JP2015128341A - Power supply device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device for a vehicle, capable of reducing electric wires, attaining miniaturization, and reducing a cost.SOLUTION: A power supply device 1 for a vehicle is arranged between an on-vehicle battery 2 and a load 3. The power supply device 1 for a vehicle includes: a capacitor 6 to be charged by the on-vehicle battery 2; a changeover switch SW9 for changing over a power supply to the load 3 into one of the power output from the on-vehicle battery 2 and power output from the capacitor 6; a first voltage detection circuit 14 and a second voltage detection circuit 7 for respectively detecting the output voltage values V1 and V2 of the on-vehicle battery 2; and a control section 20 for controlling the changeover switch SW9 on the basis of the detected output voltage value. The control section 20 is a body system control device.

Description

  The present invention relates to a vehicle power supply device including a vehicle body control device.

  Generally, an in-vehicle battery is used as a power source for supplying electric power to each in-vehicle load. However, the in-vehicle battery may not be able to supply power due to disconnection or power shortage due to, for example, a vehicle collision. In such a case, each vehicle-mounted load cannot be driven.

  For this reason, an emergency power supply device has been developed to allow each on-board load to be driven in an emergency by mounting a capacitor or the like as an auxiliary power source in addition to the on-board battery.

  As such an emergency power supply device, for example, an emergency power supply device as shown in Patent Document 1 has been proposed. The emergency power supply device is connected between the in-vehicle battery and the load, and includes a capacitor that charges the power of the in-vehicle battery, a charge control circuit that controls charging of the capacitor, a booster circuit that is connected to the capacitor, and a booster circuit The output voltage detection circuit of the vehicle-mounted battery or the capacitor connected to, and a control unit for controlling the entire circuit. In addition, when a load is connected to the output voltage detection circuit, the control unit feeds back the boost circuit so that the output voltage of the output voltage detection circuit has a predetermined output voltage characteristic over time when the power of the capacitor is output. Control. As a result, the load can be driven with a small number of capacitors.

JP 2007-60822 A

  In a vehicle equipped with such an emergency power supply device, an in-vehicle battery is usually used as a power source for a load such as a motor. When the vehicle collides, the body ECU receives a signal notifying that the vehicle ECU has collided, for example, and determines whether or not the in-vehicle battery power supply is interrupted. When it is determined that the power supply of the in-vehicle battery is interrupted, the body ECU switches the power source to the emergency power supply device. Thus, the load is driven by the power supply from the emergency power supply device.

  However, since the body ECU and the emergency power supply device are installed separately, a long electric wire is required to connect the body ECU and the emergency power supply device. The vehicle also needs a wiring space for wiring these electric wires. As a result, it is difficult to downsize the vehicle on-board control system as a whole.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a vehicular power supply apparatus that can reduce the number of electric wires and reduce the size and cost.

  A vehicle power supply device according to a first aspect of the present invention is a vehicle power supply device that is provided between a vehicle-mounted battery and a load, and includes a capacitor that is charged by the vehicle-mounted battery, and outputs power supply to the load from the vehicle-mounted battery. Based on the output voltage value detected by the output voltage detection means, the output voltage detection means for detecting the output voltage value of the in-vehicle battery, the changeover switch for switching to any one of the outputted power and the power output from the battery And a control means for controlling the changeover switch, wherein the control means is a body-type control device.

  In the present invention, the body control device is integrated with the vehicle power supply device, and is also used as the control means of the vehicle power supply device.

  According to a second aspect of the present invention, there is provided a vehicular power supply apparatus comprising: a charging voltage detection unit that detects a charging voltage value of the capacitor; and the control unit is configured to control the capacitor based on the charging voltage value detected by the charging voltage detection unit. It is characterized in that the charging to is controlled.

  In the present invention, the control means monitors the charging voltage of the capacitor and controls the charging of the capacitor. As a result, the charging voltage of the battery can always be controlled to the target voltage, and overcharging of the battery can be reliably prevented.

