JP2014012998A - Power supply device for engine mounted vehicle with idle stop - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid adverse effects along with battery voltage drop by performing restart after idle stop, using a capacitor connected in parallel to a battery to assist battery charging performance.SOLUTION: A battery 3, a capacitor 4 and an electrical equipment load 5 are connected in parallel to an alternator 2, and a switch 10 is inserted and placed into a positive-side electrical circuit for the capacitor 4. A starter motor 1 which is connected via a starter switch 6 in parallel to the alternator 2 and the battery 3 is also connected in parallel to the capacitor 4, and a restarting switch 9 is inserted and placed into an electrical circuit 8 therefor. When restarting an engine in the state of being stopped with the idle stop after initially started with the starter switch 6 temporarily closed (a current A1), the switch 10 is opened as the starter switch 6 is being opened and the restarting switch 9 is temporarily closed, and so the starter motor 1 is driven with a current A2 to restart the engine. Thus, the drive of the starter motor 1 serving to restart the engine does not cause the voltage drop of the battery 3.

Description

  The present invention relates to a power supply device for a vehicle equipped with an engine with an idle stop, and in particular, when an engine is restarted by driving a starter motor from an engine stopped state due to idle stop, adverse effects on peripheral devices including a battery are alleviated. The present invention relates to a power supply device for a vehicle equipped with an engine with an idle stop that has been made possible.

  Various technologies have been proposed for improving the fuel efficiency of vehicles equipped with engines, but typical examples of improving fuel efficiency include stopping the vehicle without intention to start, such as when the brake pedal is depressed. An idle stop technique is known in which the engine is stopped while the engine is stopped and the engine is restarted when an intention to start is detected, such as when the foot is released from the brake pedal.

  When restarting the engine, it is usual to restart the engine by driving the starter motor with a battery such as a lead acid battery and cranking the engine with the starter motor.

  As another fuel efficiency improvement technology, it is coupled to the engine (vehicle drive system) while the fuel supply to the engine is interrupted (fuel cut is performed) while driving without coasting (inertia). The alternator (generator) is driven by the kinetic energy (deceleration energy) when the vehicle is decelerating, so that the deceleration energy is converted into electric power, and the generated power of the alternator is stored in the battery so that the deceleration energy can be reused. The deceleration energy regeneration technology that has been made possible is also known.

However, in this deceleration energy regeneration technology, in order to improve the fuel efficiency improvement effect by increasing the amount of energy regeneration, it is necessary to improve the charging performance of the battery, but the charging performance of a lead acid battery generally used as a battery has to be improved. There are limits.
Therefore, as described in Patent Document 1, a capacitor such as an electric double layer capacitor is used as the second battery, and a lead acid battery and an electric double layer capacitor are sequentially connected in parallel to the alternator, thereby increasing the amount of energy regeneration. Conventionally, a technology that can improve the fuel efficiency improvement effect has been proposed.

JP 2009-148090 A

By the way, when the engine is restarted by driving the battery of the starter motor from a state in which the engine is stopped by idle stop, a large current flows from the battery to the starter motor, so that the voltage drop of the battery becomes large.
Such a voltage drop of the battery may cause a malfunction of a peripheral electronic device connected to the battery or reset the peripheral device to an initial state.

  In order to solve these problems, conventionally, using the technology described in Japanese Patent No. 4474939, an expensive DC / DC converter is additionally installed upstream of some peripheral electronic devices, and the above voltage of the battery is It is necessary to take measures so as not to cause malfunction or reset of the peripheral electronic device even if it falls, and the problem of high cost is inevitable.

  Also, if the lead acid battery is deteriorated or its charge / discharge performance is lowered due to low outside air temperature, from the viewpoint of battery protection, it is necessary to prohibit idle stop that places a heavy load on the battery. There is also a problem that the improvement effect is not as expected.

  The present invention described in the above-mentioned Patent Document 1, that is, in order to increase the deceleration energy regeneration amount and improve the fuel efficiency improvement effect, a battery and a capacitor are sequentially connected in parallel to the generator, By following the configuration that enables energy regenerative charging by a generator, the power stored in the capacitor is used to drive the starter motor that is used to restart the engine during idle stop. An object of the present invention is to provide a power supply device for a vehicle equipped with an engine with an idle stop that can be eliminated.

