JP6542601B2 - Power supply and control method of power supply - Google Patents

Description

  The present invention relates to a power supply device and a control method of the power supply device.

  In recent years, vehicle by wire technology has become widespread. In the by-wire technology, operations such as an accelerator and a brake are performed not by mechanical transmission but by transmission by electrical signals.

  With the proliferation of such by-wire technology, the reliability of the battery, which is the source for generating electrical signals, is becoming more important.

  Therefore, in the technology disclosed in Patent Document 1, a capacitor unit having a plurality of capacitors is provided, the capacitor unit is charged at the start of the operation of the vehicle, and the capacitor unit is discharged at the end of the operation of the vehicle. When the battery is abnormal, the capacitor unit supplies power to the electronic control unit. According to such a configuration, the reliability and safety of the power supply of the vehicle can be enhanced.

JP 2004-322987 A

  By the way, in the technique disclosed in Patent Document 1, the capacitor unit is discharged at the end of the operation of the vehicle. Therefore, there is a problem that power can not be supplied since the capacitor unit is not charged before the start of the operation of the vehicle.

  In particular, when the battery can not supply sufficient power supply to the brake system, operating the brake to start the engine causes kickback due to the backflow of the hydraulic pressure, which causes the driver to feel uncomfortable. is there.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a power supply device and a control method of the power supply device which enable stable supply of power supply to the load before starting the engine. There is.

In order to solve the above problems, the present invention is a power supply device mounted on a vehicle and supplying power source power to a load, provided separately from the main battery mounted on the vehicle, and having an electric capacity than the main battery And a supply means for supplying the power stored in the sub-battery to the load if the main battery can not sufficiently supply power to the load or the state of charge of the main battery is insufficient. And charging means for charging the sub-battery by power output from the alternator or the main battery, and the supply means unlocks the door of the vehicle or the door is opened. from the vehicle engine is started until it is started, it to is ready supply of electric power from the sub-battery , At least one of before and after the period for supplying the voltage of the sub-battery to the load, said main battery and providing a timing for supplying electric power to the load from both of the sub-battery, wherein the.

Further, the present invention is characterized in that the supply means supplies the power stored in the sub-battery to a plurality of loads.
According to such a configuration, by supplying stable power to a plurality of loads, the loads can be operated reliably.

Further, the present invention is characterized in that the load is a brake system for braking the vehicle.
According to such a configuration, it is possible to prevent kickback from occurring by supplying stable power supply power to the brake system.

Further, the present invention is characterized in that the supply means supplies power to the brake system when the brake pedal is operated by a predetermined amount or more at the time of the engine start.
According to such a configuration, when the brake pedal is operated by a predetermined amount or more, kickback can be reliably prevented by supplying power to the brake system.

Further, in the present invention, the load is a starter motor, and the supply means is configured to supply the electric power from the main battery to the starter motor when the power can not be sufficiently supplied, or when the charging state of the main battery is not sufficient Power supply power is supplied from the battery to the starter motor.
According to such a configuration, the engine can be reliably started even when sufficient power can not be supplied from the main battery.

Further, the invention is characterized in that, when the engine is started, the supply means supplies the voltage of the sub-battery to the load via a regulator for stabilizing the voltage.
According to such a configuration, stable power can be supplied to the load even when the voltage of the main battery becomes unstable at the time of cranking.

Further, the present invention is characterized in that, after power supply power is supplied from the sub-battery to the load by the supply means, the charging means charges until the sub-battery is fully charged. Do.
According to such a configuration, by charging the sub-battery immediately after using it, it is possible to prevent lead sulfate from being generated in the sub-battery and shortening the life.

Further, the supply means is configured to prevent the sub-battery from being discharged by dark current flowing from the sub-battery to the load when the engine of the vehicle is stopped. It is characterized by shutting off the supply.
According to such a configuration, shortening of the life of the sub-battery can be prevented by preventing discharge due to dark current.

