JP2005282427A - Power supply unit for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply unit for a vehicle which is provided with at least two batteries, and can prevent one-side reduction of a battery capacity incident to the feed to electrical auxiliary equipment under conditions of an engine stop at the time of an idle stop. <P>SOLUTION: The power supply unit installed on a vehicle is provided with a first battery and a second battery, a relay means, a control means, and a means of detecting residual capacity. The first and second batteries are for starting a starter motor for starting an engine. Then the relay means is arranged between the first and second batteries and the electrical auxiliary equipment of the vehicle, and performs an on-off switching action. Then the control means controls the switching action of the relay means. Then the means of detecting residual capacity detects the residual capacity of the first and second batteries. The control means switches the relay means so that the feed is performed from the battery which has more residual capacity to the auxiliary equipment on the basis of the information obtained from the means of detecting residual capacity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power supply device mounted on a vehicle such as an automobile.

  In recent years, from the viewpoints of energy saving and environmental protection, idle stop is encouraged in which the engine is temporarily stopped when the vehicle is stopped and the engine is restarted with a starter when starting. However, in this idle stop, when the starter is operated, power is supplied from the battery to the starter.However, if the engine restart is repeated, the battery cannot be sufficiently charged from the alternator. As a result, when starting the starter, Engine startability may deteriorate.

  In view of the repeated operation of the starter, an engine automatic start system that can smoothly restart the engine and suppress the deterioration of the battery by using at least two batteries has been proposed. (For example, refer to Patent Document 1). In this system, a starter generator having a plurality of batteries, a relay for connecting these batteries in parallel or in series, a starter function for restarting the engine, and a power generation function driven by the engine to generate electric power, A controller that temporarily stops the engine and energizes the starter generator to restart the engine when a vehicle start instruction is issued, and is connected in parallel by a relay based on the controller during engine operation. When the battery is charged by the starter generator and a vehicle start instruction is issued while the engine is temporarily stopped, the relay is switched from the parallel connection side to the series connection side by the relay based on the controller. Then, the engine is restarted by energizing the starter generator.

JP 2003-155968 A

  By the way, in the configuration of a power supply apparatus provided with a plurality of batteries, power is normally supplied from an alternator to an electrical accessory such as an illuminator or an audio device installed in a vehicle when the engine is in operation. On the other hand, in the engine stop state at the time of idling stop, the electricity stored in each battery as a backup power source is supplied as a dark current. In supplying dark current from such a battery, if only one battery is used, the battery is reduced. For example, when the battery is used for starting the starter motor, there is a possibility that the starter motor cannot be started normally due to the battery being depleted. Further, as one battery is depleted, there is a possibility that the charging frequency of the battery is high and the life is shortened.

  The present invention has been made in view of the above technical problem, and is configured to include at least two batteries, and can reduce the amount of battery that accompanies power supply to electrical auxiliary devices when the engine is stopped during an idle stop. An object of the present invention is to provide a power supply device for a vehicle that can be prevented.

  According to a first aspect of the present invention, in a power supply device mounted on a vehicle, a first battery and a second battery for starting a starter motor for starting an engine, and the first and second batteries, A relay unit disposed between the electrical accessories of the vehicle and performing an on / off switching operation; a control unit controlling the switching operation of the relay unit; and a remaining unit for detecting a remaining capacity of the first and second batteries Capacity detecting means, and the control means, based on the information acquired from the remaining capacity detecting means, supplies power to the auxiliary devices from the battery with the larger remaining capacity. It is characterized by switching means.

  Further, the invention according to claim 2 of the present application is the invention according to claim 1, wherein the control means performs the next engine start based on information acquired from the engine operating state detecting means for detecting the operating state of the engine. When the stop of the engine accompanying the start of the second starter motor is detected, the switching operation of the relay means is controlled.