  For this purpose, the power supply apparatus for an engine-equipped vehicle according to the present invention has the following configuration.

First of all, to explain the power supply of the engine equipped vehicle with idle stop, which is the premise,
An engine that is started by battery operation of the starter motor through closing of the starter switch means is provided as a power source, and the engine is stopped when the vehicle is not intended to start and is restarted when an intention to start is detected. It is the power supply device used for the vehicle used as the engine.

The power supply device for an engine-equipped vehicle with an idle stop according to the present invention, first,
In addition to the battery, capacitors are sequentially connected in parallel to the generator coupled to the vehicle drive system including the engine to enable energy regenerative charging for the battery and the capacitor.

The power supply device of the present invention is provided with a restart starter motor circuit for connecting the starter motor to the capacitor in parallel, and a restart switch means is inserted into the restart starter motor circuit,
Capacitor disconnecting switch means for disconnecting the capacitor from the battery is inserted in the electric path between the capacitor and the battery.

  In the present invention, when the engine is restarted, the starter switch means is held open, the restart switch means is closed, and the capacitor disconnecting switch means is opened.

In the above-described power supply device for an engine-equipped vehicle according to the present invention,
When the engine is restarted during idling stop, the starter switch means is held open and the restart switch means is closed, so that power is supplied to the starter motor from the capacitor.

For this reason, the drive of the starter motor that controls the restart of the engine does not cause a voltage drop of the battery.
Therefore, the peripheral device connected to the battery does not malfunction due to the voltage drop of the battery or is reset to the initial state, and this peripheral device is expensive to prevent malfunction and reset of the peripheral device. This eliminates the need for additional DC / DC converters and is advantageous in terms of cost.

  In addition, since the battery is not involved in restarting the engine during idle stop, the idle stop control can be continued without interruption even if the battery deteriorates or the performance decreases at low temperatures. Can be achieved as scheduled without being affected by the state of the battery.

  In addition, the capacitor disconnecting switch means is opened when the engine is restarted during idle stop, so that the capacitor is disconnected from the battery, and the power supply to the electrical load is supplied from the battery. The start (idle stop control) can be performed for a long time, and the fuel efficiency improvement effect by the idle stop can be further enhanced.

1 is a system diagram showing a power supply device for an engine-equipped vehicle with an idle stop according to an embodiment of the present invention. FIG. 4 is an operation logic explanatory diagram related to operation 3 of the power supply device in FIG. FIG. 6 is an operation logic explanatory diagram related to operation 4 of the power supply device in FIG. 1; FIG. 6 is an operation logic explanatory diagram related to operation 5 of the power supply device in FIG. FIG. 7 is an explanatory diagram of operation logic related to operation 6 of the power supply device in FIG. 1. (a) is an explanatory diagram of operation logic during fuel supply, and (b) is an explanatory diagram of operation logic during fuel cut.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
<Configuration of Example>
FIG. 1 is a system diagram showing a power supply device for a vehicle equipped with an engine with an idle stop according to an embodiment of the present invention.

The power supply device shown in FIG. 1 is for use in a vehicle that uses an unillustrated engine as a power source. The engine is started by a starter motor 1 and automatically stops when the vehicle is not intended to start, such as when the brake pedal is depressed. The engine with the idle stop is restarted by the starter motor 1 when a start intention is detected such as when the vehicle is stopped and the foot is released from the brake pedal.
The engine is also an engine with a fuel cut that interrupts the fuel supply (fuel cut) in order to save fuel consumption because the engine driving force is unnecessary during vehicle coasting (inertia / deceleration).

