JP2021127715A - Power supply control device - Google Patents

Abstract

To provide a power supply control device capable of reliably determining an off fixation state without erroneously determining it at the time of instantaneous interruption of power supply.SOLUTION: When an ignition switch 20 is turned on, a micro computer 12 is started with a drive circuit 14 turning on a main relay 30 to periodically give a reset signal to a soak timer 13 in a feeding state. When the ignition switch 20 is turned off, the micro computer 12 gives an on-holding signal to the drive circuit 14 to hold the feeding state and sets an off-flag to stop it. When a soak timer 13 reaches a timer threshold value and the micro computer 12 is waked up by a wake-up signal, a diagnostic process is executed. When the on-holding signal is valid, the off-flag is set, and so a determination is made that it is normal. On the other hand, when the micro computer 12 is instantaneously stopped, it is not waked up to be restarted, and so no diagnosis is executed to avoid erroneous determination.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power supply control device.

In an ECU (Electronic Control Unit) mounted on a vehicle, when the ignition switch (hereinafter referred to as IGSW) for supplying power from the in-vehicle battery is turned off, the main relay is completed until a predetermined process is completed by the microcomputer. The main relay holding control is performed so that the power supply state is held by outputting the on holding signal.

If the on-hold state of the main relay by such an on-hold signal is not executed, the power supply to the microcomputer is stopped when the ignition switch is turned off. This is because there is an "off-fixed" failure state in which the on-hold signal is not transmitted and the main relay remains fixed in the off state.

An off-fixed failure state in which the on-hold signal is not transmitted is, for example, an on-hold signal cannot be transmitted because the microcomputer and the drive circuit are disconnected even though the on-hold signal is output from the microcomputer to the drive circuit. In some cases, or when the on-holding signal is not output from the microcomputer, it is assumed.

For this reason, in order to ensure that the main relay holding control can be performed when the ignition switch is turned off, conventionally, it is detected whether or not a fixed off failure state has occurred during normal operation. It has a diagnostic function.

However, in the conventional method, when a phenomenon equivalent to a momentary power failure occurs due to a sudden drop in the voltage of the in-vehicle battery, the state immediately after the power is restored becomes unstable, so the diagnostic function is normally performed. There was a possibility that it would not be done.

Japanese Unexamined Patent Publication No. 2006-316638 Japanese Patent No. 3491358

The present invention has been made in consideration of the above circumstances, and an object of the present invention is a power supply control capable of reliably determining an off-fixed state without erroneously determining an off-fixed state when the power is momentarily interrupted. To provide the equipment.

The power supply control device according to claim 1 is an electronic device including a control circuit (12) that drives a main relay in an on state when the ignition switch of the vehicle is on and supplies power from an in-vehicle battery via the main relay. A control device that generates a backup power supply from the drive circuit (14) that drives the main relay when any of the ignition switch on signal, wakeup signal, and on hold signal is given, and the in-vehicle battery. A power supply circuit (11) that generates a predetermined voltage when power is supplied from the vehicle-mounted battery via the main relay to supply power to the control circuit, and a timer that counts up based on the backup power supply after the power supply is stopped by the power supply circuit. The control circuit includes a timer circuit (13) that outputs the wake-up signal to the drive circuit when the operation is performed and the timer count value reaches the set timer threshold value, and the control circuit is in an off flag set state or reset. It has a non-volatile storage unit (12a) that stores the state, and when the ignition switch is turned on, the main relay is turned on and activated when power is supplied from the power supply circuit, and at this point, the off flag When is in the set state, it switches to the reset state and outputs a reset signal to the timer circuit at predetermined time intervals. When the ignition switch is turned off, the off flag is set to the set state and the drive circuit is turned on. When the holding signal is output for a certain period of time and the ignition switch is off and the wakeup is based on the wakeup signal, the off flag is referred to and the execution of the diagnostic process is determined when the ignition switch is in the set state.

By adopting the above configuration, when the ignition switch is turned off, the control circuit outputs an on-holding signal to the drive circuit for a certain period of time, and during this period, the off flag is set to the non-volatile storage unit. Remember. After that, when the timer count value by the timer circuit reaches the set timer threshold value, a wake-up signal is output to the drive circuit. As a result, the control circuit wakes up when the main relay is turned on and power is supplied from the power supply circuit, and the diagnostic process is executed. At this time, since the off flag is set first, the diagnosis result is normal.