  Furthermore, the invention according to claim 3 of the present application is the invention according to claim 1 or 2, wherein the control means is used to supply power to the auxiliary devices based on information acquired from the remaining capacity detection means. When it is detected that the remaining capacity of the remaining battery is lower than the remaining capacity of the unused battery by a predetermined amount, the relay means is configured to supply power to the auxiliary devices from the battery that has not been used before. It is characterized by switching.

  Furthermore, the invention according to claim 4 of the present application is the battery according to any one of claims 1 to 3, wherein the first battery activates a first starter motor for starting the engine. The second battery is a battery for starting a second starter motor for restarting the engine stopped at the time of idling stop.

  According to the invention according to claim 1 of the present application, at the time of idling stop, the battery having the larger remaining capacity is alternately used as a dark current supply source to the auxiliary devices, thereby preventing one battery from being reduced. The remaining capacity of the first and second batteries can be balanced.

  Further, according to the invention according to claim 2 of the present application, the invention according to claim 1 can be more effectively implemented in the engine stop state at the time of idling stop.

  Further, according to the invention of claim 3 of the present application, when the remaining capacity of the battery used for supplying power to the auxiliary devices falls below the remaining capacity of the unused battery by a predetermined amount, dark current is supplied. Since the battery as the source is switched, the battery can be weighted in consideration of the use frequency or the like depending on the setting of a predetermined amount.

  Further, according to the invention according to claim 4 of the present application, in addition to the effects exhibited by the inventions according to the above claims, it is possible to smoothly restart the engine accompanying the idle stop.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram schematically showing a power supply device for a vehicle according to the present invention. The power supply device 1 supplies power to a first starter motor M1 for starting an engine (not shown) to start the first starter motor M1, and the engine at the time of idling stop. A second battery B2 for supplying power to the second starter motor M2 for restarting and starting the second starter motor M2. The first and second batteries B1 and B2 have the same storage capacity.

  The power supply device 1 also includes an alternator A that supplies power to the first and second batteries B1 and B2, and first and second power supplies that are turned on and off from the alternator A to the first battery B1. Relays R1 and R2. The first and second relays R1 and R2 are connected to the alternator A so that both are arranged in parallel with each other, and the first battery B1 is connected in series to the first relay R1. On the other hand, the second battery R2 is connected in series to the second relay R2. Further, the first starter motor M1 is connected to the first battery B1 so as to be able to receive power from the first battery B1, while the second starter motor M2 is connected to the second battery B2 by the second starter motor M2. The battery B2 is connected so as to be able to receive power.

  Moreover, as shown in FIG. 1, with respect to such a power supply device 1, electrical auxiliary equipments L1 to Ln such as an illuminator and an audio device installed in the vehicle include an alternator A or first and second batteries B1 and It is connected so as to be able to receive power from B2. Normally, these electrical accessories L1 to Ln are supplied with power from the alternator A in the engine operating state, and stored in the first and second batteries B1 and B2 as backup power sources in the engine stopped state. The supplied electricity is supplied as a dark current.

  The power supply device 1 further includes a control circuit C that can control the switching operation of the first and second relays R1 and R2. The control circuit C includes information representing the remaining capacities P1 and P2 of the respective batteries detected on the first and second batteries B1 and B2, and information representing the traveling speed (vehicle speed) of the vehicle detected by the vehicle speed sensor. Information indicating the elapsed time from engine stop measured by the engine stop time measurement timer, information received at the receiver for keyless entry that receives the door lock / unlock signal sent from the transmitter carried by the user, Information indicating the on / off state of the ignition switch for switching the operation state of the engine control unit, information indicating the operation state of the parking brake, information indicating the operation state of the change lever for performing the shifting operation, and the door detected by the door switch Various information such as information indicating the open / close state of the Can. Then, the control circuit C makes a predetermined determination based on these pieces of information, and controls the on / off switching operation of the first and second relays R1 and R2.