A vehicle (wheel) drive system including an engine drives an alternator (generator) 2 coupled to the engine (wheel drive system) to generate electric power, and charges the generated power to the power supply device of FIG.
During coasting, the alternator 2 that is driven by the engine is applied with a power generation load corresponding to the maximum allowable target power generation voltage, and there is no maximum target power generation voltage that can increase the power generation voltage by the alternator 2. By generating power in this state, the deceleration energy during coasting is regenerated.
The allowable maximum target power generation voltage of the alternator 2 (hereinafter simply referred to as the target power generation voltage) is determined so as to correspond to the required deceleration of the vehicle, and in consideration of prevention of overcharge and deterioration of the lead acid battery 3 And decide.

The power supply device of FIG. 1 is provided with a lead acid battery 3, a capacitor 4, and a vehicle electrical load 5 connected in parallel to the alternator 2 sequentially from the side close to the alternator 2.
As described above, the capacitor 4 cannot be obtained with the lead acid battery 3 alone, and the energy regeneration amount is limited. Therefore, the capacitor 4 is added in parallel to the lead acid battery 3 to support this. It is an electric double layer capacitor.

Connection of the starter motor 1 to the power supply device of FIG. 1 is performed in the following manner, particularly in this embodiment.
The starter motor 1 is connected in parallel to the alternator 2 and the lead acid battery 3, and a starter switch (starter switch means) 6 is inserted in the electric path for the parallel connection.
The starter motor 1 is also connected in parallel to the capacitor 4, and a restart starter motor circuit 8 for the parallel connection is provided on the positive side of the starter motor 1, and a restart switch ( The restart switch means) 9 is inserted.

In the present embodiment, a capacitor disconnecting switch (capacitor disconnecting switch means) 10 is further inserted in the upstream (positive side) circuit of the capacitor 4.
The capacitor disconnecting switch 10 is arranged at a position where only the capacitor 4 is disconnected from the alternator 2 without being involved in the connection between the lead acid battery 3 and the electrical load 5 and the alternator 2.

The starter motor switch 6, the restart switch 9 and the capacitor disconnecting switch 10 are opened and closed by the controller 11,
Therefore, the controller 11 sends the fuel cut signal Sfc and the idle stop signal Sid from the engine, the vehicle speed VSP information, the brake switch signal Sbr, the storage state SOC of the lead acid battery 3 and the battery electromotive voltage Vba, and the start of the capacitor 4. Input the voltage Vca.

<Idle stop control and effect of embodiment>
The controller 11 performs drive control (idle stop control) of the starter motor 1 based on these input information as follows.
(Operation 1)
When the driver gives an instruction to start the engine for the first time using an ignition switch or the like, the controller 11 receives this, and the starter motor switch 6 is temporarily closed with the restart switch 9 and the capacitor disconnection switch 10 open. The starter motor 1 is driven by the battery by the initial starting current indicated by the arrow A1 from the lead acid battery 3 to start the engine.

When deceleration energy is generated in the wheel drive system during coasting or the like while the vehicle is running after the engine is started, the controller 11 regenerates the deceleration energy as follows.
When it is determined that the engine is decelerating in the fuel cut state where the fuel supply is interrupted due to the presence of the fuel cut signal Sfc, if the generated voltage of the alternator 2 is higher than the electromotive voltage Vca of the capacitor 4, fuel consumption is accompanied. In order to effectively regenerate the power generated with no deceleration energy, and since no current flows from the capacitor 4 to the lead-acid battery 3 and the electrical load 5 to reduce the capacitor electromotive voltage Vca, the capacitor separation switch 10 is closed. And
By closing the capacitor disconnecting switch 10, the alternator 2 can charge both the lead acid battery 3 and the capacitor 4 with the power generated by the deceleration energy without fuel consumption, and can efficiently regenerate energy.

If it is determined from the idle stop signal Did that the engine needs to be restarted from the state stopped by the idle stop, the controller 11 holds the starter motor switch 6 in the open state and restarts the capacitor disconnecting switch 10 With the open, the restart switch 9 is temporarily closed.
At this time, the starter motor 1 is driven by the restart current indicated by the arrow A2 from the capacitor 4 to restart the engine.

