JP6331850B2 - In-vehicle power supply - Google Patents

Description

  The present invention relates to an in-vehicle power supply device, and in particular, includes a main power source to which a first electric load that is not a backup target is connected, a sub power source to which a second electric load to be backed up is connected, a main power source and a sub power source. The present invention relates to an in-vehicle power supply device including a relay provided on a power line to be connected.

  2. Description of the Related Art Conventionally, an in-vehicle power supply device that includes a main power source and a sub power source mounted on a vehicle and can supply power to a backup target electric load from the sub power source when a main power source failure is determined is known (for example, a patent) Reference 1).

JP 2013-95238 A

  By the way, as an in-vehicle power supply device having a main power source and a sub power source, the main power source and the sub power source are connected via a relay, and an electric load that is not a backup target is connected to the main power source, and the backup is backed up to the sub power source Some of the target electrical loads are connected. In such a device, in order to appropriately supply power from the secondary power source to the electrical load to be backed up when determining the failure of the main power source as in the technique described in Patent Document 1 described above, the relay is shut off (off) immediately after the main power source failure occurs. Therefore, it is necessary to disconnect between the sub power source side on the power line and the main power source and the electric load side not to be backed up. If the relay is turned off immediately after the failure of the main power supply, the secondary power supply side on the power line is disconnected from the main power supply and the electrical load side that is not subject to backup. Only the power supply to the backup electrical load is performed without power supply to the electrical load.

  However, if the turn-off of the relay is delayed with respect to the occurrence of the failure of the main power supply, power is temporarily supplied from the secondary power supply to the electric load that is not the backup target via the relay. In general, the sub power supply has a power supply configuration with a smaller capacity than the main power supply. For this reason, the power supply voltage is greatly reduced while power is being supplied from the sub power supply to the electrical load that is not to be backed up. When such a drop in power supply voltage occurs, there is a high possibility that the voltage required for operation cannot be obtained for the electrical load to be backed up, so that the electrical load to be backed up is easily stopped.

  As an activation signal for activating each system in a vehicle, an ignition signal that is linked to a switch operation is usually used, and this ignition signal is generated using the power of the main power supply. For this reason, as described above, after the failure of the main power supply, if the electrical load to be backed up stops due to a drop in the power supply voltage, it becomes difficult to generate the start signal using the power of the main power supply. Therefore, the inconvenience that the backup load electric load cannot be restarted may occur.

  The present invention has been made in view of the above points, and even if the backup target electrical load is stopped due to a drop in the power supply voltage after the failure of the main power source, the backup target electrical load is restarted. It is an object of the present invention to provide an in-vehicle power supply device that can be used.

One aspect of the present invention includes a main power source to which a first electrical load that is not to be backed up is connected, a sub power source to which a second electrical load to be backed up is connected, and power that connects the main power source and the sub power source. A relay provided on the line, and the second electric load is activated when the activation signal generated by the first activation means using the power of the main power supply is supplied in the normal state. A power-on device, a relay-on means for turning on the relay as the vehicle starts, a relay-off means for turning off the relay when a failure occurs in the main power supply, and a failure in the main power supply , Bei and a start control means for activating the second electrical load by supplying an activation signal generated by the second starting means using power of the secondary power source to said second electric load That an in-vehicle power supply.

  According to the present invention, even if a backup target electrical load stops operating due to a drop in power supply voltage after a failure of the main power source, the backup target electrical load can be restarted.

It is a block diagram of the vehicle-mounted power supply device which is one Example of this invention. It is a flowchart of an example of the control routine performed when the relay is turned on in the in-vehicle power supply device of the present embodiment.

  Hereinafter, specific embodiments of an in-vehicle power supply device according to the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration diagram of an in-vehicle power supply device 10 according to an embodiment of the present invention. The in-vehicle power supply device 10 according to the present embodiment is a dual power supply system that supplies electric power from two power supplies to an electric load to be supplied with power, and is an in-vehicle system that is mounted on a vehicle.

  The in-vehicle power supply device 10 includes a main power supply 12. The main power source 12 is a normally used in-vehicle battery that can be charged and discharged, and is, for example, a lead live battery. Various electric loads 14 mounted on the vehicle are connected to the main power source 12 (specifically, its positive terminal). The electric load 14 is an in-vehicle electric device that can be operated mainly by supplying power from the main power supply 12. The electrical load 14 includes at least an engine starter that starts the engine. The main power supply 12 can output a predetermined DC voltage (for example, about 12 volts) at which the electric load 14 can operate.