On the other hand, in the above case, when the ignition switch is turned off and the on-holding signal output from the control circuit to the drive circuit is not functioning in the off-fixed state, the main relay is turned off without being held on. The state shifts to the state, and the power supply to the control circuit is stopped. Therefore, the control circuit cannot set the off flag. After that, when the timer count value by the timer circuit reaches the set timer threshold value, a wakeup signal is output to the drive circuit, and the control circuit wakes up for diagnosis. In this case, the off flag is set. Since the on-holding signal is not transmitted to the drive circuit, it is assumed that the on-holding control is not functioning effectively, and the abnormal state is determined.

If the power supply circuit stops supplying power to the control circuit due to a drop in the voltage of the in-vehicle battery while the ignition switch is on, the control circuit cannot output an on-holding signal to the drive circuit. , The off flag is not set when the power is cut off. After that, the temporary voltage drop of the vehicle-mounted battery is eliminated, the power supply by the power supply circuit is restarted, and the control circuit is put into the activated state. However, at this point, the control circuit is not a wakeup due to the wakeup signal from the timer circuit, so it does not execute diagnostic processing and misdiagnoses that it is an off-fixed abnormality even when the off flag is not set. Can be avoided.

Electrical configuration diagram showing the first embodiment Normal timing chart Timing chart when off fixed occurs Timing chart when a momentary interruption occurs Configuration diagram showing the second embodiment Operation explanatory diagram Diagram showing the flow when IG is on Diagram showing the flow during wakeup Timing chart Operation explanatory diagram

(First Embodiment)
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 4.
In FIG. 1, the power supply control device 10 is configured to energize the main relay 30 based on the on operation of the ignition switch 20 provided in the vehicle, thereby supplying the DC voltage VD of the vehicle-mounted battery. The main relay 30 includes a relay coil 30a and a relay switch 30b.

The power supply control device 10 includes a power supply circuit 11, a microcomputer 12, a soak timer 13, a drive circuit 14, and the like. The power supply circuit 11 generates a power supply for the microcomputer 12, and a backup power supply circuit 11a is also provided inside to supply power to the soak timer 13. The drive circuit 14 includes an OR circuit 15 and a relay switching element 16.

The microcomputer 12 starts when power is supplied from the power supply circuit 11 and outputs an on-holding signal to the drive circuit 14. The microcomputer 12 has a non-volatile memory 12a inside, in addition to a configuration mainly composed of a CPU. Further, the microcomputer 12 receives an on / off signal from the ignition switch 20 via the buffer 17. The microcomputer 12 periodically transmits a reset signal to the soak timer 13 in a normal start-up state due to the on operation of the ignition switch 20.

The soak timer 13 as a timer circuit starts the timer operation when power is supplied from the backup power supply 11a of the power supply circuit 11. The soak timer 13 has a timer threshold value Pth set by the microcomputer 12, and when the timer count value P reaches the timer threshold value Pth, a wakeup signal is output to the OR circuit 15 of the drive circuit 14. Further, in the soak timer 13 in the state where the microcomputer 12 is activated, a reset signal is periodically given at a time interval shorter than the time until the threshold value is reached, and each time the reset signal is given. Then, the timer count value P is reset to zero and the timer operation is restarted.

In the drive circuit 14, the OR circuit 15 gives a drive signal to the relay switching element 16 made of a MOS transistor to transmit and disconnect the relay coil 30a, and three systems of input signals are provided. A diode 16a is connected in parallel to the relay switching element 16. The inputs of the OR circuit 15 are an on signal of the ignition switch 20, a wakeup signal of the soak timer 13, and an on holding signal from the microcomputer 12. When any of them is input, the relay switching element 16 is driven on.

Next, the operation of the above configuration will be described with reference to FIGS. 2 to 4. In this embodiment, an operation of diagnosing whether or not the holding control of the main relay 30 by the relay switching element 16 is normally performed by giving an on-holding signal from the microcomputer 12 to the OR circuit 15 will be described in detail. ..

(1) Normal-When the main relay holding control is normal First, the operation of the diagnostic processing when the holding control of the main relay 30 by the microcomputer 12 is normally performed, that is, when the off fixed state has not occurred, is shown in FIG. Will be explained with reference to. When the ignition switch 20 is turned on from the off state at time t0, an on signal is input to the OR circuit 15, whereby the relay switching element 16 is driven on.