Therefore, the engine is restarted during idling stop with the electric power from the capacitor 4.
For this reason, the drive of the starter motor 1 that controls the restart of the engine does not cause a voltage drop of the lead acid battery 3.
Therefore, peripheral devices such as the electrical load 5 connected to the lead acid battery 3 will not cause malfunction due to the voltage drop of the lead acid battery 3, and will not be reset to the initial state. In order to prevent resetting, it is not necessary to add an expensive DC / DC converter to this peripheral device, which is advantageous in terms of cost.

  In addition, since the lead acid battery 3 is not involved in restarting the engine during idle stop, the idle stop control can be continued without stopping even if the lead acid battery 3 deteriorates or the performance decreases at low temperatures. The fuel efficiency improvement effect due to the idle stop can be achieved as scheduled without being influenced by the state of the lead acid battery 3.

  Furthermore, the capacitor 4 is disconnected from the lead acid battery 3 in order to open the capacitor disconnection switch 10 when the engine is restarted during idle stop, and the power supply to the electrical load 5 is supplied from the lead acid battery 3 with power. Thus, the engine restart (idle stop control) by the capacitor 4 can be performed for a long time, and the fuel efficiency improvement effect by the idle stop can be further enhanced.

(Operation 2)
The controller 11 receives the initial engine start command, and with the restart switch 9 and the capacitor disconnection switch 10 open, the controller 11 temporarily closes the starter motor switch 6 to indicate the first time indicated by the arrow A1 from the lead acid battery 3. When the starter motor 1 is driven by the starting current to start the engine for the first time, the storage state SOC (deterioration state) of the lead acid battery 3 is detected.
The battery deterioration state is not limited to the storage state SOC, and the battery internal resistance can be calculated from the relationship between the discharge current and the voltage drop, and can be diagnosed based on the increase margin of the battery internal resistance.
Therefore, the controller 11 constitutes a battery deterioration state detecting means in the present invention.

When the deterioration state of the battery 3 determined from the battery storage state SOC is a relatively small first stage, the controller 11 permits the idle stop by the opening / closing control of the restart switch 9 and opens the capacitor disconnecting switch 10 to open the capacitor Prohibits the energy regenerative charging for 4
When the battery deterioration state is a large second stage, idle stop is prohibited by opening the restart switch 9, and energy regenerative charging to the capacitor 4 is prohibited by opening the capacitor disconnecting switch 10.

  Thus, according to the open / close control of the restart switch 9 and the capacitor disconnection switch 10 according to the deterioration state of the lead acid battery 3, when the deterioration of the lead acid battery 3 is a relatively mild first stage, the capacitor Although energy regenerative charging for 4 is prohibited, since the idle stop control is continued, it is possible to extend the life of the lead acid battery 3 without causing a significant deterioration in fuel consumption or a sense of discomfort to the driver. The maintenance cost of 3 can be reduced.

(Operation 3)
The controller 11 reads information related to the electromotive voltage Vca of the capacitor 4 and obtains the capacitor electromotive voltage Vca.
Therefore, the controller 11 constitutes a capacitor electromotive voltage detection means in the present invention.

Based on the capacitor electromotive voltage Vca, the controller 11 performs idle stop control by opening and closing the restart switch 9 as follows.
That is, as shown in FIG. 2, only when the capacitor electromotive voltage Vca is within a relatively high specified range (13.5 to 14.0 V), idling stop by opening and closing the restart switch 9 is permitted, and during the idling stop, When the capacitor electromotive voltage detected by the capacitor electromotive voltage detection means becomes lower than the set value (13.0 V) lower than the specified range, the engine is forcibly restarted by temporarily closing the restart switch 9 Let

According to the idling stop control according to the capacitor electromotive voltage Vca, the variation in the voltage applied to the starter motor when the engine is restarted by the capacitor 4 is reduced, so that the variation in the engine restart time can be reduced. The driver does not feel discomfort due to variations in engine restart time during stop control.
In addition, since the engine is forcibly restarted while the engine 4 has the engine starting ability, it is possible to avoid the engine from being brought into a restart impossible state.

(Operation 4)
The controller 11 reads information related to the electromotive voltage Vca of the capacitor 4 to obtain the capacitor electromotive voltage Vca, and also reads information related to the electromotive voltage Vba of the lead acid battery 3 to obtain the battery electromotive voltage Vba.
Therefore, the controller 11 constitutes a capacitor electromotive voltage detection means and a battery electromotive voltage detection means in the present invention.

