JP2004106621A - Automatic stopping/automatic restarting device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein an automatic stopping of an engine can not be continued because of rapid lowering of storage amount of a battery when using a plurality of electrical equipment without limitation during the automatic stopping of the engine. <P>SOLUTION: When a prescribed automatic stopping condition of the engine is established (S1), the automatic stopping of engine is performed (S2). When a prescribed automatic restarting condition of the engine is established (S4), the automatic restarting of the engine is performed (S5). During the automatic stopping of the engine, voltage reduction of a DC-DC converter is performed to uniformly suppress power consumption of the battery by the plurality of electrical equipment (S3). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an automatic stop / restart device for an engine, and more particularly to power control during automatic stop of an engine.
[0002]
[Prior art]
In recent years, in order to reduce exhaust gas and suppress fuel consumption, the engine is automatically stopped when a predetermined engine automatic stop condition is satisfied at an intersection or the like, and the engine is automatically restarted when the vehicle restarts afterwards. 2. Description of the Related Art An idle stop vehicle equipped with an automatic stop / automatic restart device for a starting engine has been put to practical use. In such vehicles, power cannot be generated by the driving force of the engine while the engine is automatically stopped.Therefore, if electric components such as lamps are used during the automatic stop of the engine, the amount of charge stored in the battery decreases rapidly. The engine cannot be stopped automatically for a long time.
[0003]
As a countermeasure, Patent Literature 1 discloses a technique in which when the automatic engine stop state continues for a predetermined time or more, power supply to a lamp (headlight) by a relay is cut off and the lamp is turned off. Patent Document 2 discloses a technique in which the lamp is dimmed during an automatic engine stop and the lamp is turned off when the battery capacity is equal to or less than a predetermined value.
[0004]
[Patent Document 1]
JP-A-11-278149 [0005]
[Patent Document 2]
JP 2001-10405 A
[Problems to be solved by the invention]
In Patent Literature 1 and Patent Literature 2, since the lamp is turned off or dimmed while the engine is automatically stopped, the function of only the lamp is significantly impaired, and only the power saving of the lamp is limited. Therefore, when other electric components such as an audio device and a wiper are used, the amount of stored power in the battery also decreases rapidly, and the automatic engine stop cannot be performed for a long time.
[0007]
The present invention has been made in view of such a problem, and has as its main object to provide a new automatic stop / restart apparatus for an engine that enables automatic stop of an engine for a long time.
[0008]
[Means for Solving the Problems]
The automatic stop / restart device for an engine according to the present invention performs the automatic stop of the engine when a predetermined engine automatic stop condition is satisfied, and the predetermined engine automatic restart condition is satisfied during the automatic stop of the engine. Then, the engine is automatically restarted. Further, it has a battery that can be stored by the power of the engine, and a plurality of electrical components that operate by consuming the power of the battery. Further, the present invention is characterized by having a suppression means for uniformly suppressing power consumption by the plurality of electrical components during the automatic engine stop.
[0009]
【The invention's effect】
According to the present invention, the power consumption during the automatic stop of the engine can be significantly suppressed, and the automatic operation of the engine can be prolonged. In addition, since the power consumption by the plurality of electrical components is uniformly reduced, the function of the specific electrical component is not significantly impaired.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a system configuration diagram showing an example of an idle stop vehicle provided with an automatic stop / automatic restart device for an engine according to the present invention. The battery controller 1 is connected to the battery 8, and performs integration of the amount of charge (SOC) of the battery 8, power consumption from the battery 8, and the like. The DC-DC converter 2 as a transforming means is disposed between the battery 8 and the plurality of electrical components 6, more specifically, between the battery controller 1 and the fusible link (F / L) 3. The DC voltage supplied to the plurality of electrical components 6 is reduced (stepped down), and has a function of suppressing power consumption from the battery 8 by performing step-down during automatic engine stop, as described later. . A plurality of fuses including the fuse of the ignition switch line 7 are integrally incorporated in the fusible link 3 to form a unit.
[0011]
An ECM (Engine Control Module) 4 is a digital computer system having a CPU, a ROM, a RAM, and an input / output interface, and having a function of storing and executing various control processes. In addition to the control, various controls to be described later, that is, automatic stop of the engine, step-down of the DC-DC converter 2 during automatic stop of the engine, automatic restart of the engine, and step-up of the DC-DC converter 2 after the automatic restart of the engine And so on.
