JP2013053578A - Idle stop control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an idle stop control device that prevents the establishment of an unnecessary idle stop prohibition period after a vehicle turns into an IG (ignition) ON state from an IG OFF state.SOLUTION: A microcomputer 19 of an ECU 1 stops an engine 3 (idle stop) when the automatic stop condition is approved during an ON state of an IG switch 37, executes a process for restarting an engine 3 by driving a starter 7 when an automatic start-up condition is established, a process for measuring the elapsed time after the engine restart is completed by forcing a counter in a backup RAM 35 to count up for each constant time, and a process for prohibiting the idle stop until determining that a counter value reaches a threshold value. Further, the microcomputer 19 stops the operation by turning off a power supply relay 11 when the counter value reaches a threshold value by forcing the counter to count up for each given time after the IG switch 37 is turned off. Off-time of the IG switch 37 is included in the counter value.

Description

  The present invention relates to an idle stop control device that automatically stops and restarts an engine of a vehicle.

  In recent years, in vehicles (automobiles), an automatic stop / restart control device that automatically stops an engine when a predetermined automatic stop condition is satisfied, and then automatically restarts the engine when a predetermined automatic start condition is satisfied. A device equipped with a device (generally called an idle stop (or idling stop) control device) has been put into practical use (see, for example, Patent Documents 1 and 2).

  In this type of idle stop control device, the engine is started (restarted) by driving a starter that cranks the engine. However, if the starter is repeatedly driven in a heated state, the starter is damaged. There is a possibility that.

  Therefore, the idle stop control device measures an elapsed time after restarting the engine (hereinafter also referred to as a time after restart) and waits until it is determined that the measured value has reached a predetermined threshold value. By prohibiting the starter, a starter pause period in which the starter is not driven is provided, and the starter is prevented from being damaged by overheating (see, for example, Patent Documents 1 and 2). The “idle stop” referred to here is a stop of the engine that is automatically restarted thereafter.

  In addition, this type of idle stop control device is operated when an operation voltage is supplied from a vehicle battery when the vehicle is in an ignition (IG) on state.

  For this reason, the present inventor stores the measured value of the post-restart time in, for example, a backup RAM (always powered RAM) as a configuration of the idle stop control device. Even if the vehicle is in an ignition-off state before the threshold value is reached and the supply of the operating voltage to the idle stop control device is stopped, the measurement value is not lost.

  And if comprised in this way, even if supply of the operating voltage to the said apparatus is stopped before the time after a restart reaches a threshold value, and the supply of the operating voltage to the said apparatus is stopped, a vehicle will be in an ignition-on state again. When the apparatus starts operating, the time after restart can be continuously measured, and the idle stop prohibition period necessary for protecting the starter from overheating can be secured.

The ignition-on state is a state in which battery voltage is supplied to the ignition system power line in the vehicle and all the electrical components of the vehicle are operable. It can be said that the ignition switch is turned on by an operator), but the conventional ignition key cylinder for turning on / off the ignition switch does not exist. That is, the ignition switch is turned on by operating the push switch. / Off, accessory power on / off, and starter on), so that the vehicle user performs a predetermined ignition-on operation until a predetermined ignition-off operation is performed. It can be said. Conversely, the ignition-off state is a state in which the battery voltage is not supplied to the ignition system power line in the vehicle, and is a state from when the vehicle user performs the ignition-off operation to when the ignition-on operation is performed. I can say that.

JP 58-28565 A Japanese Unexamined Patent Publication No. Hei 6-007991

  By the way, in the idle stop control device considered as described above, even if the vehicle is in an ignition-off state and the supply of the operating voltage to the device is stopped before the time after restart reaches the threshold value, it is necessary. While the idle stop prohibition period can be secured, while the vehicle is in the ignition off state, the measurement operation of the time after restart is stopped despite the starter stop period in which the starter is not driven. After the vehicle changes from the ignition off state to the ignition on state, an unnecessary (extra) idle stop prohibition period is provided.

  Accordingly, an object of the present invention is to prevent an unnecessary idle stop prohibition period from being provided in an idle stop control device.

  The idle stop control device according to the first aspect is mounted on a vehicle, and when the vehicle is in an ignition-on state, an operation voltage is supplied from the vehicle battery, and when the vehicle is in an ignition-off state, the supply of the operation voltage is stopped. Device.

The idle stop control device includes storage means that can continuously store data even when the supply of the operating voltage to the device is stopped.
Further, a control means, a measurement means, and a prohibition means are provided as means for operating the operation voltage as a power source when the vehicle is in an ignition-on state.

  Of these means, the control means stops the engine of the vehicle when it is determined that a predetermined automatic stop condition is satisfied, and then restarts the engine by driving the starter when it is determined that the predetermined automatic start condition is satisfied. Let

The measuring means measures an elapsed time after the control means restarts the engine (that is, the above-mentioned time after restart) and stores the measured value in the storage means.
Then, the prohibiting means determines whether or not the measurement value stored in the storage means has reached a predetermined threshold value, and the control means stops the engine until it is determined that the measurement value has reached the threshold value. Is prohibited.

  Further, this idle stop control device includes an adding means, and the adding means detects a time during which the vehicle is in an ignition off state (hereinafter also referred to as an ignition off time), and the detected time is detected. It adds to the measured value memorize | stored in the memory | storage means.

  According to such an idle stop control device, when the vehicle is in an ignition-off state before the post-restart time measured by the measuring unit reaches the threshold, the post-restart time measurement in the storage unit is performed. The ignition off time detected by the adding means is added to the value.

For this reason, when the vehicle is in the ignition-on state again and the prohibiting means operates, the prohibiting means detects the time after restart measured by the measuring means when the vehicle was in the ignition-on state last time and the adding means detects It is determined whether or not the time obtained by adding the ignition off time has reached the threshold value. Therefore, it is possible to prevent an unnecessary (extra) idle stop prohibition period from being provided after the vehicle changes from the ignition off state to the ignition on state.

  Next, an idle stop control device according to a second aspect of the present invention is the idle stop control device according to the first aspect, further comprising a power supply maintaining means, and the power supply maintenance means is configured to shut off the power supply even after the vehicle is turned off. Until the permission is given, the operation voltage is supplied to the device.

  The adding means operates using the operating voltage as a power source, measures an elapsed time after the vehicle is in an ignition-off state, and adds the measured elapsed time to a measured value stored in the storage means. Measurement addition processing to be performed, and power cutoff judgment processing for giving power cutoff permission to the power maintenance means when the added measured value reaches the threshold value are performed. The adding means indicates that the vehicle is in the ignition-off state, for example, whether the vehicle is in the ignition-on state or the ignition-off state, such as a signal indicating the on / off state of the ignition switch. Detection can be based on the signal.

  According to this configuration, when the post-restart time including the time from when the vehicle changes from the ignition-on state to the ignition-off state (that is, the real post-restart time) reaches a threshold value, The supply of voltage is stopped. After that, when the vehicle is again in the ignition-on state and the prohibiting unit operates, the measured value in the storage unit has already reached the threshold value, so the prohibiting unit cancels the prohibition of engine stop (that is, The control means permits the engine to be stopped without prohibiting it).