Further, the present invention is a power supply device mounted on a vehicle and supplying power source power to a load, the sub-battery being provided separately from the main battery mounted on the vehicle and having a smaller electric capacity than the main battery In the method of controlling a power supply device, the power stored in the sub-battery is supplied to the load when the main battery can not sufficiently supply power to the load or when the state of charge of the main battery is not sufficient. And a charging step of charging the sub-battery with power output from the alternator or the main battery, wherein the supplying step unlocks the door of the vehicle or the door is closed. It is started between the time it is opened and the time the engine of the vehicle is started, and Supply Do to the possible states of Ri, the voltage of the sub-battery to at least one of the front and rear of the period to be supplied to the load, providing the timing for supplying electric power to the load from both of the said main battery sub-battery, it is characterized in.

  According to the present invention, it is possible to provide a power supply device and a control method of the power supply device capable of supplying stable power supply power to a load before starting an engine.

It is a figure showing an example of composition of a power supply device concerning a 1st embodiment of the present invention. It is a figure which shows the detailed structural example of the auxiliary power supply part shown in FIG. It is a figure for demonstrating the operation | movement of 1st Embodiment shown in FIG. It is a flowchart which shows an example of the process performed in 1st Embodiment shown in FIG. It is a figure which shows the structural example of the auxiliary power supply part which concerns on 2nd Embodiment of this invention. It is a figure which shows the structural example of the auxiliary power supply part which concerns on 3rd Embodiment of this invention. It is a figure for demonstrating the operation | movement of 3rd Embodiment shown in FIG.

  Next, an embodiment of the present invention will be described.

(A) Description of Configuration of First Embodiment FIG. 1 is a diagram showing a power supply system of a vehicle having a power supply device according to a first embodiment of the present invention. As shown in this figure, the power supply system of the vehicle has an alternator 10, a main battery 11, a voltage sensor 12, a current sensor 13, a temperature sensor 14, a control unit 15, an auxiliary power supply unit 16, a diode 17, and a load 18. doing.

  Here, the alternator 10 is driven by an engine (not shown), generates AC power, converts it into DC power by the rectifier circuit, and charges the main battery 11.

  Main battery 11 is formed of a secondary battery such as a lead storage battery, a nickel cadmium battery, a nickel hydrogen battery, or a lithium ion battery, for example, and is charged by alternator 10 to drive a starter motor (not shown) to start the engine. And supplies power to the load 18 through the diode 17.

  The voltage sensor 12 detects the terminal voltage of the main battery 11 and notifies the control unit 15 of it. The current sensor 13 detects the current flowing through the main battery 11 and notifies the control unit 15 of it. The temperature sensor 14 detects the temperature of the main battery 11 itself or the surrounding environment, and notifies the control unit 15 of it.

  The control unit 15 refers to the outputs of the voltage sensor 12, the current sensor 13, and the temperature sensor 14 to detect the state of the main battery 11, and controls the generated voltage of the alternator 10 to control the charge state of the main battery 11. Control. When control unit 15 determines that sufficient power can not be supplied from main battery 11 to load 18, or when the charge state of main battery 11 is not sufficient (for example, SOC (State of Charge) is predetermined). (If it is lower than the threshold), the auxiliary power supply unit 16 is instructed to supply power to the load 18.

  As described later, the auxiliary power supply unit 16 has the sub battery 164, and when the main battery 11 can not sufficiently supply power from the main battery 11 to the load 18, or when the charging state of the main battery 11 is not sufficient, Power is supplied from the battery 164 to the load 18.

  The diode 17 prevents the backflow of power from the auxiliary power supply unit 16 to the main battery 11 when power supply power is supplied from the auxiliary power supply unit 16 to the load 18.

  The load 18 is, for example, a brake system for braking a vehicle, and for example, a detection unit that detects an operation amount of a brake pedal, a braking unit for braking a wheel, and an operation amount detected by the detection unit. And a drive unit for driving the braking unit.

  FIG. 2 is a diagram showing a detailed configuration example of the auxiliary power supply unit 16 shown in FIG. As shown in FIG. 2, the auxiliary power supply unit 16 includes a charging unit 161, an auxiliary power control unit 162, a state detection unit 163, a sub battery 164, a voltage sensor 165, a current sensor 166, a temperature sensor 167, a switch 168, and a diode. It has 169.

