiment of the present disclosure; A fourth circuit block diagram showing the configuration of a vehicle power cut-off system according to an embodiment of the present disclosure. A fifth circuit block diagram showing the configuration of a vehicle power cut-off system according to an embodiment of the present disclosure. FIG. 1 is a first schematic diagram of a pyrotechnic cutoff unit used in a vehicle power cutoff system according to an embodiment of the present disclosure; FIG. 2 is a second schematic diagram of a pyrotechnic cutoff unit used in a vehicle power cutoff system according to an embodiment of the present disclosure.

The following describes an embodiment of the present disclosure with reference to the drawings.

(Embodiment)
1 is a first circuit block diagram showing a configuration of a vehicle power cut-off system according to an embodiment of the present disclosure. The vehicle power cut-off system 1 includes a cut-off unit 2 and a backup unit 3.

The backup unit 3 includes a power supply control unit 4, a first discharge circuit 5, a second discharge circuit 6, and a power storage unit 7. The circuit breaker unit 2 includes a first power end 8, a circuit breaker control unit 9 connected to the first power end 8, a second power end 10, and a pyrotechnic circuit breaker unit 11 connected to the second power end 10. The circuit breaker control unit 9 controls the operation of the pyrotechnic circuit breaker unit 11.

The cutoff unit 2 is capable of supplying and cutting off power from the vehicle propulsion drive storage unit 12 to the vehicle propulsion drive load 13. The first power terminal 8 and the second power terminal 10 are supplied with operating power. The first power terminal 8 and the second power terminal 10 are connected to the auxiliary battery 14. The first discharge circuit 5 is connected to the first power terminal 8. The second discharge circuit 6 is connected to the second power terminal 10.

The power storage unit 7 supplies the stored power to the first discharge circuit 5 and the second discharge circuit 6. The first discharge circuit 5 can output a first voltage V1 to the cutoff control unit 9 through the first power terminal 8. Furthermore, when the first discharge circuit 5 outputs the first voltage V1 to the cutoff control unit 9, the second discharge circuit 6 can output a second voltage V2, which is higher than the first voltage V1, to the pyrotechnic cutoff unit 11 through the second power terminal 10.

The above configuration and operation allow the cutoff control unit 9 and the pyrotechnic cutoff unit 11 to be able to receive power from both the auxiliary battery 14 and the storage unit 7. Therefore, even if the vehicle 15 encounters an accident and the auxiliary battery 14 fails, or even if the voltage of the auxiliary battery 14 becomes unstable before the accident, the cutoff control unit 9, which executes control to cut off the power from the vehicle propulsion drive storage unit 12 to the vehicle propulsion drive load 13 by the pyrotechnic cutoff unit 11, can receive a stable power supply from the first discharge circuit 5. Furthermore, it is possible to supply a sufficiently high voltage to the pyrotechnic cutoff unit 11 from the second discharge circuit 6. As a result, the operation of the cutoff control unit 9 is stable, the pyrotechnic cutoff unit 11 is able to perform a high-speed cutoff operation, and the reliability of the power cutoff operation by the cutoff control unit 9 and the pyrotechnic cutoff unit 11 is improved.

The details of the configuration and operation of the vehicle power cutoff system 1 are described below using the second circuit block diagram of FIG. 2 showing the configuration of the vehicle power cutoff system in the embodiment of the present disclosure, the third circuit block diagram of FIG. 3 showing the configuration of the vehicle power cutoff system in the embodiment of the present disclosure, the fourth circuit block diagram of FIG. 4 showing the configuration of the vehicle power cutoff system in the embodiment of the present disclosure, and the fifth circuit block diagram of FIG. 5 showing the configuration of the vehicle power cutoff system in the embodiment of the present disclosure.

The vehicle power cutoff system 1 is mounted on the vehicle body 16 of the vehicle 15. The cutoff unit 2 of the vehicle power cutoff system 1 is disposed between the vehicle propulsion drive storage unit 12 and the vehicle propulsion drive load 13, and can connect or cut off the vehicle propulsion drive storage unit 12 and the vehicle propulsion drive load 13, and is in the connected state when the vehicle 15 and the vehicle body 16 are in a normal state.

In other words, the cutoff unit 2 is initially in a connected state, and goes into a cutoff state when an accident occurs with the vehicle 15 or the vehicle body 16, or when an overcurrent flows from the vehicle propulsion drive storage unit 12 to the vehicle propulsion drive load 13. The vehicle propulsion drive storage unit 12 is provided with a plurality of storage elements, with secondary batteries such as lithium batteries being used as storage elements to obtain a terminal voltage of, for example, about 500V. The vehicle propulsion drive load 13 is, for example, a motor for propelling the vehicle 15 and an inverter device for supplying AC power to the motor.

The circuit breaker unit 2 is normally operable by using power supplied from the auxiliary battery 14. As described above, the circuit breaker unit 2 includes a circuit breaker control unit 9 connected to the first power terminal 8 and a pyrotechnic circuit breaker unit 11 connected to the second power terminal 10. The circuit breaker control unit 9 controls the operation of the pyrotechnic circuit breaker unit 11. For example, when the vehicle 15 falls into an abnormal state or when an overcurrent or abnormal current occurs in the conductor unit 18 described below, the circuit breaker control unit 9 switches the pyrotechnic circuit breaker unit 11 from a connected state to a disconnected state by physically destroying it.

