JPH1070844A - Battery power supplying method for vehicle and battery power supply for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery power supplying method for a vehicle capable of definitely preventing low battery during parking. SOLUTION: The residual capacity of a battery 14 after engine stop is calculated. The supply of battery power to an operable load is forcibly stopped even when the ignition switch is in the off position be fore the residual battery capacity calculated is lowered to a minimum limit capacity required to restart the engine. By doing this, the battery is prevented from becoming dead due to the headlights or room lights kept operating mistakenly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for supplying a battery power to a vehicle, and more particularly, to a method and a device suitable for applying to a case where a battery is prevented from running out when the vehicle is parked.

[0002]

2. Description of the Related Art In a conventional vehicle battery power supply device, as shown in FIG. 14, electric power output from a battery 1 provided in an engine room of a vehicle body is generally equal to that of the battery 1.
And a fusible link 2 housed in a fuse box (not shown) provided in the vicinity of the vehicle, and an ignition key switch 3 in a driver's seat via a battery power line L1 arranged in an engine room. Is supplied to each load provided in each part of the vehicle through fuses 4a to 4c and power supply lines L1a to L1c in a fuse box (not shown) arranged inside the cowl side of the driver's seat according to each position. In addition, the fuse 5 and the battery power line L accommodated in a fuse box (not shown) provided near the battery 1
For example, a timepiece 6 or an electronic control unit (so-called ECU (Electoronic Control)
l Unit)) 7 and so on.

In this battery power supply, a voltage across a resistor 8a connected to the battery 1 is measured by a voltmeter 8b.
, The current voltage of the battery 1 is detected, and the detection result is displayed on a display unit 8 such as a voltmeter provided on an instrument panel or a warning lamp which lights up when the remaining battery power is low. Display by _C.

[0004] In this way the driver can know that life and charging time of the battery 1 is closer by looking at the display unit 8 _C. The driver, for example, if actuates the load such as room light or tail lamp in the parked state by looking at the display unit 8 _C, minimum for starting the Holding actuated engine further these loads By judging that the battery voltage drops below the required voltage, the operations of those loads can be stopped in advance to prevent the so-called battery running out.

[0005]

One of the major causes of the dead battery is forgetting to turn off the headlights and interior lights when parking. Therefore, conventionally, in order to prevent the battery from running out due to forgetting to turn off the light, for example, a method of sounding an alarm buzzer when the key is removed from the key cylinder while the headlight is turned on has been used.

However, when the driver intends to return to the vehicle immediately, for example, stops the engine and leaves the vehicle with the headlights and interior lights on, the load current of the headlights is large. The battery may run out sooner than before, and the engine may not be able to restart. Also, if the driver looks at the voltmeter on the instrument panel, determines that there is still enough time to run out of battery, and turns on the interior lights with the engine stopped. In some cases, the battery may run down against the driver's expectations.

As one cause of this, generally, as shown in FIG. 15, the voltage of the battery 1 mounted on the vehicle does not always decrease in proportion to time, but becomes lower than a certain voltage. Is characterized in that it has such a characteristic that the voltage decreases rapidly. Incidentally, FIG.
FIG. 4 shows voltage-time characteristics when a certain current is continuously supplied from the battery 1.

For this reason, for example, at the time of parking,
If the driver determines that there is still enough room in the remaining battery level and continues to operate the load such as the interior light and the tail lamp, the driver At time t2, which is much earlier than expected, the voltage of the battery 1 drops below the minimum voltage V2 required to start the engine, and as a result, the engine cannot be started.

The present invention has been made in view of the above points, and an object of the present invention is to propose a vehicle battery power supply method and a vehicle battery power supply device capable of reliably preventing a battery from running down during parking.

[0010]

According to a first aspect of the present invention, there is provided a method for supplying battery power to a vehicle, comprising the steps of: converting a battery mounted on a vehicle to a load mounted on the vehicle; In a battery power supply method for supplying battery power, a remaining capacity calculating step of calculating a remaining capacity of the battery after the engine is stopped, and before the remaining capacity of the battery is reduced to at least a minimum required capacity for restarting the engine. And a power cutoff step of forcibly stopping the supply of battery power to a predetermined load among the loads.

According to a ninth aspect of the present invention, there is provided a battery power supply device for a vehicle, comprising: a battery mounted on the vehicle; A1, A2, ..., AX, AY
In a battery power supply apparatus for supplying battery power via a power line, a remaining capacity calculating means for calculating the remaining capacity of the battery 14 after the engine is stopped, and a minimum capacity CE required at least to restart the engine , AX, AY based on the remaining capacity Cnow obtained by the remaining capacity calculation means and the minimum capacity CE stored in the storage means 41. , AX, AY and a power supply line that connects the battery to the load, and is provided at a subsequent stage when the power supply is closed. Connected loads A1, A2, ..., AX, AY
Power line opening / closing means R1 for supplying power of the battery 14 to the
R2,..., RX, RY, and the power supply line switching means R1, R2,. An open / close control means 40-2 is provided.

In the above configuration, the consumption of the battery power is automatically suppressed before the remaining capacity of the battery decreases until the engine cannot be restarted, so that the battery is prevented from running out.

According to a second aspect of the present invention, a load for forcibly stopping the supply of the battery power is operable even when the ignition switch is in an off position. The load that is being done.