  The in-vehicle power supply device 10 also includes a sub power supply 16. The sub power supply 16 is a power supply that can be charged / discharged and used as an auxiliary to the main power supply 12, and is, for example, a capacitor. The sub power supply 16 has a power supply configuration with a smaller capacity than the main power supply 12. The sub power supply 16 (specifically its positive terminal) and the main power supply 12 (specifically its positive terminal) are connected via a power line 18. A relay 20 is provided on the power line 18. That is, the main power supply 12 and the sub power supply 16 are connected via the relay 20 on the power line 18. The relay 20 is a relay that connects / disconnects the main power source 12 and the sub power source 16.

  The relay 20 is turned on when the vehicle is started (specifically, when the engine start using the engine starter is completed), and after that, the vehicle is mainly turned off (or the ignition switch is turned off). It is turned off at the time or when the operation of the electric load 22 described later is finished. When the relay 20 is off, the main power source 12 and the sub power source 16 are cut off, so that power cannot be supplied from the sub power source 16 to the main power source 12 and the electrical load 14. On the other hand, when the relay 20 is on, the main power supply 12 and the sub power supply 16 are conducted, so that power can be supplied from the sub power supply 16 to the main power supply 12 and the electrical load 14 (excluding the engine starter). is there.

  An electric load 22 mounted on the vehicle, which is different from the electric load 14 described above, is connected to the sub power source 16 (specifically, its positive terminal). The electric load 22 is an in-vehicle electric device that can be operated by power supply from the main power supply 12 and the sub power supply 16, and needs to be operated by power supply from the sub power supply 16 even when the main power supply 12 fails. The electrical load to be backed up. The electrical load 22 is, for example, an electronic control unit (ECU) mainly composed of a microcomputer. Hereinafter, the electrical load 22 is appropriately referred to as an ECU 22. The sub power supply 16 can output a predetermined DC voltage (for example, about 12 volts) at which the electric loads 14 and 22 can operate.

  The sub power supply 16 constitutes a sub power supply unit 26 together with an electronic control unit (hereinafter referred to as sub power supply side ECU) 24 mainly composed of a microcomputer. That is, the sub power supply unit 26 includes the sub power supply 16 and the sub power supply side ECU 24. A relay 20 is connected to the sub power supply side ECU 24. The sub power supply side ECU 24 is a control device that controls ON / OFF of the relay 20 and has a function of switching whether or not the sub power supply 16 is electrically connected to the main power supply 12.

  The auxiliary power supply side ECU 24 is also connected with a power line 18 that connects the positive terminal of the main power supply 12 or the main power supply 12 and the relay 20. The sub power supply side ECU 24 detects a failure in the main power supply 12 by detecting a voltage generated in the main power supply 12 and determining whether or not the detected voltage has decreased to a predetermined value or less. When the sub power supply side ECU 24 detects a failure of the main power supply 12, the sub power supply side ECU 24 turns off the relay 20 to cut off the sub power supply 16 and the main power supply 12.

  The ECU 22 and the sub power supply side ECU 24 are connected to each other via the communication line 30. Each of the ECU 22 and the sub power supply side ECU 24 is configured to operate in cooperation with each other by transmitting a signal representing its own state via the communication line 30.

  An IG generation circuit 32 is connected to the ECU 22. The IG generating circuit 32 is a power line 18 that connects the main power supply 12 and the relay 20 with the voltage generated at the positive terminal of the main power supply 12 when the ignition switch or the power switch operated by the vehicle driver is turned on. It is a circuit that generates a high ignition (IG) signal using the above voltage. The IG signal generated by the IG generation circuit 32 is supplied to the ECU 22. The ECU 22 is normally activated when the activation trigger signal is input when the IG signal from the IG generation circuit 32 is switched from the Lo signal to the Hi signal.

  When the sub power supply side ECU 24 detects a failure of the main power supply 12, the sub power supply side ECU 24 generates a signal indicating the detection state using the voltage generated at the positive terminal of the sub power supply 16, and sends the signal via the communication line 30. It supplies to ECU22. The signal supply from the sub power supply side ECU 24 to the ECU 22 is performed only for a predetermined time when the signal state is the Hi signal (the predetermined time only needs to be set to a sufficient time necessary for starting the ECU 22). What is fixed is sufficient. The ECU 22 is activated when the activation trigger signal is input when the signal state from the auxiliary power supply side ECU 24 via the communication line 30 indicates a failure detection state of the main power supply 12.

  Next, operation | movement of the vehicle-mounted power supply device 10 of a present Example is demonstrated.

  In the in-vehicle power supply device 10 of the present embodiment, the relay 20 is turned off before the vehicle is started. When ignition on is requested by the switch operation of the vehicle driver, the IG generation circuit 32 generates a high IG signal and supplies it to the ECU 22. The ECU 22 is activated when the IG signal from the IG generation circuit 32 is switched from the Lo signal to the Hi signal. After such activation, the ECU 22 can operate by supplying power from the sub power supply 16 even if the relay 20 is off.