As shown in FIG. 3, the controller 11 opens and closes the capacitor disconnecting switch 10 while the engine is stopped due to idle stop, based on the capacitor electromotive voltage Vca and the battery electromotive voltage Vba as follows.
(1) When the capacitor electromotive voltage Vca is sufficiently high (Vca ≧ 13.5 V), the capacitor disconnecting switch 10 is closed.
As a result, when the capacitor electromotive voltage Vca is sufficiently high, sufficient power stored in the capacitor 4 can be supplied also to the vehicle electrical load 5 by closing the capacitor disconnecting switch 10, and idling can be stopped for a long time. Thus, the fuel efficiency improvement effect due to idling stop can be enhanced.

(2) When the capacitor electromotive voltage Vca is relatively high (in the case of FIG. 3, Vca = 13.0 to 13.5 V), the capacitor disconnecting switch 10 is opened.
When the capacitor electromotive voltage Vca is relatively high (Vca = 13.0 to 13.5 V), if the capacitor disconnection switch 10 is kept closed as described in (1) above, the capacitor 4 continues to discharge and the engine is restarted several times. It falls into a power storage state where starting cannot be guaranteed.
However, if the capacitor electromotive voltage Vca is relatively high (Vca = 13.0 to 13.5 V), the capacitor disconnect switch 10 is opened, so that the capacitor 4 is not discharged any further, and there is no additional charge to the capacitor 4 Multiple engine restarts can be guaranteed.

(3) When the capacitor electromotive voltage Vca is less than the set value (13.0V in the case of Fig. 3), the capacitor disconnect switch 10 is closed if the battery electromotive voltage Vba is equal to or greater than the specified value (13.5V in the case of Fig. 3). .
Thus, when the capacitor electromotive voltage Vca is less than the set value (13.0 V), the engine can be restarted only once or twice.
However, the capacitor 4 can be charged by the lead acid battery 3 if the battery electromotive voltage Vba is equal to or higher than a specified value (13.5 V).
Therefore, even if the capacitor electromotive voltage Vca is less than the set value (13.0V), if the battery electromotive voltage Vba is equal to or higher than the specified value (13.5V), the capacitor disconnecting switch 10 is closed to lead the capacitor 4 to lead. The battery is charged by the acid battery 3, so that enough power can be stored in the capacitor 4 to restart the engine a plurality of times.

(4) When the capacitor electromotive voltage Vca is less than the set value (13.0V in the case of FIG. 3) and the battery electromotive voltage Vba is less than the specified value (13.5V in the case of FIG. 3), the capacitor separation switch 10 is The engine is forcibly restarted by closing the restart switch 9 while being open.
Therefore, if the backup of the capacitor storage state by the battery electromotive voltage Vba cannot be expected, the engine is forcibly restarted before the storage state of the capacitor 4 decreases to a level at which the engine cannot be restarted. It is possible to prevent the start from being disabled.
During this time, since the capacitor disconnecting switch 10 is in the open state, a large starter motor driving current at the time of forced engine start does not lower the voltage of the lead acid battery 3, and the electrical load 5 is not adversely affected.

(Operation 5)
The controller 11 reads information related to the electromotive voltage Vca of the capacitor 4 and obtains the capacitor electromotive voltage Vca.
Then, the controller 11 performs the opening / closing control of the capacitor disconnecting switch 10 during the engine rotation after the restart through the closing of the restart switch 9 according to the capacitor electromotive voltage Vca and the engine fuel cut ON / OFF in FIG. I'll do it as shown.

(5) During the fuel cut, the capacitor disconnecting switch 10 is closed regardless of the capacitor electromotive voltage Vca.
As a result, during fuel cut with zero fuel consumption, the power generated by the alternator 2 driven by the engine is preferentially charged to the capacitor 4 having a small internal resistance.
Therefore, it is possible to store a large amount of electric power regenerated by the alternator 2 during fuel cut in the capacitor 4, and preferentially store electric power for restarting the engine that has been stopped due to idle stop in the capacitor 4.