Alternatively, the circuit breaker unit 2 is normally operable by using power supplied from the auxiliary battery 14. The circuit breaker unit 2 includes a circuit breaker control unit 9 connected to the first power terminal 8 and a pyrotechnic circuit breaker unit 11 connected to the second power terminal 10 via a switch 26. The circuit breaker control unit 9 controls the operation of the pyrotechnic circuit breaker unit 11 by controlling the switch 26 to be in a connected state or a disconnected state. For example, when the vehicle 15 falls into an abnormal state or when an overcurrent or abnormal current occurs in the conductor unit 18 described below, the circuit breaker control unit 9 supplies power to the pyrotechnic circuit breaker unit 11 by switching the switch 26 from a disconnected state to a connected state. The pyrotechnic circuit breaker unit 11 is switched from a connected state to a disconnected state by being physically destroyed.

Furthermore, the cutoff unit 2 is usually operable by using power supplied from the auxiliary battery 14. The cutoff unit 2 includes a cutoff control unit 9 connected to the first power end 8 and the first power end 8, and a switch 26 connected to the second power end 10. The cutoff control unit 9 can control the operation of the pyrotechnic cutoff unit 11 after receiving power from the second power end 10 via the switch 26 in the connected state. For example, when the vehicle 15 falls into an abnormal state or when an overcurrent or abnormal current occurs in the conductor unit 18 described below, the cutoff control unit 9 supplies power to the pyrotechnic cutoff unit 11 using power supplied from the switch 26 in the connected state. Then, the pyrotechnic cutoff unit 11 is switched from the connected state to the cutoff state by being physically destroyed. Although not shown here, the cutoff control unit 9 and the switch 26 may be connected by a conductor for control and a conductor for power supply. Also, although not shown, the second power end 10 and the cutoff control unit 9 may be directly connected by a conductor for power supply without the switch 26.

In this embodiment, the cutoff control unit 9 and the switch 26 are described as different elements and circuits, but the cutoff control unit 9 and the switch 26 may be provided as a cutoff circuit unit (not shown) that is a single control circuit. In other words, the cutoff circuit unit (not shown) may be capable of supplying power for operating the pyrotechnic cutoff unit 11 using signals and power supplied from the first power terminal 8 and the second power terminal 10.

The pyrotechnic cutoff unit 11 of the cutoff unit 2, in particular, has the vehicle propulsion drive power storage unit 12 and the vehicle propulsion drive load 13 connected in an initial state. As shown in the first schematic diagram of the pyrotechnic cutoff unit 11 used in the vehicle power cutoff system in the embodiment of the present disclosure in Fig. 6, the pyrotechnic cutoff unit 11 has a pyrotechnic unit 17 and a conductor unit 18. The pyrotechnic unit 17 further has an energy generation unit 17A that generates large mechanical energy by exploding explosives, etc., and a destruction piece 17B that uses the mechanical energy generated by the energy generation unit 17A as kinetic energy to cause a position change. The cutoff control unit 9 issues a cutoff instruction to the pyrotechnic cutoff unit 11, causing the pyrotechnic cutoff unit 11 to execute a cutoff operation of detonating the pyrotechnic unit 17 and destroying the conductor unit 18.
In other words, the pyrotechnic section 17 receives a signal for initiating the detonation of the energy generating section 17A from the cutoff control section 9, and power for promoting the detonation in the energy generating section 17A from the second power terminal 10.

Alternatively, as shown in the second schematic diagram of the pyrotechnic cutoff unit 11 used in the vehicle power cutoff system in the embodiment of the present disclosure in FIG. 7, the pyrotechnic unit 17 may receive power from the second power terminal 10 through the switch 26 switched from the cutoff state to the connected state under the control of the cutoff control unit 9 in order to detonate the energy generating unit 17A. Then, by detonating the energy generating unit 17A, the destructive fragment 17B irreversibly mechanically destroys the conductor unit 18, and the connection state between the vehicle propulsion drive storage unit 12 and the vehicle propulsion drive load 13 is switched to the cutoff state. Here, the destructive fragment 17B is generally a blade-shaped metal fragment or a bullet-shaped metal fragment, but it is not limited to a metal fragment as long as it is a material that can destroy and cut the conductor unit 18.

The interruption control unit 9 of the interruption unit 2 changes the state of the pyrotechnic interruption unit 11 from the connected state to the interrupted state when the vehicle control unit 19 mounted on the vehicle body 16 detects the occurrence of an accident or the like and the interruption control unit 9 receives an instruction to interrupt from the vehicle control unit 19, or when the interruption control unit 9 detects an overcurrent in the interruption unit 2.

As mentioned above, the power supplied from the first power terminal 8 to the cutoff control unit 9 to enable the cutoff control unit 9 to operate is supplied by the auxiliary battery 14 when the auxiliary battery 14 is normal or the vehicle 15 is normal. In addition, the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generation unit 17A is supplied by the auxiliary battery 14 when the auxiliary battery 14 is normal or the vehicle 15 is normal.

Here, the backup unit 3 is connected to the first power terminal 8 and the second power terminal 10. Strictly speaking, the first power terminal 8 is connected to the first discharge circuit 5. The second power terminal 10 is connected to the second discharge circuit 6. The first discharge circuit 5 and the second discharge circuit 6 can output voltage or supply power from the first power terminal 8 to the cutoff control unit 9 or from the second power terminal 10 to the pyrotechnic cutoff unit 11 using the power stored in the power storage unit 7. In other words, the auxiliary battery 14 and the backup unit 3 are connected in parallel to the first power terminal 8 and the second power terminal 10.

The first discharge circuit 5 and the second discharge circuit 6 may be independent circuits, or may be configured as circuits capable of outputting different voltages using a voltage divider circuit. Here, it is preferable to use a DC-DC converter so that the first discharge circuit 5 and the second discharge circuit 6 are activated at different times and can be controlled by the power supply control unit 4 to stably and continuously output different powers.