[0014] In the above configuration, when the ignition switch such as a headlight, a tail lamp, and a room light, which is a major cause of the battery running out during parking, is operable even when the ignition switch is in the off position, the load at the time of parking due to forgetting to switch off the load is considered. The problem of running out of battery can be solved collectively.

According to a third aspect of the present invention, in the power supply shut-off step of the first aspect, at least the minimum necessary for restarting the engine is determined based on the remaining capacity of the battery. The capacity obtained by subtracting the capacity is calculated, and the supply of the battery power is permitted only for the time obtained by dividing the capacity by the current value flowing out of the battery.When the time has elapsed, the supply of the battery power is stopped. Stopped.

According to a fourth aspect of the present invention, in the method of supplying power to a battery of a vehicle according to the first aspect of the present invention, at least a minimum power is required to restart the engine based on the remaining capacity of the battery. Capacity, the natural discharge capacity of the battery, and the capacity obtained by subtracting the capacity required to operate the load operable during parking for a certain period of time, and dividing the capacity by the current value flowing out of the battery. Then, the supply of the battery power is permitted only for the determined time, and the supply of the battery power is stopped when the time has elapsed.

The battery power supply device for a vehicle according to the present invention according to a tenth aspect of the present invention further comprises a load A1, A2,.
, And current value detecting means FU1 and 52 for detecting the total current value supplied to AX and AY.
Further, a spontaneous discharge capacity CL3 of the battery 14 and a capacity CL2 required to operate the load AY operable at the time of parking for a certain period are stored. From the capacity Cnow, the minimum capacity C required to restart the engine
E, after obtaining the capacity obtained by subtracting the capacity CL2 required for operating the natural discharge capacity CL3 of the battery 14 and the load AY operable during parking for a certain period of time, and then calculating the total current value I _LOAD Time T obtained by dividing by
(H) is set as the battery power cutoff time T (H).

In the above configuration, the supply of the battery power to the load is performed until immediately before the battery runs out. As a result, the user uses the battery power as much as possible, for example, as compared with a case in which the supply of the battery power is stopped when a certain period of time has elapsed since the parking was started regardless of the remaining battery capacity. The battery can be reliably prevented from running out due to forgetting to turn off the light.

According to a fifth aspect of the present invention, there is provided a method for supplying battery power to a vehicle, wherein in the power-off step of the first aspect, the remaining capacity of the battery is a minimum required for restarting the engine. Even if the load is lowered, the battery power is continuously supplied to the load having the anti-theft function and the load for unlocking the door.

In the vehicle battery power supply device according to the ninth aspect of the present invention, the opening / closing control means 40-2 according to the ninth aspect is configured such that the opening / closing control means 40-2 determines whether the opening / closing control means 40-1 has the shutdown timing T (H). Even if it is determined that the load AY has been detected, the power line corresponding to the load AY having the anti-theft function and the load AY for unlocking the door is kept closed.

In the above configuration, the battery power is supplied to the load having the anti-theft function and the load for unlocking the door in preference to the dead battery, so that the reliability is improved in terms of security. Can be.

According to a sixth aspect of the present invention, there is provided a vehicle battery power supply method according to the present invention.
There is provided a held information transfer step of collectively transferring the held information of the information holding circuit to which the battery power is not supplied to the information holding circuit to which the battery power is continuously supplied.

According to a twelfth aspect of the present invention, there is provided a vehicle battery power supply apparatus for connecting a plurality of electronic control units mounted on a vehicle to transmit and receive data between the electronic control units. Is provided, and the opening / closing control means 40-2 is provided with
Even if it is determined that the cutoff time has come due to 0-1,
The power line opening / closing means R1, R2,..., RX, RY are controlled so that the power of the battery 14 is continuously supplied to at least one of the plurality of electronic control units. The electronic control unit supplied as
The information held in the information holding circuit of the electronic control unit whose battery power is cut off after the cutoff time is input via the data transmission line and stored in its own information holding circuit.

In the above configuration, the held information stored in the information holding circuit where battery power is not supplied is stored and held by the information holding circuit continuously supplied with battery power. Even if it is not given, the retained information will not be lost. As a result, it is not necessary to supply the battery power to all the information holding circuits, so that the dark current can be reduced, and the battery does not easily run out.

In the battery power supply method for a vehicle according to the present invention, in the remaining capacity calculating step, the plurality of loads receiving the power supply from the battery are differently combined. Detecting a plurality of battery voltage values and a current value flowing out of the battery obtained when the ON operation is performed, and obtaining a linear expression representing a relationship between the plurality of battery voltage values and the battery current value,
The present estimated voltage value of the battery in consideration of the characteristics of the battery is obtained based on the linear expression, and the remaining capacity of the battery is obtained based on the estimated voltage value.

According to a thirteenth aspect of the present invention, in the vehicle battery power supply apparatus, the remaining capacity calculating means includes a plurality of loads A1, A2,. , AY and the battery 14 are provided on a common power supply line, and the voltage value detection means FU1, 52 and the current value detection means 50, 51 for detecting the voltage value and the current value of the common power supply line; , 52 and a plurality of battery voltage values and the battery current value obtained from the current value detection means 50 and 51, and a linear expression (V) representing the relationship between the plurality of battery voltage values and the battery current value.
= A × I + b), and the linear equation (V = a × I
+ B) to calculate the current estimated voltage value Vn of the battery 14 in consideration of the characteristics of the battery 14 based on the calculated voltage value + b), and to further include a calculating means 40-3 for calculating the remaining capacity of the battery 14 based on the estimated voltage value Vn. I do.