  In the vehicular power supply device according to the third aspect of the invention, the control means notifies the predetermined signal to the outside when the charging voltage value detected by the charging voltage detecting means is smaller than the predetermined voltage value. Features.

  In the present invention, the control means monitors the charging voltage of the battery, and when the charging voltage is lower than the predetermined voltage, notifies the predetermined signal to the outside. Thereby, it is possible to notify the outside of the voltage shortage of the battery.

  According to a fourth aspect of the present invention, there is provided a vehicular power supply apparatus comprising temperature detection means for detecting the temperature of the battery, wherein the control means controls the charging voltage of the battery based on the temperature detected by the temperature detection means. It is characterized by that.

  In the present invention, the control means monitors the temperature of the battery and controls the charging voltage of the battery. When the storage battery is at a high temperature, it is possible to avoid charging the storage battery at a high voltage by reducing the target charging voltage of the storage battery.

  The vehicular power supply apparatus according to a fifth aspect is characterized in that the control means notifies a predetermined signal to the outside when the temperature detected by the temperature detecting means is higher than a predetermined temperature.

  In the present invention, the control means monitors the temperature of the battery, and when the temperature is higher than the predetermined temperature, notifies the outside of a predetermined signal. Thereby, the overheating of the battery can be notified to the outside.

  The vehicle power supply device of the present invention can be reduced in size and cost while being reduced in the number of electric wires by integrating the body system control device into the vehicle power supply device as a control means.

It is a block diagram which shows schematic structure of the power supply device for vehicles which concerns on this invention. It is a flowchart which shows an example of the process sequence which the control part in the vehicle power supply device which concerns on this invention performs. It is a flowchart which shows an example of the process sequence of the control part which concerns on the subroutine of charge. It is a flowchart which shows an example of the process sequence of the control part which concerns on the subroutine of temperature detection.

  FIG. 1 is a block diagram showing a schematic configuration of a vehicle power supply device 1 according to the present invention. The vehicle power supply device 1 is provided between an in-vehicle battery 2 and a load 3 such as a motor mounted on the vehicle and supplied with electric power by the in-vehicle battery 2.

  The vehicle power supply device 1 includes a battery 6 charged by an in-vehicle battery 2, a booster circuit 8, a power supply switching relay 9, a control unit (control means) 20, and the like. The capacitor 6 is configured by, for example, connecting a plurality of electric double layer capacitors in series. The electric power from the in-vehicle battery 2 is charged into the battery 6 via the ignition switch 30, the fuse F1, the backflow prevention diode D1, the charging switch SW1, and the limiting resistor 5.

  The in-vehicle battery 2 has a negative electrode grounded and a positive electrode connected to the anode of the diode D1 through the ignition switch 30 and the fuse F1. The limiting resistor 5 is connected to the cathode of the diode D1 through the charge switch SW1. The charge switch SW1 is, for example, a P-channel MOSFET (Metal Oxide Semiconductor Field Effect Transistor), the source of the MOSFET is connected to the cathode of the diode D1, the drain is connected to one end of the limiting resistor 5, and the gate is the control unit. 20.

  The vehicular power supply device 1 supplies the load 3 with the electric power discharged from the battery 6 when the in-vehicle battery 2 is not supplied with power due to a failure or the like. Specifically, the electric power discharged from the battery 6 is given to the load 3 via the booster circuit 8, the power supply switching relay 9, and the load switch SW2. The charging voltage value Vc of the battery 6 is detected by a charging voltage detection circuit (charging voltage detection means) 10. The charging voltage detection circuit 10 is a voltage dividing resistor connected to the positive electrode of the battery 6, for example. Further, a temperature sensor (temperature detection means) 11 including an element (thermistor) whose electric resistance value changes according to a temperature change is provided in the vicinity of the battery 6. The temperature sensor 11 detects the temperature Tc of the battery 6.