As a result, the cutoff control unit 9 and pyrotechnic cutoff unit 11 are able to receive power from both the auxiliary battery 14 and the storage unit 7. Therefore, even if the vehicle 15 encounters an accident and the auxiliary battery 14 fails, or even if the voltage of the auxiliary battery 14 becomes unstable before an accident occurs, the cutoff control unit 9, which executes control to cut off the power from the vehicle propulsion drive storage unit 12 to the vehicle propulsion drive load 13 by the pyrotechnic cutoff unit 11, can receive a stable power supply from the first discharge circuit 5.

Here, the second voltage V2 that the second discharge circuit 6 can output to the pyrotechnic cutoff unit 11 through the second power terminal 10 is set to a higher voltage value than the first voltage V1 that the first discharge circuit 5 can output to the cutoff control unit 9 through the first power terminal 8. The cutoff control unit 9 is composed of a calculation element and a memory element, and therefore can perform control and detection operations at a low voltage value of, for example, about 3V to 5V. On the other hand, when the pyrotechnic cutoff unit 11 operates, a high voltage of, for example, about 10V can be applied to the pyrotechnic cutoff unit 11 to allow a large current to flow through the pyrotechnic section 17 of the pyrotechnic cutoff unit 11, and the detonation speed in the energy generation unit 17A can be increased. Therefore, when power is supplied to the cutoff control unit 9 through the first power terminal 8 and power is supplied to the pyrotechnic cutoff unit 11 through the second power terminal 10, the cutoff speed in the pyrotechnic cutoff unit 11 is improved, and the reliability of the cutoff is also improved.

Here, the backup unit 3 may be provided with a diode 20 that connects the first power terminal 8 and the first discharge circuit 5. Similarly, the backup unit 3 may be provided with a diode 20 that connects the second power terminal 10 and the second discharge circuit 6. Here, the anode of the diode 20 is connected to the first discharge circuit 5 and the second discharge circuit 6. The cathode of the diode 20 is connected to the first power terminal 8 and the second power terminal 10. As a result, when the auxiliary battery 14 is normal or the vehicle 15 is normal, even if the voltage supplied to the first power terminal 8 and the second power terminal 10 by the auxiliary battery 14 is the standard voltage V0, which is a voltage value higher than the first voltage V1 or the second voltage V2, the power does not flow back to the backup unit 3.

The voltage supplied to the first power terminal 8 and the second power terminal 10 by the auxiliary battery 14 may be supplied at different voltage values from the auxiliary battery 14 to the first power terminal 8 and the second power terminal 10 via the voltage conversion circuit 21 by providing the voltage conversion circuit 21 in the vehicle power cutoff system 1. At this time, the first power terminal 8 receives the first steady-state voltage V01 from the auxiliary battery 14 via the voltage conversion circuit 21, and the second power terminal 10 receives the second steady-state voltage V02 from the auxiliary battery 14 via the voltage conversion circuit 21. At this time, the voltage conversion circuit 21 may have two independent DC-DC converters, and each DC-DC converter may supply the first steady-state voltage V01 and the second steady-state voltage V02. Alternatively, the first steady-state voltage V01 and the second steady-state voltage V02 may be supplied by a voltage divider circuit included in the voltage conversion circuit 21.

Here, by setting the first voltage V1 described above to a value lower than the first steady-state voltage V01, even if the first voltage is output from the first discharge circuit 5, no power is actually discharged from the first discharge circuit 5, and the power stored in the power storage unit 7 can be maintained.

The above configuration and operation allows the cutoff control unit 9 and the pyrotechnic cutoff unit 11 to be able to receive power from both the auxiliary battery 14 and the storage unit 7. Therefore, even if the auxiliary battery 14 fails when the vehicle 15 encounters an accident, or even if the voltage of the auxiliary battery 14 becomes unstable before the accident, the cutoff control unit 9, which controls the pyrotechnic cutoff unit 11 to cut off the power from the vehicle propulsion drive storage unit 12 to the vehicle propulsion drive load 13, can receive a stable power supply from the first discharge circuit 5. Furthermore, it is possible to supply a sufficiently high voltage and a large current from the second discharge circuit 6 to the pyrotechnic cutoff unit 11. This stabilizes the operation of the cutoff control unit 9, enables the pyrotechnic cutoff unit 11 to perform a high-speed cutoff operation, and improves the reliability of the power cutoff operation by the cutoff control unit 9 and the pyrotechnic cutoff unit 11.

The operation of the backup unit 3 will be described in detail below. The backup unit 3 may start operating in response to the start-up of the vehicle 15. For example, in response to the vehicle start-up signal receiving end 4A provided in the power supply control unit 4 receiving a vehicle start-up signal from a device provided in the vehicle 15, such as the vehicle control unit 19, the power supply control unit 4 may execute control to cause the first discharge circuit 5 to output the first voltage V1. Here, the first discharge circuit 5 may output the first voltage V1 simultaneously with the vehicle start-up signal receiving end 4A receiving the vehicle start-up signal, or may output the first voltage V1 a predetermined time after the vehicle start-up signal receiving end 4A receives the vehicle start-up signal and before the vehicle 15 starts running.

Furthermore, the power supply control unit 4 executes control so as to cause the second discharge circuit 6 to output the second voltage V2. Here, the second discharge circuit 6 may output the second voltage V2 at the same time as it starts to output the first voltage V1 to the first discharge circuit 5, or after it starts to output the first voltage V1 to the first discharge circuit 5. In other words, the first discharge circuit 5 starts to operate preferentially. Therefore, the interruption control unit 9 of the interruption unit 2 is preferentially placed in a state in which it has a backup of driving power, and the operation of the pyrotechnic interruption unit 11 requires that the interruption control unit 9 is operating, improving the operational reliability of the interruption unit 2.

Here, the first voltage V1 is capable of operating the cutoff control unit 9 and has a voltage value lower than the first steady-state voltage V01, and the second voltage V2 is a voltage value lower than the second steady-state voltage V02. Therefore, if the auxiliary battery 14 is normal, no power is output even if the backup unit 3 applies a voltage. Therefore, the power stored in the power storage unit 7 is not wasted and can be maintained for a long period of time.