When the relay switching element 16 is turned on, the relay coil 30a of the main relay 30 is energized to turn on the relay switch 30b. As a result, the power supply circuit 11 is supplied with power from the DC power supply VD, and the microcomputer 12 is started by being supplied with a predetermined drive power supply.

When the ignition switch 20 is turned on, the microcomputer 12 outputs an on-holding signal to the OR circuit 15 to hold the main relay 30 on, sets the timer threshold value Pth in the soak timer 13, and sets a reset signal. Is periodically output so that the timer count value P does not reach the timer threshold value Pth. Further, when the state of the IG off experience flag as the off flag stored in the memory 12a is the set state, the microcomputer 12 rewrites the state to the reset state and stores it.

Next, when the ignition switch 20 is turned off at time t1, the ON signal of the OR circuit 15 is stopped, but the ON holding signal is continuously output from the microcomputer 12 for a certain period of time, so that the relay switching element 16 is turned off. Keep it on. At this time, the microcomputer 12 detects that the ON signal of the ignition switch 20 has been stopped via the buffer circuit 17 and continues the ON holding signal for a predetermined period of time.

In response to the ignition switch 20 being turned off, the microcomputer 12 stores the IG off experience flag in the memory 12a in the set (S) state during the period held in the ON state, and then executes the termination operation. Then, it shifts to the off state at time t2. As a result, the output of the on-holding signal from the microcomputer 12 is stopped, the OR circuit 15 turns off the relay switching element 16, and the power supply to the microcomputer 12 is also stopped.

After the main relay 30 is turned off, the soak timer 13 is in a state in which a reset signal is not given from the microcomputer 12, so that the timer count value P is counted up without being reset by the timer operation. As a result, when the timer count value P reaches the timer threshold value Pth at time t3 after a lapse of time, the soak timer 13 resets the timer count value P and outputs a wakeup signal to the OR circuit 15 for a predetermined time. Then, wake-up control is performed.

As a result, the relay switching element 16 is driven on, the main relay 30 is turned on, and power is supplied to the power supply circuit 11. The microcomputer 12 is put into a wake-up state by being activated by being supplied with power from the power supply circuit 11 based on the wake-up signal regardless of the on operation of the ignition switch 20.

At the time of wake-up by the wake-up signal from the soak timer 13, the microcomputer 12 executes a diagnostic process of whether or not the main relay holding control is normally executed at time t4. In this diagnostic process, when the microcomputer 12 reads the state of the IG off experience flag from the memory 12a and recognizes that it is in the set state, the main relay holding control is normally performed when the microcomputer 12 stops operating. When recognizing that it is a result, it is determined that the off-fixed state has not occurred and the diagnosis result is normal.

After that, the microcomputer 12 performs an end operation and stops until the wake-up signal is turned off at time t5. During this wake-up operation period, the microcomputer 12 does not output a reset signal to the soak timer 13, but the timer count value P does not reach even if the timer operation continues. The wakeup signal is not output by setting a large timer threshold value.

After that, when the ignition switch 20 is turned on from the off state at time t6, an on signal is input to the OR circuit 15, whereby the relay switching element 16 is driven on. As a result, a predetermined drive power supply is supplied to the microcomputer 12 in the same manner as described above, and the microcomputer 12 is in a normal startup state.

When the microcomputer 12 enters the activated state due to the on operation of the ignition switch 20, the OR circuit 15 outputs an ON holding signal to hold the ON state of the main relay 30 and sets the timer threshold value Pth to the soak timer 13 as described above. In addition to setting, the reset signal is output periodically so that the wakeup signal is not output. Further, the microcomputer 12 rewrites the IG off experience flag in the set state stored in the memory 12a to the reset state.

The process of rewriting the IG off experience flag to the reset state at the time of normal startup of the microcomputer 12 can be performed immediately after the diagnosis process is executed after the diagnosis process is executed before this.

As described above, in the state where the main relay holding control is normally executed, the microcomputer 12 executes the diagnostic process at the time of wake-up by the soak timer 13 in the off state of the ignition switch 20, and assumes that this is the normal state. Can be diagnosed.

(2) Abnormal-When the main relay holding control is not normal Next, referring to FIG. 3, when the ignition switch 20 is turned off for some reason, the holding control of the main relay 30 is not normally performed. The operation when the "state" occurs will be described. The following failures are presumed as the cause of the state in which the holding control of the main relay 30 is not normally executed.