  The capacitor 6 has a positive electrode connected to the other end of the limiting resistor 5 and a negative electrode grounded. A booster circuit 8 is connected to the positive electrode of the battery 6. The booster circuit 8 includes an input capacitor C8a, a booster coil L8, a booster switch SW8, a rectifier diode D8, and an output capacitor C8b. One end of the input capacitor C8a is connected to the positive electrode of the battery 6 and the other end is grounded. One end of the input capacitor C8a is connected to one end of the booster coil L8. The other end of the booster coil L8 is connected to the anode of the rectifier diode D8. Further, a boost switch SW8 is connected to the other end of the boost coil L8. The boost switch SW8 is, for example, an N-channel MOSFET, and the drain of the MOSFET is connected to the other end of the boost coil L8, the source is grounded, and the gate is connected to the control unit 20. The grounded output capacitor C8b and the power supply switching relay 9 are connected to the cathode of the rectifier diode D8. The booster circuit 8 boosts the voltage output from the battery 6 under the control of the control unit 20 described later.

  The power switching relay 9 is provided between the in-vehicle battery 2 and the battery 6 and the load switch SW2. In the power supply switching relay 9, one switching contact 91 is connected to the cathode of the diode D8 of the booster circuit 8, the other switching contact 92 is connected to the positive electrode of the in-vehicle battery 2 via the fuse F2, and the common contact 93 is a load. Connected to the switch SW2. One end of the switching coil L9 of the power supply switching relay 9 is connected between the switching contact 91 and the cathode of the diode D8, and the other end is connected to the changeover switch SW9. The changeover switch SW9 is, for example, a transistor. The collector of the transistor is connected to the other end of the switching coil L9, the emitter is grounded, and the base is connected to the control unit 20. The changeover switch SW9 switches the connection between the power supply switching relay 9 and the load switch SW2 to one of the changeover contact 91 and the changeover contact 92 according to the control of the control unit 20. Thereby, the power supply to the load 3 can be switched to either the power output from the in-vehicle battery 2 or the power output from the battery 6.

  The common contact 93 of the power supply switching relay 9 is connected to one end of the dark current cut switch SW3. The other end of the dark current cut switch SW3 is connected to a first voltage detection circuit (output voltage detection means) 14 for detecting an output voltage value V1 output from the in-vehicle battery 2 to the load 3. The first voltage detection circuit 14 is, for example, a voltage dividing resistor. The first voltage detection circuit 14 is connected to the anode of the diode D3. The cathode of the diode D3 is connected to the control unit 20.

  The cathode of the diode D8 of the booster circuit 8 is connected to the anode of the backflow preventing diode D2. In addition, a capacitor output voltage detection circuit 12 for detecting an output voltage value Vout when the capacitor 6 is discharged is connected to the cathode of the diode D8 of the booster circuit 8. The capacitor output voltage detection circuit 12 is, for example, a voltage dividing resistor.

  A regulator 13 for supplying a constant voltage of 5V to the control unit 20 is connected to the cathode of the diode D2. Further, the cathode of the diode D5 for backflow prevention is connected to the cathode of the diode D2. The anode of the diode D5 is connected to the positive electrode of the in-vehicle battery 2 via the fuse F3. As described above, the battery 6 is connected to the regulator 13 via the booster circuit 8 and the diode D2, and the on-vehicle battery 2 is connected to the regulator 13 via the fuse F3 and the diode 5. Since the regulator 13 is connected between the cathode of the diode D2 and the cathode of the diode D5, the power is supplied by the higher voltage among the power from the in-vehicle battery 2 and the power from the battery 6. For this reason, even when the vehicle-mounted battery 2 is out of order and power is not supplied, the regulator 13 is supplied with power from the battery 6.

  The anode of the diode D5 is connected to one end of the dark current cut switch SW4. A second voltage detection circuit (output voltage detection means) 7 for detecting the output voltage value V2 of the in-vehicle battery 2 is connected to the other end of the dark current cut switch SW4. The second voltage detection circuit 7 is, for example, a voltage dividing resistor. The second voltage detection circuit 7 is connected to the anode of the diode D4. The cathode of the diode D4 is connected to the control unit 20.

  Further, the ignition switch 30 is connected to the anode of the diode D6 through the fuse F1. The cathode of the diode D6 is connected to the control unit 20.

