JP5781734B2 - Idling stop device and battery deterioration notification method - Google Patents

Description

  The present invention relates to an idling stop technique for automatically stopping / starting a vehicle engine.

  In recent years, an idling stop device for automatically stopping / starting a vehicle engine while a vehicle is stopped for a relatively short time such as waiting for a signal has been put into practical use for the purpose of saving fuel and exhaust gas. In a vehicle equipped with an idling stop device, the engine is automatically stopped when a stop condition such as when the brake is stepped on from a running state and the engine is stopped, and the start condition is such that the brake is released while the engine is stopped. When the above is established, the engine is automatically started (see, for example, Patent Document 1).

JP 2009-13953 A

  Electric power for driving a starter motor for starting the engine of the vehicle is supplied from a battery provided in the vehicle. Since the power required by the starter motor to start the engine is very large, if the engine is stopped / started by the idling stop function when the battery voltage is low, the battery voltage further decreases. The engine may not be able to start. Therefore, when the battery has deteriorated and its voltage has dropped, it is desirable to notify the user of information indicating the deterioration of the battery in order to replace the battery.

  As described above, since the power required by the starter motor for starting the engine is very large, the voltage of the battery greatly decreases when the engine is started. For this reason, for example, the microcomputer provided in the idling stop device monitors the voltage of the battery at the start of the engine, and if the battery voltage falls below a predetermined threshold value, the battery is deteriorated thereafter. It may be configured to notify the user of the information to be shown.

  However, since the electric power for operating the microcomputer is also supplied from the battery, when starting the engine, if the voltage of the battery drops significantly below the voltage at which the microcomputer can operate, the microcomputer itself It cannot be operated and is reset. The microcomputer reset and restarted in this manner cannot grasp the cause of the reset and the voltage of the battery before the reset. The microcomputer is reset not only when the voltage of the power supply is reduced, but also when, for example, a runaway state occurs, but the cause of such a reset cannot be grasped.

  For this reason, even when the voltage of the battery is greatly reduced and reset, the microcomputer after reset cannot know that the voltage of the battery has greatly declined, and informs the user of information indicating the deterioration of the battery. I could not. As a result, the deteriorated battery is continuously used, and there is a possibility that the engine cannot be started finally.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technology capable of grasping the voltage drop of the battery even after resetting the microcomputer and notifying the user of information indicating the deterioration of the battery. To do.

In order to solve the above-mentioned problem, the invention of claim 1 is an idling stop device that is mounted on a vehicle and automatically stops / starts the engine of the vehicle, and automatically activates the engine when a predetermined stop condition is satisfied. And a microcomputer having an idling stop function for automatically starting the engine when a predetermined start condition is satisfied while the engine is stopped, and the microcomputer are configured separately from the battery of the vehicle. comparing the power supply voltage and the microcomputer operable minimum operation voltage of the microcomputer obtained by stepping down the voltage, the power supply voltage of the microcomputer detects that becomes lower than the minimum operating voltage When the voltage of the detection means and the power source becomes less than the minimum operating voltage, Storage means for storing the voltage drop information indicating, regardless of the state of the microcomputer, based on a signal from the detection means, and when the voltage drop information is stored in the storage means, Informing means for informing the user of deterioration information indicating deterioration.

  According to a second aspect of the present invention, in the idling stop device according to the first aspect, the notifying unit displays the deterioration information on a display unit provided in a passenger compartment of the vehicle.

  Further, the invention according to claim 3 is the idling stop device according to claim 1, wherein the notification means stores the deterioration information in a storage device in response to a signal from the storage device and an external device. Transmitting means for transmitting the deteriorated information to the external device.