(6) On the other hand, during fuel supply without fuel cut, if the capacitor electromotive voltage Vca is a high voltage exceeding a predetermined range (13.0 to 13.5 V in FIG. 4), the capacitor disconnecting switch 10 is closed.
As a result, when the fuel is being supplied and the capacitor electromotive voltage Vca is a high voltage, the capacitor disconnection switch 10 is closed, so that the discharge from the capacitor 4 to the lead acid battery 3 and the electrical load 5 becomes possible. It is possible to reduce the power generation load and improve the fuel efficiency.

(7) Even when the same fuel is being supplied, if the capacitor electromotive voltage Vca is an intermediate voltage within a predetermined range (13.0 to 13.5 V), the capacitor disconnecting switch 10 is opened.
Here, the intermediate voltage within a predetermined range (13.0 to 13.5V) related to the capacitor electromotive voltage Vca is the voltage range in which the capacitor 4 can restart the engine only once or twice without additional charging, and the engine is restarted several times. The boundary voltage range between the voltage range that can be started.
As a result, when the fuel is being supplied and the capacitor electromotive voltage Vca is an intermediate voltage, the capacitor disconnection switch 10 is opened to avoid further discharging of the capacitor 4 and charging of the capacitor due to the alternator power generation during fuel supply. As a result, the engine restart guarantee at the time of idling stop can be realized, and the deterioration of the fuel consumption due to the alternator power generation for charging the capacitor can be prevented.

(8) When the fuel is being supplied and the capacitor electromotive voltage Vca is a low voltage lower than a predetermined range (13.0 to 13.5 V), the capacitor disconnecting switch 10 is closed.
Thus, when the fuel is being injected and the capacitor 4 has a low voltage that can restart the engine only once or twice without additional charging, the capacitor disconnecting switch 10 is closed to close the capacitor. 4 is charged, so that it is possible to prepare for idle stop when the vehicle stops.

(Operation 6)
The controller 11 shows the target power generation voltage of the alternator 2 during engine rotation after restart via closing of the restart switch 9 and while fuel is being supplied to the engine due to non-operation of the fuel cut. Determine as shown in a).

Therefore, the controller 11 obtains and sets the capacitor required voltage required by the capacitor 4 according to the electromotive voltage Vca as shown in FIG.
The battery required voltage required by the lead acid battery 3 according to the storage state SOC (deterioration state) is obtained and set as shown in FIG.
Therefore, the controller 11 constitutes a capacitor required voltage setting means and a battery required voltage setting means in the present invention.

As shown in FIG. 5 (a), it is assumed that the required capacitor voltage increases as the capacitor electromotive voltage Vca decreases.
Thus, by setting the capacitor required voltage high when the capacitor electromotive voltage Vca is low, charging of the capacitor 4 is promoted, and the power necessary for restarting the engine from the idle stop is promptly supplied to the capacitor 4. Charging becomes possible.
In addition, when the capacitor electromotive voltage Vca is high, the required voltage is eliminated, and the discharge from the capacitor 4 becomes possible, thereby improving the fuel efficiency of the engine by suppressing the power generation amount of the alternator 2. it can.

On the other hand, as shown in FIG. 5 (a), the battery required voltage is assumed to increase as the degree of deterioration of the lead acid battery 3 increases (the storage state SOC decreases).
Thus, when the deterioration degree of the lead acid battery 3 is large (when the state of charge SOC is small), the charging of the lead acid battery 3 is promoted by setting the battery required voltage higher. It is possible to prevent deterioration and battery exhaustion.
In addition, when the degradation level of the lead acid battery 3 is small (when the state of charge SOC is large), by setting the required battery voltage low, the lead acid battery 3 can be discharged, and the power generation amount of the alternator 2 can be reduced. By suppressing it, the fuel consumption of the engine can be improved.