  The control unit (control means) 20 of the vehicle power supply device 1 includes a CPU (Central Processing Unit) (not shown), and controls the locking (unlocking) / unlocking (unlocking) of a door as a vehicle-mounted control device or lighting of a light. This is a body-type control device that performs control such as turning off / off. That is, the control unit 20 has a function of a body ECU (Electronic Control Unit). The control unit 20 includes an IG signal indicating the on / off state of the ignition switch 30, a door switch signal indicating that the vehicle door switch 40 has been operated, and a collision signal notified from the airbag ECU 50 when the vehicle collides. Is given. Further, the control unit 20 includes the second voltage detection circuit 7, the charging voltage detection circuit 10, the capacitor output voltage detection circuit 12, each voltage value signal detected by the first voltage detection circuit 14, and the temperature detected by the temperature sensor 11. A signal is given. The control unit 20 performs on / off control of the charge switch SW1, the load switch SW2, the boost switch SW8, the dark current cut switches SW3 and SW4, and the changeover switch SW9 based on the given signals.

  Further, the control unit 20 includes a storage unit (not shown). The storage unit stores various parameters set in advance, which will be described later. For example, a table that associates the temperature Tc of the battery 6 with the target charging voltage value V (T) at the temperature is stored. In the present embodiment, target charging voltage value V (T) is set in advance so as to decrease as temperature Tc increases. That is, the higher the temperature Tc, the smaller the target charging voltage value V (T). In addition, you may memorize | store the formula which shows the relationship between temperature Tc and the target charging voltage value V (T) not only in a table but in a memory | storage part. The control unit 20 determines the target charging voltage value V (T) of the battery 6 based on the temperature Tc of the battery 6, and controls the charging voltage Vc of the battery 6 to the target charging voltage value V (T). The control unit 20 can communicate with each in-vehicle ECU outside the vehicle power supply device 1 via a LAN or CAN (not shown).

  In the vehicle power supply device 1 configured as described above, when the ignition switch 30 of the vehicle is turned on, the control unit 20 turns on the charging switch SW1 to charge the battery 6 with the electric power of the in-vehicle battery 2. The power supply switching relay 9 is switched to the switching contact 92 side to supply power from the in-vehicle battery 2 to the load 3.

  Further, the control unit 20 determines whether one of the output voltage values V1 and V2 of the in-vehicle battery 2 detected by the first voltage detection circuit 14 and the second voltage detection circuit 7 is the minimum voltage value Vmin required for driving the load 3. When smaller than (predetermined voltage value), the charging switch SW1 is turned off and the changeover switch SW9 is turned on to control the power supply switching relay 9 to be switched to the switching contact 91 side. Thereby, the electric power output from the battery 6 is supplied to the load 3.

  FIG. 2 is a flowchart showing an example of a processing procedure executed by the control unit 20 in the vehicle power supply device 1 according to the present invention. When the ignition switch 30 is turned on, the control unit 20 executes the process shown in FIG.

  The control unit 20 controls the power switch relay 9 to be switched to the switching contact 92 side by turning off the switch SW9 (step S1), turns on the load switch SW2 (step S2), and loads from the in-vehicle battery 2 to the load. Power is supplied to 3. Then, the control unit 20 calls and executes a subroutine related to charging (step S3).

  Next, the control unit 20 determines whether or not a collision signal notifying that the vehicle has collided from the airbag ECU 50 has been received (step S4). If it is determined that the signal indicating the collision of the vehicle has not been received (step S4: NO), the control unit 20 turns on the switch SW4 and detects the vehicle-mounted battery 2 detected by the second voltage detection circuit 7. The output voltage value V2 is read (step S5), and the switch SW4 is turned off. Then, the control unit 20 determines whether or not the read output voltage value V2 is smaller than a preset minimum voltage value Vmin required for driving the load 3 (step S6).

  When it determines with the output voltage value V2 being smaller than the minimum voltage value Vmin (step S6: YES), the control part 20 transfers a process to step S17. When it is determined that the output voltage value V2 is not smaller than the minimum voltage value Vmin (step S6: NO), the control unit 20 calls and executes a subroutine relating to temperature detection (step S7).

