JP2007176210A - Controlling device for vehicle power source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power source controlling device for vehicle which prevents a dead battery from occurring while ensuring visibility right after the starting of traveling. <P>SOLUTION: This power source controlling device for vehicle is used for loads excepting essential loads of a traveling system and a safety system. The power source controlling device is equipped with a current detecting means or a voltage detecting means, a controlling means, and a time measuring means. In this case, the current detecting means measures a current which flows from a battery to the load, and the voltage detecting means measures a voltage which is fed from the battery to the load. The controlling means performs a power feeding control which limits a power feeding to the load when the current value or the voltage value measured by the current detecting means or the voltage detecting means is lower than a specified threshold value. The time measuring means measures a period of time since an ignition key has been turned on. The controlling means sorts loads into a visibility ensuring load regarding the ensuring of visibility and general loads other than that. The controlling device for vehicle power source is constituted in such a manner that the power feeding is performed to the visibility ensuring load until a specified period of time of the time measured by the time measuring means has passed even when the current value or the voltage value detected by the current detecting means or the voltage detecting means is at the specified threshold value or lower. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicular power supply control device, and more particularly to a vehicular power supply control device that prevents a battery from being overdischarged (so-called battery exhaustion) while securing a field of view immediately after the start of traveling.

Conventionally, since various electric loads (ECU: Electronic Control Unit, actuator, etc.) are operated using electric power charged in a battery in an automobile, it is important to suppress the electric power consumption of the battery as much as possible.
When the electric load is in the activated state, the load current is large, and when the electric load is in the standby state, the load current (that is, the standby current) is small. Therefore, the power consumption of the electric load varies greatly between the activated state and the standby state. Therefore, in a state where the ignition key is turned off or in a standby state, a desired control signal is given so that a part of the electric load is in a standby state, power supplied to the electric load is reduced, or power supply is performed. It is considered to reduce the power consumption by interrupting.

In Japanese Patent Laid-Open No. 2003-226209 (Patent Document 1), the remaining battery capacity and the battery discharge current are measured, and load control is performed to cut off the power supply to the electric load based on these values. It is preventing.
However, immediately after the start of driving, that is, immediately after the ignition key is turned on, for example, when the window glass is fogged, it is necessary to remove the fog by using a defogger or the like. May block. First, this is because heaters and coolers that are loads other than the traveling system are subject to load control. Even if the fog on the window glass is not removed, safety during driving cannot be ensured, but the power supply to the defogger is cut off, so that quick vision cannot be secured, causing a problem in safety.

JP 2003-226209 A

  The present invention has been made in view of the above problems, and an object of the present invention is to propose a system capable of preventing the battery from running up while ensuring the field of view immediately after the start of traveling.

In order to solve the above-mentioned problem, the present invention is a vehicle power supply control device for a load excluding an important load of a traveling system and a safety system,
Current detection means for measuring the current flowing from the battery to the load or voltage detection means for measuring the voltage supplied from the battery to the load;
Control means for performing power supply control for limiting power supply to a load when the voltage value or voltage value measured by the current detection means or the voltage detection means is below a predetermined threshold;
And a time measuring means for measuring the time after the ignition key is turned on,
The control means includes
The load is grouped into a view securing load related to view securing and other general loads,
For the visibility ensuring load, even if the current value or voltage value detected by the current detection means or the voltage detection means is equal to or less than a predetermined threshold, the time until the specified time measured by the time measurement means elapses. Provides a power supply control device for a vehicle that is configured to perform power supply (in other words, power supply control is not performed).

  With this configuration, the control means does not control power supply to the rear defogger, deisa, mirror heater, etc., which are the visibility securing loads, until the time measured by the time measuring means has passed the specified time. Electric power is supplied without restriction, and a field of view immediately after the start of traveling can be secured. In addition, since power supply control is performed for general loads other than the visibility ensuring load, it is possible to prevent the battery from running out.

  Further, by measuring the current value using the current detection means, it is possible to determine the charge / discharge state of the battery and determine whether or not to perform power supply control on the load. The power supply control can prevent a decrease in the supply current of the battery, and can prevent the operation of the load from being stopped due to a current shortage.

  Furthermore, by measuring the voltage value using the voltage detection means, it is possible to determine the charge / discharge state of the battery and determine whether to perform power supply control on the load. Since the power supply control prevents the battery voltage from being lowered, even if the current value is secured, it is possible to prevent the operation from stopping even for a load that does not operate unless the voltage value is equal to or higher than a certain voltage value.

