JP5699927B2 - Vehicle power supply - Google Patents

Description

  The present invention relates to a vehicle power supply device, and more particularly to a vehicle power supply device including a capacitor that functions as a power supply for an electrical component mounted on the vehicle.

  Many electric devices are usually mounted on a vehicle, and the need to stably supply electric power to these electric devices is increasing. For this reason, there is a case where a capacitor is mounted on the vehicle as an auxiliary power source in order to stably supply power to the electric equipment even when an abnormality is found in the main power supply device. Here, a technique has been proposed in which a capacitor is charged at the start of vehicle operation and discharged at the end of vehicle operation (see, for example, Patent Document 1).

JP 2004-322987 A

  It is known that a capacitor is likely to cause performance degradation when placed in a high temperature environment, for example. For this reason, if the battery is always charged in the same manner after the vehicle operation is started as in the technique described in the above-mentioned patent document, there is a possibility that the performance deterioration is accelerated, and it is necessary to increase the replacement frequency of the capacitor.

  Therefore, the present invention has been made to solve the above-described problems, and an object thereof is to suppress the replacement frequency of a capacitor that functions as a power source for an electric device mounted on a vehicle.

In order to solve the above-described problems, a vehicle power supply device according to an aspect of the present invention includes a capacitor that functions as a power source for an electric device mounted on a vehicle, and a charge control unit that controls charging of the capacitor. The charge control unit obtains a stop state signal indicating that the shift position is in the parking range in a travel preparation state where the vehicle can travel , and outputs the stop state signal when the brake pedal is not depressed. The charging voltage when charging the capacitor is reduced compared to the case where the capacitor is not acquired. According to this aspect, when the necessity of power supply by the capacitor is low, such as when the vehicle is stopped, by suppressing the charging voltage to a voltage lower than usual, the charging at the start of vehicle traveling can be performed compared to the case where charging is completely avoided. While shortening the time to full charge, the performance deterioration of the capacitor due to charging can be suppressed, and the replacement frequency of the capacitor can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the replacement frequency of the capacitor which functions as a power supply of the electric equipment mounted in the vehicle can be suppressed.

1 is a system diagram showing a brake control device according to an embodiment of the present invention. It is a figure showing the electrical configuration of a brake control device and its periphery. It is a flowchart which shows in detail the execution procedure of the charge control of the capacitor which concerns on 1st Embodiment. It is a flowchart which shows in detail the execution procedure of the charge control of the capacitor which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a system diagram showing a brake control device according to an embodiment of the present invention. The brake control device 10 constitutes an electronically controlled brake system (ECB) for a vehicle and controls braking force applied to four wheels provided in the vehicle. The brake control device 10 is mounted on, for example, a hybrid vehicle that includes an electric motor and an internal combustion engine as a travel drive source. In such a hybrid vehicle, regenerative braking that brakes the vehicle by regenerating kinetic energy of the vehicle into electrical energy and hydraulic braking by the brake control device 10 can be used for braking the vehicle. A vehicle on which the brake control device 10 according to the present embodiment is mounted can execute brake regenerative cooperative control in which a desired braking force is generated by using these regenerative braking and hydraulic braking together.

  The brake pedal 12 is connected to a master cylinder 14 that delivers hydraulic fluid in response to a depression operation by the driver. The brake pedal 12 is provided with a stroke sensor 46 for detecting the depression stroke.

  Connected to the first output port 14a of the master cylinder 14 is a stroke simulator 24 that creates a pedal stroke according to the depression force of the brake pedal 12 by the driver. A simulator cut valve 23 is provided in the middle of the flow path connecting the master cylinder 14 and the stroke simulator 24. The simulator cut valve 23 is a normally-closed electromagnetic on-off valve that opens when energized during normal operation and closes when de-energized such as during an abnormality. The master cylinder 14 is connected to a reservoir tank 26 for storing hydraulic fluid.

  A brake fluid pressure control pipe 16 for the right front wheel is connected to the first output port 14 a of the master cylinder 14. The brake fluid pressure control pipe 16 is connected to a wheel cylinder 20FR for the right front wheel that applies a braking force to the right front wheel (not shown). A brake fluid pressure control pipe 18 for the left front wheel is connected to the second output port 14b of the master cylinder 14. The brake fluid pressure control pipe 18 is connected to a wheel cylinder 20FL for the left front wheel that applies a braking force to the left front wheel (not shown).