  That is, when the vehicle is in the ignition off state, the adding means measures as the ignition off time only the time when the measured value in the storage means (the value obtained by adding the ignition off time) reaches the threshold, and when the measurement is finished. The supply of the operating voltage to the device is stopped. Therefore, the power consumption of the device when the vehicle is in the ignition off state can be suppressed.

  Next, an idle stop control device according to a third aspect is the idle stop control device according to the first aspect, further comprising an activation means, and the activation means includes an addition means when the vehicle is in an ignition off state. Starts every predetermined time Tw. The adder adds the predetermined time (that is, the activation interval of the adder) Tw to the measurement value stored in the storage device every time it is activated by the activation unit.

  According to this configuration, when the vehicle is in the ignition-off state, the adding unit is activated only every predetermined time Tw, so that the power consumption of the device (power consumption for operating the adding unit) can be suppressed. it can.

  Next, an idle stop control device according to a fourth aspect of the present invention is the idle stop control device according to the third aspect, wherein when the measured value stored in the storage means reaches a threshold value, the activation means changes the addition means every predetermined time Tw. It is supposed to stop starting.

According to this configuration, when the vehicle is in the ignition-off state, the adding means measures as the ignition-off time only the time when the measured value in the storage means (the value obtained by adding the ignition-off time) reaches the threshold value. When the measurement is over, it will not start. Therefore, it is possible to further suppress the power consumption (power consumption for operating the adding means) of the device when the vehicle is in the ignition off state.

  Next, the idle stop control device according to claim 5 is the idle stop control device according to claim 1, wherein the adding means operates using the operating voltage as a power source, and the coolant temperature of the engine immediately before the vehicle enters the ignition off state. Alternatively, the first process of detecting the engine coolant temperature as the first water temperature from when the vehicle is in the ignition off state to when the supply of the operating voltage to the device is stopped is performed. For this reason, the first water temperature is the cooling water temperature immediately before the vehicle enters the ignition-off state or immediately after the vehicle enters the ignition-off state, and is considered to have the same value as the cooling water temperature when the vehicle enters the ignition-off state.

  Further, the adding means detects the cooling water temperature of the engine as the second water temperature and detects it in the first process when the vehicle is in an ignition-on state and the supply of the operating voltage to the device is started. Based on the first water temperature and the second water temperature, the time during which the vehicle has been in the ignition off state is estimated, and the estimated time is added to the measured value stored in the storage means as the detected time. A second process is performed.

  In other words, the adding means determines the ignition off time based on the cooling water temperature (first water temperature) when the vehicle is in the ignition off state and the cooling water temperature (second water temperature) when the vehicle is in the ignition on state. Is detected in the form of estimation.

  According to this configuration, the adding means can detect the ignition off time during the period when the vehicle is in the ignition off state, without intentionally supplying the operation voltage to the device. Therefore, the power consumption of the battery can be suppressed.

It is a block diagram showing idle stop ECU of 1st Embodiment. It is a flowchart showing an idle stop control process. It is a flowchart showing a prohibition determination process. It is a flowchart showing the process at the time of IG OFF of 1st Embodiment. It is a time chart showing operation of a comparative example. It is a time chart showing operation | movement of the idle stop ECU of 1st Embodiment. It is a block diagram showing idle stop ECU of 2nd Embodiment. It is a flowchart showing the timer setting process of 2nd Embodiment. It is a flowchart showing the process at the time of starting of 2nd Embodiment. It is a block diagram showing idle stop ECU of 3rd Embodiment. It is a flowchart showing the detection process of 3rd Embodiment. It is a flowchart showing the process at the time of starting of 3rd Embodiment. It is explanatory drawing explaining the map for IG off time calculation.

Hereinafter, an idle stop control device according to an embodiment to which the present invention is applied will be described. In the following description, “ignition” is described as “IG”.
[First Embodiment]
First, FIG. 1 is a configuration diagram showing an electronic control device (hereinafter referred to as “idle stop ECU” or simply “ECU”) 1 as an idle stop control device of the first embodiment.

The idle stop ECU 1 is mounted on a vehicle and cooperates with an electronic control unit (hereinafter referred to as an engine ECU) 5 that controls the engine 3 of the vehicle to automatically stop and start the engine 3. In addition, as a part of the idle stop control, the starter 7 for starting the engine 3 is controlled.

  The idle stop ECU 1 is always connected to a power supply line 13 connected to a plus terminal of a battery 9 of the vehicle via a power feeding relay (hereinafter referred to as a main relay) 11 and a plus terminal of the battery 9. A power supply line 15 is connected, and a battery voltage VB that is a voltage of the battery 9 is supplied from each of the power supply lines 13 and 15. In the following, the battery voltage VB input to the idle stop ECU 1 via the main relay 11 and the power supply line 13 is referred to as a first battery voltage VB1, and is always input to the idle stop ECU 1 via the power supply line 15. The battery voltage VB to be performed is referred to as a second battery voltage VB2.

  The idle stop ECU 1 generates and outputs a constant power supply voltage Vm from the first battery voltage VB1 input via the main relay 11 and the power supply line 13 and also inputs it via the power supply line 15. A power supply circuit 17 that generates and outputs a constant power supply voltage Vs from the second battery voltage VB2, a microcomputer 19 that executes various processes for idle stop control, and a signal from the outside of the ECU 1 An input circuit 21 that is supplied to the microcomputer 19 as a signal that can be input to the microcomputer 19, a communication circuit 23 for the microcomputer 19 to communicate with the engine ECU 5, and a starter relay for energizing the starter 7 in response to a command from the microcomputer 19 And a drive circuit 27 for turning on 25.

  The two power supply voltages Vm and Vs output from the power supply circuit 17 are, for example, 5V. In this example, turning on the starter relay 25 and energizing the starter 7 corresponds to driving the starter 7.

  The microcomputer 19 includes a CPU 31 that executes a program, a ROM 32 that stores a program executed by the CPU 31, a RAM 33 that stores calculation results by the CPU 31, an input / output interface (I / O) 34, and the like, as well as a backup RAM that is constantly powered ( BRAM) 35 is also provided. The microcomputer 19 is supplied with two power supply voltages Vm and Vs output from the power supply circuit 17, and the part other than the backup RAM 35 in the microcomputer 19 operates with the power supply voltage Vm. The backup RAM 35 operates with the power supply voltage Vs.

  That is, parts other than the backup RAM 35 such as the CPU 31, ROM 32, RAM 33 and input / output interface 34 in the microcomputer 19 use the first battery voltage VB1 supplied to the idle stop ECU 1 when the main relay 11 is turned on. The backup RAM 35 operates using the second battery voltage VB2 constantly supplied to the idle stop ECU 1 as a power source.