According to a fourth aspect of the present invention, the engine of the vehicle is automatically stopped when a predetermined stop condition is satisfied, and the engine is automatically started when a predetermined start condition is satisfied while the engine is stopped. a battery deterioration notification method in a vehicle microcomputer is mounted with idling stop function, supply voltage and the microcomputer can operate the lowest of the microcomputer obtained by stepping down the voltage of the battery of the vehicle A step of detecting by the detection means configured separately from the microcomputer that the voltage of the power source of the microcomputer is less than the minimum operating voltage, and the voltage of the power source is the minimum When the voltage is lower than the operating voltage, the voltage drop information indicating the fact is a signal from the detection means. A step of storing the storage means regardless of the state of the microcomputer, and a step of notifying a user of information indicating deterioration of the battery when the voltage drop information is stored in the storage means; It has.
According to a fifth aspect of the present invention, in the idling stop device according to any one of the first to third aspects, the minimum operating voltage at which the storage means can hold the stored contents is lower than the minimum operating voltage at which the microcomputer can operate. Is also low.
According to a sixth aspect of the present invention, in the idling stop device according to any one of the first to third aspects, means for resetting the microcomputer when the voltage of the power source becomes lower than the minimum operating voltage. It has more.
The invention of claim 7 further includes a step of resetting the microcomputer when the voltage of the power source becomes less than the minimum operating voltage in the battery deterioration notification method according to claim 4. Yes.
According to an eighth aspect of the present invention, in the idling stop device according to any one of the first to third aspects, the storage means is a logic circuit capable of storing 1-bit information.
According to a ninth aspect of the present invention, in the battery deterioration notification method according to the fourth aspect, the storage means is a logic circuit capable of storing 1-bit information.

  According to the first to third aspects of the present invention, when the voltage of the power source of the microcomputer becomes less than the minimum operating voltage of the microcomputer, the voltage drop information is stored in the storage means even if the microcomputer is reset. For this reason, the microcomputer after reset can grasp | ascertain the voltage drop of a battery based on voltage drop information, and can alert | report a user the information which shows deterioration of a battery.

  In particular, according to the invention of claim 2, it is possible to promptly notify the user in the vehicle compartment of the vehicle that the battery has deteriorated.

  In particular, according to the invention of claim 3, it is possible to notify the user who handles the external device of the battery deterioration.

FIG. 1 is a block diagram showing a configuration of an idling stop device according to the first embodiment. FIG. 2 is a diagram illustrating a processing flow of the idling stop device according to the first embodiment. FIG. 3 is a diagram illustrating changes in various signals when the battery voltage decreases. FIG. 4 is a block diagram illustrating a configuration of the idling stop device according to the second embodiment. FIG. 5 is a diagram illustrating a processing flow of the idling stop device according to the second embodiment. FIG. 6 is a diagram illustrating a processing flow of the idling stop device when reading deterioration information.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
<1-1. Configuration>
FIG. 1 is a block diagram showing a configuration of an idling stop device 1 and its peripheral elements according to the first embodiment. The idling stop device 1 is mounted on a vehicle such as an automobile, for example, and has a function of automatically stopping / starting an engine 57 included in the vehicle while the vehicle is stopped for a relatively short time such as waiting for a signal. .

  A vehicle on which the idling stop device 1 is mounted includes a battery 51 that supplies electric power to an electric load of each part of the vehicle. A power line 91 is connected to the battery 51, and an ignition switch 92 that can be operated by the user is provided on the power line 91. When the ignition switch 92 is turned on, power is supplied from the battery 51 to the idling stop device 1 via the power line 91. In addition, when the ignition switch 92 is turned on, power is supplied from the battery 51 via the power supply line 91 to various electric loads mounted on the vehicle.

  The battery 51 is charged by an alternator 52 that is a generator. Alternator 52 converts mechanical kinetic energy transmitted from engine 57 into alternating current power, and further rectifies it into direct current power with a rectifier including a diode. The generated power is stored in the battery 51 via the power line 91. When the alternator 52 generates power, a target voltage that is a target of power generation is set, and the alternator 52 generates power so that the voltage of the power supply line 91 becomes the target voltage.

  Further, a warning lamp 59 that displays information indicating deterioration of the battery 51 to the user by lighting is provided at a position where the user can visually recognize the vehicle interior. The warning light 59 is switched on and off by the warning light driving unit 58.

  The idling stop device 1 is configured as an ECU (Electronic Control Unit) and includes a microcomputer 2 as a main component. The microcomputer 2 includes a CPU 21, a RAM 22, and a ROM 23. Various functions provided in the microcomputer 2 are realized by the CPU 21 performing arithmetic processing according to a program recorded in advance in the ROM 23. The functions of the microcomputer 2 include an idling stop function and a warning function for turning on the warning lamp 59.