  Here, based on the control of the auxiliary power supply control unit 162, the charging unit 161 charges the sub-battery 164 with the power output from the alternator 10 (or the main battery 11).

  The auxiliary power supply control unit 162 controls each unit of the auxiliary power supply unit 16 based on the state of the sub battery 164 detected by the state detection unit 163, the output voltage from the main battery 11, and the state of the vehicle.

  The state detection unit 163 detects the state (for example, SOC) of the sub battery 164 with reference to the outputs of the voltage sensor 165, the current sensor 166, and the temperature sensor 167, and notifies the auxiliary power control unit 162.

  The sub-battery 164 is configured by, for example, a secondary battery such as a lead storage battery, a nickel cadmium battery, a nickel hydrogen battery, or a lithium ion battery. The sub battery 164 is configured by a battery independent of the main battery 11, and is configured by a battery having a smaller electric capacity than the main battery 11. More specifically, while the main battery 11 has a capacity of about several tens of Ah, the sub-battery 164 has a capacity of several Ah to several dozen Ah. Further, the main battery 11 is accommodated in the bonnet in front of the vehicle, but the sub-battery 164 is accommodated not in the bonnet but in, for example, a spare tire storage portion in the rear of the vehicle. Of course, although it may be accommodated in other places, in order to prolong the life of the sub-battery 164, a place with a small temperature change is desirable. Also, by arranging the battery in a different place from the main battery 11, for example, even if one of them is broken, power can be supplied from the other even if it is broken. From the viewpoint of risk distribution, these are arranged in different places. Is desirable.

  The voltage sensor 165 detects the terminal voltage of the sub battery 164 and notifies the state detection unit 163. The current sensor 166 detects the current flowing through the sub battery 164 and notifies the state detection unit 163 of the current. The temperature sensor 167 detects the temperature of the sub battery 164 itself or the surrounding environment, and notifies the state detection unit 163 of the detected temperature.

  The switch 168 is configured of, for example, a semiconductor switch or an electromagnetic switch (electromagnetic relay), and the auxiliary power control unit 162 controls the on / off state. When the switch 168 is controlled to the on state, power is supplied from the sub battery 164 to the load 18.

  The diode 169 is a diode for backflow prevention and prevents the power output from the main battery 11 or the alternator 10 from flowing back to the circuit inside the auxiliary power supply unit 16. The diode 17 prevents the power supplied from the auxiliary power supply 16 from flowing back to the main battery 11 or the like, as shown in FIG.

(B) Description of Operation of First Embodiment Next, an operation of the first embodiment will be described. FIG. 3 is a diagram showing changes in voltage and the like at the start of the vehicle. If the driver approaches the vehicle and the door of the vehicle is opened at time t1 while the vehicle is stopped, the control unit 15 detects this and sends the auxiliary power control unit 162 of the auxiliary power supply unit 16 Instruct them to start. As a result, as shown in FIG. 3B, the auxiliary power control unit 162 is put into the “start” state, and start processing such as initialization processing is performed.

  When the auxiliary power supply unit 16 is activated, the state detection unit 163 detects the state of the sub battery 164 and determines whether or not it is normal. More specifically, the state detection unit 163 measures the terminal voltage of the sub battery 164 by the voltage sensor 165, and when the voltage falls within the predetermined range, determines that the state is normal. Alternatively, the state detection unit 163 pulse discharges the sub-battery 164 by, for example, a discharge circuit (not shown), and obtains the impedance of the sub-battery 164 from changes in voltage and current at that time. Then, the SOC is calculated from the determined impedance, and when the calculated SOC is equal to or greater than a predetermined threshold value, it is determined that the state of sub battery 164 is normal.

  When it is determined that the state of the sub battery 164 is normal, the auxiliary power control unit 162 turns the switch 168 on and the charging unit 161 off. As a result, the source power output from sub battery 164 is supplied to load 18 via switch 168 and diode 169. As a result, as shown in FIG. 3C, the auxiliary power supply unit 16 is in a state of supplying the starting power to the load 18.