The controller 11 determines the higher voltage value (select high value) as the target power generation voltage of the alternator 2 for every combination of the above-described capacitor required voltage and battery required voltage, and at this time the target power generation voltage of the alternator 2 is By setting an upper limit on the gassing voltage of the lead acid battery 3, the deterioration of the lead acid battery 3 is prevented.
Therefore, the controller 11 constitutes the generator target generated voltage determining means in the present invention.

As described above, since the target power generation voltage of the alternator 2 is determined by selecting the capacitor required voltage and the battery required voltage, it is possible to prevent either the capacitor 4 or the hydrochloric acid battery 3 from falling into a low charge state.
In addition, when there is a margin in the charge amount of the capacitor 4 and the hydrochloric acid battery 3, the required voltage is lowered and the target power generation voltage of the alternator 2 is lowered. Therefore, the discharge from the lead acid battery 3 or the capacitor 4 or both As a result, the power generation load of the alternator 2 is reduced and the fuel efficiency of the engine can be improved.

  The controller 11 is rotating the engine after restarting via closing of the restart switch 9, but the target power generation voltage of the alternator 2 during the fuel cut to the engine due to the fuel cut is shown in FIG. ).

Therefore, the controller 11 obtains the required voltage upper limit value of the capacitor 4 and the required voltage upper limit value of the lead acid battery 3 from each component and function.
Therefore, the controller 11 constitutes a capacitor required voltage upper limit calculating means and a battery required voltage upper limit calculating means in the present invention.
Then, the controller 11 selects the target power generation voltage of the alternator 2 during engine rotation in a state where fuel supply to the engine is interrupted by fuel cut, by selecting the above-mentioned capacitor request voltage upper limit value and battery request voltage upper limit value, That is, it is determined to be the same value as the lower voltage value of these.

  Thus, the generator power generation voltage of alternator 2 is high because the target power generation voltage of alternator 2 during engine rotation in the fuel cut state after restart is determined by the select low of the capacitor required voltage upper limit value and the battery required voltage upper limit value. As the lead acid battery 3 and the capacitor 4 are charged, the charging capacity is increased.

In addition, since the capacitor required voltage upper limit value and the battery required voltage upper limit value are the upper limit values required by each component and function, the target power generation voltage of the alternator 2 determined by these select lows is the highest voltage within the allowable range, Since the regenerative power generation is performed at this voltage during the fuel cut, the regenerative charge amount is maximized.
And since the electric power for this maximum regenerative charge is used, the alternator power generation amount during fuel injection can be suppressed, and the fuel efficiency of the engine can be improved accordingly.

1 Starter motor
2 Alternator (generator)
3 Lead acid battery
4 capacitors
5 Electrical load
6 Starter switch (starter switch means)
8 Starter motor circuit for restart
9 Restart switch (restart switch means)
10 Capacitor disconnect switch (Capacitor disconnect switch means)
11 Controller ()

Claims (7)