  A right electromagnetic on-off valve 22FR is provided in the middle of the brake fluid pressure control pipe 16 for the right front wheel, and a left electromagnetic on-off valve 22FL is provided in the middle of the brake fluid pressure control pipe 18 for the left front wheel. Yes. The right solenoid on-off valve 22FR and the left solenoid on-off valve 22FL are both normally open solenoid valves that are open when not energized and switched to closed when energized. Hereinafter, the right electromagnetic on-off valve 22FR and the left electromagnetic on-off valve 22FL are collectively referred to as “electromagnetic on-off valve 22” as appropriate.

  A right master pressure sensor 48FR for detecting the master cylinder pressure on the right front wheel side is provided in the middle of the brake fluid pressure control pipe 16 for the right front wheel. Is provided with a left master pressure sensor 48FL for measuring the master cylinder pressure on the left front wheel side. In the brake control apparatus 10, when the brake pedal 12 is depressed by the driver, the stroke operation amount is detected by the stroke sensor 46. The master detected by the right master pressure sensor 48FR and the left master pressure sensor 48FL is detected. The depressing operation force (depressing force) of the brake pedal 12 can also be obtained from the cylinder pressure. As described above, it is preferable from the viewpoint of fail-safe that the master cylinder pressure is monitored by the two pressure sensors 48FR and 48FL on the assumption of the failure of the stroke sensor 46. Hereinafter, the right master pressure sensor 48FR and the left master pressure sensor 48FL are collectively referred to as “master cylinder pressure sensor 48” as appropriate.

  On the other hand, one end of a hydraulic pressure supply / discharge pipe 28 is connected to the reservoir tank 26, and a suction port of an oil pump 34 driven by a motor 32 is connected to the other end of the hydraulic pressure supply / discharge pipe 28. ing. The discharge port of the oil pump 34 is connected to a high-pressure pipe 30, and an accumulator 50 and a relief valve 53 as a pressure accumulating portion of a hydraulic pressure source are connected to the high-pressure pipe 30. In the present embodiment, a reciprocating pump having two or more pistons (not shown) that are reciprocally moved by the motor 32 is employed as the oil pump 34. Further, as the accumulator 50, an accumulator 50 that converts the pressure energy of the hydraulic fluid into pressure energy of an enclosed gas such as nitrogen and stores it is employed.

  The accumulator 50 normally stores the hydraulic fluid whose pressure has been increased to a predetermined hydraulic pressure range (for example, about 14 to 21 MPa) by the oil pump 34. Further, the valve outlet of the relief valve 53 is connected to the hydraulic pressure supply / discharge pipe 28. When the pressure of the hydraulic fluid in the accumulator 50 increases abnormally to, for example, about 25 MPa, the relief valve 53 is opened and the high pressure is increased. The hydraulic fluid is returned to the hydraulic supply / discharge pipe 28. Further, the high-pressure pipe 30 is provided with an accumulator pressure sensor 51 (functioning as a “hydraulic pressure detection unit”) that detects the outlet pressure of the accumulator 50, that is, the pressure of the working fluid in the accumulator 50.

  The high pressure pipe 30 is connected to the right front wheel wheel cylinder 20FR, the left front wheel wheel cylinder 20FL, the right rear wheel wheel cylinder 20RR, and the left rear wheel through the pressure increasing valves 40FR, 40FL, 40RR, and 40RL. It is connected to the cylinder 20RL. Hereinafter, as appropriate, the wheel cylinders 20FR to 20RL are collectively referred to as “wheel cylinder 20”, and the pressure increase valves 40FR to 40RL are collectively referred to as “pressure increase valve 40”. Each of the pressure increasing valves 40 is a normally closed electromagnetic valve (linear valve) that is closed when not energized and is used to increase the pressure of the wheel cylinder 20 as necessary. A disc brake unit is provided for each wheel of the vehicle (not shown), and each disc brake unit generates a braking force by pressing the brake pad against the disc by the action of the wheel cylinder 20.