  Next, the control unit 20 reads the charge voltage value Vc of the battery 6 detected by the charge voltage detection circuit 10 (step S8), and determines whether or not the read charge voltage value Vc is smaller than the minimum charge voltage value V0. (Step S9). Here, the minimum charging voltage value V0 is a preset lower limit value of the charging voltage of the battery 6, and is stored in the storage unit of the control unit 20. The minimum charging voltage value V0 is smaller than the target charging voltage value V (T).

  When it determines with the charge voltage value Vc not being smaller than the minimum charge voltage value V0 (step S9: NO), the control part 20 transfers a process to step S11. When it is determined that the charging voltage value Vc is smaller than the minimum charging voltage value V0 (step S9: YES), the control unit 20 outputs a signal (predetermined signal) indicating that a sufficient voltage cannot be output from the battery 6 for example An external device such as an ECU is notified (step S10).

  Next, the control unit 20 determines whether or not an end instruction, that is, a signal with the ignition switch 30 turned off has been received (step S11). When it determines with having received the completion | finish instruction | indication (step S11: YES), the control part 20 turns off load switch SW2 (step S12), and complete | finishes a process.

  When it determines with not having received the completion | finish instruction | indication (step S11: NO), the control part 20 reads the charge voltage value Vc of the battery 6 detected by the charge voltage detection circuit 10 (step S13), and the read charge voltage is read. It is determined whether or not the value Vc is smaller than the target charging voltage V (T) (step S14).

  When it is determined that the read charging voltage value Vc is smaller than the target charging voltage V (T) (step S14: YES), the control unit 20 returns the process to step S3. When it is determined that the read charging voltage value Vc is not smaller than the target charging voltage V (T) (step S14: NO), the control unit 20 returns the process to step S4.

  When it determines with having received the signal which shows the notification which the vehicle collided (step S4: YES), the control part 20 turns ON switch SW3 and the output voltage of the vehicle-mounted battery 2 detected by the 1st voltage detection circuit 14 The value V1 is read (step S15), and the switch SW3 is turned off. Then, the control unit 20 determines whether or not the read output voltage value V1 is smaller than a preset minimum voltage value Vmin necessary for driving the load 3 (step S16).

  When it determines with the output voltage value V1 not being smaller than the minimum voltage value Vmin (step S16: NO), the control part 20 complete | finishes a process. When it is determined that the output voltage value V1 is smaller than the minimum voltage value Vmin (step S16: YES), the control unit 20 controls the power switch relay 9 to be switched to the switching contact 91 side by turning on the switch SW9. (Step S17).

  Next, the control unit 20 reads the output voltage value Vout of the battery 6 detected by the battery output voltage detection circuit 12 (step S18), and determines whether or not the read output voltage value Vout is smaller than the minimum voltage value Vmin. (Step S19).

  When it determines with the output voltage value Vout not being smaller than the minimum voltage value Vmin (step S19: NO), the control part 20 complete | finishes a process. When it is determined that the output voltage value Vout is smaller than the minimum voltage value Vmin (step S19: YES), the control unit 20 activates the booster circuit 8 and controls the booster switch SW8, thereby boosting the output voltage of the capacitor 6. Then, the load 3 is driven (step S20), and the process ends.

  FIG. 3 is a flowchart showing an example of a processing procedure of the control unit 20 according to the charging subroutine.

  The control unit 20 turns on the charging switch SW1 (step S31), and reads the temperature Tc of the battery 6 detected by the temperature sensor 11 (step S32). The control unit 20 reads the charging voltage value Vc of the battery 6 detected by the charging voltage detection circuit 10 (step S33), and the read charging voltage value Vc corresponds to the temperature Tc read in step S32. It is determined whether or not V (T) is reached (step S34).

  When it is determined that the charging voltage value Vc has not reached the target charging voltage value V (T) (step S34: NO), the control unit 20 returns the process to step S33.