Further, the idle stop ECU 1 is also provided with a main relay drive circuit 29 for turning on the main relay 11.
The main relay drive circuit 29 is a circuit that operates by, for example, the power supply voltage Vs from the power supply circuit 17, and receives an IG on signal Si indicating whether or not the vehicle is in an IG on state and a power holding signal Sh from the microcomputer 19. Is done. The main relay drive circuit 29 energizes the coil of the main relay 11 when at least one of the IG ON signal Si and the power holding signal Sh is at an active level (high level in this example). 11 is turned on.

  Here, the vehicle is provided with an IG switch 37 as a power switch for supplying the battery voltage VB to the ignition system power line in the vehicle, and the vehicle is turned on when the IG switch 37 is turned on. IG is turned on.

  Specifically, when the IG switch 37 is turned on by the user of the vehicle, the battery voltage VB is supplied to the ignition power supply line 39 via the IG switch 37. The voltage of the power line 39 is also input to the input circuit 21 as an IG switch signal indicating whether the IG switch 37 is on or off (whether the vehicle is in the IG on state). A signal whose level is converted to a signal having a high level of 5V by the circuit 21 is input to the main relay drive circuit 29 and the microcomputer 19 as the IG ON signal Si.

For this reason, in the idle stop ECU 1, the following power supply self-holding control is performed.
First, when the IG switch 37 is turned on and the vehicle is in the IG on state, the IG on signal Si becomes high level, and the main relay drive circuit 29 turns on the main relay 11. Then, the microcomputer 19 is activated upon receiving the power supply voltage Vm from the power supply circuit 17.

  When the microcomputer 19 is activated, the power holding signal Sh to the main relay drive circuit 29 is set to a high level, thereby supplying the first battery voltage VB1 to the ECU 1 (and extending to the microcomputer 19). (Supply of power supply voltage Vm) is not stopped.

  Further, after starting up, the microcomputer 19 performs processing for reading and determining the level of the IG on signal Si at regular intervals, and the IG switch 37 is turned off based on the level of the IG on signal Si ( When it is detected that the vehicle is in the IG off state), a predetermined process to be performed after the IG switch 37 is turned off (hereinafter also referred to as an operation end process) is executed. The power holding signal Sh to 29 is set to a low level.

  At that time, since the IG ON signal Si is already at the low level, the main relay 11 is turned off, the supply of the first battery voltage VB1 to the ECU 1 is stopped, and the microcomputer 19 stops its operation. It becomes. This state is a state in which the ECU 1 stops operating.

  The vehicle does not include the IG switch 37. For example, when the user operates a push switch (more specifically, a push-type engine start switch), the vehicle is switched between an IG on state and an IG off state. If the vehicle is a push switch type vehicle, there is an electronic control device for power control that creates an IG on state and an IG off state according to the operation of the push switch, and the electronic control device has In order to output a state signal indicating whether or not the device is in the on state, the state signal may be input to the input circuit 21 instead of the IG switch signal.

  Although not shown, for example, the engine ECU 5 includes a power supply relay similar to the main relay 11. Then, by performing power supply self-holding control similar to that of the idle stop ECU 1, the battery voltage VB for operating the engine ECU 5 is supplied to the engine ECU 5.

Furthermore, although not shown, the idle stop ECU 1 is supplied with an information signal for controlling the starter 7 and idle stop control in addition to the IG switch signal. This is input to the microcomputer 19 via the input circuit 21. For example, as the information signal, an operation for starting the engine (for example, an operation for turning on a start switch by twisting a key inserted in a key cylinder to a start position or an operation for pushing a push-type engine start switch) is used. When it is done, it detects the starter signal that becomes active level, the brake signal from the sensor that detects when the brake pedal is depressed, the accelerator signal from the sensor that detects that the accelerator pedal is depressed, and the vehicle traveling speed (vehicle speed) Vehicle speed signals from the sensors that rotate, rotation signals from the crankshaft sensors and camshaft sensors, and the like. Further, all or part of the information signals may be input from the engine ECU 5 to the microcomputer 19 by communication.

Next, the contents of the process performed by the microcomputer 19 of the idle stop ECU 1 will be described.
When the microcomputer 19 is activated when the IG switch 37 is turned on and detects that the above-described starter signal has become an active level (for example, high), the microcomputer 19 performs a starter control process for driving the starter 7 to start the engine.

  As a specific process, the microcomputer 19 first drives the starter 7 by turning on the starter relay 25 in the drive circuit 27 and causes the starter 7 to crank the engine 3. Then, fuel injection and ignition for the engine 3 are performed by the engine ECU 5. If the engine 3 is a diesel engine, ignition is not performed and only fuel injection is performed. Then, the microcomputer 19 determines whether or not the engine 3 has reached a complete explosion state (a state in which the engine 3 has been started, which has been started), based on the engine speed calculated from the rotation signal described above. If the determination is made and it is determined that the engine 3 is in a complete explosion state, the drive of the starter 7 is stopped.

By such a starter control process, the engine 3 is started and is in operation.
The process for starting the engine 3 for the first time after the IG switch 37 is turned on, and the process for starting the engine 3 in response to the engine start operation by the vehicle user, is performed by a device other than the idle stop ECU 1. It may be like this.

  Next, FIG. 2 is a flowchart showing the idle stop control process. The microcomputer 19 repeats this idle stop control process at regular intervals while it determines that the IG on signal Si is at the high level (that is, while the vehicle is in the IG on state). Run.

  As shown in FIG. 2, when the microcomputer 19 starts to execute the idle stop control process, first, in S110, the microcomputer 19 determines whether or not the engine 3 is in operation. For example, if the engine speed calculated based on the aforementioned rotation signal is equal to or greater than a predetermined value, it is determined that the vehicle is in operation.

If it is determined that the engine 3 is not in operation, the process proceeds to S150 described later. If it is determined that the engine 3 is in operation, the process proceeds to S120.
In S120, it is determined whether or not an automatic stop condition that is a condition for automatically stopping the engine 3 is satisfied. As the automatic stop condition, for example, a plurality of subdivision conditions such as the brake pedal being depressed, the accelerator pedal not being depressed, the vehicle speed being a predetermined value or less, and the steering angle being a predetermined value or less are all satisfied. However, these are merely examples, and other conditions may be used.

If it is determined that the automatic stop condition is not satisfied, the process proceeds to S150. If it is determined that the automatic stop condition is satisfied, the process proceeds to S130.
In S130, it is determined whether or not idle stop (automatically stopping the engine 3) is permitted (in other words, whether or not idle stop is prohibited) by a prohibition determination process of FIG. 3 to be described later. . Specifically, it is determined whether the idle stop prohibition flag set to “1” or “0” in the prohibition determination process of FIG. 3 is “1” or “0”, and the idle stop prohibition flag is determined. If "1", it is determined that idle stop is prohibited, and if the idle stop prohibition flag is "0", it is determined that idle stop is permitted. The idle stop prohibition flag is 1-bit data stored in the RAM 33, for example.

  If the idle stop is not permitted (if prohibited), the process proceeds to S150. If the idle stop is permitted, the process proceeds to S140, and a process for automatically stopping the engine 3 is performed. The process proceeds to S150.

