JP2004197638A - Engine control device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain compatibility between restraining of incompatible feeling when a driver has a traveling will and improvement of fuel economy when a driver has no traveling will. <P>SOLUTION: This engine control device includes an automatic stop/restart means 20c adapted to automatically stop an engine when designated automatic stop conditions including the conditions that at least a vehicle is in the state of stopping and that the elapsed time from the restart of the engine is above a designated elapsed time are established, and restart the engine when a designated restart condition is established during the automatic stop of the engine. The engine control device includes: an automatic stop condition setting means 20g for setting the designated elapsed time under the automatic stop condition shorter than that in the traveling range when the variable speed range at the time of stopping the vehicle is non-traveling range. Accordingly, fuel economy in the case of selecting the non-traveling range from which the driver seems to have no traveling will can be improved, and also it is possible to restrain incompatible feeling due to frequent automatic stop and restart in the case of selecting the traveling range from which the driver seems to have a traveling will. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an engine control device for a vehicle, and more particularly to an engine for a vehicle that automatically stops an engine when a predetermined automatic stop condition is satisfied and restarts the engine when a predetermined restart condition is satisfied during automatic engine stop. The present invention relates to a control device.
[0002]
[Prior art]
2. Description of the Related Art In recent years, for the purpose of improving fuel efficiency, etc., an engine control of a vehicle that automatically stops an engine when a predetermined automatic stop condition is satisfied and restarts the engine when a predetermined restart condition is satisfied during the automatic stop of the engine. A device has been proposed.
For example, when the shift lever is in the N or D position, the vehicle speed is zero, the foot brake switch is on, and the accelerator pedal is off, the engine is automatically stopped and the engine is automatically stopped. The engine is restarted when predetermined restart conditions such as depression of an accelerator pedal are satisfied.
In other words, when the above-described automatic stop condition is satisfied, the vehicle is in a stopped state, and it can be determined that the driver has no intention to drive. In such a case, the engine is automatically stopped and When the above-described restart condition is satisfied, the driver is in a state where the driver wants to run the vehicle. In such a case, the automatic stop of the engine is released and the engine is restarted. It is called "idle stop".
[0003]
Also, if the above-mentioned `` idle stop '' is executed during a traffic jam in which the stopping and running of the vehicle are frequently repeated, an automatic stop / restart is executed each time the stopping and running of the vehicle is performed, Give the driver a sense of incongruity.
Therefore, when the elapsed time from the restart is less than a predetermined time, by prohibiting the automatic stop, it is performed to prevent frequent automatic stop / restart during a traffic jam. It is disclosed in Patent Document 1.
[0004]
[Patent Document 1]
JP 2000-18060 A
[Problems to be solved by the invention]
However, in the above-described prior art, when the elapsed time from the restart is less than a predetermined time, the automatic stop is uniformly prohibited without considering the driver's intention, so that the fuel efficiency is improved and the driver's discomfort is suppressed. There is a problem that it is not possible to achieve both.
In other words, even if the elapsed time from the restart is less than the predetermined time and the traffic is estimated to be congested, the traveling range of the transmission is selected as the non-traveling range, and it can be considered that the driver does not originally intend to travel. In this case, even if the automatic stop / restart is repeated frequently within a short period of time, the driver is unlikely to feel uncomfortable. It is desirable to work.
Conversely, if the shift range is selected as the driving range and the driver is deemed to have the will to drive, frequent automatic stop and restart will be performed if the automatic stop / restart is performed frequently. Is desirably suppressed as much as possible.
In this way, if the elapsed time from the restart as the automatic stop condition is set uniformly, it is possible to achieve both the prevention of discomfort when the driver has the will to drive and the improvement of fuel efficiency when the driver does not have the drive intention It cannot be done.
[0006]
The present invention has been made in consideration of the above-described problems, and its object is to achieve both suppression of discomfort when the driver has a willingness to drive and improvement in fuel efficiency when the driver does not have a willingness to drive. An object of the present invention is to provide an engine control device for a vehicle.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides the following as a solution. That is, in the first configuration of the present invention, the preset predetermined automatic stop condition including at least that the vehicle is stopped and the elapsed time from the restart of the engine is equal to or longer than the predetermined elapsed time is satisfied. When the engine is automatically stopped, the engine control device of the vehicle having an automatic stop / restart means for restarting the engine when a preset restart condition is satisfied during the automatic stop of the engine,
Shift range detecting means for detecting a shift range of a transmission mounted on the vehicle;
An automatic stop condition setting means for setting a predetermined elapsed time in the automatic stop condition shorter than when the travel range is detected, when the shift range detected when the vehicle is stopped is detected by the shift range detection means; Are provided.