  The idling stop function is a function for automatically stopping / starting the engine 57 of the vehicle according to the traveling state of the vehicle. A signal indicating the running state of the vehicle is input to the microcomputer 2 via the interface 18 from various sensors provided in the vehicle. Specifically, vehicle speed is input from the vehicle speed sensor, shift lever position from the shift sensor, accelerator operation content from the accelerator sensor, and brake operation content from the brake sensor.

  When a predetermined stop condition is established based on signals indicating these running states, the engine 57 is stopped by the idling stop function. For example, when all the conditions “vehicle speed is 0”, “shift lever is“ D ”or“ N ””, “no accelerator operation”, and “with brake operation” are all satisfied, Is determined to have been established.

  When the engine 57 is stopped by the idling stop function, the microcomputer 2 transmits a predetermined stop signal to the engine ECU 56 that controls the engine 57. The engine ECU 56 stops the engine 57 in response to this signal.

  Further, when the engine 57 is stopped by the idling stop function and the predetermined start condition is established based on the signal indicating the running state, the engine 57 is automatically started by the idling stop function. For example, the start condition is determined to be satisfied when all of the conditions “shift lever is“ D ””, “accelerator operated”, and “brake not operated” are all satisfied.

  When the engine 57 is started with the idling stop function, the microcomputer 2 transmits a predetermined start signal to the starter control circuit 16 provided in the idling stop device 1. The starter control circuit 16 energizes the relay coil 53 in response to this signal. By energizing the relay coil 53, the relay switch 54 connected to the starter motor 55 that starts the engine 57 of the vehicle is turned on. Thereby, electric power is supplied from the battery 51 to the starter motor 55, the starter motor 55 is driven, and the engine 57 is started. The relay coil 53 is also energized by turning on a start switch 93 that can be operated by the user. When the user gets into the vehicle, the starter motor 55 is driven in response to the operation of the start switch 93, and the engine 57 is started.

  The idling stop device 1 also includes a regulator 11 that steps down the input voltage to a constant voltage as a power supply circuit to the microcomputer 2. For example, the regulator 11 is configured by combining a switching regulator and a series regulator.

  The power of the microcomputer 2 is supplied from the battery 51 of the vehicle. The ideal value of the voltage of the power supply of the microcomputer 2 is, for example, 5V, while the normal voltage of the battery 51 is, for example, 12V. Therefore, in the idling stop device 1, the voltage BATT of the battery 51 is stepped down by the regulator 11 to obtain the voltage VCC of the power source of the microcomputer 2.

  Note that the regulator 11 adjusts the output voltage within a range where the input voltage is the upper limit. If the input voltage falls below the target voltage that should be constant, the output voltage of the regulator 11 also falls below the target voltage. It will be. Therefore, when the battery 51 is deteriorated, if the battery voltage BATT is lowered, the voltage VCC of the power source of the microcomputer 2 obtained by stepping down by the regulator 11 is also lowered accordingly.

  The idling stop device 1 includes a voltage drop detection unit 13, a reset unit 14, and a runaway detection unit 15 as a circuit for resetting the microcomputer 2.

  The reduced voltage detection unit 13 is connected to a power supply line from the regulator 11 to the microcomputer 2 and monitors the voltage VCC of the power supply of the microcomputer 2. When the voltage VCC of the power source of the microcomputer 2 becomes lower than the minimum operating voltage at which the microcomputer 2 can operate (hereinafter, the symbol “Vt” is used), it indicates that the reset unit 14 should be reset. An instruction signal is output. The minimum operating voltage Vt of the microcomputer 2 is, for example, 3.9V. The reduced voltage detection unit 13 is constituted by, for example, a comparator that compares the voltage VCC with the minimum operating voltage Vt.

  The runaway detection unit 15 detects whether the microcomputer 2 is in a runaway state such as freezing. For example, the runaway detection unit 15 monitors an operation signal of a watchdog timer of the microcomputer 2 and determines that the microcomputer 2 is in a runaway state when a regular signal is not detected. In the runaway state, the microcomputer 2 cannot recover its function unless it is reset. For this reason, the runaway detection unit 15 outputs an instruction signal indicating that the reset unit 14 should be reset.