  In S140, specifically, an engine stop command is transmitted to the engine ECU 5. Then, the engine ECU 5 stops the engine 3 by, for example, stopping fuel injection to the engine 3 or blocking an intake air supply path to the engine 3.

  Further, after the engine 3 is stopped by the process of S140, the engine 3 is automatically restarted by the process of S170 described later. Therefore, in the present embodiment, stopping the engine 3 in the process of S140 is an idle stop (automatic stop), and the engine 3 is automatically restarted after the engine 3 is stopped in the process of S140. The period until is idle stop (automatic stop).

  In S150, it is determined whether or not an idle stop is being performed. That is, it is determined whether or not it is during the period in which the engine 3 is not restarted yet after the engine 3 is stopped in S140.

  If it is determined in S150 that the engine is not idling, the idle stop control process is terminated. If it is determined that the engine is idling, the process proceeds to S160.

  In S160, it is determined whether or not an automatic start condition that is a condition for automatically restarting the engine 3 is satisfied. Examples of the automatic start condition include that the brake pedal is released, the operation angle is equal to or greater than a predetermined value, the brake pedal remains depressed, but the driver performs another operation to drive the vehicle. However, these are merely examples, and other conditions may be used.

  If it is determined in S160 that the automatic stop condition is not satisfied, the idle stop control process is terminated as it is. If it is determined that the automatic start condition is satisfied, the process proceeds to S170 and the engine is stopped. In order to automatically restart 3, the starter control process described above is performed.

And the microcomputer 19 complete | finishes the said idle stop control process, after restarting the engine 3 by the process of this S170.
Next, FIG. 3 is a flowchart showing the prohibition determination process. The microcomputer 19 repeatedly executes this prohibition determination process at regular intervals while determining that the IG on signal Si is at a high level. Further, the prohibition determination process and the idle stop control process of FIG. 2 are executed in parallel in the form of multitasking.

  As shown in FIG. 3, when the microcomputer 19 starts executing the prohibition determination process, first, in S210, the microcomputer 19 determines whether or not the restart is in progress from the idle stop state (automatic stop state). Specifically, whether or not the starter 7 is being driven to restart the engine 3 is determined by the starter control process in S170 of FIG.

If it is determined that the engine is restarting from the idle stop state, the process proceeds to S220, and the time after restart, which is the elapsed time since the engine 3 is restarted in S170 of FIG. 2, is measured. The counter C is initialized to 0, and then the process proceeds to S240. In the present embodiment, the counter C is data stored in the backup RAM 35.

  If it is determined in S210 that the engine is not restarting from the idle stop state, the process proceeds to S230, the counter C is incremented (+1), and then the process proceeds to S240. Therefore, when the engine 3 is restarted from the idle stop state, the value of the counter C is incremented by 1 at S230 each time the prohibition determination process is executed.

In S240, it is determined whether or not the value of the counter C has reached a predetermined threshold value Nth. Specifically, it is determined whether or not the value of the counter C is equal to or greater than a threshold value Nth.
Note that the threshold value Nth is a value corresponding to a forced pause time Tint in which the drive of the starter 7 should be paused in order to protect the starter 7 from overheating. Specifically, the forced pause time Tint is determined as the prohibition determination. It is set to a value divided by the process execution cycle Ta. Further, the threshold value Nth (forced stop time Tint) may be a fixed value. For example, the threshold value Nth (forced stop time Tint) depends on the drive time of the immediately preceding starter 7 (that is, the drive time of the starter 7 when the engine 3 is restarted). The longer the driving time, the larger the value may be set.

  If it is determined in S240 that the value of the counter C has not reached the threshold value Nth, the process proceeds to S250, where the engine 3 is automatically set in S140 of FIG. 2 by setting the idle stop prohibition flag to “1”. Stopping (that is, idling stop of engine 3) is prohibited. Then, the prohibition determination process ends.

  If it is determined in S240 that the value of the counter C has reached the threshold value Nth, the process proceeds to S260, and the engine 3 is allowed to stop idling by setting the idle stop prohibition flag to “0”. To do. Then, the prohibition determination process ends.

  Therefore, when the engine 3 is restarted from the idle stop state, the idle stop prohibition flag becomes “1” until it is determined in S240 that the value of the counter C has reached the threshold value Nth. The idle stop of the engine 3 is prohibited.

  Although explanation is omitted, in S230, the counter C is not incremented when the idle stop prohibition flag is already "0" by the process of S260. On the other hand, if the value of the counter C does not return to 0 (no wrap round) after reaching the maximum countable value, in S230, regardless of whether the idle stop prohibition flag is “1” or “0”. Instead, the counter C may be incremented.

Next, FIG. 4 is a flowchart showing processing at the time of IG OFF.
When the microcomputer 19 detects that the IG ON signal Si is changed from the high level to the low level (that is, the IG switch 37 is turned off and the vehicle is in the IG off state), the microcomputer 19 performs later-described S340. This IG-off-time process is performed at the same fixed time Ta as the execution period Ta of the prohibition determination process in FIG. 3 until the operation is stopped by the process or until it is determined that the IG ON signal Si has become high level. Repeatedly. In other words, “when IG is turned off” named “IG off-time processing” means “when the IG switch 37 is turned off (when the vehicle is in the IG off state)”.

As shown in FIG. 4, when the microcomputer 19 starts executing the processing at the time of IG OFF, first, in S310, the counter C in the backup RAM 35 is incremented (+1), and in the next S320, the value of the counter C is increased. Whether or not the threshold value Nth has been reached is determined. Specifically, it is determined whether or not the value of the counter C is equal to or greater than a threshold value Nth.

  If it is determined that the value of the counter C has not reached the threshold value Nth, the process proceeds to S330, and the main relay 11 is turned on by keeping the power holding signal Sh to the main relay drive circuit 29 at a high level. Then, the process at the time of turning off the IG is terminated.

If it is determined in S320 that the value of the counter C has reached the threshold value Nth, the process proceeds to S340.
In S340, it is determined whether or not there is another process to be performed after the IG switch 37 is turned off. If there is another process, the process at the time of turning off the IG is terminated as it is. If this processing is not performed, the power holding signal Sh to the main relay drive circuit 29 is set to a low level.

  When the power holding signal Sh becomes a low level, the main relay 11 is turned off, the supply of the first battery voltage VB1 to the idle stop ECU 1 is stopped, and the microcomputer 19 stops its operation.

  After that, when the IG switch 37 is turned on again and the microcomputer 19 is activated, the value of the counter C has already reached the threshold value Nth. Therefore, when the microcomputer 19 executes the prohibition determination process of FIG. 3 for the first time after activation, the idle stop prohibition flag is set to “0” in S260 in the first prohibition determination process after activation.

  Next, the effect of the idle stop ECU 1 of the present embodiment in which the IG off-time process of FIG. 4 is executed will be described using the idle stop ECU 1 assuming that the IG off-time process of FIG. 4 is not executed as a comparative example. Here, description will be made with reference to FIGS. FIG. 5 is a time chart showing the operation of the comparative example, and FIG. 6 is a time chart showing the operation of the idle stop ECU 1 of the present embodiment.