[0012]
When the ignition key is set to the start position or when a restart command is output from the ECM 4, the starter 5 is started with the ON of the relay 9, and rotates the crankshaft of the engine to drive the engine. Start up. Further, the vehicle is equipped with various electrical components 6, for example, an audio 6a, lights (lamp) 6b such as a head lamp and a tail lamp, a wiper 6c, a compressor of an air conditioner, and the like.
[0013]
FIGS. 2 to 4 are flowcharts each showing a control flow according to the first to third embodiments of the present invention, and are executed by the ECM 4 described above. Note that the same control processing is given the same step (S) number, and redundant description will be omitted as appropriate.
[0014]
FIG. 2 shows a control flow according to the first embodiment. In S (step) 1, an idle stop permission determination is made. Specifically, when the vehicle is stopped, the brake pedal is depressed, and when a predetermined engine automatic stop condition including that the state of charge (SOC) of the battery exceeds a predetermined value is satisfied, S1 is executed. Is affirmed and the process proceeds to S2. In S2, fuel injection of the engine is prohibited, and the engine is automatically stopped. During this automatic engine stop, the DC-DC converter 2 is stepped down (S3). As a result, the power load, that is, the power consumption, supplied from the battery 8 to all of the plurality of electrical components 6 during the automatic engine stop is uniformly reduced. Here, the amount of suppression of the power consumption due to the step-down of the DC-DC converter 2 is limited so that the functions of the plurality of electric components 6 do not excessively deteriorate even after the power is suppressed and the driver does not feel uncomfortable. I do. Specifically, the step-down amount is limited so that the step-down voltage of the DC-DC converter 2 becomes equal to or higher than a predetermined voltage (for example, 11 V).
[0015]
In S4, it is determined whether an automatic restart condition of the engine is satisfied. For example, when the brake pedal is released, when the accelerator pedal is depressed, or when the charged amount of the battery 8 becomes lower than a predetermined lower limit, the condition for automatically restarting the engine is satisfied and the routine proceeds to S5. .
[0016]
In S5, the engine is automatically restarted. Specifically, the starter 5 is driven by the electric power from the battery 8, the engine is cranked by the starter 5, and fuel injection (and spark ignition in the case of a gasoline engine) is restarted.
[0017]
In S6, the DC-DC converter 2 is boosted. In other words, the step-down of the DC-DC converter 2 during the automatic stop of the engine is released, the voltage is increased to a normal value, and the power consumption from the battery 8 to the plurality of electrical components 6 is reduced to a value in a normal idling state. Let it return.
[0018]
In the first embodiment, the following operational effects are obtained. Since the power consumption by all the electrical components 6 is uniformly reduced during the automatic engine stop, the power consumption during the automatic engine stop is greatly reduced, and the operation time in the automatic engine stop state can be extended. Can be planned. In addition, the power consumption of the plurality of electrical components 6 can be uniformly reduced by the step-down of the DC-DC converter 2, so that the voltage adjustment of each electrical component is not required, and the control thereof is simple. Further, since the voltage after the step-down is limited to the predetermined voltage, the function of the electrical component 6 can be maintained at a minimum even during the automatic engine stop, and the driver does not feel uncomfortable. . These functions and effects can be similarly obtained in other embodiments described later.
[0019]
In particular, in the first embodiment, since the power consumption is constantly reduced during the automatic engine stop, the power consumption of the battery is always suppressed during the automatic engine stop. Can be prolonged, and the control is simple.
[0020]
FIG. 3 shows a control flow according to the second embodiment. As in the first embodiment, when the engine automatic stop condition is satisfied, the process proceeds from S1 to S2, and the engine is automatically stopped. In S3a, it is diagnosed and determined whether the battery 8 has deteriorated during the automatic engine stop. Typically, the deterioration of the battery 8 is diagnosed and determined based on the SOC, voltage, current, and the like of the battery 8 supplied from the battery controller 1. Only when it is determined that the battery is deteriorated, the process proceeds to S3, in which the DC-DC converter 2 is stepped down to uniformly suppress the power consumption by the plurality of electrical components 6. When it is determined that the battery has not deteriorated, the DC-DC converter 2 is not stepped down (S7), and when the engine automatic restart condition is satisfied (S8), the engine is automatically restarted (S9).
[0021]
In the second embodiment, the power consumption is suppressed only when the battery is deteriorated, so that when the battery is not deteriorated, the power load on the plurality of electrical components 6 is not suppressed or limited, and more power is supplied. Comfort can be obtained.