That is, for example, when the on-holding signal is output from the microcomputer 12 to the OR circuit 15 but the on-holding signal cannot be transmitted due to a disconnection between the microcomputer 12 and the OR circuit 15, or the on-holding signal is turned on from the microcomputer 12. In any case, such as when the holding signal is not output, it causes an off-fixed state.

In this embodiment, when the ignition switch 20 is turned on from the off state at time t0 in the same manner as described above, an on signal is input to the OR circuit 15, thereby driving the relay switching element 16 on. A predetermined drive power is supplied to the microcomputer 12, and the microcomputer 12 is activated.

In the normal startup state, the microcomputer 12 tries to output the on-holding signal to the OR circuit 15, but here, the on-holding signal is not input to the OR circuit 15 due to a failure of the off-fixing abnormality. In this state, the relay switching element 16 is held in the ON state by the ON signal of the ignition switch 20. The microcomputer 12 sets the timer threshold value Pth in the soak timer 13 and periodically outputs a reset signal so as not to output a wakeup signal. When the state of the IG off experience flag stored in the memory 12a is the set state, the microcomputer 12 rewrites it to the reset state.

Next, when the ignition switch 20 is turned off at time t1, the ON signal of the OR circuit 15 is stopped, and at this time, the ON holding signal from the microcomputer 12 is invalid, so that the relay switching element 16 is in the OFF state. Changes to. As a result, the operating power of the microcomputer 12 is not supplied until time t2, the operation cannot be continued, the operation is terminated, and the IG off experience flag is reset (R) in response to the ignition switch 20 being turned off. It is kept as it is.

Further, since the operation of the microcomputer 12 is stopped, the soak timer 13 is not reset, and the value of the timer count value P is continuously increased. As a result, when the timer count value P of the soak timer 13 reaches the timer threshold value Pth at time t3a after a lapse of time, the soak timer 13 outputs a wakeup signal to the OR circuit 15 for a predetermined time.

As a result, the relay switching element 16 is driven on, the main relay 30 is turned on, and power is supplied to the power supply circuit 11. The microcomputer 12 is put into a wake-up state by being activated by being supplied with power from the power supply circuit 11 based on the wake-up signal regardless of the on operation of the ignition switch 20.

At the time of wake-up, the microcomputer 12 executes a diagnostic process of whether or not the main relay holding control is normally executed at time t4. In this diagnostic process, when the microcomputer 12 reads the state of the IG off experience flag from the memory 12a and recognizes that it is in the reset (R) state, the main relay holding control is normally performed when the microcomputer 12 stops operating. When it recognizes that it is in the off-fixed state that has not been performed, it is determined that the diagnosis result is abnormal.

After that, the microcomputer 12 performs an end operation and stops until the wake-up signal is turned off at time t5. During this wake-up operation period, the microcomputer 12 does not output a reset signal to the soak timer 13, but the timer count value P does not reach even if the timer operation continues. The timer operation is disabled by setting a large timer threshold.

After that, when the ignition switch 20 is turned on from the off state at time t6, an on signal is input to the OR circuit 15, whereby the relay switching element 16 is driven on. As a result, a predetermined drive power source is supplied to the microcomputer 12 in the same manner as described above, and the microcomputer 12 is put into a normal startup state.

As described above, in the state where the main relay holding control is not normally executed, the microcomputer 12 executes a diagnostic process at the time of wake-up by the soak timer 13 with the ignition switch 20 off, and assumes that this is an abnormal state. Can be diagnosed.

(3) When a momentary interruption occurs in the normal state Next, in the normal state, when the ignition switch 20 is in the ON state, the voltage of the in-vehicle battery suddenly drops and the microcomputer 12 stops operating. The case where the state occurs will be described with reference to FIG.

In this case, as shown in FIG. 2, the operation from the time t0 to the time t6 is operating normally, and the voltage of the vehicle-mounted battery is reached after the ignition switch 20 is turned on again at the time t6. The operation when the voltage is lowered and a momentary interruption state occurs will be described.

The above-mentioned momentary interruption corresponds to, for example, a case where an in-vehicle battery as a power source is used as another load of a vehicle for starting an engine or the like. When a large current flows due to engine cranking or the like and the voltage of the vehicle-mounted battery drops sharply temporarily at time t8, the voltage falls below the operating lower limit voltage of the microcomputer 12. In this case, the microcomputer 12 is automatically reset, and when the voltage of the vehicle-mounted battery is restored at time t9, the power is supplied again and the microcomputer 12 is restarted.