In the above configuration, the remaining capacity obtained here is different from the remaining capacity obtained from only one voltage value and one current value obtained from the battery at the present time.
The remaining capacity also reflects the characteristics of the battery such that the voltage value sharply decreases with time. As a result, if the timing of stopping the power supply to the load is determined based on the remaining capacity, the battery of the vehicle can be more reliably prevented from running out.

[0028] According to the present invention, there is provided the present invention.
A battery power supply method for a vehicle according to claim 6, wherein
In the calculation step, the battery capacity when the battery is fully charged
To C _fullThe voltage value when the battery is fully charged is Vs
The minimum battery voltage required to restart the
Ve, when the estimated voltage value is Vn, the remaining battery capacity C
now is determined by equation (8).

In the above configuration, the remaining battery capacity C
Now can be calculated by performing a simple operation of the equation (8), so that the remaining capacity Cnow that easily reflects the battery characteristics such that the voltage value sharply decreases with time can be easily calculated. Become.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. (1) Overall Configuration In FIG. 2, reference numeral 10 denotes a battery power supply device for a vehicle as a whole. The battery power supply device 10 includes three junction boxes 1 provided at distant parts of the vehicle.
1, 12, and 13. Junction box 1
Numeral 1 is disposed near the battery 1 in the engine room, and junction boxes 12 and 13 are disposed, for example, on the cowl side near the driver's seat.

Here, the junction box 11 and the junction boxes 12 and 13 are connected to each other by a power supply line, and the power generated by the battery 14 and the generator (alternator) 15 is supplied to the junction boxes 12 and 13 through the power supply line. Supplied. Further, the fusible links FL1 and FL2 are connected to the power supply line, and the ignition of the power supply line when the power supply line is short-circuited is prevented by the fusible links FL1 and FL2.
A starter motor 16 is connected to the battery 14.

The junction box 11 is provided with a switch group 200 composed of a plurality of relays. Each relay of the switch group 200 is turned on / off by a switching signal from the arithmetic control unit 20A of the junction box control unit 20. By doing
Power is selectively supplied to each load connected to each relay.

The power supply line L1 connecting the junction box 11 and the junction box 12 is connected to a predetermined relay of a switch group (consisting of a plurality of relays) 201 in the junction box 12 as well as connecting the ignition switch 34 to the power supply line L1. It is connected to a predetermined relay and a junction box control unit 21 through the relay.

The power supply line L2 is connected to a predetermined relay of the switch group 201 and the junction box control unit 21 via an ignition switch 34. Each relay of the switch group 201 is operated by the operation of the junction box control unit 21. Power is selectively supplied to each load connected to each relay by being turned on / off by a switching signal from the control unit 21A. At this time, the arithmetic control unit 21A switches the power supply to each load in accordance with the switching position of the ignition switch 34.

The arithmetic control unit 21A also transmits the position information of the ignition switch 34 to other arithmetic control units 20A and 22A via the signal transmission line 100, and the arithmetic control units 20A and 22A also respond to the position of the ignition switch 34. To switch the power supply to each load.

A power supply line L3 connecting the junction box 11 and the junction box 13 is a switch group (consisting of a plurality of relays) in the junction box 13.
202 and the junction box control unit 22, and the arithmetic control unit 22A switches on and off the relays in the switch group 202, thereby selectively supplying power to a plurality of loads connected to the switch group 202. Is supplied.

Here, the junction boxes 11 to 13
Is a so-called electronic control unit, for example, a storage unit such as a RAM or a ROM, and a CPU that operates according to a predetermined program stored in the ROM.
(Central processing unit) and microcomputer control units 20A, 21A, 22A and transmission / reception units 20B, 21B, 22B of other junction boxes.
Transmission / reception units 20B, 21 for transmitting and receiving signals and data to and from the device via a signal transmission line 100 as a multiplex communication line.
B, 22B.

More specifically, each operation control unit 20A, 21
A, 22A, the RAM obtained in the own box by the monitoring function, the transmission and reception units 20B,
A predetermined area for storing data on other boxes obtained through 1B and 22B is formed, and the data stored in the predetermined area is used for various processes by the CPU.

The data transmitted through the signal transmission line 100 is transmitted to the transmission / reception units 20B, 21B and 22B of the junction boxes 11, 12 and 13 and the control units 30 and 31 of the electronic control unit constituting the car computer. 3
The time division multiplexed data is formed by a time division method according to a predetermined format by the transmission / reception units 30B, 31B, 32B, and 33B of 2, 33.

Here, the control unit 30 is provided for favorably controlling meters disposed on the instrument panel. Specifically, the control unit 30 includes vehicle speed information, fuel information,
And a meter for driving various meters such as a speedometer, a fuel gauge, and a voltmeter based on the voltage value information of the battery 14 obtained by the CPU 40 (FIG. 3) of the arithmetic control unit 20A. A drive command signal is formed and sent to the meter drive.