As a result, the backup unit 3 begins to operate in response to the start-up of the vehicle 15, and the first discharge circuit 5 in particular is able to supply power to the cutoff control unit 9 of the cutoff unit 2 almost constantly while the vehicle 15 is running. Furthermore, the second discharge circuit 6 is also able to supply power to the pyrotechnic cutoff unit 11 of the cutoff unit 2 almost constantly while the vehicle 15 is running. As a result, even if the auxiliary battery 14 fails due to an accident involving the vehicle 15, the cutoff unit 2 can continue to operate without interruption.

The operation of the backup unit 3 may be performed, for example, based on the start-up of the vehicle 15 and information about the accident from the vehicle 15 or the vehicle body 16.

Here, in response to the vehicle start signal received by the vehicle start signal receiving end 4A provided in the power supply control unit 4 from a device provided in the vehicle 15, such as the vehicle control unit 19, the power supply control unit 4 executes control to cause the first discharge circuit 5 to output the first voltage V1. Thereafter, when the first receiving end 4B provided in the power supply control unit 4 receives a vehicle accident signal from a device provided in the vehicle 15, such as the vehicle control unit 19, the power supply control unit 4 executes control to cause the second discharge circuit 6 to output the second voltage V2. Furthermore, the second receiving end 9A provided in the cutoff control unit 9, which is capable of receiving the vehicle accident signal, receives the vehicle accident signal simultaneously with the power supply control unit 4. Then, the cutoff control unit 9 causes the pyrotechnic cutoff unit 11 to perform a cutoff operation.

As a result, the backup unit 3 starts operating in response to the start-up of the vehicle 15, and the first discharge circuit 5 in particular is in a state in which it can supply power to the cutoff control unit 9 of the cutoff unit 2 almost constantly while the vehicle 15 is running.

Furthermore, here, the second discharge circuit 6 supplies power to the pyrotechnic cutoff unit 11 when the vehicle 15 encounters an accident. Then, when the vehicle 15 encounters an accident, the pyrotechnic cutoff unit 11 receives an instruction to perform cutoff from the cutoff control unit 9. This allows the cutoff unit 2 to operate without interruption even if the auxiliary battery 14 fails due to an accident of the vehicle 15 or the like. Alternatively, when the vehicle 15 encounters an accident, the cutoff control unit 9 switches the switch 26 from the cutoff state to the connected state, and the pyrotechnic cutoff unit 11 switches to the cutoff state by receiving power from the second power terminal 10. This allows the cutoff unit 2 to operate without interruption even if the auxiliary battery 14 fails due to an accident of the vehicle 15 or the like. Here, it is preferable to use a semiconductor switch such as a field effect transistor (FET) for the switch 26.

In addition, regardless of the state of the auxiliary battery 14, the second discharge circuit 6 can output the second voltage V2 at a voltage value higher than the second steady-state voltage V02. This allows the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A to be a large value. As a result, the cutoff speed in the pyrotechnic cutoff unit 11 is improved, and the cutoff reliability is also improved.

The operation of the backup unit 3 may also be performed, for example, based on the start-up of the vehicle 15 and information regarding the occurrence of an overcurrent in the pyrotechnic circuit breaker 11.

Here, in response to the vehicle start signal issued from a device provided in the vehicle 15, such as the vehicle control unit 19, being received by the vehicle start signal receiving end 4A provided in the power supply control unit 4, the power supply control unit 4 executes control to make the first discharge circuit 5 output the first voltage V1. After that, the current detection circuit 11A provided in the pyrotechnic circuit breaker 11 starts to detect the current flowing in the conductor 18. Then, when the current detection circuit 11A detects that the current flowing in the conductor 18 exceeds the overcurrent threshold, it transmits an overcurrent detection signal to the detection signal receiving unit 9B of the circuit breaker control unit 9. At this time, the power supply control unit 4 also receives an overcurrent detection signal at the third receiving end 4C from the current detection circuit 11A or the circuit breaker control unit 9. When the power supply control unit 4 receives the overcurrent detection signal, it causes the second discharge circuit 6 to output the second voltage V2. Also, the circuit breaker control unit 9 instructs the pyrotechnic circuit breaker 11 to perform circuit breaker. Alternatively, the cutoff control unit 9 controls the switch 26 to switch from the cutoff state to the connected state, causing the pyrotechnic cutoff unit 11 to perform a cutoff.

As a result, the backup unit 3 starts operating in response to the start-up of the vehicle 15, and the first discharge circuit 5 in particular is in a state in which it can supply power to the cutoff control unit 9 of the cutoff unit 2 almost constantly while the vehicle 15 is running.

Furthermore, here, the second discharge circuit 6 supplies power to the pyrotechnic circuit breaker 11 when a short circuit occurs in the vehicle propulsion drive load 13 or the like due to the vehicle 15 encountering an accident or the like, causing an overcurrent to flow through the conductor 18. Then, when an overcurrent occurs in the conductor 18, the pyrotechnic circuit breaker 11 receives an instruction to perform circuit breaker from the circuit breaker control unit 9. Alternatively, when an overcurrent flows through the conductor 18, the circuit breaker control unit 9 controls the switch 26 to switch from the circuit breaker state to the circuit breaker state, causing the pyrotechnic circuit breaker 11 to perform circuit breaker. This allows the circuit breaker unit 2 to operate uninterruptedly even if the auxiliary battery 14 fails due to an accident involving the vehicle 15 or the like.

At this time, regardless of the state of the auxiliary battery 14, the second discharge circuit 6 can output the second voltage V2 at a voltage value higher than the second steady-state voltage V02. This allows the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A to be a large value. As a result, the cutoff speed in the pyrotechnic cutoff unit 11 is improved, and the cutoff reliability is also improved.