When the first relay R1 is set to the on state (closed state) by the control circuit C, the first battery B1 is charged by the power supply from the alternator A, and the first relay R1 is turned off (open). When the state is set, the first battery B1 is disconnected from the alternator A and the electrical auxiliary equipments L1 to Ln, and the first starter motor M1 can be started.
On the other hand, when the second relay R2 is set to the on state (closed state), the second battery B2 is charged by the power supply from the alternator A, and when the second relay R2 is set to the off state, the second battery B1 is It is disconnected from the alternator A and the electrical auxiliary equipments L1 to Ln, and the second starter motor M2 can be activated.

  Further, the control circuit C sets the first and second relays R1 and R2 to the ON state as necessary, and from both the first and second batteries B1 and B2 to the first starter motor M1. It is also possible to perform control such that power is supplied to start the first starter motor M1, or power is supplied to the second starter motor M2 to start the second starter motor M2.

  In the power supply device 1 according to the present embodiment, the pieces of the first and second batteries B1 and B2 that accompany dark current supply to the electrical auxiliary devices L1,. In order to prevent the decrease, the on / off switching operation of the first and second relays R1 and R2 for determining the connection state between the alternator A and the first and second batteries B1 and B2 has been devised. More specifically, the remaining capacity P1 and P2 of the first and second batteries B1 and B2 are compared with the engine stop state at the time of idling stop, and the auxiliary devices L1,. Switch the first and second relays R1 and R2 so that dark current is supplied to Ln. In addition, when the remaining capacity of the battery used for supplying dark current to the auxiliary devices L1,..., Ln falls below the remaining capacity of the unused battery by a predetermined amount, it has not been used until then. The first and second relays R1 and R2 are switched so that a dark current is supplied from the battery to the auxiliary devices L1,.

  2A is a diagram schematically showing a state in which dark current is supplied from the first battery B1 to the auxiliary devices L1,..., Ln, and FIG. FIG. 4 is a diagram showing changes in remaining capacities P1 and P2 of first and second batteries B1 and B2 in that case. In the state shown in FIG. 2A, the first relay R1 is set to the closed state and the second relay R2 is set to the open state, and as shown by the arrows, from the first battery B1 to the auxiliary devices L1, ..., dark current is supplied to Ln. Due to this dark current power supply, the remaining capacity P1 of the first battery B1 is changed from the capacity corresponding to the upper side of the white rectangle to the capacity corresponding to the upper side of the hatched rectangle as shown in FIG. And is lower than the remaining capacity P2 of the second battery B2 by p1. In this embodiment, when the remaining capacity P1 of the first battery B1 falls below the remaining capacity P2 of the second battery B2 by p1, the auxiliary devices L1,..., Ln from the second battery B2 The first relay R1 is set in the open state and the second relay R2 is set in the closed state so as to switch to the dark current supply to.

Similarly, (a) of FIG. 3 is a diagram schematically showing a state in which a dark current is supplied from the second battery B2 to the auxiliary devices L1,..., Ln. b) is a diagram showing changes in remaining capacities P1 and P2 of the first and second batteries B1 and B2 in that case. In the state shown in FIG. 3 (a), the first relay R1 is set to the open state and the second relay R2 is set to the closed state, and as shown by the arrows, the second battery B2 is connected to the auxiliary devices L1, ..., dark current is supplied to Ln. By this dark current power supply, the remaining capacity P2 of the second battery B2 is changed from the capacity corresponding to the upper side of the white rectangle to the capacity corresponding to the upper side of the hatched rectangle as shown in FIG. And is lower by p2 than the remaining capacity P1 of the first battery B1. In this embodiment, when the remaining capacity P2 of the second battery B2 falls below the remaining capacity P1 of the first battery B1 by p2, the auxiliary devices L1,..., Ln from the first battery B1. The first relay R1 is set in the closed state and the second relay R2 is set in the open state so as to switch to the dark current supply.
If the difference p1 and p2 in the remaining capacity at the time of switching the battery as the dark current supply source can be arbitrarily set, the weighting considering the use frequency and the like between the first and second batteries B1 and B2 Depending on the setting.