  When it is determined that the charging voltage value Vc has reached the target charging voltage value V (T) (step S34: YES), the control unit 20 turns off the charging switch SW1 (step S35) and returns the process.

  FIG. 4 is a flowchart illustrating an example of a processing procedure of the control unit according to the temperature detection subroutine.

  The controller 20 reads the temperature Tc of the battery 6 detected by the temperature sensor 11 (step S41). The control unit 20 determines whether or not the read temperature Tc is higher than a threshold temperature (predetermined temperature) T1 (step S42). Here, the threshold temperature T <b> 1 is a preset upper limit value of the normal use temperature of the battery 6, and is stored in the storage unit of the control unit 20.

  When it determines with temperature Tc not being higher than threshold temperature T1 (step S42: NO), the control part 20 returns a process. When it is determined that the temperature Tc is higher than the threshold temperature T1 (step S42: YES), the control unit 20 transmits a signal (predetermined signal) indicating that the battery 6 is abnormal in temperature to an external device such as another ECU. Notification is made (step S43), and the process returns.

  In the present embodiment, the body-type control device is integrated with the vehicle power supply device 1 and is also used as the control means of the vehicle power supply device 1. Thereby, while reducing an electric wire, size reduction and cost reduction can be achieved.

  Further, the control unit 20 controls the charging of the battery 6 based on the charging voltage value Vc of the battery 6 detected by the charging voltage detection circuit 10. Thereby, the charging voltage value Vc of the battery 6 can always be controlled to the target charging voltage value V (T), and overcharging of the battery 6 can be reliably prevented. Thereby, deterioration of the battery 6 can be prevented. Further, when the charging voltage Vc of the battery 6 is too low, the control unit 20 can notify the abnormality of the battery 6 to the outside by notifying a signal to the outside. Thereby, the failure of the battery 6 can be detected.

  Further, the control unit 20 controls the charging voltage of the battery 6 based on the temperature Tc of the battery 6 detected by the temperature sensor 11. When the battery 6 is at a high temperature, an increase in the temperature of the battery 6 can be suppressed by reducing the target charging voltage of the battery 6. Thereby, deterioration of the battery 6 can be prevented. Further, when the temperature Tc of the battery 6 is too high, the control unit 20 can notify the outside of the battery 6 overheating by notifying the outside of the signal. Thereby, the failure of the battery 6 can be detected.

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

DESCRIPTION OF SYMBOLS 1 Power supply device for vehicles 2 Car-mounted battery 3 Load 5 Limit resistance 6 Capacitor 7 Second voltage detection circuit 8 Booster circuit 9 Power supply switching relay 10 Charge voltage detection circuit 11 Temperature sensor 14 First voltage detection circuit SW1 Charge switch SW2 Load switch SW3 Dark Current cut switch SW4 Dark current cut switch SW8 Boost switch SW9 selector switch

Claims (5)

In a vehicle power supply device provided between a vehicle-mounted battery and a load and provided with a capacitor charged by the vehicle-mounted battery,
A changeover switch for switching power supply to the load to either power output from the in-vehicle battery and power output from the battery,
Output voltage detection means for detecting the output voltage value of the in-vehicle battery;
Control means for controlling the changeover switch based on the output voltage value detected by the output voltage detection means,
The vehicle power supply apparatus, wherein the control means is a body-type control apparatus. Charging voltage detecting means for detecting a charging voltage value of the capacitor,
2. The vehicle power supply device according to claim 1, wherein the control means controls charging of the battery based on a charging voltage value detected by the charging voltage detecting means.   3. The vehicle according to claim 2, wherein the control means notifies a predetermined signal to the outside when a charging voltage value detected by the charging voltage detecting means is smaller than a predetermined voltage value. Power supply. Comprising temperature detecting means for detecting the temperature of the capacitor;
The vehicle according to any one of claims 1 to 3, wherein the control means controls the charging voltage of the battery based on the temperature detected by the temperature detection means. Power supply. 5. The vehicle power supply device according to claim 4, wherein the control means notifies a predetermined signal to the outside when the temperature detected by the temperature detecting means is higher than a predetermined temperature.

Images