  Further, the wheel cylinder 20FR for the right front wheel and the wheel cylinder 20FL for the left front wheel are connected to the hydraulic pressure supply / discharge pipe 28 via the pressure reducing valve 42FR or 42FL, respectively. The pressure reducing valves 42FR and 42FL are normally closed electromagnetic valves (linear valves) used for pressure reduction of the wheel cylinders 20FR and 20FL as necessary. On the other hand, the wheel cylinder 20RR for the right rear wheel and the wheel cylinder 20RL for the left rear wheel are connected to the hydraulic pressure supply / discharge pipe 28 via a pressure reducing valve 42RR or 42RL which is a normally open electromagnetic valve. Hereinafter, the pressure reducing valves 42FR to 42RL are collectively referred to as “pressure reducing valve 42” as appropriate.

  Wheel cylinders for detecting the wheel cylinder pressure, which is the pressure of the hydraulic fluid acting on the corresponding wheel cylinder 20, in the vicinity of the wheel cylinders 20FR to 20RL for the right front wheel, the left front wheel, the right rear wheel, and the left rear wheel Pressure sensors 44FR, 44FL, 44RR and 44RL are provided. Hereinafter, the wheel cylinder pressure sensors 44FR to 44RL are collectively referred to as “wheel cylinder pressure sensor 44” as appropriate.

  The electromagnetic on-off valve 22, the pressure increasing valve 40, the pressure reducing valve 42, the motor 32, etc. constitute a hydraulic actuator 80 of the brake control device 10. The hydraulic actuator 80 is controlled by the brake ECU 200.

  The brake ECU 200 functions as a control unit that controls the wheel cylinder pressure in the wheel cylinder 20. The brake ECU 200 is a nonvolatile memory such as a CPU that executes various arithmetic processes, a ROM that stores various control programs, a RAM that is used as a work area for data storage and program execution, and a backup RAM that can retain stored contents even when the engine is stopped. A / D converter and the like for converting analog signals input from a memory, an input / output interface, various sensors, etc. into digital signals.

  The brake ECU 200 is electrically connected to the electromagnetic on-off valve 22, the simulator cut valve 23, the pressure increasing valve 40, the pressure reducing valve 42, the motor 32, and the like constituting the hydraulic pressure actuator 80. In addition, the brake ECU 200 can communicate with an upper hybrid ECU (not shown) and the like.

  The brake ECU 200 is electrically connected to various sensors and switches that output signals for use in control. That is, a signal indicating the wheel cylinder pressure in the wheel cylinder 20 is input from the wheel cylinder pressure sensor 44 to the brake ECU 200, and a signal indicating the pedal stroke of the brake pedal 12 is input from the stroke sensor 46, and the master cylinder pressure sensor 48. A signal indicating the master cylinder pressure is input from, and a signal indicating the accumulator pressure is input from the accumulator pressure sensor 51.

  Further, although not shown, the brake ECU 200 receives a signal indicating the wheel speed of each wheel from a wheel speed sensor installed for each wheel, a signal indicating the yaw rate from the yaw rate sensor, and a vehicle sensor from the G sensor. A signal indicating acceleration is input, and a signal indicating the steering angle of the steering wheel is input from the steering angle sensor.

  The brake control device 10 configured as described above can execute brake regeneration cooperative control. The brake control device 10 receives the braking request and starts braking. The braking request is generated when a braking force should be applied to the vehicle, for example, when the driver operates the brake pedal 12. In response to the braking request, the brake ECU 200 calculates a required braking force, and calculates a required hydraulic braking force that is a braking force to be generated by the brake control device 10 by subtracting the braking force due to regeneration from the required braking force. Here, the information on the braking force by regeneration is supplied to the brake ECU 200 from a higher-level hybrid ECU (not shown). The brake ECU 200 calculates the target hydraulic pressure of each wheel cylinder 20 based on the calculated required hydraulic braking force. The brake ECU 200 determines the value of the control current to be supplied to the pressure increasing valve 40 and the pressure reducing valve 42 based on the feedback control law so that the wheel cylinder pressure becomes the target hydraulic pressure.