According to the first configuration of the present invention, when the non-traveling range in which the driver does not intend to travel is selected, the predetermined elapsed time until the start of the automatic stop is set short, and the vehicle is automatically stopped earlier. If the driving range is selected so that the driver is willing to drive, the predetermined time until the start of automatic stop is set longer, and automatic stop and restart are frequently performed. Discomfort associated with the operation can be suppressed.
[0008]
In the second configuration of the present invention, the vehicle further includes a stop time measuring unit that measures an elapsed time from a start of the stop of the vehicle,
The automatic stop condition setting means is configured to determine whether or not a predetermined time has elapsed in the automatic stop condition based on a shift range detected by the shift range detecting means after the stop time measuring means has measured that a predetermined stop time has elapsed. It is configured to set the time.
The switching of the shift range requires a predetermined delay time until the shift is switched to the shift range after the shift by the shift operation. Therefore, when the driver switches the shift range from the running range to the non-running range immediately after the vehicle is stopped, the driver may change the shift range after the vehicle stops. As the shift range immediately detected, the travel range before the change may be detected, and there is a possibility that the shift range indicating the intention of the actual driver may not always be detected.
According to the second configuration of the present invention, since the predetermined elapsed time under the automatic stop condition is set based on the shift range after the measurement that the predetermined time has elapsed, the vehicle stop time is determined after the vehicle stops. The predetermined elapsed time under the automatic stop condition can be set based on the shift range thus set.
[0009]
In the third configuration of the present invention, an automatic stop time measuring means for measuring an automatic stop time by the automatic stop / restart means is provided,
The automatic stop condition setting means, when the last automatic stop time measured by the automatic stop / restart means is equal to or less than a predetermined automatic stop time, a predetermined time in a non-traveling range set by the automatic stop condition setting means. It is configured to correct in the direction of increasing the time.
Even when the non-travel range is selected as the shift range, if the degree of traffic congestion is large, the frequency of repeating the automatic stop and restart increases, which may cause the driver to feel uncomfortable.
According to the third configuration of the present invention, if the previous automatic stop time is short and the degree of congestion can be considered to be large even in the non-travel range, the predetermined elapsed time in the automatic stop condition in the non-travel range is set to be long. Therefore, it is possible to suppress a sense of incongruity due to frequent repetition of automatic stop / restart when the degree of congestion is large.
[0010]
According to the fourth configuration of the present invention, when it is detected that the shift range has been switched from the travel range to the non-travel range when the vehicle is stopped, the elapsed time from the restart at the time of the switch is the non-travel range. When the predetermined elapsed time set corresponding to the time has elapsed, the automatic stop is immediately executed.
Immediately after the vehicle stops, if the driving range remains selected and traffic congestion continues thereafter, the driving range may be switched to the non-driving range.In such a case, when the vehicle is switched to the non-driving range, the driver The predetermined elapsed time under the above automatic stop condition is fixed on the basis of the shift range selected immediately after the vehicle is stopped, although the predetermined elapsed time until the automatic stop can be shortened. If this is done, there is a concern that the automatic stop will not be performed until a predetermined elapsed time set immediately after the vehicle stops.
According to the fourth configuration of the present invention, when the shift range is switched from the traveling range to the non-traveling range when the vehicle is stopped, the predetermined time in the automatic stop / restart means is the elapsed time from the restart at the time of the switching. When the time has passed a predetermined elapsed time in the non-traveling range, the automatic stop is performed immediately. Therefore, even if the shift range is switched from the traveling range to the non-traveling range after the vehicle stops, Automatic stop can be performed immediately.
[0011]
【The invention's effect】
According to the present invention, it is possible to achieve both suppression of discomfort when the driver has a willingness to drive and improvement in fuel efficiency when the driver does not have a willingness to drive.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram of an engine according to the embodiment, and FIG. 2 is a system block diagram according to the embodiment.