  The reset unit 14 outputs a reset signal that instructs the microcomputer 2 to reset. The reset signal is normally “H” and becomes “L” to instruct the microcomputer 2 to reset. The reset unit 14 sets the reset signal to “L” when an instruction signal indicating that the reset is to be performed from either the voltage drop detection unit 13 or the runaway detection unit 15. The microcomputer 2 constantly monitors this reset signal, and resets when the reset signal becomes “L”. That is, the microcomputer 2 is restarted after being temporarily stopped.

  The idling stop device 1 provides information indicating that the voltage VCC is less than the minimum operating voltage Vt when the voltage VCC of the power source of the microcomputer 2 is less than the minimum operating voltage Vt (hereinafter referred to as “voltage drop information”). .) Is stored. The instruction signal output from the reduced voltage detection unit 13 is also input to the storage unit 3. That is, when the voltage VCC of the power source of the microcomputer 2 becomes less than the minimum operating voltage Vt, the storage unit 3 is notified by an instruction signal, and the voltage drop information is stored in the storage unit 3 in response thereto. It will be.

  The storage unit 3 is configured by, for example, a flip-flop that is a logic circuit capable of storing 1-bit information. The minimum operating voltage of the storage unit 3 is lower than the minimum operating voltage Vt (eg, 3.6V) of the microcomputer 2 and is, for example, 1.6V. That is, even if the power supply voltage becomes lower than the minimum operating voltage Vt of the microcomputer 2, the storage unit 3 can hold the stored contents. For this reason, the memory | storage part 3 can memorize | store voltage drop information during reset of the microcomputer 2 irrespective of the state of the microcomputer 2. FIG.

  When the voltage of the battery 51 decreases and the voltage VCC becomes lower than the minimum operating voltage Vt, the microcomputer 2 is reset, while the storage unit 3 stores the voltage decrease information. Based on the fact that the voltage drop information is stored in the storage unit 3, the microcomputer 2 after the reset can grasp that the power supply voltage VCC has become less than the minimum operating voltage Vt before the reset. Become.

  Therefore, when the voltage drop information is stored in the storage unit 3, the reset microcomputer 2 notifies the user of deterioration information indicating the deterioration of the battery 51 in order to replace the battery 51. Specifically, the microcomputer 2 transmits a predetermined lighting signal to the warning lamp driving unit 58 by a warning function. The warning lamp driving unit 58 turns on the warning lamp 59 in response to this signal. Thereby, the deterioration information which shows deterioration of the battery 51 is alert | reported to the user in a vehicle interior.

  The phenomenon that the voltage of the battery 51 greatly decreases occurs when the engine 57 is started because the power required by the starter motor 55 is very large. Hereinafter, when the engine 57 is started in this manner, a process in the case where the voltage of the battery 51 greatly decreases and the microcomputer 2 is reset will be described in detail.

<1-2. Processing>
FIG. 2 is a diagram showing a processing flow of the idling stop device 1 related to the resetting of the microcomputer 2.

  First, it is determined whether or not a condition for resetting the microcomputer 2 is satisfied. Specifically, the reduced voltage detection unit 13 determines whether the voltage VCC of the power source of the microcomputer 2 is less than the minimum operating voltage Vt of the microcomputer 2 (step S11). At the same time, the runaway detection unit 15 determines whether the microcomputer 2 is in a runaway state (step S12). If voltage VCC is equal to or higher than minimum operating voltage Vt (No in step S11) and microcomputer 2 is not in a runaway state (No in step S12), the process ends.

  When the voltage VCC of the power source of the microcomputer 2 becomes less than the minimum operating voltage Vt (Yes in step S11), an instruction signal is output from the reduced voltage detection unit 13 to the reset unit 14. The instruction signal is also input to the storage unit 3, and in response thereto, the voltage drop information is stored in the storage unit 3 (step S13).

  On the other hand, when the microcomputer 2 is in a runaway state (Yes in step S12), an instruction signal is output from the reduced voltage detection unit 13 to the reset unit 14.

  The reset unit 14 sets the reset signal to “L” when an instruction signal is input from either the voltage drop detection unit 13 or the runaway detection unit 15. The microcomputer 2 is reset in response to the reset signal becoming "L" (step S14). When the voltage drop information is stored in the storage unit 3, the storage of the voltage drop information in the storage unit 3 is held even during resetting of the microcomputer 2.