First, operation contents common to the comparative example and the present embodiment will be described.
As shown in FIG. 5 (or FIG. 6), when the automatic start condition is established during the idle stop and the starter 7 is driven to restart the engine 3 (S170 in FIG. 2), the time after restart The value of the counter C corresponding to the measured value is initialized to 0 (S220 in FIG. 3).

  When the restart of the engine 3 is completed and the drive of the starter 7 is completed, the idle stop prohibition flag becomes “1” and the engine 3 is prohibited from idling stop (S250 in FIG. 3). Further, the counter C is incremented (incremented) one by one for every fixed time Ta that is the execution period Ta of the prohibition determination process of FIG. 3 (S230 of FIG. 3).

  Although not shown in FIGS. 5 and 6, if the IG switch 37 is not turned off before the value of the counter C reaches the threshold value Nth, the value of the counter C is set to the threshold value in S240 of the prohibition determination process of FIG. When it is determined that Nth has been reached, the idle stop prohibition flag becomes “0”, and the engine 3 is allowed to stop idling (S260 in FIG. 3).

The above is the operation content common to the comparative example and this embodiment.
On the other hand, as shown in FIG. 5, in the comparative example, it is assumed that the IG switch 37 is turned off before the value of the counter C reaches the threshold value Nth.

  Then, while the IG switch 37 is turned off, the prohibition determination process of FIG. 3 is not executed, so that the value of the counter C does not increase in spite of the period during which the starter 7 is not driven. It is held at the value when was turned off.

  Thereafter, when the IG switch 37 is turned on again and the microcomputer 19 is activated, the count-up of the counter C is restarted by the prohibition determination process of FIG. 3, and when the value of the counter C reaches the threshold value Nth (S240 in FIG. 3). : YES), the idle stop prohibition flag becomes “0”, and the idle stop is permitted (S260 in FIG. 3).

In such a comparative example, the counter C is not used effectively.
That is, the counter C is a counter for measuring the time after restart, and is also a counter for measuring the time during which the starter 7 is not driven (hereinafter referred to as starter pause time). However, in the comparative example, during the period in which the IG switch 37 is off, the start-up pause time is not correctly measured in order to stop the counter C from counting up.

  Therefore, in the comparative example, even if the time during which the IG switch 37 is turned off is sufficiently long and the actual post-restart time (starter pause time) exceeds the aforementioned forced pause time Tint corresponding to the threshold Nth. As shown in FIG. 5, after the IG switch 37 is turned on again, idle stop is prohibited until the value of the counter C reaches the threshold value Nth. In this case, a period from when the IG switch 37 is turned on until idle stop is permitted becomes an unnecessary (extra) idle stop prohibition period.

In FIG. 5, the entire period during which the IG switch 37 is turned off is shown as an idle stop prohibition state, but this is substantially the same.
That is, in practice, when the IG switch 37 is turned off and the main relay 11 is turned off, the power supply voltage Vm to the microcomputer 19 is cut off, so that the idle stop prohibition flag in the RAM 33 becomes indefinite from “1”. However, while the IG switch 37 is off, the engine 3 is stopped in the first place, so the idle stop is not performed. Therefore, even if the idle stop prohibition flag is not “1”, the idle stop is not performed. Is the same as prohibiting When the IG switch 37 is turned on again and the microcomputer 19 executes the prohibition determination process of FIG. 3 for the first time after startup, the first prohibition determination process determines “NO” in S240 and idles in S250. The stop prohibition flag is set to “1”. Therefore, when the IG switch 37 is turned on again, the idle stop prohibition flag immediately becomes “1”, and the same idle stop prohibition state as before the IG switch 37 is turned off is entered.

  On the other hand, as shown in FIG. 6, in the idle stop ECU 1 of the present embodiment, even if the IG switch 37 is turned off before the value of the counter C reaches the threshold value Nth, the counter C performs the IG off processing ( In step S310), the count is continuously incremented for every predetermined time Ta.

  If the value of the counter C reaches the threshold value Nth while the IG switch 37 is off (during the period when the IG switch 37 is off) (S320: YES in FIG. 4), the main relay 11 is turned off ( In step S340 in FIG. 4, the microcomputer 19 stops operating.

After that, when the IG switch 37 is turned on again and the microcomputer 19 is activated, the value of the counter C has already reached the threshold value Nth at that time.
Therefore, when the microcomputer 19 is started and the prohibition determination process of FIG. 3 is first executed, it is determined that the value of the counter C has reached the threshold value Nth (S240: YES in FIG. 3), and the idle stop prohibition flag is set to “0”. In this case, the idle stop is permitted (S260 in FIG. 3). For this reason, when the IG switch 37 is turned on, the idle stop permission state is immediately set, and it is possible to prevent an unnecessary idle stop prohibition period occurring in the comparative example from being provided.

In FIG. 6, the value of the counter C is changed to the threshold value Nt after the IG switch 37 is turned on again.
The reason why the counter C is incremented by 1 is that the counter C is incremented in S230 in the prohibition determination process of FIG.

  Also, in FIG. 6, as in FIG. 5, the entire period in which the IG switch 37 is turned off is shown as an idle stop prohibition state, which is substantially the same. That is, in the example shown in FIG. 6, when the main relay 11 is turned off, the idle stop prohibition flag becomes indefinite from “1”, but the IG switch 37 is turned off as described with reference to FIG. In the meantime, even if the idle stop prohibition flag is not “1”, the idle stop is prohibited. When the IG switch 37 is turned on again and the microcomputer 19 executes the prohibition determination process of FIG. 3 for the first time after startup, the idle stop prohibition flag is set to “0” in S260 in the first prohibition determination process. It becomes. On the other hand, the idle stop prohibition flag may be stored in, for example, the backup RAM 35. In this case, the idle stop prohibition flag reads “permission” as “0” at the bottom of FIG. It will change as read as 1 ″. This also applies to FIG.

  Although not shown in FIG. 6, if the IG switch 37 is turned on again from before the counter C reaches the threshold value Nth, the microcomputer 19 does not turn off the main relay 11. Continue to work. In this case, when the microcomputer 19 first executes the prohibition determination process of FIG. 3 after the IG switch 37 is turned on, the microcomputer 19 determines “NO” in S240 and sets the idle stop prohibition flag to “ It will be set to 1 ″. After that, the prohibition determination process of FIG. 3 is executed every predetermined time Ta, so that the counter C is continuously counted up, and when the value of the counter C reaches the threshold value Nth, S260 of FIG. As a result, the idle stop prohibition flag is set to “0”. Also in this case, when the IG switch 37 is turned on, a value corresponding to the time when the IG switch 37 was turned off is added to the value of the counter C. Therefore, it is possible to prevent an unnecessary idle stop prohibition period from being provided.