In order to solve the above-mentioned problem, the present invention is a vehicle power supply control device for a load excluding an important load related to traveling and safety,
Current detection means for measuring the current flowing from the battery to the load;
Voltage detection means for measuring the voltage supplied from the battery to the load;
Control means for performing power supply control to the load when the remaining battery capacity determined from the current and voltage measurement values measured by the current detection means and the voltage detection means falls below a predetermined threshold;
And a time measuring means for measuring the time after the ignition key is turned on,
The control means includes
The load is grouped into a view securing load related to view securing and other general loads,
A vehicle that is configured to supply power to the visibility securing load even when the battery remaining capacity is equal to or less than a predetermined threshold until the specified time of the time measured by the time measuring means elapses. Power supply control devices are provided.

  The remaining battery capacity is calculated from the current value and voltage value measured by the current detection means and the voltage detection means, and the remaining battery capacity value is used to determine the charge / discharge state of the battery and to control the power supply to the load. It can be determined whether or not. The power supply control can prevent a decrease in the power supplied to the battery, and can prevent the operation of the load from stopping due to power shortage.

Temperature detecting means for measuring the temperature of the battery;
It is desirable that the control means adjusts the threshold value based on a measured value of temperature.

  Since the power output by the battery varies depending on the battery temperature, it is possible to more accurately determine the charge / discharge state of the battery by adjusting a threshold value that is a criterion for determining whether to perform power supply control depending on the battery temperature. And power supply control can be performed appropriately.

  According to the present invention, the control means is configured not to perform power supply control to the view securing load until the time measured by the time measuring means has passed the specified time, so that sufficient power is supplied to the view securing load. The field of view immediately after the start of traveling can be secured. And since it is set as the structure which performs electric power supply control to general loads other than a visual field ensuring load, a battery run-up can be prevented.

Furthermore, the current value or voltage value is measured using the current detection means, the voltage detection means, or both, so that the battery can be calculated from the current value, voltage value, battery remaining capacity value calculated from the current value or voltage value. It is possible to determine whether or not to perform power supply control on the load by obtaining the charge / discharge state. Since power supply control prevents a decrease in battery voltage or supply power, it is possible to prevent the load operation from stopping.
In addition, since the power output by the battery varies depending on the battery temperature, the battery charge / discharge state can be accurately determined by adjusting the threshold value that is a criterion for determining whether or not to control power supply depending on the battery temperature. Therefore, power supply control can be performed appropriately.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention.
In FIG. 1, the vehicle power supply control device 10 is configured such that one is connected to the battery 1 and the other is connected to the ECUs 2 a and 2 b and the generator 3.

  The ECU 2a is a visibility ensuring load. For example, if the window glass is fogged, the car cannot travel safely unless the fog is removed with a defogger or the like immediately after turning on the ignition key. For this reason, electric loads such as a rear defogger, deisa, mirror heater, and air conditioner blower motor in the defroster mode are used as a view securing load, and power is always supplied to these electric loads within a predetermined time after the ignition key is turned on.

  The ECU 2b is a load excluding an important load related to the traveling system and the safety system, and is a general load other than the visibility securing load. For example, seat heaters, air purifiers, and air conditioner blower motors other than those in the defroster mode do not have any problem in safe driving of the vehicle even if power is supplied intermittently within a predetermined time after turning on the ignition key.

The vehicle power supply control device 10 includes a current sensor 11, a control unit 12, and a timer 13.
The current sensor 11 constitutes current measuring means and measures the current of the battery 1.
The control means 12 receives the ignition key ON / OFF signal 21 and the measurement result of the current sensor 11 input to the control means 12, and determines from these whether the ECU 2a, 2b should be in a standby state or an activated state, and the ECU 2a, 2b. A standby command and start command are issued.
The timer 13 measures the time t from when the ignition key is turned on until the control to the ECU 2a is started.

FIG. 2 is a flowchart showing the operation of the vehicle power supply control device 10.
Step S1 determines whether the ignition key is on or off. If the ignition key is on, the process proceeds to S2, and if it is off, S1 is repeated until it is on.
In step S 2, the battery current is measured by the current sensor 11, and the measurement result is input to the control means 12.

  In step S3, it is determined whether or not the control unit 12 performs power supply control for limiting power supply to the load based on the battery current value. In this embodiment, a threshold value for determining whether the battery 1 is charged from the generator or whether the battery is discharged is determined, and the current value of the battery 1 is compared with the threshold value to determine whether the battery is charged or discharged. Judging. When the battery 1 is charged, it is not necessary to perform power supply control, and the flowchart returns to the start. On the other hand, when the battery 1 is discharged, power supply control is performed on the load excluding the important load in order to secure power supply to the important load related to traveling and safety, and the process proceeds to S4.