  Thereafter, the microcomputer 2 restarts. The restarted microcomputer 2 checks whether or not the voltage drop information is stored in the storage unit 3 (step S15). If voltage drop information is not stored in storage unit 3 (No in step S15), it is determined that microcomputer 2 has been reset due to a runaway state, and the process is terminated.

  On the other hand, if the voltage drop information is stored in the storage unit 3 (Yes in step S15), it is determined that the microcomputer 2 has been reset due to the voltage VCC being less than the minimum operating voltage Vt. In this case, the battery 51 is deteriorated and its voltage is lower than usual. For this reason, in order to replace the battery 51, the microcomputer 2 transmits a predetermined lighting signal to the warning lamp drive unit 58 by the warning function, and turns on the warning lamp 59 (step S16).

  FIG. 3 is a time chart showing changes in various signals when the voltage of the battery 51 decreases at the start of the engine. At the start of the chart, the ignition switch 92 is turned off, the engine 57 is not started, and the warning light 59 is extinguished.

  First, at time T1, the ignition switch 92 is turned on by a user operation. Thereby, electric power is supplied from the battery 51 to the idling stop device 1, and the microcomputer 2 is activated.

  Next, at time T2, the start switch 93 is turned on by the user's operation, and the starter motor 55 is driven. As the starter motor 55 is driven, the voltage BATT of the battery 51 decreases. As a result, the voltage of the power supply line 91 decreases. Further, when the battery 51 is deteriorated, the voltage VCC of the power source of the microcomputer 2 is also lowered.

  In this way, when the voltage VCC of the power source of the microcomputer 2 decreases and becomes lower than the minimum operating voltage Vt of the microcomputer 2 at time T3, the reduced voltage detection unit 13 detects this and generates an instruction signal. (Referred to as “H”). In response to this, the reset unit 14 sets the reset signal to “L”, and the microcomputer 2 stops its operation for resetting. At the same time, an instruction signal from the reduced voltage detection unit 13 is also input to the storage unit 3, and the voltage drop information is stored in the storage unit 3.

  Thereafter, when the load on the starter motor 55 decreases as the engine 57 rotates, the voltage BATT of the battery 51 gradually increases. For this reason, the voltage of the power supply line 91 and the voltage VCC of the power supply of the microcomputer 2 also rise. When the voltage VCC of the power source of the microcomputer 2 rises and becomes equal to or higher than the minimum operating voltage Vt of the microcomputer 2 at time T4, the reduced voltage detection unit 13 stops the instruction signal (set to “L”). In response to this, the reset unit 14 sets the reset signal to “H” and the microcomputer 2 is restarted.

  The restarted microcomputer 2 confirms that the voltage drop information is stored in the storage unit 3, and transmits a predetermined lighting signal to the warning lamp drive unit 58 by a warning function. Thereby, after time T4, the warning lamp 59 is turned on, and the deterioration information indicating the deterioration of the battery 51 is notified to the user in the vehicle interior.

  At time T5, when the ignition switch 52 is turned off by a user operation, the voltage VCC of the power source of the microcomputer 2 becomes 0, and the microcomputer 2 stops its operation. Further, the voltage drop information is erased from the storage unit 3.

  As described above, in the idling stop device 1 of the present embodiment, when the voltage of the battery 51 decreases and the voltage VCC of the power source of the microcomputer 2 becomes less than the minimum operating voltage Vt of the microcomputer 2, The microcomputer 2 is reset. On the other hand, the voltage drop information is stored in the storage unit 3. For this reason, the microcomputer 2 after reset can grasp | ascertain that the voltage of the battery 51 fell based on the voltage drop information, and can notify the deterioration information which shows deterioration of the battery 51 to the user in a vehicle interior. Thereby, the user can take measures such as replacing the battery 51.

  Further, since the deterioration information is displayed on the warning light 59 provided in the vehicle interior, it is possible to promptly notify the user (particularly, the driver who is driving the vehicle) that the battery 51 has deteriorated.

<2. Second Embodiment>
Next, a second embodiment will be described. In the first embodiment, the warning light 59 is turned on to notify deterioration information indicating the deterioration of the battery 51 to the user in the passenger compartment. In the second embodiment, the vehicle is maintained. The deterioration information is notified to a user such as a maintenance staff. Since the configuration and processing of the idling stop device 1 of the second embodiment are substantially the same as those of the first embodiment, the following description will focus on the differences from the first embodiment.