[0022]
As a modification of the second embodiment, in S3a, it may be determined whether or not the SOC of the battery is lower than a predetermined lower limit during the automatic engine stop. Only when it is determined that the SOC of the battery is lower than the lower limit value, the process proceeds to S3, in which the DC-DC converter 2 is stepped down to uniformly suppress the power consumption by the plurality of electrical components 6. When the SOC of the battery is equal to or higher than the lower limit, the DC-DC converter 2 is not stepped down (S7), and when the engine automatic restart condition is satisfied (S8), the engine is automatically restarted (S9).
[0023]
In the modification of the second embodiment, the power consumption is suppressed only when the SOC of the battery 8 is low, and the power load on the plurality of electrical components 6 is suppressed when the SOC of the battery is sufficiently left. Because there is no more comfort can be obtained.
[0024]
Alternatively, the SOC of the battery may be detected, and the magnitude of the voltage drop by the DC-DC converter 2 may be adjusted according to the SOC. Specifically, the step-down is increased as the SOC increases. Thereby, power consumption can be more appropriately suppressed according to the SOC.
[0025]
FIG. 4 shows a control flow according to the third embodiment. As in the first embodiment, when the engine automatic stop condition is satisfied, the process proceeds from S1 to S2, and the engine is automatically stopped. In S3b, 1 is added to the value T of the counter for the number of times of automatic engine stop. The value T of this counter represents an integrated value of the number of times the engine has been automatically stopped since the battery was new or replaced. In S3c, it is determined whether the value T of the counter exceeds a predetermined value T0. Only when the counter value T exceeds the predetermined value T0, it is presumed that the battery is deteriorated, and the process proceeds to S3, where the DC-DC converter 2 is stepped down, and the consumption of the plurality of electrical components 6 is reduced. Reduce power consumption uniformly. If the counter value T is equal to or less than the predetermined value T0, the DC-DC converter 2 is not stepped down (S7), and if the engine automatic restart condition is satisfied (S8), the engine is automatically restarted (S9).
[0026]
According to the third embodiment, the power consumption is suppressed only when the number of times of automatic engine stop T exceeds a predetermined value T0. Otherwise, the power load of the plurality of electrical components 6 during the automatic stop of the engine is reduced. Is not suppressed, so that more comfort can be obtained.
[0027]
As described above, the present invention has been described based on the specific embodiments. However, the present invention is not limited to the above embodiments, and includes various modifications and changes. For example, if the battery is deteriorated during the automatic engine stop, the SOC of the battery is lower than the lower limit value, or the number T of the automatic engine stop exceeds the predetermined value T0, the step-down of the DC-DC converter 2 is reduced. You may make it implement.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing an example of an idle stop vehicle to which an automatic stop / restart device for an engine according to the present invention is applied.
FIG. 2 is a flowchart showing a flow of control according to the first embodiment.
FIG. 3 is a flowchart illustrating a control flow according to a second embodiment.
FIG. 4 is a flowchart illustrating a control flow according to a third embodiment.
[Explanation of symbols]
1: Battery controller 2: DC-DC converter (transformer)
6: Multiple electrical components 8: Battery

Claims (6)

When the predetermined engine automatic stop condition is satisfied, the engine is automatically stopped, and when the predetermined engine automatic restart condition is satisfied during the automatic stop of the engine, the engine is automatically restarted. In an automatic stop / automatic restart device for an engine having a battery capable of storing electricity and a plurality of electrical components that operate by consuming the power of the battery,
An automatic engine stop / restart device, characterized in that the automatic stop / restart device comprises a suppression means for uniformly suppressing power consumption by the plurality of electrical components during the automatic stop of the engine. 2. The automatic engine stop / restart apparatus according to claim 1, further comprising a limiter configured to limit an amount of power consumption suppressed by the suppressor. 3. The automatic stop / automatic restart of the engine according to claim 1, wherein the power consumption is suppressed by the suppressor only when it is determined that the battery is deteriorated during the automatic stop of the engine. Starting device. 3. The engine according to claim 1, wherein the power consumption is suppressed by the suppression unit only when the engine is being automatically stopped and the charged amount of the battery is lower than a predetermined lower limit. 4. Automatic stop / restart device. The power consumption is suppressed by the suppression means only when the engine is being automatically stopped and the number of times of the engine automatic stop exceeds a predetermined number. Automatic stop / restart device for engine. Having a transformer means between the battery and a plurality of electrical components,
The engine according to any one of claims 1 to 5, wherein the suppression unit uniformly reduces power consumption by the plurality of electrical components by performing step-down by the transformer. Automatic restart device.

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