  In the idle stop ECU 1 of the present embodiment as described above, the time during which the vehicle is in the IG off state by the process of S310 in the IG off process of FIG. 4 (in this embodiment, the IG switch 37 has been turned off). Time, and hereinafter referred to as the IG off time), and a value corresponding to the detected value of the IG off time is added to the value of the counter C corresponding to the measured value of the time after restart. Become.

  For this reason, when the value of the counter C reaches the threshold value Nth after the engine 3 is restarted, when the IG switch 37 is turned off and then the IG switch 37 is turned on again, the value of the counter C is The total value of the value until the switch 37 is turned off and the value added in S310 of FIG. 4 while the IG switch 37 is turned off. That is, the value of the counter C includes the IG off time. When the microcomputer 19 first performs the prohibition determination process of FIG. 3 after the IG switch 37 is turned on, in S240, whether the total value (strictly, the value obtained by adding 1 in S230) has reached the threshold value Nth. It will be determined whether or not.

  Therefore, it is possible to prevent the determination target value from being a post-restart time including the IG off time, and providing an unnecessary idle stop prohibition period after the IG switch 37 is turned off and turned on again.

  Further, in the idle stop ECU 1 of the present embodiment, in the process at the time of IG OFF in FIG. 4, if the value of the counter C after counting up in S310 reaches the threshold value Nth (S320: YES), the process proceeds to the main relay drive circuit 29. The power holding signal Sh is set to a low level to turn off the main relay 11 (S340).

  That is, in the IG off time process of FIG. 4, the IG off time is measured only for the time until the value of the counter C reaches the threshold value Nth, and when the measurement ends, the ECU 1 supplies the first battery as the operating voltage. The supply of the voltage VB1 is stopped. Therefore, it is possible to suppress power consumption of the ECU 1 (and hence power consumption of the battery 9) when the vehicle is in the IG off state.

  In the present embodiment, the backup RAM 35 corresponds to an example of a storage unit, and the microcomputer 19 corresponds to an example of a control unit, a measurement unit, and a prohibition unit. In particular, the microcomputer 19 that executes the process of FIG. 2 is an example of the control means, and the microcomputer 19 that executes the processes of S210 to S230 of FIG. 3 is an example of the measurement means, and the processes of S240 to S260 of FIG. The microcomputer 19 that executes is an example of the prohibiting means.

  The microcomputer 19 corresponds to an example of an adding unit. In particular, the microcomputer 19 that executes the processing of FIG. 4 is an example of an adding unit. 4 is an example of a measurement addition process, and S320 to S340 in FIG. 4 are an example of a power shutdown determination process. The main relay drive circuit 29 corresponds to an example of a power supply maintaining unit, and the low-level power holding signal Sh corresponds to an example of a power supply cutoff permission.

[Second Embodiment]
Regarding the idle stop ECU 41 of the second embodiment shown in FIG. 7, differences from the first embodiment will be described.

The idle stop ECU 41 shown in FIG. 7 includes a timer circuit 43 that operates by the power supply voltage Vs that is always output from the power supply circuit 17.
The timer circuit 43 sets the timer time by the microcomputer 19 and starts measuring time when receiving a start command from the microcomputer 19. When the measured time value reaches the timer time, the timer circuit 43 Output signal St is set to high level. Further, the output signal St of the timer circuit 43 is reset from a high level to a low level by a reset command from the microcomputer 19.

Further, the output signal St of the timer circuit 43 is input to the main relay drive circuit 29.
In the main relay drive circuit 29, at least one of the IG ON signal Si from the input circuit 21, the power holding signal Sh from the microcomputer 19, and the output signal St from the timer circuit 43 is active level (this example Is high level), the main relay 11 is turned on by energizing the coil of the main relay 11.

On the other hand, the microcomputer 19 executes the processes of FIGS. 8 and 9 instead of not executing the process at the time of IG OFF of FIG.
First, FIG. 8 is a flowchart showing the timer setting process.

  When the microcomputer 19 detects that the IG ON signal Si has changed from the high level to the low level, the microcomputer 19 executes the timer setting process as one of the operation completion processes to be performed after the IG switch 37 is turned off.

  As shown in FIG. 8, when the microcomputer 19 starts executing the timer setting process, the timer circuit 43 is activated so that the ECU 41 is activated (that is, the microcomputer 19 is activated) after a predetermined time Tw in S400. Process to set.

  Specifically, first, the predetermined time Tw is set in the timer circuit 43 as a timer time. Then, a reset command is given to the timer circuit 43 to set the output signal St of the timer circuit 43 to a low level. Finally, a start command is given to the timer circuit 43 to start measuring time.

Then, when the process of S400 ends, the timer setting process ends.
Thereafter, the microcomputer 19 executes another process to be performed after the IG switch 37 is turned off. When the process is completed, the microcomputer 19 sets the power holding signal Sh to the main relay drive circuit 29 to a low level. Then, the main relay 11 is turned off and the microcomputer 19 stops its operation.

  Even when the IG switch 37 remains off, the output signal St of the timer circuit 43 becomes high level and the main relay 11 is turned on when the predetermined time Tw elapses after the processing of S400 is performed. Then, the microcomputer 19 is activated. The predetermined time Tw may be the same time as the execution cycle Ta of the prohibition determination process of FIG. 3 or may be a time different from the execution cycle Ta.

And in this embodiment, the microcomputer 19 performs the process at the time of starting of FIG. 9 immediately after starting.
As shown in FIG. 9, when the microcomputer 19 starts executing the startup process, first, in S405, the ECU 41 sets the power holding signal Sh to the main relay drive circuit 29 to a high level as described above, thereby causing the ECU 41 to become high. The supply of the first battery voltage VB1 is prevented from being stopped.

  Then, in next S410, it is determined whether or not the current activation is activation by the timer circuit 43. Specifically, the level of the IG ON signal Si is read, and if it is low level, it is determined that the timer circuit 43 is activated, and if it is high level, it is not activated by the timer circuit 43 (that is, the IG switch 37 is activated). If the output signal St of the timer circuit 43 is input to the microcomputer 19, the activation factor may be determined from the level of the output signal St.

  If it is determined in S410 that the current activation is not the activation by the timer circuit 43, the activation process is terminated as it is, and other processes to be executed when the IG switch 37 is turned on. However, if it is determined that the current activation is the activation by the timer circuit 43, the process proceeds to S420.

  In S420, the value corresponding to the predetermined time Tw (specifically, a value obtained by dividing the predetermined time Tw by the execution period Ta of the prohibition determination process in FIG. 3) NTw is added to the value of the counter C. The process of S420 corresponds to a process of adding the predetermined time Tw to the count value of the time after restart.

Next, in S430, it is determined whether or not the value of the counter C has reached the aforementioned threshold value Nth. Specifically, it is determined whether or not the value of the counter C is equal to or greater than a threshold value Nth.
If it is determined in S430 that the value of the counter C has not reached the threshold value Nth, the process proceeds to S440.