The control unit 31 is provided to control the antilock brake system well. Specifically, the control unit 31 inputs vehicle speed information, and the CPU 30A controls the vehicle deceleration based on the vehicle speed information. By detecting the rotation of the tire and comparing the two decelerations, when the deceleration of the tire increases, a control signal for instructing to reduce the oil pressure applied to the wheel cylinder is transmitted to the wheel cylinder driving unit to lock the tire. prevent.

The control section 32 is provided to control the air suspension satisfactorily. Specifically, the control section 32 receives oil pressure information from a wheel cylinder, forms a compressor control signal based on the information, and outputs this signal. Send to compressor. Further, the control unit 33 is provided to control the air conditioner satisfactorily. Specifically, the control unit 33 inputs operation signals such as temperature setting information from an operation panel and also inputs room temperature information, and controls the room temperature. An air conditioner control signal is generated so as to approach the set temperature.

The control signals formed by the control units 30 to 33 are sent directly to the respective control targets, and the signal transmission lines 1
00 through the junction box control unit 20
To junction box 11
The power supply to the control target is controlled by turning on / off the switch in the switch 12 in response to the control signal.

In addition to this configuration, a fundamental power supply line derived from the battery 14 is connected to the arithmetic and control unit 20A via the fuse FU1, whereby the voltage of the battery 14 is detected by the arithmetic and control unit 20A. It is possible to do. A current sensor 5 serving as a current value detecting means is provided on a fundamental power line derived from the battery 14.
0 is provided, and the current value obtained by the current sensor 50 is sent to the arithmetic and control unit 20A.

The current sensor 50 detects a magnetic flux having a magnitude corresponding to a current value generated when a current flows through the power supply line, thereby detecting a voltage corresponding to the magnitude of the current flowing through the power supply line. For example, a device having a configuration in which a magnetically sensitive element such as a Hall element is provided in a magnetic path of a ring core so as to output a detection signal may be used.

FIG. 3 shows a junction box 1
1 shows a detailed configuration of the power supply 1 and a state of a load connected to the junction box 11. The junction box control unit 20 stabilizes the power supply voltage by the regulator 44 and supplies this to the arithmetic and control unit 20A.

The arithmetic control unit 20A includes a CPU 40 and a ROM 41 storing a processing program for the CPU 40.
And a RAM for storing processing results of the CPU 40 and reception data obtained through the transmission / reception unit 21B. The arithmetic control unit 20A is provided with an analog / digital conversion circuit (A /
D) having a digital signal 51 detected by the current sensor 51 and converted into a digital signal by the A / D 51 and sending the digital signal to the CPU 40; After that, the digital signal is sent to the CPU 40.

Further, the arithmetic and control unit 20A has a control voltage generation circuit 43, and the control voltage generation circuit 43
Each transistor Tr connected to the subsequent stage controlled by
A control voltage corresponding to a command from the CPU 40 is applied to each of the control input terminals 1 to TrY.

A power supply voltage stabilized by the regulator 44 is input to the input terminals of the transistors Tr1 to TrY, and relays R1, R2, R3,... , R1, ...
…, Rm, RX, RY are connected and these relays R
, Rn, r1,..., Rm, RX, and RY are supplied with output voltages of the transistors Tr1 to TrY, respectively.

Thus, each of the relays R1, R2, R3,.
, Rn, r1, ..., rm, RX, and RY are closed when the corresponding transistors Tr1 to TrY are on-controlled, and the loads A1, A2, A3,
.., An, B1,..., Bm, AX, AY. On the other hand, each relay R1, R2, R3,.
r1, ..., rm, RX, RY are the corresponding transistors Tr
1 to TrY are opened when TrY is controlled to be off,
Loads A1, A2, A3,..., An,
B1,..., Stop the power supply to Bm, AX and AY.

Here, each of the relays R1, R2, R3,.
Loads A1, A2, A3,... after n, r1,.
.., An, B1,..., Bm are connected to a headlight, a tail lamp, a fog lamp,..., An interior light, an air conditioner (A / C),.

Here, loads A1, represented as group A in the figure,
A2, A3, ..., An are normally operable loads even when the ignition switch 34 is in the OFF position (that is, the relays R1, R2, R3, ..., Rn are controlled to be closed even when the ignition switch 34 is in the OFF position). ). On the other hand, load B expressed as group B
1,..., Bm are normally inoperable loads when the ignition switch 34 is in the OFF position (that is, when the ignition switch 34 is in the OFF position, the relays R1, R2, R3,. Controlled).

The load AX connected to the subsequent stage of the relay RX stores information such as an electronic control unit (specifically, for example, the junction box control units 21 and 22 and the control units 30 to 33 in FIG. 2) and a radio. In this embodiment, the loads that need to be constantly supplied with power, and in which the supply of battery power is stopped when the remaining battery power is low in this embodiment, are collectively represented.

The load AY connected to the rear stage of the relay RY includes a so-called keyless entry section that enables door lock and door unlock by remote control,
A load that requires constant power supply, such as an anti-theft sensor or a buzzer, or a clock, etc., and in this embodiment, stops supplying battery power even when the remaining battery power is low. This is a collective representation of the loads that do not occur.