  As a result, in the brake control device 10, the hydraulic fluid is supplied from the accumulator 50 to each wheel cylinder 20 via each pressure increasing valve 40, and braking force is applied to the wheels. Further, hydraulic fluid is discharged from each wheel cylinder 20 through the pressure reducing valve 42 as necessary, and the braking force applied to the wheel is adjusted. In the present embodiment, a wheel cylinder pressure control system that includes the accumulator 50, the pressure increasing valve 40, the pressure reducing valve 42, and the like and that can control the hydraulic pressure of the wheel cylinder 20 independently of the operation of the brake pedal 12 is configured. Yes. A so-called brake-by-wire braking force control is performed by the wheel cylinder pressure control system.

  On the other hand, at this time, the electromagnetic on-off valves 22FR and 22FL are closed, and the simulator cut valve 23 is opened. Therefore, the hydraulic fluid sent from the master cylinder 14 by the depression of the brake pedal 12 by the driver flows into the stroke simulator 24 through the simulator cut valve 23.

  Further, when the accumulator pressure is equal to or lower than the lower limit value of the preset setting range, current is supplied to the motor 32 by the brake ECU 200, and the oil pump 34 is driven to increase the accumulator pressure. When the accumulator pressure enters the set range and reaches the upper limit value due to this pressure increase, power supply to the motor 32 is stopped.

  FIG. 2 is a diagram illustrating an electrical configuration of the brake control device and its periphery. The brake ECU 200 includes a wheel speed sensor 102, a yaw rate sensor 104, a G sensor 106, a rudder angle sensor 108, a voltage detection sensor 109, a stroke sensor 46, a master cylinder pressure sensor 48, a wheel cylinder pressure in order to realize appropriate braking control. The sensor 44, the accumulator pressure sensor 51, etc. are connected, and each output signal is input. Moreover, the hybrid ECU 100 is connected to the brake ECU 200 via a predetermined communication line. The brake ECU 200 acquires information such as regenerative braking force from the hybrid ECU 100, and calculates the target hydraulic pressure of each wheel cylinder 20 as described above. Then, a control current is supplied to the pressure increasing valve 40, the pressure reducing valve 42, the electromagnetic opening / closing valve 22, the motor 32, and the like of the hydraulic actuator 80 so that each wheel cylinder pressure becomes the target hydraulic pressure.

  A power supply device 110 is also connected to the brake ECU 200. The power supply device 110 includes a main power supply device 112 and an auxiliary power supply device 114. The main power supply device 112 is not dedicated to the brake control device, but is provided as a common power supply device that can supply power to other in-vehicle devices such as an engine control device. On the other hand, the auxiliary power device 114 is provided as a power device dedicated to the brake control device.

  The main power supply device 112 includes a high voltage battery 116 and an auxiliary battery 118 as a main power supply, a DC / DC converter 120, a control circuit (not shown), and the like. The high voltage battery 116 is a battery for a hybrid vehicle having an output voltage of, for example, 288 V, and supplies electric power to an electric motor (not shown) that drives wheels in a normal traveling state. The high voltage battery 116 stores electric power regenerated by a motor generator (not shown) during vehicle braking. On the other hand, the auxiliary battery 118 is a battery having an output voltage of, for example, 12V, and a starting current and a control current required for various control units such as the brake ECU 200 and the hybrid ECU 100, various hydraulic machines 80, various auxiliary machines such as a headlamp, and the like. Supply. The output voltage of the high voltage battery 116 is stepped down to, for example, 12 V by the DC / DC converter 120 and used to charge the auxiliary battery 118.

  The auxiliary power supply 114 includes a capacitor 122 as an auxiliary power supply, a monitoring circuit 124, a switching circuit 126, and the like. The auxiliary power supply device 114 can store the electric energy supplied from the main power supply device 112 and supply the electric energy to the hydraulic actuator 80 via the brake ECU 200. The capacitor 122 includes a plurality of cells made of capacitors, and the charge / discharge state is controlled for each cell. The current supplied from the main power supply device 112 is supplied to the capacitor 122 through a storage circuit including a constant current circuit. Such a capacitor structure and power storage control are well known, and detailed description thereof will be omitted.

  The monitoring circuit 124 monitors the output voltage of the auxiliary battery 118, and determines whether the auxiliary battery 118 or the high voltage battery 116 has failed when the output voltage becomes equal to or lower than the set value. When the monitoring circuit 124 detects the failure of the battery, the switching circuit 126 switches so that power is supplied from the capacitor 122 to the brake ECU 200, the hydraulic actuator 80, and the like instead of the auxiliary battery 118. The output voltage of auxiliary battery 118 is also detected by voltage detection sensor 109 serving as a voltage detection unit, and the detection information is input to brake ECU 200.