  FIG. 4 is a block diagram showing a configuration of the idling stop device 1 and its peripheral elements according to the second embodiment. In the second embodiment, the microcomputer 2 includes an SRAM (Standby RAM) 24 and a communication unit 25 in addition to the CPU 21, the RAM 22 and the ROM 23.

  The SRAM 24 is a storage device configured such that its power supply voltage is directly supplied from the battery 51. With such a configuration, the SRAM 24 holds the stored contents until the battery 51 is replaced regardless of whether the ignition switch 52 is on or off. The SRAM 24 stores a diagnosis code indicating various information related to the idling stop device 1.

  Moreover, the communication part 25 communicates with the apparatus connected to the communication line 81 via the communication line 81 for in-vehicle LAN provided in the vehicle. A user who maintains the vehicle can connect a reading tool T, which is an external device for reading a diagnosis code, to the communication line 81. When the communication unit 25 receives a read signal from the read tool T via the communication line 81, the communication unit 25 reads the diag code stored in the SRAM 24 in response to this and transmits it to the read tool T. As a result, the contents of the diagnosis code are displayed on the reading tool T.

  In the second embodiment, when the voltage drop information is stored in the storage unit 3, the deterioration information indicating the deterioration of the battery 51 is stored in the SRAM 24 as a diag code. By reading the diagnostic code using the reading tool T, the deterioration information indicating the deterioration of the battery 51 is notified to the user.

  FIG. 5 is a diagram showing a processing flow of the idling stop device 1 related to the resetting of the microcomputer 2 in the second embodiment. Steps S21 to S25 in this process are the same as steps S11 to S15 in FIG. Only the processing in step S26 is different from the first embodiment.

  That is, the restarted microcomputer 2 confirms whether or not the voltage drop information is stored in the storage unit 3. If the voltage drop information is stored in the storage unit 3 (Yes in step S25), the microcomputer 2 The computer 2 stores deterioration information indicating the deterioration of the battery 51 in the SRAM 24 as a diagnosis code (step S26). Thus, the deterioration information stored in the SRAM 24 can be read by the reading tool T connected to the communication line 81.

  FIG. 6 is a diagram illustrating a processing flow of the idling stop device 1 when reading deterioration information. This process is executed, for example, when the vehicle is maintained.

  First, it is determined whether or not the communication unit 25 receives a readout signal for requesting readout of the diagnostic code from the readout tool T (step S31).

  When the communication unit 25 receives the read signal (Yes in Step S31), if the deterioration information is stored in the SRAM 24 (Yes in Step S32), the deterioration information is read and the communication is performed. The data is transmitted from the unit 25 to the reading tool T (step S33).

  As a result, deterioration information is displayed on the reading tool T, and a user who maintains a vehicle that handles the reading tool T can clearly understand that the battery 51 is deteriorated. Measures such as exchanging 51 can be taken.

<3. Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible. Below, such a modification is demonstrated. All forms including those described in the above embodiment and those described below can be combined as appropriate.

  In the first embodiment, the deterioration information is notified to the user in the passenger compartment, and in the second embodiment, the deterioration information is notified to the user who maintains the vehicle. The first embodiment In combination with the second embodiment, the deterioration information indicating the deterioration of the battery 51 may be notified to both the user in the passenger compartment and the user who maintains the vehicle.

  In the first embodiment, the warning light 59 is used as the display means for displaying the deterioration information. However, any display means provided in the vehicle compartment such as a navigation device may be used. May be.

  Further, in the first embodiment, the deterioration information is notified to the user by display, but the deterioration information may be notified to the user by outputting a warning sound or the like.

  Further, when the voltage drop information is stored in the storage unit 3, the microcomputer 2 may invalidate the idling stop function thereafter. In this way, the charging of the battery by the alternator 52 can be strengthened, and the voltage drop of the battery 51 can be prevented.