(2) Processing for Preventing Dead Battery when Parking Next, processing for preventing dead battery when parking will be described. In the battery power supply device 10, this battery dead-up prevention processing is performed by the junction box control unit 1.
The first arithmetic control unit 20A executes the battery exhaustion prevention processing routine RT1 as shown in FIG.

That is, in step SP1, the CPU 40 of the arithmetic and control unit 20A starts parking based on the vehicle state signal S1 such as half door information, door lock information, and vehicle speed information input via the signal transmission line 100 and the transmission and reception unit 20B. It is determined whether or not it has been performed. That is, if the door is half-open, the door lock is released, or the vehicle speed is not zero, the process waits at step SP1. When the CPU 40 determines that parking has been started, the process proceeds to step SP2, and the A / D 51
By reading the current value data Di output from the
After detecting _LOAD , the process proceeds to step SP3.

In step SP3, the current battery 14
Is calculated. The battery remaining amount measurement processing will be described later in detail.

Next, in step SP4, the CPU 40 calculates a remaining time until the supply of the battery power is cut off (hereinafter referred to as an energization time). This will be described with reference to FIG. The CPU 40 first determines the remaining battery capacity C
From now on, the capacity CE required to start the engine and the battery 14
The natural discharge capacity CL3, the capacity obtained by subtracting the capacity CL2 required for operation of the load AY to be operated even when parked for 30 days, can be used by the load A group and the load AX that are currently supplied with battery power. Allowable capacity CB + CL1
Asking. Then, the energizing time T (H) is obtained by dividing the allowable operating capacity CB + CL1 by the load current I _LOAD detected in step SP2.

That is, the allowable operating capacity CB + CL1 is calculated by the following equation.

(Equation 2) And the energization time T (H) is calculated by the following equation:

(Equation 3) Ask by

The capacity CE required for starting the engine is:
The natural discharge capacity CL3 of the battery 14 and the capacity CL2 required to operate the load AY to be operated even during parking for 30 days
Are stored in the ROM 41 in advance. Incidentally, the capacity CE required for starting the engine is the starter motor 16, the ignition coil (not shown), the EFI (El
(Electronic Fuel Injection) This is a value obtained by multiplying the sum of the currents supplied to the control unit (not shown) and the fuel pump (not shown) by the cranking time. In addition, the natural discharge capacity CL3 of the battery 14 can be obtained on the assumption that the battery is discharged by approximately 3% per day.

When the energization time T (H) is obtained as described above,
The CPU 40 calculates the elapsed time in step SP5, and determines in a subsequent step SP6 whether the elapsed time has exceeded the energizing time T (H). If the elapsed time exceeds the power-on time T (H), the process proceeds to step SP7 to perform a storage process of the held information. The storage processing of the held information means that the held information stored in the memory of the load AX and the stored held information S2 such as radio channel selection information are transferred to the RAM 4 via the signal transmission line 100.
2 means to store them all at once.

That is, in the battery power supply device 10,
When the energizing time T (H) has passed while the vehicle is parked, the power supply to the load AX requiring the dark current is stopped. There is a possibility that stored storage information S2 may be lost. Therefore, in the battery power supply device 10, the storage processing of the held information as described above (step SP
The load AX whose power supply is stopped by performing 7)
Is prevented from being lost.

In practice, the stored information storage process (step S
P7) is performed as shown in FIG. That is, C
The PU 40 instructs the load AX to transfer the storage holding information S2 stored in its own memory via the signal transmission line 100 to the load AX in step SP7-1.
The stored information S2 transferred in 7-2 is stored in the RA
In step SP7-3, the process of storing the held information is ended, and the process returns to the main routine.

In step SP8, the CPU 40 controls the relays R1 to Rn and RX to open, thereby controlling the load group A (that is, the load which is normally allowed to be supplied with the battery power even when the ignition switch 34 is OFF as in parking) and the load. The supply of battery power to AX (that is, a load that normally requires the supply of backup power at all times) is stopped. As a result, the dark current when parking is
By completely shutting off except for the above, the battery is prevented from running out.

Next, in step SP8, the CPU 40 switches itself to the sleep mode by lowering the operation clock, for example, to save current consumption. Incidentally, at the stage of step SP9, the load to which the battery power is supplied is only the arithmetic control unit 20A and the load AY.

In the following step SP10, the CPU 40 waits for the parking to be completed based on the vehicle state signal S1. When it is determined that the parking has been completed, the CPU 40 proceeds to step SP11, where the operation clock is returned to the original frequency. Release the sleep mode and continue to step SP1
In step 2, the relays R1 to Rn and RX are controlled to close to restart the supply of battery power to the load groups A and AX.

Next, the CPU 40 performs a process of transferring the stored information in step SP13. The transfer processing of the storage information is to transfer the storage holding information S2 stored in the memory to the load AX stored in the RAM 42 collectively in step SP7 to the original storage unit via the signal transmission line 100. Say.

In practice, the storage information transfer process (step S
P13) is performed as shown in FIG. That is, the CPU 40 determines in step SP13-1 that the RAM 4
2 is read out, and in the following step SP13-2, the stored information S2 is transferred via the signal transmission line 100, and the following step SP13-3 is performed.
In step SP13-4, the electronic control unit, radio, or the like at the transfer destination instructs the storage device to store the stored information S2 in its own memory, and ends the storage information transfer process (step SP13) in step SP13-4.