  In S440, a process of setting the timer circuit 43 is performed so that the ECU 41 is activated again after a predetermined time Tw. Specifically, the same process as S400 of the timer setting process of FIG. 8 is performed.

In step S460, the power holding signal Sh to the main relay drive circuit 29 is set to a low level. Then, the main relay 11 is turned off, and the microcomputer 19 stops its operation.

  Even if the IG switch 37 remains off, the output signal St of the timer circuit 43 becomes high level and the main relay 11 is turned on when the predetermined time Tw elapses after the processing of S440 is performed. Thus, the microcomputer 19 is activated again.

On the other hand, if it is determined in S430 that the value of the counter C has reached the threshold value Nth, the process proceeds to S450.
In S450, a reset command is given to the timer circuit 43, and the output signal St of the timer circuit 43 is set to a low level. However, a start command is not given to the timer circuit 43. That is, the timer circuit 43 is not restarted. Then, the process proceeds to S460, where the power holding signal Sh to the main relay drive circuit 29 is set to a low level.

  Then, the main relay 11 is turned off, and the microcomputer 19 stops its operation. In this case, since the timer circuit 43 is not restarted, the microcomputer 19 starts up again when the IG switch 37 is turned on next time.

  In the idle stop ECU 41 of the second embodiment as described above, even if the IG switch 37 is turned off before the value of the counter C reaches the threshold value Nth, the microcomputer 19 performs the predetermined time Tw by the processing of FIGS. The value NTw corresponding to the predetermined time (that is, the driving interval of the microcomputer 19) Tw is added to the value of the counter C (S420).

  Also in the second embodiment, the IG off time is detected by the process of S420 in the start-up process of FIG. 9, and the value corresponding to the detected value of the IG off time is used as the measured value after the restart. Is added to the value of the counter C corresponding to.

  For this reason, when the value of the counter C reaches the threshold value Nth after the engine 3 is restarted, when the IG switch 37 is turned off and then the IG switch 37 is turned on again, the value of the counter C is The total value of the value until the switch 37 is turned off and the value added in S420 of FIG. 9 while the IG switch 37 is turned off, and the value of the counter C includes the IG off time. When the microcomputer 19 first performs the prohibition determination process of FIG. 3 after the IG switch 37 is turned on, in S240, whether the total value (strictly, the value obtained by adding 1 in S230) has reached the threshold value Nth. It will be determined whether or not.

Therefore, according to the second embodiment as well, it is possible to prevent an unnecessary idle stop prohibition period from being provided after the IG switch 37 is turned off and turned on again.
Further, while the IG switch 37 is off, the microcomputer 19 is activated only every predetermined time Tw, so that the power consumption of the ECU 41 (and hence the power consumption of the battery 9) can be suppressed.

  In particular, in the startup process of FIG. 9, when the value of the counter C updated in S420 reaches the threshold value Nth (S430: YES), the automatic startup of the ECU 41 and the microcomputer 19 by the timer circuit 43 is stopped. (S450). For this reason, in the startup process of FIG. 9, the IG off time is measured only for the time until the value of the counter C reaches the threshold value Nth, and the ECU 41 and the microcomputer 19 are not automatically started when the measurement ends. . Therefore, the power consumption of the ECU 41 when the vehicle is in the IG off state can be further suppressed.

In the present embodiment, the microcomputer 19 that executes the process of S420 in FIG. 9 is an example of an adding unit. Further, the main relay drive circuit 29 and the timer circuit 43, the processing of FIG.
The microcomputer 19 that executes the processes of S405, S410, and S430 to S460 is an example of an activation unit.

[Third Embodiment]
A difference from the first embodiment regarding the idle stop ECU 51 of the third embodiment shown in FIG. 10 will be described.

  In the idle stop ECU 51 shown in FIG. 10, the microcomputer 19 receives a signal from a water temperature sensor 53 that detects a cooling water temperature (hereinafter simply referred to as a water temperature) of the engine 3, and an outside air temperature sensor 55 that detects an outside air temperature of the vehicle. A signal is input via the input circuit 21.

And the microcomputer 19 performs each process of FIG. 11 and FIG. 12 instead of not performing the process at the time of IG OFF of FIG.
First, FIG. 11 is a flowchart showing a detection process for detecting the water temperature and the outside air temperature when the IG switch 37 is turned off (hereinafter referred to as IG off time).

  When the microcomputer 19 detects that the IG switch 37 is turned off, the microcomputer 19 executes this detection process from that time until the power holding signal Sh is set to the low level. That is, the detection process of FIG. 11 is executed as one of the process at the end of the operation.

  Then, as shown in FIG. 11, when the microcomputer 19 starts executing the detection process, the microcomputer 19 detects the water temperature and the outside air temperature based on the signals from the water temperature sensor 53 and the outside air temperature sensor 55 in S505, and the detection. The water temperature and the outside temperature are stored in the backup RAM 35. Then, when the process of S505 ends, the detection process ends.

  That is, in this detection process, the water temperature and the outside air temperature from when the vehicle is in the IG off state to when the supply of the first battery voltage VB1 to the ECU 51 is stopped, and the vehicle is in the IG off state. The water temperature and the outside air temperature immediately after being stored are stored in the backup RAM 35 as the water temperature and the outside air temperature when the IG is off.

  The microcomputer 19 executes the detection process of FIG. 11 at regular intervals while determining that the IG switch 37 is on (the IG on signal Si is at a high level). May be. In this case, the last water temperature and the outside air temperature stored in the backup RAM 35 at the time when the IG switch 37 is turned off, and the water temperature and the outside air temperature just before the vehicle enters the IG off state are the IG off. The water temperature and the outside air temperature at the time are stored in the backup RAM 35. Such a method is configured such that the first battery voltage VB1 is supplied to the ECU 51 only when the main relay 11 is not provided and the IG switch 37 is turned on (that is, immediately when the IG switch 37 is turned off). This is advantageous in the case of the configuration in which the first battery voltage VB1 is cut off.

Next, FIG. 12 is a flowchart showing a startup process.
When the microcomputer 19 is started as the IG switch 37 is turned on, the power holding signal Sh described above is set to a high level and the start-up process of FIG. 12 is executed.

  Then, as shown in FIG. 12, when the microcomputer 19 starts executing the startup process, first, in S510, the microcomputer 19 detects the water temperature based on the signal from the water temperature sensor 53, and uses the detected water temperature as the IG switch 37. Is stored in the RAM 33, for example, as the water temperature when the is turned on (hereinafter referred to as IG on).

Next, in S520, the water temperature at the time of IG off is read from the backup RAM 35, and the I
A value obtained by subtracting the water temperature at the time of IG on detected in S510 from the water temperature at the time of G off is calculated as a water temperature difference (that is, a water temperature difference from the time of IG off to the time of IG on).

  In subsequent S530, based on the water temperature difference calculated in S520, the IG OFF time is estimated in consideration of the outside air temperature stored in the backup RAM 35 when the IG is OFF. Specifically, as illustrated in FIG. 13, the ROM 32 stores an IG off time calculation map in which the relationship between the water temperature difference, the outside air temperature, and the IG off time is recorded. In S530, the IG off time corresponding to the water temperature difference calculated in S520 and the outside air temperature during IG off is calculated from the IG off time calculation map.