  When the vehicle is started, specifically, when engine start is requested by a switch operation of the vehicle driver, an engine starter which is one of the electric loads 14 is supplied with power from the main power supply 12. The engine is started by operating. When the start of the engine is completed and the engine starts to operate, the operation of the engine starter is stopped.

  The auxiliary power supply side ECU 24 of the auxiliary power supply unit 26 turns on the relay 20 after the start of the engine is completed and the operation of the engine starter is stopped. When the relay 20 is turned on, the main power source 12 and the sub power source 16 are subsequently conducted, so that power is supplied from the sub power source 16 to the main power source 12 and the electric load 14 (excluding the engine starter) via the relay 20. In addition to being able to supply power, it is possible to supply electric power from the main power supply 12 to the ECU 22 via the relay 20. Further, if the relay 20 is turned on after the engine start is completed, it is possible to avoid the supply of electric power from the sub power source 16 to the engine starter via the relay 20, so that the sub power source 16 of the engine starter is activated. It becomes possible to prevent the battery from running out.

  FIG. 2 shows a flowchart of an example of a control routine executed when the relay 20 is turned on in the in-vehicle power supply device 10 of the present embodiment.

  In the in-vehicle power supply device 10 of the present embodiment, the sub power supply side ECU 24 monitors the voltage generated in the main power supply 12 after turning on the relay 20 as described above (step 100), and the detected voltage is below a predetermined value. The presence or absence of a failure of the main power supply 12 is determined based on whether or not it has decreased (step 102). The determination of whether or not there is a failure in the main power supply 12 is not limited to using the voltage generated in the main power supply 12, but other methods, for example, using the charge / discharge current from the main power supply 12, or It is good also as performing using both the charging / discharging electric current and the voltage which arises in the main power supply 12. FIG.

  If the sub power supply side ECU 24 determines that the failure of the main power supply 12 has not occurred as a result of the process of step 102, then the power supply (or ignition switch) of the vehicle is turned off and the operation of the ECU 22 is activated. It is determined whether or not any of the completions is established (step 104). As a result, when it is determined that the vehicle power supply is not turned off and the operation of the ECU 22 is not completed, the current routine is terminated without any further processing. On the other hand, when it is determined that the vehicle power supply is turned off or the operation of the ECU 22 is finished, the relay 20 is then turned off (step 106), and then the current routine is finished.

  On the other hand, if the sub power supply side ECU 24 determines that the main power supply 12 has failed as a result of the process of step 102, the sub power supply side ECU 24 turns off the relay 20 (step 110) and sends a signal indicating the detected state to the communication line. It supplies to ECU22 via 30 (step 112). When the relay 20 is turned off, the main power supply 12 and the sub power supply 16 are cut off thereafter. The ECU 22 is activated when the signal state from the sub power supply side ECU 24 via the communication line 30 is a signal indicating a failure detection state of the main power supply 12. After such activation, the ECU 22 can operate by supplying power from the sub power supply 16 even when the relay 20 is turned off. The sub power supply side ECU 24 may continue to supply a signal indicating the detection state of the failure of the main power supply 12 to the ECU 22 for a predetermined time, and thereafter perform normal signal transmission / reception with the ECU 22. do it.

  Thus, in the in-vehicle power supply device 10 of the present embodiment, when the failure of the main power supply 12 is detected, the main power supply 12 and the sub power supply 16 are shut off by the relay 20 being turned off. For this reason, when the main power supply 12 fails, the sub power supply 16 is disconnected from the main power supply 12 and the electric load 14 on the power line 18, so that the power supply from the sub power supply 16 is not backed up. 12 and only to the ECU 22 to be backed up. Therefore, when the main power supply 12 fails, it is possible to appropriately ensure power supply from the sub power supply 16 to the backup target ECU 22.

  Here, if the relay 20 is turned off with respect to the failure of the main power supply 12, power is temporarily supplied from the sub power supply 16 to the non-backup target electric load 14 or the like through the relay 20 for the delay time. Will be performed. The capacity of the sub power supply 16 is smaller than the capacity of the main power supply 12. For this reason, when power is temporarily supplied from the sub power supply 16 to the electrical load 14 that is not a backup target via the relay 20 as described above, the power supply voltage on the power line 18 greatly decreases during that time. When such a decrease in power supply voltage occurs, the backup target ECU 22 is likely to stop operating.