In this state, since the period during which the voltage of the vehicle-mounted battery drops is short, the timer count value P of the soak timer 13 does not reach the timer threshold value Pth, and the microcomputer 12 does not start due to the wake-up signal. Therefore, since the microcomputer 12 is not in the wake-up operation by the soak timer 13 but in the normal startup state, the IG off experience flag stored in the memory 12a at this time is in the reset state, but it is not a condition for performing the diagnostic operation. Therefore, the initial operation in the normal startup state is executed.

As a result, when the microcomputer 12 is restored after being reset due to a momentary interruption, the microcomputer 12 performs the same processing as at the time of normal startup, so that a diagnosis may be erroneously performed or the IG off experience flag may be reset. It is possible to eliminate the erroneous determination that the holding control of the main relay is in an abnormal state based on the fact that the main relay is in an abnormal state.

According to this embodiment, the soak timer 13 is provided so that the timer count operation is always performed regardless of whether the ignition switch 20 is on or off, and when the ignition switch 20 is off, the IG off experience flag is set during the main relay holding control. It was set and stored in the memory 12a.

As a result, when the microcomputer 12 wakes up when a wakeup signal is output from the soak timer 13 after the ignition switch 20 is turned off, a diagnostic process for determining the state of the main relay holding control is executed. Therefore, the ignition is executed. When a momentary interruption occurs when the switch 20 is on, it is possible to suppress the execution of the diagnostic process and prevent the occurrence of a misdiagnosis.

Further, the soak timer 13 is used to set the state in which the counting operation is constantly performed, a reset signal is periodically given when the microcomputer 12 is in the activated state, and the timer count value P becomes the timer threshold value Pth after the microcomputer 12 is stopped. When the signal is reached, a wake-up signal is output to wake up the microcomputer 12, so that the wake-up can be performed regardless of the state of the microcomputer 12.

(Second Embodiment)
5 to 10 show the second embodiment, and the parts different from the first embodiment will be described below. In this embodiment, an example is shown in which the soak timer 13 is also used for other purposes. Here, for example, in addition to the diagnosis of the off-fixed failure of the main relay performed in the first embodiment, the soak timer 13 is also used in the case of performing the evapolite diagnosis when the engine is stopped.

As shown in FIG. 5, the EVA polite diagnosis is to check whether or not there is a hole in the fuel tank 100. Since the diagnosis is performed by using the pressure in the fuel tank 100, the diagnosis is made after the fuel tank 100 has cooled sufficiently. Need to be done. Therefore, the diagnosis is performed, for example, 5 hours after the ignition switch 20 is turned off. In order to realize this, the soak timer 13 that executes the above-mentioned diagnosis is used.

In the process of diagnosing the off-fixed state of the main relay holding control signal shown in the first embodiment, the diagnosis can be made without a long time after the ignition switch 20 is turned off. For this reason, there is a concern that the frequency of diagnosis will be reduced if a method of diagnosing at the time of wake-up for evapolitic diagnosis is adopted.

FIG. 5 shows the configuration of an evaporator diagnostic system provided for the fuel tank 100 and the intake device 110 connected to the engine. The evapolite diagnostic system includes a canister 120 as a suction means, a check module 130, an ECU 10 having a microcomputer 12 shown in the first embodiment, and the like. In the fuel tank 100 for storing fuel, an evaporator generated by evaporation of fuel exists in the internal space.

The canister 120 has an adsorbent inside and adsorbs the evaporator, which is the evaporated fuel generated in the fuel tank 100. In the canister 120, the purge passage 112 is connected to the intake pipe 111 of the intake device 110. The intake pipe 111 is provided with a throttle valve 113 for adjusting the intake flow rate flowing inside. A purge valve 114 is provided in the purge passage 112. When the purge valve 114 is opened while the intake pipe 110 is flowing the intake air, a negative pressure is generated in the purge passage 112, and the evaporator adsorbed by the adsorbent of the canister 120 is purged to the intake pipe 111.

The check module 130 includes a switching valve 140, a vacuum pump 150, a pressure sensor 160, and the like. The switching valve 140 switches the connection of the pipes by energizing the coil 142 and moving the valve body 141 provided in the valve chamber by magnetic attraction. One opening of the valve chamber of the switching valve 140 is connected to the canister 120 via the tank passage 143a, and the canister 120 is connected to the fuel tank 100 by the tank passage 143b.