For ease of explanation, the current detection circuit 11A, the cutoff control unit 9, and the detection signal receiving unit 9B are described here as separate elements, but they may be collectively considered as functions included in the cutoff control unit 9.

In other words, in the above description, the current detection circuit 11A detects the current flowing through the conductor 18 as a detection voltage value using a shunt resistor (not shown) or a Hall element (not shown), and the current detection circuit 11A has a function of using a calculation device (not shown) to compare the detected voltage value with a voltage value corresponding to an overcurrent threshold value previously stored in a storage device (not shown). The result of the calculation device (not shown) determining that the current flowing through the conductor 18 exceeds the overcurrent threshold corresponds to the transmission of an overcurrent detection signal. As described above, the storage device (not shown) and the calculation device (not shown) are considered to be elements that constitute the current detection circuit 11A, separate from the cutoff control unit 9. However, the cutoff control unit 9 may be provided with the function of the current detection circuit 11A, including the storage device (not shown) and the calculation device (not shown). In other words, it may be considered that the cutoff control unit 9 having the current detection circuit 11A and the detection signal receiving unit 9B is provided in the pyrotechnic cutoff unit 11, except for the shunt resistor (not shown) and the Hall element (not shown).

The operation of the backup unit 3 may also be performed, for example, based on the start-up of the vehicle 15, the state of the power supply from the auxiliary battery 14, and information regarding an accident from the vehicle 15 or the vehicle body 16.

Here, in response to the vehicle startup signal issued from a device provided in the vehicle 15, such as the vehicle control unit 19, being received by the vehicle startup signal receiving end 4A provided in the power supply control unit 4, the power supply control unit 4 executes control to cause the first discharge circuit 5 to output a first voltage V1. In addition, when the vehicle startup signal receiving end 4A receives the vehicle startup signal, the power supply control unit 4 detects the voltage of the receiving end 22 provided in the backup unit 3. The auxiliary battery 14 supplies power to the power storage unit 7 through the receiving end 22. Alternatively, the auxiliary battery 14 charges the power storage unit 7 through the receiving end 22.

After that, when the vehicle start signal receiving end 4A is receiving the vehicle start signal, in other words, when the vehicle 15 is in a driving state and the power supply control unit 4 detects that the voltage of the receiving end 22 has dropped below the battery voltage threshold, the power supply control unit 4 causes the second discharge circuit 6 to output the second voltage V2. Furthermore, the power supply control unit 4 transmits a vehicle accident signal to the second receiving end 9A, which is provided in the cutoff control unit 9 and can receive a vehicle accident signal. Then, the cutoff control unit 9 causes the pyrotechnic cutoff unit 11 to perform a cutoff operation. Alternatively, the cutoff control unit 9 controls the switch 26 to switch from a cutoff state to a connected state, causing the pyrotechnic cutoff unit 11 to perform a cutoff.

As a result, the backup unit 3 starts operating in response to the start-up of the vehicle 15, and the first discharge circuit 5 in particular is in a state in which it can supply power to the cutoff control unit 9 of the cutoff unit 2 almost constantly while the vehicle 15 is running.

Furthermore, even though the vehicle 15 is being driven, the voltage of the auxiliary battery 14 has dropped below the battery voltage threshold, causing the second discharge circuit 6 to supply power to the pyrotechnic cutoff unit 11. The power supply control unit 4 then issues a cutoff instruction to the cutoff control unit 9 to forcibly cause the pyrotechnic cutoff unit 11 to perform a cutoff. In other words, in response to a battery failure state in which the auxiliary battery 14 is lost while the vehicle 15 is being driven, the second discharge circuit 6 supplies power to the pyrotechnic cutoff unit 11 and further causes the pyrotechnic cutoff unit 11 to perform a cutoff. For this reason, the battery voltage threshold may be set to a level close to 0V, which is a low value far removed from the battery voltage fluctuation range that would not normally occur. This suppresses false detection of battery failure.

As a result, even if the auxiliary battery 14 fails due to an accident involving the vehicle 15, the circuit breaker unit 2 can continue to operate continuously to prevent leakage current, regardless of whether an overcurrent condition exists.

The second discharge circuit 6 can also output the second voltage V2 at a voltage value higher than the second steady-state voltage V02. This allows the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A to be a large value. As a result, the cutoff speed in the pyrotechnic cutoff unit 11 is improved, and the cutoff reliability is also improved.

The operation of the backup unit 3 may also be performed based on, for example, the start-up of the vehicle 15, the state of the power supply from the auxiliary battery 14, and information regarding the occurrence of an overcurrent in the pyrotechnic circuit breaker 11.

Here, in response to the vehicle startup signal issued from a device provided in the vehicle 15, such as the vehicle control unit 19, being received by the vehicle startup signal receiving end 4A provided in the power supply control unit 4, the power supply control unit 4 executes control to cause the first discharge circuit 5 to output a first voltage V1. In addition, when the vehicle startup signal receiving end 4A receives the vehicle startup signal, the power supply control unit 4 detects the voltage of the receiving end 22 provided in the backup unit 3. The auxiliary battery 14 supplies power to the power storage unit 7 through the receiving end 22. Alternatively, the auxiliary battery 14 charges the power storage unit 7 through the receiving end 22.

After that, when the vehicle start signal receiving end 4A is receiving the vehicle start signal, in other words, when the vehicle 15 is in a driving state and the power supply control unit 4 detects that the voltage of the receiving end 22 has dropped below the battery voltage threshold, the power supply control unit 4 causes the second discharge circuit 6 to output the second voltage V2. Furthermore, after that, the cutoff control unit 9 detects the occurrence of an overcurrent in the conductor portion 18, and the pyrotechnic cutoff unit 11 receives an instruction from the cutoff control unit 9 to perform cutoff. Alternatively, when the cutoff control unit 9 detects the occurrence of an overcurrent in the conductor portion 18, the cutoff control unit 9 controls the switch 26 to switch from the cutoff state to the connected state, causing the pyrotechnic cutoff unit 11 to perform cutoff.