(3) Battery Remaining Measurement Next, the process for measuring the remaining battery in step SP3 described above will be described in detail with reference to FIGS. As shown in FIG. 8, the CPU 40 performs a battery remaining amount calculation processing step SP3.
Is started, in step SP3-1, the current voltage value of the battery 14 and the current value flowing from the battery 14 to the load are detected.

At this time, the CPU 40 sets the relays R1 to Rn, r
Opening / closing control is sequentially performed for different combinations of 1 to rm and the like, and voltage value data DV and current value data Di in each case are collected. Specifically, as shown in FIG. 9, first, as the first data collection process, the ignition switch 34 is set to the accessory position and the relay R
By closing 1, R2, R3 and Rn, the headlight A
1, tail lamp A2, fog lamp A3, interior light An
Is supplied with the battery power, and the detected value at the point P1 in FIG. 10 is obtained from the voltage value data DV and the current value data Di detected at this time.

Next, the CPU 40 sets the ignition switch 34 to the OFF position and sets the relays R1, R2, R3, Rn as the second data collection process.
Is closed, battery power is supplied to the headlight A1, the tail lamp A2, the fog lamp A3, and the interior light An, and the detected value at the point P2 in FIG. 10 is obtained from the voltage value data DV and the current value data Di detected at this time. Get.

Next, as a third data collection process, the CPU 40 turns the ignition switch 34 to the OFF position, opens the relay R1, and sets the relays R2 and R
3. By closing Rn, the supply of the battery power to the headlight A1 is stopped, and the voltage value data DV and the current value detected when the battery power is supplied to the tail lamp A2, the fog lamp A3, and the interior light An. From the data Di, the detection value of the point P3 in FIG. 10 is obtained.

Similarly, the CPU 40 performs the fourth and fifth data collection processes by changing the combination of loads for supplying battery power as shown in FIG. 9, and detects the voltage value data DV and the current value detected at this time. From the value data Di to FIG.
Of the points P4 and P5 are obtained.

The data collection process in step SP3-1 is performed by setting the closing times of the relays R1, R2, R3, and Rn as short as possible, so that unnatural headlights when the vehicle is parked. A1, the tail lamp A2, the fog lamp A3, and the interior light An are prevented from blinking.

Next, the CPU 40 proceeds to step SP3-2, and based on the plurality of pieces of detection data P1 to P5 detected in step SP3-1, compares a plurality of battery voltage values and battery current values as shown in FIG. A linear expression (V = a
× I + b). The coefficients a and b of the linear expression can be easily and accurately obtained by performing a linear approximation by the least square method.

Next, the CPU 40 proceeds to step SP3-3, and obtains the current estimated voltage value Vn of the battery 14 in consideration of the characteristics of the battery 14. This estimated voltage Vn is
The coefficients a and b are constants corresponding to the characteristics of the battery 14 such that the voltage of the battery 14 decreases linearly with time when a certain current flows out of the battery 14, and are obtained in advance and stored in the ROM 41. Using the virtual current value i, the following equation is obtained by the CPU 40.

(Equation 4) Is required by: In this embodiment,
-10 is used as the virtual current value i.

Here, the virtual current value i will be described. FIG. 11 shows current values flowing out of the battery 14 from 0 [A], -10 [A], -20 [A],-
The state of the voltage value that changes with time when 30 [A] and -40 [A] are obtained by experiments. FIG.
As is clear from FIG. 1, near the end of discharge, the rate of voltage decrease is large when the current value is 0 [A], and increases when the current value is -20 [A] or less. You can see that it will.

On the other hand, when the current value is -10 [A], it can be seen that the voltage value decreases with linearity from the fully charged state to the end of discharge. FIG. 12 shows the relationship between the estimated voltage and the current value obtained when the current value and the voltage value of the battery 14 measured at different points in time when the current continues to flow from the battery 14 are respectively applied to the above-described linear expression. Show. As is clear from FIG. 12, when the current value is −10 [A], the estimated voltage decreases at regular intervals from the fully charged state to the discharge end state.

Thus, in this embodiment, the virtual current value i
-10 is used to determine the current estimated voltage Vn at which the voltage of the battery 14 can be assumed to decrease linearly with time according to equation (4).

When the estimated voltage Vn is obtained in this manner,
Next, the CPU 40 proceeds to step SP3-4 and obtains the remaining capacity Cnow of the battery 14. Here, as described above, the estimated voltage Vn that decreases linearly with the passage of time is obtained, and the relationship between the estimated voltage Vn and the elapsed time is shown in FIG.
3 can be shown. As is clear from FIG. 13, there is no curved portion in the figure that appears in the battery characteristics, so that the remaining capacity Cnow can be obtained by simple area calculation.

Specifically, assuming that the full charge voltage of the battery 14 is Vs and the discharge end voltage (that is, the minimum required battery voltage value for starting the engine) is Ve, the total capacity of the battery is expressed by the following equation.