The other two openings provided in the valve chamber of the switching valve 140 are provided so that the air can pass through the open passage 144, and the other opening is connected to the vacuum pump 150 via the pump passage 145. A filter and a check valve are provided in the middle of the pump passage 145. The discharge side of the vacuum pump 150 communicates with the atmosphere through a filter.

An orifice passage 146 is connected between the middle portion of the tank passage 143a and the middle portion of the pump passage 145. The orifice passage 146 is provided with an orifice 147 and a filter. The orifice 147 corresponds to the size of the opening to which the eva polyke is allowed. Further, the pressure sensor 160 described above is provided so as to detect the pressure in the orifice passage 146.

As shown in FIG. 5, the switching valve 140 closes the pump passage 145 side and connects the tank passage 142a to the open passage 144 in the off state in which the coil 142 is not energized. As a result, the orifice passage 147 is in a state of communicating with the atmosphere, and in this state, the pressure sensor 160 is connected to the passage shown by the thick solid line in the figure, and the atmospheric pressure can be measured.

On the other hand, in the ON state in which the coil 142 is energized, the switching valve 140 closes the open passage 144 and connects the tank passage 142a to the pump passage 145, as shown in FIG. As a result, the vacuum pump 150 can be driven to suck the canister 130 and the fuel tank 100 side into a vacuum. In this state, the pressure sensor 160 is in a state where it can measure the pressure of the path to the fuel tank 100, which has been decompressed through the passage indicated by the thick solid line in the figure.

The microcomputer 12 performs the evacuation diagnosis by controlling the energization of the switching valve 140 to the coil 142, controlling the drive of the vacuum pump 150, and taking in the detection signal of the pressure sensor 160.

In the evacuation pork diagnosis, the microcomputer 12 has five detection periods [1] to [5] shown in FIG. 10 from the detection results of the pressure sensor 160 at that time according to the state by the drive control of the switching valve 130 and the vacuum pump 150. ], The change state of the detected pressure can be obtained. The microcomputer 12 diagnoses the abnormal state of the fuel tank 100 from the changed state of the detected pressure.

When the evapolite diagnosis is started, the microcomputer 12 first sets the switching valve 140 to the off state and detects the atmospheric pressure by the pressure sensor 160 as shown in FIG. 5 as the detection period [1]. At this time, the microcomputer 12 calculates the altitude at the current position of the vehicle from the detected atmospheric pressure, and determines whether or not it is within the predetermined range. As a result, the correction parameters are acquired from the pre-stored data so that the eva polyke diagnosis can be performed under the conditions corresponding to the altitude.

Next, the microcomputer 12 shifts to the detection period [2] for confirming the occurrence status of the evaporator in the fuel tank 100. Here, the microcomputer 12 drives the switching valve 140 on so that the pressure in the fuel tank 100 can be detected by the pressure sensor 160 as the pipe connection state as shown in FIG. In this state, the microcomputer 12 measures the pressure of the evaporator in the fuel tank 100 by detecting the pressure with the pressure sensor 160. Due to the generation of evaporation, the inside of the fuel tank 100 rises slightly above the atmospheric pressure.

Next, the microcomputer 12 shifts to the detection period [3]. In order to detect the reference pressure for evapolite diagnosis, the microcomputer 12 turns off the switching valve 140, returns it to the pipe connection state shown in FIG. 5, drives the vacuum pump 150, sucks the inside of the pump passage 145, and reduces the pressure. At this time, since the mixed gas and the air in the open passage 144 flow in through the orifice 147 provided in the orifice passage 146 communicating with the pump passage 145a, the pressure detected by the pressure sensor 160 does not reach the vacuum level and is a predetermined pressure. It will be in a lowered state. The microcomputer 12 stores the pressure detected by the pressure sensor 160 at this time as a reference pressure Pref for evapolite diagnosis.

Next, the microcomputer 12 shifts to the detection period [4] of the evacuation diagnosis, drives the switching valve 140 on, and turns on the vacuum pump 150 as the pipe connection state shown in FIG. As a result, the pressure is once returned to the pressure in the fuel tank 100 by being connected to the tank passage 143a, so that the pump passage 145 approaches the atmospheric pressure, and the pressure detected by the pressure sensor 160 also approaches the atmospheric pressure. Ascend to.