  In the modification, the monitoring circuit 124 and the switching circuit 126 may be mounted in the brake ECU 200. Then, the brake ECU 200 may monitor the output voltage of the auxiliary battery 118 and appropriately switch the power supply source to the auxiliary battery 118 or the capacitor 122. Further, the voltage value supplied from auxiliary battery 118 may be monitored in brake ECU 200 without separately providing voltage detection sensor 109 for detecting the output voltage of auxiliary battery 118.

  The brake ECU 200 is connected with an ignition switch 150, a shift sensor 152, a stroke sensor 46, a temperature sensor 156, and a stop switch 158, and the detection result is acquired from these switches and sensors. When the ignition switch 150 is turned on, an engine (not shown) is started, and the vehicle is ready to travel. In some cases, for example, an electric vehicle or the like can be brought into a travel preparation state (Ready state) in which the vehicle can travel without starting an engine. In such a case, when the Ready switch to be in the Ready state is turned on, the vehicle is ready for traveling.

  The shift sensor 152 detects the position of the shift lever such as P (parking), N (neutral), D (drive), or R (reverse). The stop switch 158 is turned on when the brake pedal 12 is depressed. The detection result of the stop switch 158 is mainly used for lighting a brake lamp (not shown).

  The temperature sensor 156 is disposed around the capacitor 122 and detects the ambient temperature around the temperature sensor 156. Note that the temperature sensor 156 may be disposed at another location. Even when the temperature sensor 156 is arranged at a place other than the periphery of the capacitor 122, the brake ECU 200 detects the detection result of the temperature sensor 156 when the detection result by the temperature sensor 156 can be regarded as the same as the ambient temperature around the capacitor 122. May be used as the ambient temperature around the capacitor 122.

  The auxiliary power supply device 114 has a charge control circuit 128. Charging control circuit 128 controls charging from main power supply device 112 to capacitor 122. Specifically, the charging control circuit 128 switches between prohibition of charging and permission of charging from the main power supply device 112 to the capacitor 122 by switching between cutoff and release of conduction between the main power supply device 112 and the capacitor 122. Note that the brake ECU 200 may be provided with a charge control unit that controls charging from the main power supply device 112 to the capacitor 122.

  The charge control circuit 128 acquires the detection result by the ignition switch 150 from the brake ECU 200 as a signal indicating whether or not the vehicle is in a ready state indicating that the vehicle is ready to travel. Further, the charging control circuit 128 acquires the detection result by the stroke sensor 46 from the brake ECU 200. The charge control circuit 128 acquires the detection result by the stop switch 158 from the brake ECU 200. Further, the charging control circuit 128 acquires the detection result by the temperature sensor 156 from the brake ECU 200 as a signal indicating the ambient temperature around the capacitor 122.

  The monitoring circuit 124 monitors not only the high voltage battery 116 and the auxiliary battery 118 but also whether or not the capacitor 122 is defective. The monitoring circuit 124 monitors the output voltage of the capacitor 122, and determines that there is a failure in the capacitor 122 when the output voltage falls below a set value. The determination result of the presence or absence of the capacitor 122 by the monitoring circuit 124 is input to the charge control circuit 128.

  An electronically controlled brake such as the brake control device 10 may have difficulty in properly controlling the braking force when a vehicle power supply fails. For this reason, an auxiliary power supply device 114 is provided as a backup power supply in the brake control device 10 in case a failure occurs in the power supply. The 144 may be assumed to be normal over a long period of time. For this reason, the auxiliary power supply device 114 is required not to deteriorate over a long period of time.

  On the other hand, since the capacitor 122 is assumed to be normal for a long time, it is necessary to discharge all accumulated charges when the ignition switch 150 is turned off. Further, there may be a case where quick charging is required in preparation for a power failure immediately after turning on the ignition switch 150. For this reason, in the first embodiment, the auxiliary power supply device 114 uses the capacitor 122 that is an electric double layer capacitor.