As a result, the backup unit 3 starts operating in response to the start-up of the vehicle 15, and the first discharge circuit 5 in particular is in a state in which it can supply power to the cutoff control unit 9 of the cutoff unit 2 almost constantly while the vehicle 15 is running.

Furthermore, even though the vehicle 15 is being driven, the voltage of the auxiliary battery 14 drops below the battery voltage threshold, causing the second discharge circuit 6 to be able to supply power to the pyrotechnic cutoff unit 11. After this, when an overcurrent occurs, the pyrotechnic cutoff unit 11 executes cutoff. In other words, in response to a battery failure state in which the auxiliary battery 14 is lost while the vehicle 15 is being driven, the second discharge circuit 6 is able to supply power to the pyrotechnic cutoff unit 11. For this reason, the battery voltage threshold may be set to a level close to 0V, which is a low value far removed from the battery voltage fluctuation range that would not normally occur. This suppresses false detection of battery failure.

As a result, even if the auxiliary battery 14 fails due to an accident involving the vehicle 15, sufficient voltage and power can be supplied to the pyrotechnic circuit breaker 11 when an overcurrent state occurs, and the circuit breaker unit 2 can operate normally. If there is a time difference between the timing of the battery failure state while the vehicle 15 is in operation and the timing of the detection of an overcurrent by the circuit breaker control unit 9, the second discharge circuit 6 may have a standby state in which it maintains a state in which it is possible to supply power to the pyrotechnic circuit breaker 11 and waits for the circuit breaker control unit 9 to detect an overcurrent.

Here, the procedure when the interruption control unit 9 or the current detection circuit 11A detects an overcurrent in the conductor portion 18 may be the same as described above.

The second discharge circuit 6 can also output the second voltage V2 at a voltage value higher than the second steady-state voltage V02. This allows the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A to be a large value. As a result, the cutoff speed in the pyrotechnic cutoff unit 11 is improved, and the cutoff reliability is also improved.

The operation of the backup unit 3 may also be performed based on, for example, a prediction of a collision in the vehicle 15, information about an accident from the vehicle 15 or the vehicle body 16, or information about the occurrence of an overcurrent in the pyrotechnic breaker 11.

Here, in response to a danger prediction signal, such as a collision prediction signal, being issued from a device provided in the vehicle 15, such as the vehicle control unit 19, being received by the fourth receiving end 4D provided in the power supply control unit 4 as a vehicle start signal, the power supply control unit 4 executes control to cause the first discharge circuit 5 to output the first voltage V1. Then, the power supply control unit 4 executes control to cause the second discharge circuit 6 to output the second voltage V2. The timing at which the first voltage V1 is output may precede the timing at which the second voltage V2 is output, but it is desirable that the first voltage V1 and the second voltage V2 are output simultaneously.

Then, when the cutoff control unit 9 receives a vehicle accident signal at the second receiving end 9A provided in the cutoff control unit 9, or when the current detection circuit 11A of the cutoff unit 2 detects that the current flowing through the conductor portion 18 has exceeded the overcurrent threshold, the cutoff control unit 9 causes the pyrotechnic cutoff unit 11 to perform a cutoff operation.

In other words, when a dangerous state is imminent before an accident such as a collision occurs with the vehicle 15, the power supply control unit 4 executes control to cause the first discharge circuit 5 to output the first voltage V1 and the second discharge circuit 6 to output the second voltage V2, regardless of the state of the auxiliary battery 14. Then, when the vehicle 15 actually encounters an accident or when an overcurrent occurs as a result of the vehicle 15 encountering an accident, the cutoff control unit 9 causes the pyrotechnic cutoff unit 11 to perform a cutoff operation. Alternatively, when the vehicle 15 actually encounters an accident or when an overcurrent occurs as a result of the vehicle 15 encountering an accident, the cutoff control unit 9 controls the switch 26 to switch from the cutoff state to the connected state, causing the pyrotechnic cutoff unit 11 to perform a cutoff.

As a result, the backup unit 3 is able to supply all the power required by the cutoff unit 2 before the vehicle 15 encounters an accident, regardless of the state of the auxiliary battery 14. Therefore, when the vehicle 15 encounters an accident and the cutoff unit 2 needs to operate, it is able to operate immediately and normally.

Here, the procedure when the interruption control unit 9 or the current detection circuit 11A detects an overcurrent in the conductor portion 18 may be the same as described above.

The second discharge circuit 6 can also output the second voltage V2 at a voltage value higher than the second steady-state voltage V02. This allows the power supplied from the second power terminal 10 to the pyrotechnic cutoff unit 11 to promote detonation in the energy generating unit 17A to be a large value. As a result, the cutoff speed in the pyrotechnic cutoff unit 11 is improved, and the cutoff reliability is also improved.

The storage unit 7 of the backup unit 3 is charged by receiving power from the auxiliary battery 14 via the power receiving end 22. Here, a charging circuit 23 may be provided between the power receiving end 22 and the storage unit 7. In other words, the charging circuit 23 is provided in the charging path of the storage unit 7, and the first discharge circuit 5 and the charging circuit 23 are provided in parallel in the discharging path of the storage unit 7. Here, the charging circuit 23 may adjust the charging state and charging speed of the storage unit 7 under control of the power supply control unit 4. The charging circuit 23 may charge the storage unit 7 by either a step-up operation or a step-down operation.