After that, the pressure is gradually reduced by reducing the pressure in the passage connected to the fuel tank 100. At this time, if there is no leak in the fuel tank 100 and the passage connected to the fuel tank 100, the pressure decreases as shown by the thick solid line in FIG. 10, so that the pressure is lower than the reference pressure Pref.

On the other hand, as shown by the broken line in FIG. 10, when the detected pressure of the pressure sensor 160 does not drop to the reference pressure Pref, the microcomputer 12 determines that the evaporative from the fuel tank 100 is excessive. In this case, it is considered that air has entered from the outside due to the decompression inside the fuel tank 100, and when the evaporator is generated in the fuel tank 100, it is considered that the air is discharged to the outside.

As shown by the middle dotted line in FIG. 10, when the pressure inside the fuel tank 100 is substantially the same as the reference pressure Pref, it is estimated that the fuel tank 100 has a crack or the like corresponding to the orifice 147. ..

When the above-mentioned evacuation diagnosis is completed, the microcomputer 12 shifts to the detection period [5] in FIG. 10, turns off the vacuum pump 150, and turns off the switching valve 140. As a result, the pressure in the pump passage 146 is restored to atmospheric pressure as shown in FIG. After that, the microcomputer 12 stops the operation of the pressure sensor 160.
Next, the function of the soak timer 13 in the above configuration will be described with reference to FIGS. 7 to 9.

In the present embodiment, as in the first embodiment, when the ignition switch 20 is turned off, the microcomputer 12 wakes up based on the wakeup signal from the soak timer 13, and the main relay holding control is performed. Executes the diagnostic process of whether or not it is. In FIG. 9, the operation is from time t0 to time t5.

In this case, as shown in FIG. 7, the microcomputer 12 is set in step S100 with respect to the soak timer 13 at the time t0 (FIG. 9) when the ignition switch 20 is turned on, as shown in FIG. The timer threshold value Pth1 for executing the main relay holding control is set.

The timer threshold value Pth1 at this time is set to output a wakeup signal when, for example, about 1 second has elapsed after the ignition switch 20 is turned off and the microcomputer 12 is turned off. Subsequently, the microcomputer 12 sets the value of the wakeup counter WUC to zero in step S110.

As a result, regarding the diagnostic processing of the main relay holding control as described above, when the timer count value P of the soak timer 13 reaches the set timer threshold value Pth1 at time t3 in FIG. 9, the microcomputer 12 is in the wake-up state. Can be implemented. At this time, the microcomputer performs the wake-up process shown in FIG.

In step S200, the microcomputer 12 sets an unreachable value as a timer threshold value for the soak timer 13. This is to prevent a new wake-up signal from being output after resetting the soak timer 13 in the wake-up state.

Next, the microcomputer 12 adds "1" to the value of the wakeup counter WUC in step S210. As a result, the value of the wakeup counter WUC becomes "1". When the microcomputer 12 proceeds to step S220, it determines whether or not the value of the wakeup counter WUC is “1”. Here, since YES, the microcomputer 12 proceeds to step S230 and executes the diagnostic process of the main relay holding control at time t4 (FIG. 9).

When the diagnosis process is completed at time t5, the microcomputer 12 proceeds to step S240, sets the timer threshold value Pth2 for performing the evaporative diagnosis on the soak timer 13, and ends the wake-up process. After that, during the period until the wake-up signal is output from the soak timer 13, the microcomputer 12 is in a stopped state when the ignition switch 20 is not turned on.

The timer threshold value Pth2 described above is set to output a wake-up signal when, for example, about 5 hours have elapsed after the ignition switch 20 is turned off and the microcomputer 12 is turned off. This is because the pressure inside the fuel tank 100 is used in the evapolique diagnosis, so it is necessary to perform the diagnosis after the fuel tank has cooled sufficiently.

Then, when the timer count value P of the soak timer 13 reaches the timer threshold value Pth2 at the time t6 in FIG. 9 and the wakeup signal is output, the microcomputer 12 wakes up, and the wakeup time also shown in FIG. Execute the process.

In step S200, the microcomputer 12 sets an unreachable value as a timer threshold value for the soak timer 13, and in a subsequent step S210, adds "1" to the value of the wakeup counter WUC. As a result, the value of the wakeup counter WUC becomes "2". When the microcomputer 12 proceeds to step S220, it determines whether or not the value of the wakeup counter WUC is “1”. Here, since the result is NO, the microcomputer 12 proceeds to step S250 and executes the above-mentioned evacuation diagnosis at time t7.