  On the other hand, when the capacitor 122, which is an electric double layer capacitor, is used for the auxiliary power supply device 114, problems such as being easily deteriorated in a high temperature environment arise. For this reason, there has been a demand for the development of a new technology that suppresses the deterioration of the capacitor 122 within the normal use range while suppressing the deterioration of the function of the main power supply device 112 as a backup power supply.

  Therefore, in the first embodiment, when the charge control circuit 128 acquires a stop state signal indicating that the vehicle is in a stop state while the ignition switch 150 is turned on, the charge control circuit 128 acquires the stop state signal. The charging of the capacitor 122 is limited compared to the case where there is not. As a result, charging can be restricted when the necessity of power supply by the capacitor 122 is low, such as when the vehicle is stopped. For this reason, the performance deterioration by charge can be suppressed. Hereinafter, the execution procedure of the charging control of the capacitor 122 will be described in detail with reference to the flowchart.

  FIG. 3 is a flowchart showing in detail the execution procedure of the charging control of the capacitor 122 according to the first embodiment. The processing in this flowchart is repeatedly executed every predetermined time.

  The charge control circuit 128 determines whether or not the capacitor 122 is normal based on the detection result by the monitoring circuit 124 (S10). When it is determined that there is an abnormality in the capacitor 122 (N in S10), the charging control circuit 128 prohibits charging of the capacitor 122 from the main power supply device 112 (S24). At this time, a warning lamp in the vehicle compartment is also turned on. As a result, the driver can be notified that a failure has occurred in the auxiliary power supply device 114. In addition, you may alert | report to a driver | operator that a failure has occurred in the auxiliary power supply device 114 by voice from a speaker provided in the vehicle compartment.

  When it is determined that the capacitor 122 is normal (Y in S10), the charge control circuit 128 determines whether or not the ignition switch 150 is on (S12). When the ignition switch 150 is on (Y in S12), the charging control circuit 128 determines whether or not the shift position is in the P range based on the detection result of the shift sensor 152 (S14). If the shift shift position is not in the P range (Y in S14), it is considered that the driver has a driving intention, so the charging control circuit 128 permits charging of the capacitor 122 from the main power supply device 112 (S16).

  When the ignition switch 150 is off (N in S12), the charging control circuit 128 determines whether or not the vehicle speed is equal to or higher than a predetermined speed V1 determined while the vehicle is stopped based on the detection result of the wheel speed sensor 102 ( S18). In the first embodiment, the predetermined speed V1 is set to 3 km / h. Of course, the predetermined speed V1 is not limited to this speed.

  When the ignition switch 150 is off and the vehicle speed is less than the predetermined speed V1, it is considered that the vehicle is stopped (N in S18). Charging from 112 to capacitor 122 is prohibited (S24). On the other hand, even when the ignition switch 150 is off, if the vehicle speed is equal to or higher than the predetermined speed V1 (Y in S18), the brake control device 10 may require a braking force. And charging of the capacitor 122 from the main power supply device 112 is permitted (S16).

  Here, if the backup mode in which electric power is supplied from the auxiliary power supply device 114 is disabled while the brake pedal 12 is depressed by the driver, a “pedal return” is generated in which the brake pedal 12 is returned to the driver. There is a possibility of feeling uncomfortable. Therefore, when the shift position is in the P range (N in S14), the charging control circuit 128 determines that the vehicle is in a stopped state and determines whether or not the brake pedal 12 is depressed (S20). When the brake pedal 12 is depressed (Y in S20), the charging control circuit 128 permits charging of the capacitor 122 from the main power supply device 112 (S16) in order to avoid the pedal return.

  When the brake pedal 12 is not depressed (N in S20), based on the detection result of the temperature sensor 156, the charging control circuit 128 determines whether or not the environmental temperature of the capacitor 122 is equal to or higher than the predetermined temperature T1 (S22). . In the first embodiment, the predetermined temperature T1 is set to 65 ° C., which is an assumed ambient temperature. Of course, the predetermined temperature T1 is not limited to this temperature.