  In addition, the map for calculating the IG off time shows that “the longer the IG off time, the larger the water temperature difference becomes. If the IG off time is the same, the water temperature difference becomes smaller as the outside air temperature during IG off increases. (The water temperature is unlikely to drop). For this reason, the value of the IG off time calculated (estimated) in S530 increases as the water temperature difference increases and the outside air temperature during IG off increases.

  Next, in S540, the value corresponding to the IG OFF time estimated in S530 (specifically, the estimated IG OFF time divided by the execution period Ta of the prohibition determination process in FIG. 3) is added to the value of the counter C. ) Is added. The process of S540 corresponds to a process of adding the estimated IG off time to the count value of the time after restart, and when this process ends, the start-up process ends.

  In the idle stop ECU 51 of the third embodiment as described above, the IG off time is detected in the form of estimation by the startup process of FIG. 12, and a value corresponding to the detected value of the IG off time is set after the restart. The value is added to the value of the counter C corresponding to the time measurement value.

  The idle stop ECU 51 also turns off the IG switch 37 before the value of the counter C reaches the threshold value Nth after the engine 3 is restarted, and then turns on the IG switch 37 again. In addition, when the prohibition determination process of FIG. 3 is performed, the value of the counter C includes a value corresponding to the IG off time. Therefore, according to the third embodiment, it is possible to prevent an unnecessary idle stop prohibition period from being provided after the IG switch 37 is turned off and turned on again.

  Further, according to the third embodiment, the IG off time can be detected without intentionally supplying the operation voltage (first battery voltage VB1) to the ECU 51 while the IG switch 37 is off. . Therefore, power consumption of the battery 9 can be suppressed.

  In the present embodiment, the microcomputer 19 that executes the processes in FIGS. 11 and 12 is an example of an adding unit. The detection process in FIG. 11 is an example of the first process, and the startup process in FIG. 12 is an example of the second process. Moreover, the water temperature at the time of IG OFF is an example of 1st water temperature, and the water temperature at the time of IG ON is an example of 2nd water temperature.

  On the other hand, in S530 of FIG. 12, the IG off time may be estimated from only the water temperature difference, or the IG off time may be estimated further using the water temperature when the IG is off or when the IG is on. By using the value of the water temperature itself, the estimation accuracy of the IG off time can be increased.

  Further, for example, in the startup process of FIG. 12, the outside air temperature when the IG is on is also detected, and in S530, the IG off time is estimated using the outside air temperature when the IG is on instead of the outside air temperature when the IG is off. May be. For example, in S530 of FIG. 12, the IG off time may be estimated based on the difference between the outside air temperature when the IG is off and the outside air temperature when the IG is on (outside air temperature difference) and the water temperature difference.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to such Embodiment at all, Of course, in the range which does not deviate from the summary of this invention, it can implement in a various aspect. .

  For example, the memory in which the counter C is provided (that is, a memory that stores the value of the counter C and stores a measured value of the time after restart) is not limited to the backup RAM 35, and is a nonvolatile memory that can rewrite data. It may be a memory (for example, EEPROM or flash memory).

  Further, the idle stop prohibition flag may be stored in the backup RAM 35 as described above, or may be stored in, for example, a nonvolatile memory capable of rewriting data.

  Similarly, in the detection process of FIG. 11 in the third embodiment, the water temperature and the outside air temperature may be stored in a nonvolatile memory capable of rewriting data.

1, 41, 51 ... Idle stop ECU, 3 ... Engine, 5 ... Engine ECU
7 ... starter, 9 ... battery, 11 ... main relay (relay for power supply)
DESCRIPTION OF SYMBOLS 13,15,39 ... Power supply line, 17 ... Power supply circuit, 19 ... Microcomputer, 21 ... Input circuit 23 ... Communication circuit, 25 ... Starter relay, 27 ... Drive circuit 29 ... Main relay drive circuit, 31 ... CPU, 32 ... ROM 33 ... RAM
34 ... Input / output interface (I / O), 35 ... Backup RAM
37 ... IG (ignition) switch, 43 ... Timer circuit, 53 ... Water temperature sensor 55 ... Outside air temperature sensor

Claims (5)

The device is mounted on a vehicle and is supplied with an operating voltage from a battery of the vehicle when the vehicle is in an ignition-on state, and stops supplying the operating voltage when the vehicle is in an ignition-off state.
A storage unit capable of continuously storing data even when the supply of the operating voltage to the device is stopped;
As means for operating the operating voltage as a power source when the vehicle is in an ignition-on state,
Control means for stopping the engine of the vehicle when it is determined that a predetermined automatic stop condition is satisfied, and then restarting the engine by driving a starter when it is determined that a predetermined automatic start condition is satisfied;
Measuring means for measuring an elapsed time since the control means restarted the engine, and storing the measured value in the storage means;
It is determined whether or not the measurement value stored in the storage means has reached a predetermined threshold value, and the control means stops the engine until it is determined that the measurement value has reached the threshold value. And prohibiting means for prohibiting
Furthermore, the device
An addition means for detecting a time when the vehicle has been in an ignition off state and adding the detected time to the measurement value stored in the storage means;
An idle stop control device characterized by the above. In the idle stop control device according to claim 1,
From the time when the vehicle is in an ignition-off state, it is provided with power supply maintaining means for supplying the operating voltage to the device until the power-off permission is given,
The adding means operates using the operating voltage as a power source, measures an elapsed time since the vehicle is in an ignition-off state, and stores the measured elapsed time in the storage means A measurement addition process to be added to the value, and a power cutoff judgment process for giving the power cutoff permission to the power maintenance means if the measurement value after the addition reaches the threshold value,
An idle stop control device characterized by the above. In the idle stop control device according to claim 1,
When the vehicle is in an ignition off state, the vehicle includes an activation unit that activates the addition unit every predetermined time;
The addition means adds the predetermined time to the measurement value stored in the storage means every time the addition means is activated by the activation means;
An idle stop control device characterized by the above. In the idle stop control device according to claim 3,
The starting means is configured to stop starting the adding means every predetermined time when the measured value stored in the storage means reaches the threshold value;
An idle stop control device characterized by the above. In the idle stop control device according to claim 1,
The adding means includes
While operating using the operating voltage as a power source,
Cooling water temperature of the engine immediately before the vehicle is in an ignition-off state, or cooling water temperature of the engine from when the vehicle is in an ignition-off state to when the supply of the operating voltage to the device is stopped Is detected as the first water temperature,
Further, when the vehicle is in an ignition-on state and the supply of the operating voltage to the device is started, the engine coolant temperature is detected as a second water temperature, and the first water temperature and the second water temperature are detected. Based on the water temperature, a second process of estimating the time when the vehicle has been in an ignition off state and adding the estimated time as the detected time to the measured value stored in the storage means To do the
An idle stop control device characterized by the above.

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