  Further, the power supply voltage of the storage unit 3 may be directly supplied from the battery 51, or a nonvolatile memory such as an EEPROM or a flash memory may be adopted as the storage unit 3. In this case, the voltage drop information can be stored in the storage unit 3 regardless of whether the ignition switch is on or off. For this reason, if the reset of the microcomputer 2 resulting from the voltage drop of the battery 51 occurs even once, information indicating the deterioration of the battery 51 can be notified to the user. The voltage drop information may be deleted from the storage unit 3 when the battery 51 is replaced. In the case of this configuration, the deterioration information may be stored in the storage unit 3, or the voltage drop information may be used as it is as the deterioration information.

  Further, a nonvolatile memory such as an EEPROM or a flash memory may be employed instead of the SRAM 24 of the above embodiment.

  In the above embodiment, the storage unit 3 is composed of a logic circuit capable of storing 1-bit information. However, a memory having a relatively large storage capacity may be employed. However, if the storage unit 3 includes only one logic circuit capable of storing 1-bit information as in the above embodiment, the storage unit 3 can be realized at a very low cost.

  Further, in the above-described embodiment, it has been described that various functions are realized in software by the arithmetic processing of the CPU according to the program. However, some of these functions are realized by an electrical hardware circuit. Also good. Conversely, some of the functions realized by the hardware circuit may be realized by software.

DESCRIPTION OF SYMBOLS 1 Idling stop apparatus 2 Microcomputer 3 Memory | storage part 13 Low voltage detection part 51 Battery 59 Warning light 81 Communication line T Reading tool

Claims (9)

An idling stop device mounted on a vehicle for automatically stopping / starting the engine of the vehicle,
A microcomputer having an idling stop function that automatically stops the engine when a predetermined stop condition is satisfied, and automatically starts the engine when a predetermined start condition is satisfied while the engine is stopped;
The microcomputer is configured separately from the microcomputer, and compares the voltage of the microcomputer power source obtained by stepping down the voltage of the battery of the vehicle with the minimum operating voltage at which the microcomputer can operate . detecting means for detecting that the voltage becomes lower than the minimum operating voltage,
Storage means for storing voltage drop information indicating that when the voltage of the power source is less than the minimum operating voltage, regardless of the state of the microcomputer, based on a signal from the detection means;
When the voltage drop information is stored in the storage means, notification means for notifying the user of deterioration information indicating deterioration of the battery;
An idling stop device comprising: The idling stop device according to claim 1,
The idling stop device, wherein the informing means displays the deterioration information on a display means provided in a passenger compartment of the vehicle. The idling stop device according to claim 1,
The notification means includes
A storage device for storing the deterioration information;
In response to a signal from an external device, transmission means for transmitting the deterioration information stored in the storage device to the external device;
An idling stop device comprising: Equipped with a microcomputer having an idling stop function for automatically stopping the engine of the vehicle when a predetermined stop condition is satisfied, and automatically starting the engine when the predetermined start condition is satisfied while the engine is stopped A method for informing a battery deterioration in a vehicle,
Comparing the power supply voltage and the microcomputer operable minimum operation voltage of the microcomputer obtained by stepping down the voltage of the battery of the vehicle, the power supply voltage of the microcomputer becomes lower than the minimum operating voltage A step of detecting the detection means configured separately from the microcomputer,
When the voltage of the power source becomes less than the minimum operating voltage, the storage means stores voltage drop information indicating that regardless of the state of the microcomputer based on the signal from the detection means; ,
When the voltage drop information is stored in the storage means, a step of notifying a user of information indicating deterioration of the battery;
A battery deterioration notification method comprising: The idling stop device according to any one of claims 1 to 3,
The idling stop device according to claim 1, wherein a minimum operating voltage at which the storage means can hold the stored contents is lower than a minimum operating voltage at which the microcomputer can operate. The idling stop device according to any one of claims 1 to 3,
Means for resetting the microcomputer when the voltage of the power source becomes less than the minimum operating voltage;
The idling stop device further comprising: The battery deterioration notification method according to claim 4,
Resetting the microcomputer when the voltage of the power supply becomes less than the minimum operating voltage;
The battery deterioration notification method further comprising: The idling stop device according to any one of claims 1 to 3,
The idling stop device according to claim 1, wherein the storage means is a logic circuit capable of storing 1-bit information. The battery deterioration notification method according to claim 4,
The battery deterioration notification method, wherein the storage means is a logic circuit capable of storing 1-bit information.