  On the other hand, in the in-vehicle power supply device 10 of the present embodiment, when a failure of the main power supply 12 is detected, the sub power supply side ECU 24 indicates the failure detection state of the main power supply 12 using the power of the sub power supply 16. A signal is generated, and a signal indicating the detection state is supplied to the ECU 22 via the communication line 30, so that the ECU 22 is activated according to the signal. For this reason, even after the failure of the main power supply 12, even if the ECU 22 to be backed up stops due to a power supply voltage drop due to the failure, the ECU 22 then uses the signal from the sub power supply side ECU 24 as an activation trigger signal. Can be restarted. Therefore, according to the in-vehicle power supply device 10 of the present embodiment, even if the backup-target ECU 22 stops operating after the failure of the main power supply 12, the operation of the ECU 22 can be ensured by restarting.

  Furthermore, in the present embodiment, an activation trigger signal supplied to the ECU 22 from the sub power supply side ECU 24 required to restart the ECU 22 after the operation of the ECU 22 to be backed up due to the failure of the main power supply 12 is It is supplied using a communication line 30 that connects the sub power supply side ECU 24 and the ECU 22. This communication line 30 is normally used for transmitting / receiving a signal representing its own state between the sub power supply side ECU 24 and the ECU 22, and is used as a signal line for transmitting / receiving the start trigger signal. Is also used. Therefore, according to the present embodiment, it is not necessary to provide a dedicated signal line for supplying the start trigger signal necessary for restarting the ECU 22 from the sub power supply side ECU 24 to the ECU 22. The cost can be reduced by reducing the number.

  In the above embodiment, the IG generating circuit 32 is connected to the “first electric load” described in the claims of the electric load 14 and the “second electric load” described in the claims of the ECU 22 to the electric load 14. The signal indicating the failure detection state of the main power supply 12 generated by the sub power supply side ECU 24 is added to the “start signal generated using the power of the main power supply” described in the claims by the generated Hi IG signal. This corresponds to the “activation signal generated using the power of the sub power supply” described in the range.

  In addition, the “relay-on means” described in the claims indicates that the auxiliary power supply side ECU 24 turns on the relay 20 when the vehicle is started, and the auxiliary power supply side ECU 24 performs the process of step 110 in the routine shown in FIG. When the sub power supply side ECU 24 detects a failure of the main power supply 12, a signal generated using the power of the sub power supply 16 is supplied to the ECU 22 in the “relay off means” described in the claims. The activation of the ECU 22 corresponds to “activation control means” described in the claims.

  By the way, in the above-described embodiment, the communication line 30 connecting the sub power supply side ECU 24 and the ECU 22 transmits and receives the start trigger signal supplied from the sub power supply side ECU 24 to the ECU 22 necessary for restarting the ECU 22. Therefore, it is also used as a signal line. However, the present invention is not limited to this. In addition to the communication line 30, the start trigger signal supplied to the ECU 22 from the sub power supply side ECU 24 required to restart the ECU 22 is transmitted and received. A dedicated signal line may be provided.

  In the above embodiment, the power source terminal of the ECU 22 to be backed up is connected between the relay 20 on the power line 18 and the sub power source 16. However, the present invention is not limited to this, and not only the power source terminal of the ECU 22 to be backed up is connected between the relay 20 on the power line 18 and the sub power source 16 but also the relay on the power line 18. It is good also as connecting between 20 and the main power supply 12. In such a modification, only the flow of current from the power supplies 12 and 16 side to the ECU 22 side is allowed in a path connecting the ECU 22 and the sub power supply 16 side and a path connecting the ECU 22 and the main power supply 12 side, respectively. A diode may be provided and both paths may be connected within the ECU 22. According to such a modification, it is possible to supply power not only from the sub power source 16 but also from the main power source 12 to the ECU 22 to be backed up.

DESCRIPTION OF SYMBOLS 10 In-vehicle power supply device 12 Main power supply 14 Electric load 16 Sub power supply 18 Power line 20 Relay 22 Electric load (ECU)
24 Sub power supply side ECU
26 Sub power supply unit 30 Communication line 32 IG generation circuit

Claims (2)

A main power source to which a first electrical load that is not to be backed up is connected; a sub power source to which a second electrical load to be backed up is connected; and a relay provided on a power line that connects the main power source and the sub power source; And the second electric load is normally activated by being supplied with the activation signal generated by the first activation means using the power of the main power supply,
Relay-on means for turning on the relay as the vehicle starts;
Relay-off means for turning off the relay when a failure occurs in the main power source;
When a failure occurs in the main power supply, the second electric load is activated by supplying an activation signal generated by the second activation means using the power of the sub power supply to the second electric load. Activation control means for causing
A vehicle-mounted power supply device comprising:   The first activation means is an ignition generation circuit,
  The second activation means is a sub power supply side ECU.
  The in-vehicle power supply device according to claim 1.

Images