  Next, at time t2, when the driver operates the brake pedal serving as a condition for starting the engine, power is supplied from the sub battery 164 to the load 18, which is the brake system, via the switch 168 and the diode 169. Be done. The sub-battery 164 is charge-controlled to be fully charged or close to it, as will be described later, so that sufficient power is supplied to operate the load 18 which is a brake system. For this reason, for example, even when the driver strongly depresses the brake pedal (for example, even when depressing with a force of 50 kgf or more which is considered to be likely to cause kickback), kickback does not occur.

  Next, at time t3, when the driver instructs rotation of the starter motor, a starter motor (not shown) is rotated, and engine cranking is performed. At this time, a large inrush current flows at the start of rotation of the starter motor, and the current increases as the piston of the engine approaches top dead center. Therefore, the voltage of the main battery 11 is a plurality of voltages as shown in FIG. It will be in the state of fluctuating with the extremum. However, power is also supplied from the auxiliary power supply unit 16 to the brake system, and since the auxiliary power supply unit 16 is supplied with power from the sub-battery 164 having a configuration independent of the main battery 11, cranking is performed by cranking. Even when the voltage of the main battery 11 becomes unstable, stable power supply power is supplied to the brake system, which can prevent, for example, kickback from occurring.

  Next, at time t4, when the engine starts to rotate, the supply of power from the main battery 11 to the starter motor is stopped. Also, when the engine starts to rotate, the driver ends the operation of the brake pedal. When the operation of the brake pedal is completed, the control unit 15 detects this and notifies the auxiliary power supply unit 16. The auxiliary power supply control unit 162 of the auxiliary power supply unit 16 stops the supply of power from the sub-battery 164 to the load 18 by turning off the switch 168. As a result, instead of stopping the supply of power from the auxiliary power supply unit 16 to the load 18, the supply of power from the main battery 11 to the load 18 is started. At this time, since the starter motor ends its rotation and charging from the alternator 10 is started, the voltage of the main battery 11 becomes stable. For this reason, even if the supply of power from the main battery 11 is started instead of the auxiliary power supply unit 16, the voltage becomes unstable and, for example, kickback does not occur.

  Further, at time t4, when the cranking is completed, the control unit 15 controls the alternator 10 to start power generation, and starts charging of the main battery 11. Further, control unit 15 controls auxiliary power supply control unit 162 to start charging of sub-battery 164. More specifically, the auxiliary power control unit 162 controls the charging unit 161 to charge the sub-battery 164 with the power generated by the alternator 10. In addition, as a charging method by the charging unit 161, constant current charging can be performed using a current value that does not shorten the life of the sub battery 164. Further, by charging immediately after using the sub-battery 164, it is possible to charge the lead sulfate generated by the discharge while it is soft and prevent the lead sulfate from growing into a hard crystal. Thereby, the life of sub battery 164 can be extended.

  As described above, according to the first embodiment of the present invention, the auxiliary power supply unit 16 having the sub-battery 164 constituted by the secondary battery is provided, and the auxiliary power supply unit 16 is activated before the engine is started to operate. It was possible. Thus, for example, when the driver operates the brake pedal before starting the engine, by supplying power from the auxiliary power supply 16, it is possible to prevent, for example, kickback from occurring.

  Also, during cranking, power is supplied from the sub-battery 164 that is configured independently of the main battery 11 to the load 18 that is the brake system, so the voltage of the main battery 11 becomes unstable due to cranking. Even in the case where it has become, it is possible to prevent the occurrence of kickback and the like by supplying stable power to the brake system.

  In addition, since the sub-battery 164 is promptly charged after cranking is completed and power generation by the alternator 10 is started, lead sulfate can be prevented from growing into a hard crystal, so It is possible to extend the life.

  Next, details of the operation of the first embodiment will be described with reference to FIG. When the process of the flowchart shown in FIG. 4 is started, the following steps are performed.

  In step S10, the auxiliary power control unit 162 turns off the switch 168. As a result, since a dark current which is a weak current does not flow from the sub battery 164 to the load 18, it is possible to prevent the sub battery 164 from discharging.