(Equation 5) Can be obtained by The remaining capacity Cnow is given by

(Equation 6) Can be obtained by Therefore, from the equations (5) and (6), the capacity remaining ratio at the present time is expressed by the following equation:

(Equation 7) Becomes

As a result, the remaining capacity Cnow of the battery 14
Is the battery capacity at full charge using C _full

(Equation 8) Can be obtained by When the CPU 40 obtains the remaining capacity Cnow of the battery 14 in step SP3-4, the CPU 40 ends the battery remaining amount processing in step SP3-5 and returns to the main routine.

Note that the battery capacity at full charge is C _{full, the} full charge voltage is Vs, and the discharge end voltage Ve is that stored in advance in R0M41.

(4) Other Embodiments In the above-described embodiment, a plurality of battery voltage values and a plurality of battery voltage values obtained when a plurality of loads supplied with power from the battery 14 are turned on in different combinations. 14 and the current value flowing out of
A primary expression representing the relationship between the plurality of battery voltage values and the battery current value is obtained, and the battery 14 is determined based on the primary expression.
A case has been described in which the current estimated voltage value Vn of the battery is determined in consideration of the characteristics of the above, and the remaining capacity Cnow of the battery is determined based on the estimated voltage value Vn.
The present invention is not limited to this. For example, the current may be obtained by a current integration method that integrates an instantaneous current. That is, the remaining capacity Cnow may be obtained by adding or subtracting the integrated current from the full charge capacity of the battery 14.

In the above embodiment, the case where a relay is used as the power supply line switching means has been described. However, the present invention is not limited to this. For example, various power supply line switching means such as a semiconductor switch and an intelligent power switch may be used. Can be used.

[0086]

As described above, according to the first and ninth aspects of the present invention, the battery power is automatically reduced before the remaining capacity of the battery decreases until the engine cannot be restarted. Since the power consumption is suppressed, a battery power supply method and a device capable of preventing the battery from running down can be realized.

According to the second aspect of the present invention, a load that is operable even when an ignition switch such as a headlight, a tail lamp, and a room light is in an off position, which is a major cause of the battery running down during parking. The problem of running out of battery at the time of parking due to forgetting to switch off can be collectively solved.

Further, according to the third, fourth and tenth aspects of the present invention, the user can make maximum use of the battery power and can surely prevent the battery from running out due to forgetting to turn off the light. Such a battery power supply method and its device can be realized.

According to the fifth and eleventh aspects of the present invention, it is possible to realize a battery power supply method and a battery power supply method capable of avoiding running out of a battery without lowering security reliability.

According to the present invention, the stored information is not lost even if a backup power supply for storing the information is not provided, so that the dark current can be reduced, and as a result, the battery power can be further reduced. A battery power supply method and its device in which the occurrence of the power is difficult can be realized.

According to the seventh and thirteenth aspects of the present invention, it is possible to obtain the remaining capacity which also reflects the characteristics of the battery such that the voltage value sharply decreases as time passes. Rising can be more reliably prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a vehicle battery power supply device according to the present invention.

FIG. 2 is a connection diagram showing one embodiment of a battery power supply device according to the present invention.

FIG. 3 is a connection diagram showing a detailed configuration of a junction box 11 and a load connected to the junction box 11 in FIG.

FIG. 4 is a flowchart showing a routine for a battery rising process during parking by a calculation control unit 20A of FIG. 3;

FIG. 5 is a diagram for explaining calculation of a remaining time until supply of battery power is cut off;

FIG. 6 is a flowchart illustrating a held information storage processing subroutine.

FIG. 7 is a flowchart showing a stored information transfer subroutine.

FIG. 8 is a flowchart showing a battery remaining amount calculation subroutine.

FIG. 9 is a chart showing an example of a combination of loads for supplying battery power for obtaining a plurality of detection voltage values and detection current values.

FIG. 10 is a graph showing a plurality of detected voltage values and current values and a linear expression obtained from the plurality of voltage values and current values.

FIG. 11 is a graph showing voltage-time characteristics when different current values flow out of a battery by an experiment.

FIG. 12 is a graph showing how an estimated voltage value changes according to a current value.

FIG. 13 is a graph for explaining calculation of a state of charge of a battery.

FIG. 14 is a connection diagram illustrating an example of a conventional battery power supply device.

FIG. 15 is a graph showing battery characteristics for explaining a conventional problem.

[Explanation of symbols]

 14 Battery 40-1 Shutdown determination means (CPU) 40-2 Opening / closing control means (CPU) 40-3 Calculation means (CPU) 41 Storage means (ROM) FU1, 52 Voltage detection means (fuse, analog)
Log digital conversion circuit) 50, 51 Current value detection means (current sensor,
Analog digital conversion circuit) A1, A2, ... AX, AY  Load (headlight, tape
Lu Lamp, Foglan , Interior light, ...) R1 ~ Rn Power line switching means (relay) Cnow  Battery remaining capacity CE Minimum capacity CL3 Natural discharge capacity T (H) Shutdown timing

Claims (13)