The charging circuit 23 may start a charging operation in response to a vehicle start-up signal being received by a vehicle start-up signal receiving end 4A provided in the power supply control unit 4. In addition, some power may be stored in the power storage unit 7 as residual power before charging is performed when the vehicle 15 is started.

It is preferable that the storage element (not shown) of the storage unit 7 be an element capable of discharging at a large current density, such as an electric double layer capacitor or a lithium ion capacitor.

In the above embodiment, the connection points that transmit signals and power between the components are given specific names for convenience of explanation, such as the vehicle start signal receiving end 4A, the first receiving end 4B, the second receiving end 9A, the third receiving end 4C, the fourth receiving end 4D, the first power end 8, and the second power end 10. The above connection points may be replaced with terminals, but on the other hand, the conductors themselves that connect the components, or parts of the electric circuit, may correspond to the above connection points. In other words, there is no need to provide connection points as specific components.

In the above embodiment, the vehicle start signal receiving end 4A, the first receiving end 4B, the third receiving end 4C, and the fourth receiving end 4D are described as being different receiving ends for the sake of convenience. However, the vehicle start signal receiving end 4A, the first receiving end 4B, the third receiving end 4C, and the fourth receiving end 4D may be different receiving ends, or may be a single receiving end, or may be any number of receiving ends, as long as the power supply control unit 4 can recognize what type of signal it has received.

As explained above, the second voltage V2 supplied from the second discharge circuit 6 to the pyrotechnic cutoff unit 11 through the second power terminal 10 is set to a value higher than the first voltage V1 supplied from the first discharge circuit 5 to the cutoff control unit 9 through the first power terminal 8. The cutoff control unit 9 mainly performs calculations, storage, and control, so its power consumption is small and the current flowing through the first power terminal 8 is a weak value. On the other hand, although the operating time of the energy generating unit 17A of the pyrotechnic cutoff unit 11 is very short and short compared to the cutoff control unit 9, the power consumption of the pyrotechnic cutoff unit 11 during operation is greater than the power consumption of the cutoff control unit 9, and a current of a value greater than that of the first power terminal 8 flows through the second power terminal 10.

For this reason, the second conductor 25 connecting the second discharge circuit 6 and the pyrotechnic cutoff unit 11 has a larger cross-sectional area and a larger current capacity than the first conductor 24 connecting the first discharge circuit 5 and the cutoff control unit 9. This stabilizes the power supply from the second discharge circuit 6 to the pyrotechnic cutoff unit 11, improving the operational reliability of the pyrotechnic cutoff unit 11.

The vehicle power cutoff system of the present invention has the effect of improving the reliability of power cutoff operations and is useful in various battery-powered vehicles.

REFERENCE SIGNS LIST 1 Vehicle power cut-off system 2 Cut-off unit 3 Backup unit 4 Power supply control unit 4A Vehicle start signal receiving end 4B First receiving end 4C Third receiving end 4D Fourth receiving end 5 First discharge circuit 6 Second discharge circuit 7 Power storage unit 8 First power end 9 Cut-off control unit 10 Second power end 11 Pyrotechnic cut-off unit 11A Current detection circuit 12 Vehicle propulsion drive power storage unit 13 Vehicle propulsion drive load 14 Auxiliary battery 15 Vehicle 16 Vehicle body 17 Pyrotechnic unit 17A Energy generation unit 17B Breaking fragment 18 Conductor unit 19 Vehicle control unit 20 Diode 21 Voltage conversion circuit 22 Power receiving end 23 Charging circuit 24 First conductor 25 Second conductor

Claims (13)