  Since the capacitor 122 is likely to deteriorate in a high temperature environment, when the environmental temperature of the capacitor 122 is equal to or higher than the predetermined temperature T1 (Y in S22), the charge control circuit 128 prohibits charging of the capacitor 122 from the main power supply device 112 ( S24). As described above, when the charging control circuit 128 determines that the ambient temperature of the capacitor 122 is higher than the predetermined temperature T1, the charging control circuit 128 does not depress the brake pedal 12 and the pedal does not return. Prohibit charging. Thereby, deterioration of the capacitor 122 due to high temperature can be suppressed. When the environmental temperature of the capacitor 122 is lower than the predetermined temperature T1 (N in S22), the charging control circuit 128 permits the charging of the capacitor 122 from the main power supply device 112 (S16).

(Second Embodiment)
FIG. 4 is a flowchart showing in detail the execution procedure of the charging control of the capacitor 122 according to the second embodiment. The processing in this flowchart is repeatedly executed every predetermined time. Unless otherwise specified, the configuration and operation of the brake control device 10 are the same as those in the first embodiment. Hereinafter, processing similar to that in FIG. 3 is denoted by the same step number and description thereof is omitted.

  As a result of research and development by the inventor, it has been found that deterioration of the capacitor 122 can be suppressed by lowering the charging voltage when charging the capacitor 122 from the main power supply device 112 than usual. For this reason, in 2nd Embodiment, when it is thought that a driver | operator does not have the driving intention, the charge restriction | limiting mode which lowers the charging voltage from the main power supply apparatus 112 to the capacitor 122 from normal is provided.

  Specifically, when the shift position is in the P range (N in S14), the charging control circuit 128 determines whether or not the stop switch 158 is on (S40). Even if the shift position is in the P range, if the stop switch 158 is on (Y in S40), the driver may shift-change, so the charge control circuit 128 connects the main power supply device 112 to the capacitor 122. Charging is permitted (S16).

  On the other hand, as a result of research and development by the inventor, when charging from the main power supply device 112 to the capacitor 122 is prohibited, charging is restricted by reducing the charging voltage from the main power supply device 112 to the capacitor 122. Thus, it was confirmed that the time required to shift to the backup mode in which power is supplied by the auxiliary power supply device 114 can be greatly shortened. Furthermore, since the vehicle speed is low immediately after the vehicle starts running, the vehicle can be stopped appropriately even if the capacitor 122 is not fully charged. For this reason, when the shift position is in the P range and the stop switch 158 is off (N in S40), the vehicle stops, for example, the driver leaves the driver's seat while the ignition switch 150 is on. Therefore, the charging control circuit 128 limits the charging from the main power supply device 112 to the capacitor 122 (S42).

  Thus, when the charge control circuit 128 obtains a signal indicating that the shift position is in the P range in the traveling preparation state in which the ignition switch 150 is on, the charge control circuit 128 indicates that the vehicle is in a stopped state. Assuming that the state signal is acquired, the charging voltage when charging the capacitor 122 is limited as compared with the case where the shift position is outside the P range. Accordingly, it is possible to avoid a prolonged charging time of the auxiliary power supply device 114 while avoiding a decrease in the power supply function of the auxiliary power supply device 114.

  The present invention is not limited to the above-described embodiments, and an appropriate combination of the elements of each embodiment is also effective as an embodiment of the present invention. Various modifications such as design changes can be added to each embodiment based on the knowledge of those skilled in the art, and embodiments to which such modifications are added can also be included in the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 Brake control apparatus, 12 Brake pedal, 46 Stroke sensor, 80 Hydraulic actuator, 102 Wheel speed sensor, 109 Voltage detection sensor, 110 Power supply apparatus, 112 Main power supply apparatus, 114 Auxiliary power supply apparatus, 116 High voltage battery, 118 Auxiliary battery , 120 DC / DC converter, 122 capacitor, 124 monitoring circuit, 126 switching circuit, 128 charge control circuit, 150 ignition switch, 152 shift sensor, 154 stroke sensor, 156 temperature sensor, 158 stop switch, 200 brake ECU.

Claims (1)

A capacitor that functions as a power source for electrical equipment mounted on the vehicle;
A charge control unit for controlling charging of the capacitor;
With
The charge control unit obtains a stop state signal indicating that the shift position is in the parking range in a travel preparation state where the vehicle can travel , and outputs the stop state signal when the brake pedal is not depressed. A vehicular power supply apparatus that reduces a charging voltage when charging the capacitor as compared with a case where the capacitor is not acquired.

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