[Claims] 1. A battery power supply method for supplying battery power from a battery mounted on a vehicle to a load mounted on the vehicle, a remaining capacity calculating step of calculating a remaining capacity of the battery after an engine stop. By the time the calculated remaining battery capacity drops to the minimum required capacity to restart the engine,
A method for supplying battery power to a vehicle, comprising a power cutoff step of forcibly stopping supply of the battery power to a predetermined load among the loads. 2. The vehicle battery power supply method according to claim 1, wherein the load for forcibly stopping the supply of the battery power is a load that can be operated even when an ignition switch is in an off position. 3. In the power-off step, a capacity obtained by subtracting at least a minimum capacity required to restart the engine from the remaining capacity of the battery is obtained, and the capacity is discharged from the battery at present. The battery power supply according to claim 1, wherein the supply of the battery power is permitted only for a time obtained by dividing the current by a current value, and the supply of the battery power is stopped when the time has elapsed. Supply method. 4. In the power-off step, a minimum capacity required for restarting the engine, a spontaneous discharge capacity of the battery and a load operable at the time of parking are determined based on a remaining capacity of the battery. Calculating the capacity obtained by subtracting the capacity required to operate only for a certain period of time, permitting the supply of the battery power for the time obtained by dividing the capacity by the current value flowing out of the battery, and 2. The method according to claim 1, wherein the supply of the battery power is stopped when the time has elapsed. 5. In the power-off step, a load having an anti-theft function and a door lock release function are performed even if the remaining battery capacity is reduced to a minimum required capacity for restarting the engine. The method according to claim 1, wherein the battery power is continuously supplied to a load. 6. A retained information transfer step of batch-transferring the retained information of the information retaining circuit to which the battery power is not supplied to an information retaining circuit to which the battery power is continuously supplied. The method for supplying battery power to a vehicle according to claim 1. 7. In the remaining capacity calculating step, a plurality of voltage values of the plurality of batteries obtained when a plurality of loads receiving power supply from the battery are turned on in different combinations, and the outflow from the battery is obtained. And calculating a linear expression representing a relationship between the plurality of battery voltage values and the battery current value, and estimating the battery at the present time in consideration of the characteristics of the battery based on the linear expression. The method according to claim 1, wherein a voltage value is obtained, and a remaining capacity of the battery is obtained based on the estimated voltage value. 8. In the remaining capacity calculating step, the battery capacity when the battery is fully charged is C _full , the voltage value when the battery is fully charged is Vs, and the minimum necessary battery for restarting the engine is The voltage value is Ve,
When the estimated voltage value is Vn, the battery remaining capacity Cnow is calculated by the following equation: 8. The method according to claim 7, wherein the battery power is supplied by the following method. 9. A battery power supply device for supplying battery power from a battery mounted on a vehicle to a plurality of loads mounted on the vehicle via a power line, wherein a remaining capacity of the battery after an engine stop is calculated. Remaining capacity calculation means; storage means for storing a minimum capacity required at least for restarting the engine; remaining capacity obtained by the remaining capacity calculation means and the minimum capacity stored in the storage means Disconnection determining means for determining a timing of shutting off the battery power to the load based on the capacity; provided on a power supply line connecting each of the loads and the battery, and connected to a subsequent stage when in a closed state. Power line opening / closing means for supplying power of the battery to the loaded load; and the power line opening / closing means when the cutoff determination means determines that the cutoff time has come. Battery power supply apparatus for a vehicle characterized in that it comprises a closing control means to appropriately open. 10. The vehicle battery power supply device,
The battery further includes current value detection means for detecting a total current value supplied to the load from the battery, and the storage means further includes a spontaneous discharge capacity of the battery and a load operable during parking. The capacity required to operate only for a certain period is stored, and the cutoff determination means calculates the minimum capacity required to restart the engine from the remaining capacity of the battery, the natural discharge capacity of the battery. And after obtaining the capacity obtained by subtracting the capacity required to operate the load operable at the time of parking for a certain period, the time obtained by dividing the capacity by the total current value is used as the time of the battery power supply. The battery power supply device for a vehicle according to claim 9, wherein the cutoff time is set. 11. The switching control means according to claim 6, wherein said shut-off determining means determines that said shut-off time has come.
10. The battery power supply device for a vehicle according to claim 9, wherein the power supply line corresponding to a load having an anti-theft function and a load for unlocking a door is kept closed. 12. The battery power supply device further comprises a data transmission line for connecting a plurality of electronic control units mounted on the vehicle and transmitting and receiving data between the electronic control units, The opening / closing control means is configured such that the power of the battery is continuously supplied to at least one of the plurality of electronic control units even when the cutoff time is determined by the cutoff determination means. The electronic control unit, which controls a power supply line opening / closing unit, to which the power of the battery is continuously supplied, is stored in an information holding circuit of the electronic control unit in which the battery power is cut off after the cutoff timing. The information is input via the data transmission line and stored in its own information holding circuit.
A vehicle battery power supply device according to claim 10 or claim 11. 13. The remaining capacity calculation means is provided on a common power supply line connecting the plurality of loads receiving power supply from the battery and the battery,
A voltage value detecting means and a current value detecting means for detecting a voltage value and a current value of the common power supply line; and a plurality of the battery voltage values and the battery current values obtained from the voltage value detecting means and the current value detecting means. A primary equation representing a relationship between the plurality of battery voltage values and the battery current value is obtained based on the plurality of battery voltages, and an estimated voltage value of the battery at the present time in consideration of the characteristics of the battery is obtained based on the primary equation. 13. The battery power supply device for a vehicle according to claim 9, further comprising: a calculating unit that calculates a remaining capacity of the battery based on the estimated voltage value.