  The switching of the dark current supply source between the first and second batteries B1 and B2 is repeated until the remaining capacity of one of the batteries becomes less than a predetermined value. As this predetermined value, for example, a capacity exceeding the capacity required for starting the first or second starter motor M1 or M2 may be set. If the remaining capacity of one battery is less than a predetermined value, in order to suppress the decrease in the remaining capacity P2, from both the first and second batteries B1 and B2 to the auxiliary devices L1,. The first and second relays R1 are set in the closed state and the second relay R2 is set in the open state so that the dark current is supplied.

  FIG. 4 is a flowchart of the relay switching control process performed by the power supply device 1. In this process, it is first determined whether or not the engine is stopped in an idle stop state (S11). As a result, if it is determined that the engine is in an operating state or is completely stopped, the immediate processing is terminated because it does not correspond to engine restart. On the other hand, if it is determined that the engine is stopped in the idle stop state, the remaining capacities P1 and P2 of the first and second batteries B1 and B2 are subsequently compared, and whether P1 is greater than P2 (P1> It is determined whether or not (P2) (S12).

  If it is determined as a result of S12 that P1 is equal to or less than P2, the process proceeds to S18. The steps after S18 will be described later. On the other hand, if it is determined that P1 is greater than P2, it is subsequently determined whether or not the remaining capacity P1 of the first battery B1 is greater than or equal to a predetermined value (S13). As a result, when it is determined that the remaining capacity P1 of the first battery B1 is less than a predetermined value, both the first and second batteries B1 and B2 are used to suppress a decrease in the remaining capacity P1. After the first and second relays R1 are set to the closed state and the second relay R2 are set to the open state so that dark current is supplied to the auxiliary devices L1,..., Ln (S23) ), The process is terminated.

  On the other hand, if it is determined as a result of S13 that the remaining capacity P1 of the first battery B1 is greater than or equal to a predetermined value, the first relay R1 is set to the closed state and the second relay R2 is set to the open state. (S14), dark current is supplied from the first battery B1 to the auxiliary devices L1,..., Ln (S15).

  Thereafter, it is determined again whether or not the remaining capacity P1 of the first battery B1 is equal to or greater than a predetermined value (S16). As a result, when it is determined that the remaining capacity P1 of the first battery B1 is less than the predetermined value, the process proceeds to S18, and on the other hand, it is determined that the remaining capacity P1 of the first battery B1 is greater than or equal to the predetermined value. If this is the case, it is subsequently determined whether or not the remaining capacity P1 of the first battery B1 is larger than the remaining capacity P2 of the second battery B2 (S17). As a result, if it is determined that P1 is greater than P2, the process returns to S15, and the subsequent steps are repeated. On the other hand, if it is determined that P1 is equal to or less than P2, the process proceeds to S18.

  In S18, it is determined again whether or not the remaining capacity P2 of the second battery B2 is equal to or greater than a predetermined value. As a result, when it is determined that the remaining capacity P2 of the second battery B2 is less than the predetermined value, both the first and second batteries B1 and B2 are used in order to suppress a decrease in the remaining capacity P2. , The first and second relays R1 and R2 are both set to the closed state so that dark current is supplied to the auxiliary devices L1,..., Ln (S23), and the process ends. Is done.

  On the other hand, if it is determined as a result of S18 that the remaining capacity P2 of the second battery B2 is greater than or equal to a predetermined value, the first relay R1 is set to the open state and the second relay R2 is set to the closed state. (S19), dark current is supplied from the second battery B2 to the auxiliary devices L1,..., Ln (S20).

  Thereafter, it is determined again whether or not the remaining capacity P2 of the second battery B2 is equal to or greater than a predetermined value (S21). As a result, when it is determined that the remaining capacity P2 of the second battery B2 is less than the predetermined value, both the first and second batteries B1 and B2 are used in order to suppress a decrease in the remaining capacity P2. , The first and second relays R1 and R2 are both set to the closed state so that dark current is supplied to the auxiliary devices L1,..., Ln (S23), and the process ends. Is done.