  In step S11, the control unit 15 controls the auxiliary power control unit 162 to stop the operation of each unit of the auxiliary power unit 16. As a result, by stopping the operation of the portion receiving the power supply from sub battery 164, the power consumption of sub battery 164 is suppressed, and the operation of the portion receiving the power supply from main battery 11 is stopped. Thus, the power consumption of the main battery 11 can be suppressed.

  In step S12, the control unit 15 determines whether the door is opened or not, and if it is determined that the door is opened (step S12: Yes), the process proceeds to step S13, otherwise (step S12: No) The same process is repeated for.

  In step S13, the control unit 15 controls the auxiliary power control unit 162 to start the operation of each unit of the auxiliary power unit 16. More specifically, the auxiliary power control unit 162 executes activation processing such as initialization processing, detects the state of the sub battery 164 by the state detection unit 163, and determines whether or not it is normal. As a result, the auxiliary power supply unit 16 becomes operable.

  In step S14, the auxiliary power control unit 162 turns on the switch 168. As a result, supply of power supply power from sub battery 164 to load 18 is started.

  In step S15, the control unit 15 determines whether or not the IG is in the on state, and if it is determined that the IG is in the on state (step S15: Yes), the process proceeds to step S16, otherwise (in the other cases) The same processing is repeated in step S15: No).

  In step S16, the starter motor is rotated by the power from the main battery 11, and the engine is cranked.

  In step S17, the control unit 15 determines whether or not the engine has been started. If it is determined that the engine has been started (step S17: Yes), the process proceeds to step S18, and otherwise (step S17: No). In step S16, the process returns to step S16 to repeat the same process as described above.

  In step S18, the auxiliary power control unit 162 turns off the switch 168. As a result, the supply of power from sub battery 164 to load 18 is stopped.

  In step S19, the auxiliary power control unit 162 controls the charging unit 161 to charge the sub-battery 164. More specifically, the auxiliary power control unit 162 refers to the SOC of the sub battery 164 detected by the state detection unit 163, and continues charging until the sub battery 164 is fully charged. As a method of charging, for example, there is a method of charging with a constant current that does not shorten the life of sub battery 164.

  In step S20, the control unit 15 determines whether the engine is stopped or not, and when it is determined that the engine is stopped (step S20: Yes), the process returns to step S10 and the same process as described above is repeated. Otherwise, the process returns to step S19 to continue the charging process.

  According to the above process, the operation described with reference to FIG. 3 can be realized.

  Although the charging process is not continued after the engine is stopped in the flowchart shown in FIG. 4, for example, even after the engine is stopped, the sub battery 164 is fully charged, The charging process may be continued by the power of the main battery 11. According to such processing, even when the vehicle is used only for a short time, the sub-battery 164 can be kept fully charged, so the life of the sub-battery 164 can be extended.

(C) Description of Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the configuration other than the auxiliary power supply unit 16 shown in FIG. 5 is the same as that in FIG. Further, in FIG. 5, the portions corresponding to those in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted. 5, the switch 168 is changed to two of the switches 168-1 and 168-2 and the diode 169 is changed to two of the diodes 169-1 and 169-2 in comparison with FIG. Also, a load 18-1 is connected to the diode 169-1 and a load 18-2 is connected to the diode 169-2. The load 18-1 is connected to the main battery 11 via the diode 17-1, and the load 18-2 is connected to the main battery 11 via the diode 17-2.

  Here, the switches 168-1 and 168-2 are configured by, for example, semiconductor switches or electromagnetic switches, controlled by the auxiliary power control unit 162, and turned on or off. The diodes 169-1 and 169-2 are backflow prevention diodes, and when power is supplied from the main battery 11 to the loads 18-1 and 18-2, the power flows back into the auxiliary power supply unit 16 To prevent. The load 18-1 is configured by a brake system as in the first embodiment. The load 18-2 may be, for example, a wiper, a blower motor, a steering motor, various lights (headlights, room lights, courtesy lights, backlights, etc.), various ECUs (Electric Control Units), or a vehicle emergency notification device (accident In the case of an emergency, etc., it is configured by a device that automatically notifies the nearest police station or fire department via an emergency call center. The diode 17-1 and the diode 17-2 are backflow prevention diodes that prevent the power supplied from the auxiliary power supply unit 16 from flowing back to the main battery 11 or the like.