When the evapolite diagnosis process is completed, the microcomputer 12 also ends the wake-up process, executes the stop process, and shifts to the stopped state at time t8. After that, the microcomputer 12 is started when the ignition switch 20 is turned on, for example, at time t9. When the microcomputer 12 is started by turning on the ignition switch 20, the microcomputer 12 returns to the state of executing the process at the time of turning on the ignition switch shown in FIG. 7 in the same manner as described above.

According to the second embodiment as described above, since the wake-up operation by the soak timer 13 can be performed in two stages, the microcomputer 12 executes the diagnosis of the off-fixed failure of the main relay holding control, and also diagnoses the evacuation. It is possible to execute the process at the same time. In other words, if there is a configuration in which the soak timer 13 is used in advance to execute the evapolite diagnosis process, the soak timer 13 can also be used to execute the diagnosis of the main relay holding control.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof. For example, the present invention can be modified or extended as follows.
As the timer circuit, a timer circuit other than the soak timer can also be used.

The reset timing of the IG off experience flag may be uniformly performed when the ignition switch 20 is turned on. Further, when the diagnostic process of the main relay holding control is executed, it may be reset at that time, and when it is not executed, it may be reset when the ignition switch 20 is turned on and started.

Although the present disclosure has been described in accordance with the examples, it is understood that the present disclosure is not limited to the examples and structures. The present disclosure also includes various modifications and modifications within a uniform range. In addition, various combinations and forms, as well as other combinations and forms that include only one element, more, or less, are also within the scope of the present disclosure.

In the drawing, 10 is a power supply control device, 11 is a power supply circuit, 12 is a microcomputer (control circuit), 13 is a soak timer (timer circuit), 14 is a drive circuit, 15 is an OR circuit, 16 is a relay switching element, and 20 is an ignition. A switch, 30 is a main relay, 100 is a fuel tank, 110 is an intake device, 120 is a canister, 130 is a check module, 140 is a switching valve, 150 is a vacuum pump, and 160 is a pressure sensor.

Claims (4)

An electronic control device having a control circuit (12) for driving a main relay in an on state when the ignition switch of a vehicle is on and supplying power from an in-vehicle battery via the main relay.
A drive circuit (14) that drives the main relay when any of the ignition switch on signal, wake-up signal, and on-hold signal is given.
A power supply circuit (11) that generates a backup power supply from the vehicle-mounted battery and generates a predetermined voltage when power is supplied from the vehicle-mounted battery via the main relay to supply power to the control circuit.
A timer circuit that executes a timer operation that counts up based on the backup power supply after the power supply is stopped by the power supply circuit, and outputs the wakeup signal to the drive circuit when the timer count value reaches the set timer threshold value. 13) and
The control circuit
It has a non-volatile storage unit (12a) that stores the set state or reset state of the off flag.
When the ignition switch is turned on, the main relay is turned on and wakes up when power is supplied from the power supply circuit. At this point, when the off flag is set, the switch is switched to the reset state and the timer circuit is switched to the reset state. Outputs a reset signal at predetermined time intervals
When the ignition switch is turned off, the off flag is set, and the on-holding signal is output to the drive circuit for a certain period of time.
A vehicle control device that determines execution of diagnostic processing when the ignition switch is in the off state and wakes up based on the wakeup signal, and when the ignition switch is in the set state with reference to the off flag. The vehicle control device according to claim 1, wherein the timer threshold value is set longer than a period in which the voltage of the vehicle-mounted battery temporarily drops due to power supply to another load. The timer circuit is configured to receive power through the backup power supply, execute the timer operation in the power supply state, and reset the timer count value by a reset signal given from the control circuit.
The vehicle control device according to claim 1, wherein the time interval of the reset signal given to the timer circuit of the control circuit is set shorter than the timer threshold value of the timer circuit. The control circuit is provided in the storage unit so as to store the number of wakeups.
When the ignition switch is in the off state and wakes up based on the wakeup signal, the diagnosis is made according to the number of wakeups stored in the storage unit when the ignition switch is in the set state with reference to the off flag. The vehicle control device according to any one of claims 1 to 3, which determines whether to execute a process or another process.

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