An engine that is started by battery operation of the starter motor through closing of the starter switch means is provided as a power source, and the engine is stopped when the vehicle is not intended to start and is restarted when an intention to start is detected. In a power supply device used for an engine vehicle,
In addition to the battery, a capacitor is sequentially connected in parallel to the generator coupled to the vehicle drive system including the engine to enable energy regenerative charging for the battery and the capacitor.
A restart starter motor circuit for connecting the starter motor to the capacitor in parallel is provided, and a restart switch means is inserted into the restart starter motor circuit,
Capacitor disconnect switch means for disconnecting the capacitor from the battery is inserted in the electric path between the capacitor and the battery;
When the engine is restarted, the starter switch means is held open, the restart switch means is closed, and the capacitor disconnecting switch means is open. Car power supply. In the power supply device of the vehicle equipped with an engine with an idle stop according to claim 1,
A battery deterioration state detection means for detecting a deterioration state of the battery at the time of initial engine start by battery drive of a starter motor through closing of the starter switch means;
According to the battery deterioration state detected by the means, when the battery deterioration state is a small first stage, allowing the idle stop control by opening and closing the restart switch means, and opening the capacitor separation switch means When the regenerative charging of the capacitor is prohibited and the battery deterioration state is a large second stage, the idle stop control is prohibited by opening the restart switch means and the capacitor disconnecting switch means is opened. A power supply device for a vehicle equipped with an engine with an idle stop, which is configured to prohibit energy regenerative charging against the engine. In the power supply device of the vehicle equipped with an engine with an idle stop according to claim 1 or 2,
Capacitor electromotive voltage detection means for detecting the electromotive voltage of the capacitor is provided,
While the capacitor electromotive voltage detected by the means is within a relatively high specified range, the idle stop control is permitted by opening and closing the restart switch means, and during the idle stop control, the capacitor electromotive voltage detection means An engine-equipped vehicle with an idle stop, wherein the engine is forcibly restarted by closing the restart switch means when the detected capacitor electromotive voltage becomes lower than the specified range. Power supply. In the power supply device of the vehicle equipped with an engine with an idle stop according to any one of claims 1 to 3,
Capacitor electromotive voltage detection means for detecting the electromotive voltage of the capacitor;
Battery electromotive voltage detection means for detecting the electromotive voltage of the battery;
In the opening / closing control of the capacitor disconnection switch means during the engine stop by the idle stop,
(1) If the capacitor electromotive voltage detected by the capacitor electromotive voltage detecting means is sufficiently high, the capacitor disconnecting switch means is closed,
(2) If the detected capacitor electromotive voltage is relatively high, open the capacitor disconnect switch means,
(3) When the detected capacitor electromotive voltage is less than a set value, if the battery electromotive voltage detected by the battery electromotive voltage detection means is a specified value or more, the capacitor disconnection switch means is closed,
(4) When the detected capacitor electromotive voltage is less than a set value, if the detected battery electromotive voltage is less than a specified value, the capacitor disconnecting switch means remains open and the restart switch means is closed. A power supply device for a vehicle equipped with an engine with an idle stop, wherein the engine is forcibly restarted. In the power supply device of the engine-equipped vehicle with an idle stop, according to any one of claims 1 to 4, wherein the engine is an engine with a fuel cut that interrupts fuel supply when the driving force is unnecessary.
Capacitor electromotive voltage detection means for detecting the electromotive voltage of the capacitor is provided,
Upon opening / closing control of the capacitor disconnection switch means during engine rotation after restart through closing of the restart switch means,
(5) During the fuel cut, the capacitor disconnection switch means is closed,
(6) During fuel supply where the fuel cut is not performed, if the capacitor electromotive voltage detected by the capacitor electromotive voltage detecting means is a high voltage exceeding a predetermined range, the capacitor disconnecting switch means is closed,
(7) While the fuel cut is not being performed and the detected capacitor electromotive voltage is an intermediate voltage within a predetermined range, the capacitor disconnecting switch means is opened,
(8) It is configured to close the capacitor separation switch means when the fuel cut is not performed and the detected capacitor electromotive voltage is a low voltage lower than a predetermined range. Power supply unit for vehicles equipped with an engine with idle stop. In the power supply device of the vehicle equipped with an engine with an idle stop according to any one of claims 1 to 5,
Capacitor required voltage setting means for setting the capacitor required voltage so as to increase as the electromotive voltage of the capacitor decreases;
Battery request voltage setting means for setting the battery request voltage so as to increase as the degree of deterioration of the battery increases,
The target power generation voltage of the generator during engine rotation after the restart through closing of the restart switch means is determined to be the same value as the higher one of the set capacitor required voltage and battery required voltage. A power supply device for a vehicle equipped with an engine with an idle stop, comprising: a target power generation voltage determining means for the generator. The engine according to claim 6, wherein the engine is an engine with a fuel cut that interrupts fuel supply when no driving force is required.
Capacitor required voltage upper limit value calculating means for obtaining a required voltage upper limit value of the capacitor;
A battery request voltage upper limit value calculating means for obtaining the battery request voltage upper limit value,
The generator target power generation voltage determining means determines the target power generation voltage of the power generator while fuel supply to the engine is interrupted by the fuel cut, out of the capacitor required voltage upper limit value and the battery required voltage upper limit value. A power supply device for a vehicle equipped with an engine with an idle stop, which is determined to be the same value as the lower voltage value.

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