  Next, the operation of the second embodiment will be described. The operation of supplying power to the load 18-1 is the same as that of the first embodiment, and thus the description thereof is omitted. In the second embodiment, in FIG. 3, when the door is opened and the load 18-2 is in operation, the switch 168-2 is turned on. When the switch 168-2 is turned on, power can be supplied from the sub battery 164 to the load 18-2. Therefore, for example, when the voltage of the main battery 11 becomes unstable due to cranking, power supply power is supplied from the sub battery 164 to the load 18-2. Thus, for example, in the case of a load having a motor or the like (for example, a wiper, a blower motor, a steering motor or the like), the operation of the motor becomes unstable, which can prevent the driver from feeling uncomfortable. In addition, when the load 18-2 is various lights (headlights, room lights, courtesy lights, backlights, etc.), the voltage of the main battery 11 becomes unstable, so that the illuminance is changed to the driver. It can prevent giving a feeling of discomfort. In addition, when the load 18-2 is any of various ECUs, the voltage of the main battery 11 becomes unstable, so that the operation of the ECU can be prevented from becoming unstable or not operating. Further, in the case of the vehicle emergency notification device, even when the vehicle is damaged due to a collision or the like and the main battery 11 becomes unusable, the main battery 11 is separate from the main battery 11. Since power can be supplied to the vehicle emergency notification device from the sub-battery 164 disposed at a different location, reliable operation can be guaranteed. Then, when the engine is stopped, the switch 168-2 is turned off, and the supply of power from the sub battery 164 to the load 18-2 is stopped.

  In the above, the switch 168-1 and the switch 168-2 are turned on when the door is opened and turned off when the engine is stopped. However, the switch 168-1 and the switch 168-2 may be turned on or off at different timings. For example, when the load 18-2 is an ECU or the like, it is desirable to supply a stable voltage at the time of start-up, so when the door is opened, the switch 168-2 is turned on. Alternatively, for example, the switch 168-2 may be turned on when the IG switch is turned on.

(D) Description of Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, the configuration other than the auxiliary power supply unit 16 shown in FIG. 6 is the same as that in FIG. Further, in FIG. 6, the portions corresponding to those in FIG. 5 are denoted by the same reference numerals, and the description thereof will be omitted. 6, a switch 168-3, a diode 169-3, a switch 170, and a regulator 171 are added as compared to FIG. Also, the diodes 17-1 and 17-2 are excluded, and the diode 17 is added to the load 18-1. The configuration other than these is the same as in the case of FIG.

  Here, the switch 170 is configured of a semiconductor switch or an electromagnetic switch, and is controlled by the auxiliary power control unit 162 to be in an on or off state. The regulator 171 is configured by a DC / DC converter or the like, and boosts or lowers the voltage of the main battery 11 or the sub battery 164 supplied from the charging unit 161 to a constant voltage, and supplies the voltage to the switch 168-2.

  The switch 168-2 is controlled to be in the on or off state by the auxiliary power supply control unit 162, and when it is controlled to be in the on state, the voltage output from the regulator 171 can be output via the diode 169-2 via the load 18-. Supply to 2.

  The switch 168-3 is controlled to be in the on or off state by the auxiliary power control unit 162, and when it is controlled to be in the on state, the voltage output from the main battery 11 is loaded through the diode 169-3. Supply to -2.

  Next, the operation of the third embodiment of the present invention will be described. In addition, since the supply operation | movement of the power supply voltage with respect to the load 18-1 is the same as that of the case of 1st Embodiment, the description is abbreviate | omitted.