a cutoff unit having a first power terminal and a second power terminal that receive an operating voltage from an auxiliary battery, a cutoff control unit connected to the first power terminal, and a pyrotechnic cutoff unit that is connected to the second power terminal and controlled by the cutoff control unit, and capable of cutting off power supply from the vehicle propulsion drive power storage unit to a vehicle propulsion drive load;
A power storage unit;
a first discharge circuit connected to the first power terminal and capable of outputting the power stored in the power storage unit to the cutoff control unit at a first voltage;
a second discharge circuit connected to the second power terminal and capable of outputting the power stored in the storage unit to the pyrotechnic interrupter at a second voltage higher than the first voltage when the first discharge circuit outputs a first voltage to the interrupter control unit;
a power supply control unit that controls operations of the first discharge circuit and the second discharge circuit;
A backup unit having
Equipped with
Vehicle power cutoff system. a cutoff unit having a first power terminal and a second power terminal that receive an operating voltage from an auxiliary battery, a cutoff control unit connected to the first power terminal, and a pyrotechnic cutoff unit connected to the second power terminal via a switch that is controlled to be opened or closed by the cutoff control unit, and capable of cutting off power supply from the vehicle propulsion drive power storage unit to a vehicle propulsion drive load;
A power storage unit;
a first discharge circuit connected to the first power terminal and capable of outputting the power stored in the power storage unit to the cutoff control unit at a first voltage;
a second discharge circuit connected to the second power terminal and capable of outputting the power stored in the storage unit to the pyrotechnic interrupter at a second voltage higher than the first voltage when the first discharge circuit outputs a first voltage to the interrupter control unit;
a power supply control unit that controls operations of the first discharge circuit and the second discharge circuit;
A backup unit having
Equipped with
Vehicle power cutoff system. a cutoff unit having a first power terminal and a second power terminal that receive an operating voltage from an auxiliary battery, a cutoff control unit that is connected to the first power terminal and is connected to the second power terminal via a switch, and a pyrotechnic cutoff unit that can be supplied with power by the cutoff control unit, and capable of cutting off power supply from the vehicle propulsion drive power storage unit to a vehicle propulsion drive load;
A power storage unit;
a first discharge circuit connected to the first power terminal and capable of outputting the power stored in the power storage unit to the cutoff control unit at a first voltage;
a second discharge circuit connected to the second power terminal and capable of outputting the power stored in the storage unit to the pyrotechnic interrupter at a second voltage higher than the first voltage when the first discharge circuit outputs a first voltage to the interrupter control unit;
a power supply control unit that controls operations of the first discharge circuit and the second discharge circuit;
A backup unit having
Equipped with
Vehicle power cutoff system. The pyrotechnic interrupter includes:
a conductor section capable of supplying electric power from the vehicle propulsion drive power storage section to the vehicle propulsion drive load;
A pyrotechnic part capable of destroying the conductor part,
The cutoff control unit issues a cutoff instruction to the pyrotechnic cutoff unit, or switches a switch connecting the cutoff control unit to the second power end from a cutoff state to a connected state, thereby causing the pyrotechnic cutoff unit to execute a cutoff operation to detonate the pyrotechnic unit and destroy the conductor portion.
4. The vehicle power cutoff system according to claim 1. The power supply control unit further includes a vehicle start signal receiving terminal capable of receiving a vehicle start signal;
The power supply control unit is
causing the first discharge circuit to output the first voltage in response to receiving the vehicle start signal, and causing the second discharge circuit to output the second voltage at the same time as the first discharge circuit outputs the first voltage or after the first discharge circuit outputs the first voltage;
5. The vehicle power cutoff system according to claim 4. The power supply control unit includes a vehicle start signal receiving end capable of receiving a vehicle start signal and a first receiving end capable of receiving a vehicle accident signal.
The cut-off control unit further includes a second receiving end capable of receiving the vehicle accident signal,
the power supply control unit causes the first discharge circuit to output the first voltage in response to receiving the vehicle start signal, and causes the second discharge circuit to output the second voltage when receiving the vehicle accident signal;
The cutoff control unit causes the pyrotechnic cutoff unit to execute the cutoff operation when the vehicle accident signal is received.
5. The vehicle power cutoff system according to claim 4. The pyrotechnic circuit breaker includes a current detection circuit capable of detecting an overcurrent flowing in the conductor,
The cutoff control unit includes a detection signal receiving unit capable of receiving an overcurrent detection signal generated by the current detection circuit,
The power supply control unit includes a vehicle start signal receiving end capable of receiving a vehicle start signal, and a third receiving end capable of receiving the overcurrent detection signal from the cutoff control unit or the current detection circuit.
Furthermore,
the power supply control unit causes the first discharge circuit to output the first voltage in response to receiving the vehicle start signal, and causes the second discharge circuit to output the second voltage when the overcurrent detection signal is received at the third receiving end;
The cutoff control unit causes the pyrotechnic cutoff unit to execute the cutoff operation when the detection signal receiving unit receives the overcurrent detection signal.
5. The vehicle power cutoff system according to claim 4. a power receiving terminal for supplying power from the auxiliary battery to the power storage unit,
The power supply control unit further has a vehicle start-up signal receiving terminal capable of receiving a vehicle start-up signal and is capable of detecting a voltage of the receiving terminal;
The cut-off control unit further includes a second receiving end capable of receiving a vehicle accident signal,
When the power supply control unit detects that the voltage at the power receiving end has dropped below a threshold value while receiving the vehicle start-up signal after causing the first discharge circuit to output the first voltage in response to receiving the vehicle start-up signal,
5. The vehicle power cut-off system according to claim 4, wherein the power supply control unit causes the second discharge circuit to output the second voltage and transmits the vehicle accident signal to the cut-off control unit, and the cut-off control unit causes the pyrotechnic cut-off unit to perform the cut-off operation. a power receiving terminal for supplying power from the auxiliary battery to the power storage unit,
The power supply control unit further has a vehicle start-up signal receiving terminal capable of receiving a vehicle start-up signal and is capable of detecting a voltage of the receiving terminal;
The interruption control unit further includes a current detection circuit that detects a current flowing through the pyrotechnic interruption unit,
When the power supply control unit detects that the voltage at the power receiving end has dropped below a threshold value while receiving the vehicle start-up signal after causing the first discharge circuit to output the first voltage in response to receiving the vehicle start-up signal,
The power supply control unit causes the second discharge circuit to output the second voltage, and thereafter, when the current detection circuit detects an overcurrent, the cutoff control unit causes the pyrotechnic cutoff unit to execute the cutoff operation.
5. The vehicle power cutoff system according to claim 4. The power supply control unit includes a fourth receiving unit capable of receiving a danger prediction signal,
The cutoff control unit includes at least one of a second receiving unit capable of receiving a vehicle accident signal and a current detection circuit that detects a current flowing through the pyrotechnic cutoff unit,
Furthermore,
the power supply control unit causes the first discharge circuit to output the first voltage in response to receiving the danger prediction signal, and further causes the second discharge circuit to output the second voltage;
The cutoff control unit causes the pyrotechnic cutoff unit to execute the cutoff operation when the vehicle accident signal is received or when the current detection circuit detects that the current has exceeded a threshold value.
5. The vehicle power cutoff system according to claim 4. the backup unit further includes a charging circuit that charges the power storage unit,
The power supply control unit further includes a vehicle start-up signal receiving terminal capable of receiving a vehicle start-up signal,
In response to the vehicle startup signal receiving terminal receiving the vehicle startup signal , the charging circuit charges the power storage unit using power supplied via a power receiving terminal connected to the charging circuit.
5. The vehicle power cutoff system according to claim 4. A voltage conversion circuit is further provided,
the first power terminal is supplied with a first steady voltage from the auxiliary battery via the voltage conversion circuit, and the second power terminal is supplied with a second steady voltage from the auxiliary battery via the voltage conversion circuit;
5. The vehicle power cutoff system according to claim 4. The first voltage is lower than the first steady voltage.
13. The vehicle power cutoff system of claim 12.