In step S <b> 4, a time t from when the ignition key is turned on to the present is acquired using the timer 13.
In step S5, it is determined whether or not the time t from when the ignition key is turned on until now is longer than a specified time. In this embodiment, the specified time is set to 15 minutes. This is because if the ignition key is turned on for 15 minutes, it is considered that the field of view can be secured by driving a vision securing load such as a defogger. The specified time is assumed to be 3 minutes to 30 minutes, and can be changed depending on the outside temperature. If the time t after the ignition key is turned on is longer than the specified time, the process proceeds to S6, and otherwise the process proceeds to S7.

In step S6, the control means 12 issues a command to control power supply for both the visual securing load and the general load.
In step S7, the control means 12 issues a command to control power supply only to the general load. Since the time t from when the ignition key is turned on is shorter than the specified time, electric power is supplied to the visual securing load to secure the visual field.

FIG. 3 is a time chart showing the operation of the vehicle power supply control device 10.
At time t1 when the ignition key is turned on from off, the battery current flows to the discharge side larger than the threshold value. At this time, the control means 12 performs power supply control to the general load. On the other hand, since the time from when the ignition key is turned on does not exceed the specified time, power supply control is not performed on the vision ensuring load, and power is supplied to ensure visibility.

When the specified time of 15 minutes has elapsed, that is, when time t2 has elapsed, the battery current is still flowing to the discharge side larger than the threshold value, and therefore, power supply control is also performed on the visual securing load.
When the battery current falls below the threshold value at time t3 and the battery is charged, the control unit 12 stops the power supply control for both the visual securing load and the general load.

  FIG. 4 shows a second embodiment of the present invention. In the first embodiment, the battery current is measured using the current sensor 11, but in the second embodiment, the battery voltage is measured using the voltage sensor 14 constituting the voltage detecting means. It is determined from the battery voltage value whether the battery is discharged or charged, and it is determined whether or not to perform power supply control.

  FIG. 5 shows a third embodiment of the present invention. In the first embodiment, the battery current is measured using the current sensor 11, but in the third embodiment, the battery current measured using the current sensor 11 and the measurement result of the battery voltage measured using the voltage sensor 14 are used. The remaining battery capacity SOC is calculated. Further, the battery temperature is also measured by the temperature sensor 15 constituting the temperature detecting means. By determining whether or not to perform power supply control based on the remaining battery capacity, more appropriate power supply control can be performed. In addition, since the power that can be output by the battery varies depending on the temperature of the battery, the threshold for determining whether to perform power supply control is adjusted depending on the temperature of the battery. By adjusting the threshold according to the battery temperature, it is possible to more accurately determine whether the battery is charged or discharged, and power supply control can be appropriately performed.

It is a block diagram which shows the 1st Example of the vehicle power supply control apparatus which is this invention. It is a flowchart which shows operation | movement of the power supply device for vehicles. It is a time chart which shows operation | movement of the power supply device for vehicles. It is a block diagram which shows the 2nd Example of the power supply control apparatus for vehicles. It is a block diagram which shows the 3rd Example of the power supply control apparatus for vehicles.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle power supply control apparatus 11 Current sensor 12 Control means 13 Timer 14 Voltage sensor 15 Temperature sensor

Claims (3)

A vehicle power supply control device for a load excluding an important load of a traveling system and a safety system,
Current detection means for measuring the current flowing from the battery to the load or voltage detection means for measuring the voltage supplied from the battery to the load;
Control means for performing power supply control for limiting power supply to a load when the voltage value or voltage value measured by the current detection means or the voltage detection means is below a predetermined threshold;
And a time measuring means for measuring the time after the ignition key is turned on,
The control means includes
The load is grouped into a view securing load related to view securing and other general loads,
For the visibility ensuring load, even if the current value or voltage value detected by the current detection means or the voltage detection means is equal to or less than a predetermined threshold, the time until the specified time of the time measured by the time measurement means elapses. Is a power supply control device for vehicles, characterized in that it is configured to supply power. A vehicle power supply control device for loads excluding important loads related to driving and safety,
Current detection means for measuring the current flowing from the battery to the load;
Voltage detection means for measuring the voltage supplied from the battery to the load;
Control means for performing power supply control to the load when the remaining battery capacity determined from the current and voltage measurement values measured by the current detection means and the voltage detection means falls below a predetermined threshold;
And a time measuring means for measuring the time after the ignition key is turned on,
The control means includes
The load is grouped into a view securing load related to view securing and other general loads,
A vehicle that is configured to supply power to the visibility securing load even when the battery remaining capacity is equal to or less than a predetermined threshold until the specified time of the time measured by the time measuring means elapses. Power supply control device. Temperature detecting means for measuring the temperature of the battery;
The power control apparatus for a vehicle according to claim 1 or 2, wherein the control means adjusts the threshold value based on a measured value of temperature.

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