  In the third embodiment, the load 18-2 is configured by, for example, a car audio system or a car navigation system. The auxiliary power control unit 162 restarts the engine after so-called idling stop for stopping the engine during idling and improving fuel efficiency, for example, when the driver gets in and the engine is first started. In this case, the switch 168-2 is turned on and the switch 168-3 is turned off. As a result, since the power supply power of the sub battery 164 whose voltage is stabilized by the regulator 171 is supplied to the load 18-2, even if the voltage of the main battery 11 becomes unstable due to cranking, car audio or car It is possible to prevent the navigation system etc. from malfunctioning or generating noise. When the engine starts to rotate, the auxiliary power control unit 162 turns off the switch 168-2 and turns on the switch 168-3. As a result, since the power supply power from the main battery 11 which is stabilized by the completion of cranking is supplied to the load 18-2 to the load 18-2, power consumption of the sub-battery 164 can be prevented.

  In the third embodiment, the switch 170 is newly provided. The switch 170 is controlled by the auxiliary power control unit 162 to be in the on state when the main battery 11 is normal, and in the off state when the main battery 11 is abnormal. Thus, when the voltage on the main battery 11 side is higher or lower than normal, it is possible to prevent the auxiliary power supply unit 16 from being affected by the abnormal voltage on the main battery 11 side.

  As described above, in the third embodiment, since the power supply power is supplied to the load 18-2 via the regulator 171 at engine start-up, the car audio or car navigation system sensitive to voltage fluctuation malfunctions. And noise can be prevented.

  Although the regulator 171 outputs stabilized power using the power of the sub battery 164 in the above description, the power of the main battery 11 may be used. Alternatively, when the switch 170 is on, the power of the main battery 11 may be used, and when the switch 170 is off, the power of the sub battery 164 may be used.

(E) Description of Modified Embodiments It goes without saying that the above embodiment is an example, and the present invention is not limited only to the case as described above. For example, in the example of FIG. 3, when the door is opened, the auxiliary power supply unit 16 is activated. For example, as indicated by a broken line in FIG. 16 may be activated. Of course, it may be started at another timing before the engine is started. Alternatively, the auxiliary power supply unit 16 may be activated when the door is unlocked before the door is opened. The case where the door is unlocked is, for example, a case where the radio wave is received from the remote control key and the lock is released in the case of the remote control key, and in the case of the manual key, for example, the key When the lock is released by inserting the key into the keyhole.

  Further, in each of the above embodiments, a starter motor is not exemplified as a load for supplying power from the sub battery 164, but of course, power may be supplied to the starter motor. More specifically, when the state of charge of the main battery 11 is not sufficient, it is difficult to rotate the engine until the engine is started by the starter motor. In such a case, the auxiliary power control unit 162 It is also possible to detect and supply power from the sub battery 164 to the starter motor. As conditions for supplying power from the sub-battery 164, for example, (1) every time supply, (2) the engine can not be started at one time, and the number of times the starter motor is rotated is two or more. In the case (3), the state of charge of the main battery 11 may fall below a predetermined threshold value.

  In each of the above embodiments, power is supplied to the load from either the main battery 11 or the sub battery 164. However, as shown in FIG. 7, for example, the main battery 11 and the sub battery 164 The timing to supply power from both may be provided. More specifically, the example of FIG. 7 corresponds to the third embodiment shown in FIG. 6, and as shown in FIG. 7 (D), when the inrush current flows during cranking, the ignition is turned off In this state, both of the switch 168-2 and the switch 168-3 are in the on state, and the state of the status B in which power is supplied from both the main battery 11 and the sub battery 164 is obtained. Also, during cranking, the switch 168-2 is turned on, the switch 168-3 is turned off, and the power of the sub battery 164 is supplied to the load 18-2 via the regulator 171. It will be in the state of C. Otherwise, the switch 168-2 is turned off, the switch 168-3 is turned on, and the state of status A in which the power of the main battery 11 is supplied to the load 18-2. Become. Thus, by providing status B in which power is supplied from both main battery 11 and sub battery 164, a logical OR circuit is formed by diode 169-2 and diode 169-3, and from the power supply with the higher voltage Since power is supplied, the power supply voltage supplied to the load 18-2 can be made constant, and switching noise can be prevented from occurring at the time of these switching. Note that, in the example of FIG. 7, the status B of supplying power from both the main battery 11 and the sub battery 164 is provided before and after both of the status C, which is a section of supplying power from the sub battery 164 to the load 18-2. However, the status B may be provided at least one of before and after the status C.