  On the other hand, if it is determined as a result of S21 that the remaining capacity P2 of the second battery B2 is greater than or equal to a predetermined value, the remaining capacity P2 of the second battery B2 continues to be the remaining capacity P1 of the first battery B1. It is determined whether or not it is larger (S22). As a result, if it is determined that P2 is greater than P1, the process returns to S20. On the other hand, if it is determined that P2 is equal to or less than P1, the process returns to S14 and the subsequent steps are repeated.

As described above, in the power supply device 1 according to the present embodiment, the battery having the larger remaining capacity is alternately used as a dark current supply source to the auxiliary devices L1,. Thus, it is possible to prevent one battery from being reduced, and to balance the remaining capacities of the first and second batteries B1 and B2.
Further, when the remaining capacity of one battery becomes less than a predetermined value, dark current is supplied from both batteries, so that each battery operation for starting the first and second starter motors M1 and M2 is performed. Can be guaranteed.
Further, by balancing the remaining capacities of the first and second batteries B1 and B2, the number of times the battery is charged can be balanced, and the risk of shortening the life of one battery can be eliminated.

  When the first and second batteries B1 and B2 having the same storage capacity are employed as in the present embodiment, the remaining capacities P1 and P2 are compared in S12, S17, or S22 of FIG. The first and second batteries B1 and B2 having different storage capacities are compared when the absolute values of the remaining capacities are compared, for example, when the storage capacity of the first battery B1 is larger than the storage capacity of the second battery B2. May be used, the remaining ratio of each battery (that is, remaining capacity / storage capacity) may be compared. This makes it possible to more reliably realize a balanced discharge between the first and second batteries B1 and B2. This is also effective in ensuring the life of each battery.

  Note that the present invention is not limited to the illustrated embodiments, and it goes without saying that various improvements and design changes are possible without departing from the scope of the present invention.

It is a figure showing roughly the basic composition of the power supply device of vehicles concerning the present invention. (A) It is a figure which shows roughly the state by which a dark current is supplied to auxiliary devices from a 1st battery. (B) It is a figure showing change of the remaining capacity of the 1st and 2nd battery at the time of dark current supply from the 1st battery. (A) It is a figure which shows roughly the state by which dark current is supplied to auxiliary devices from a 2nd battery. (B) It is a figure showing the change of the remaining capacity of the 1st and 2nd battery at the time of dark current supply from the 2nd battery. It is a flowchart about the relay switching control process by the said power supply device in the case of performing engine restart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Power supply device A ... Alternator B1 ... 1st battery B2 ... 2nd battery L1, ..., Ln ... Electrical equipment M1 ... 1st starter motor M2 ... 2nd starter motor P1 ... 1st Battery remaining capacity P2 ... Second battery remaining capacity R1 ... First relay R2 ... Second relay

Claims (4)

In a power supply device mounted on a vehicle,
A first battery and a second battery for starting a starter motor for starting the engine;
Relay means disposed between the first and second batteries and the vehicle electrical accessories and for performing an on / off switching operation;
Control means for controlling the switching operation of the relay means;
Remaining capacity detecting means for detecting the remaining capacity of the first and second batteries,
The control means switches the relay means based on the information acquired from the remaining capacity detecting means so that power is supplied from the battery with the larger remaining capacity to the auxiliary devices. apparatus.   The control means detects the engine stop accompanying the start of the second starter motor at the next engine start based on the information acquired from the engine operating state detecting means for detecting the engine operating state. The power supply device for a vehicle according to claim 1, wherein the switching operation is controlled.   The control means, based on the information acquired from the remaining capacity detection means, that the remaining capacity of the battery used for supplying power to the auxiliary devices has fallen below the remaining capacity of the unused battery by a predetermined amount. 3. The vehicle power supply device according to claim 1, wherein the relay unit is switched so that power is supplied to the auxiliary devices from a battery that has not been used until then. The first battery is a battery for starting a first starter motor for starting the engine, and the second battery is a second starter motor for restarting the engine stopped at the time of idling stop. The power supply device for a vehicle according to any one of claims 1 to 3, wherein the battery is a battery to be activated.

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