  In each of the above embodiments, when the engine is started, generation of kickback is suppressed by supplying power from the sub battery 164 to the brake system. However, since kickback occurs when the brake pedal is depressed with a predetermined force or more, when the brake pedal is depressed with a predetermined force or more, power is supplied from the sub battery 164 to the brake system. You may

  In each of the above embodiments, although the case where one or two loads are taken is described as an example, power may be supplied from the auxiliary power supply unit 16 to three or more loads.

  Further, in the flowchart shown in FIG. 4, the case where the engine is started is assumed to be the first start of the engine after the driver has boarded, but when starting the engine after the idling stop described above, the flowchart of FIG. The processing of may be performed.

  Further, in the third embodiment shown in FIG. 6, when the auxiliary power supply unit 16 is not in operation, the switch 168-3 is turned on, and the power from the main battery 11 is transferred to the load 18-2. It may be supplied.

DESCRIPTION OF SYMBOLS 10 alternator 11 main battery 12, 165 voltage sensor 13, 166 current sensor 14, 167 temperature sensor 15 control part 16 auxiliary power supply part 17 diode 18, 18-1, 18-2 load 161 charge part 162 auxiliary power supply control part 163 state detection Part 164 Sub battery 168, 168-1, 168-2, 168-3, 170 Switch 169, 169-1, 169-2, 169-3 Diode 171 Regulator

Claims (9)

In a power supply apparatus mounted on a vehicle and supplying power supply power to a load
A sub battery provided separately from the main battery mounted on the vehicle and having a smaller electric capacity than the main battery;
Supply means for supplying power stored in the sub-battery to the load when the main battery can not sufficiently supply power to the load or when the state of charge of the main battery is not sufficient;
And charging means for charging the sub-battery with power output from an alternator or the main battery,
The supply means is activated between the time the door of the vehicle is unlocked or the door is opened and the engine of the vehicle is started, and power can be supplied from the sub-battery. Ri Do in such state,
A timing is provided to supply power to the load from both the main battery and the sub-battery before and / or after a period of supplying the voltage of the sub-battery to the load.
A power supply device characterized by   The power supply device according to claim 1, wherein the supply unit supplies the power stored in the sub-battery to a plurality of loads.   The power supply device according to claim 1, wherein the load is a brake system for braking the vehicle.   The power supply device according to claim 3, wherein the supply means supplies power to the brake system when the brake pedal is operated by a predetermined amount or more at the time of starting the engine. The load is a starter motor,
The supply means supplies power from the sub-battery to the starter motor when the main battery can not sufficiently supply power to the starter motor, or when the state of charge of the main battery is not sufficient. The power supply device according to any one of claims 1 to 4, characterized by   The said supply means supplies the voltage of the said sub-battery to the said load via the regulator for stabilizing voltage, when starting the said engine. Power supply as described in. The power supply power is supplied from the sub-battery to the load by the supply unit, and the charging unit charges the sub-battery until the sub-battery is fully charged. The power supply device according to any one of the above. The supply means supplies power to the load so as to prevent the sub-battery from being discharged by dark current flowing from the sub-battery to the load when the engine of the vehicle is stopped. The power supply device according to any one of claims 1 to 7, wherein the power supply is shut off. A power supply device mounted on a vehicle and supplying power source power to a load, the control of the power supply device having a sub-battery which is provided separately from the main battery mounted on the vehicle and has a smaller electric capacity than the main battery In the method
A step of supplying power stored in the sub-battery to the load when the main battery can not sufficiently supply power to the load or when the state of charge of the main battery is not sufficient;
Charging the sub-battery with the power output from the alternator or the main battery;
The supplying step is activated between the unlocking of the door of the vehicle or the opening of the door and the start of the engine of the vehicle, and power can be supplied from the sub-battery. Be in a good condition,
A timing is provided to supply power to the load from both the main battery and the sub-battery before and / or after a period of supplying the voltage of the sub-battery to the load.
And controlling the power supply device.

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