In FIG. 1, reference numeral 1 denotes an engine body of a direct injection gasoline engine, and an intake system 2 and an exhaust system 3 are connected to the engine body 1.
The intake system 2 is provided with an air flow meter 4, a throttle valve 5, and an intake control valve 7 for giving a tumble flow or a swirl flow to the air flow flowing into the combustion chamber 6 in order from the upstream side to the downstream side. ing.
Further, the combustion chamber 6 is provided with a fuel injection valve 8 for directly injecting fuel into the combustion chamber 6 and an ignition plug 9.
The fuel is supplied to the fuel injection valve 8 through a fuel supply passage 14 in which a low-pressure fuel pump 11, a filter 12, and a high-pressure fuel pump 13 disposed in a fuel tank 10. Further, the fuel pressure supplied from the low-pressure fuel pump 11 to the high-pressure fuel pump 13 is controlled by a low-pressure regulator 16 provided in a passage connecting a fuel supply passage 14 and a return passage 15 described later to a predetermined fuel pressure (for example, 0). .39 MPa).
The return passage 15 is set to a predetermined target fuel pressure (for example, variably in accordance with the operating state of the engine) by a high-pressure regulator (not shown) as a fuel pressure adjusting means built in the high-pressure fuel pump 13, and is set between 4 and 11 MPa. (Set), and the surplus fuel after the pressure adjustment is returned to the fuel tank 10.
The high-pressure regulator is provided in a fuel passage formed in the high-pressure fuel pump 13, and is configured to change the protruding position with respect to the fuel passage so that the fuel pressure can be changed between a rising side and a lower side. It comprises a valve and a solenoid valve for driving the spool valve.
Further, a relief passage 18 connected to the return passage 15 via a relief valve 17 is connected to the fuel injection valve 8.
The relief valve 17 opens when the pressure of the fuel supplied to the fuel injection valve 8 reaches a relief pressure (for example, 12 MPa) higher than the target fuel pressure by a predetermined pressure, and the relief passage 18 and the return passage 15 are opened. Is configured to relieve surplus fuel into the fuel tank 10 through the fuel tank 10.
Reference numeral 18 denotes a fuel pressure sensor that detects a fuel pressure near the fuel injection valve 8.
In the direct injection gasoline engine according to the present embodiment, at low rotation speed and low load, the air-fuel ratio is set to be leaner than the stoichiometric air-fuel ratio, and stratified combustion (injection of fuel in the compression stroke) is performed. In the region, the air-fuel ratio is set to the stoichiometric air-fuel ratio, and uniform combustion (fuel injection during the intake stroke) is performed.
[0013]
FIG. 2 is a system block diagram according to the present embodiment. A control unit 20 for controlling an engine includes a brake pedal stroke sensor 21 for detecting an operation amount of a brake pedal (not shown) and a vehicle speed sensor 22 for detecting a vehicle speed. An inhibitor switch 23 for detecting a shift position of an automatic transmission (not shown); a parking brake switch 24 for detecting the presence or absence of a brake operation by a parking brake; an air conditioner switch 25 for detecting an operation state of an air conditioner (not shown); , A turn signal switch 27 for detecting an operation state of a turn signal (not shown), a brake negative pressure sensor 28 for detecting a negative pressure of a vacuum booster for brake (not shown), a steering (not shown). Steering angle sensor 29 for detecting the steering angle of the Various detection signals of the engine speed sensor 30 for detecting the number of revolutions and the above-described fuel pressure sensor 19 are input, and a driver 31 for driving the fuel injection valve 8 and an ignition plug 9 are ignited based on the input various detection signals. And an engine control unit 20a for automatically stopping and restarting the engine, and dedicated to an instrument panel (not shown) of the vehicle in synchronization with the start / stop / restart control of the engine. And a display control unit 20b for controlling lighting and extinguishing of three notification lamps 33 to 35 to be described later.
[0014]
When a preset automatic stop condition described later is satisfied, the engine control unit 20a stops fuel injection by the fuel injection valve 8, stops ignition by the spark plug 9, automatically stops the engine, and automatically stops the engine. When a preset restart condition described later is satisfied, an automatic stop / restart means 20c for restarting fuel injection from the fuel injection valve 8, restarting ignition by the ignition plug 9 and restarting the engine. A stop elapsed time measuring means 20d for measuring an elapsed time from the start of the vehicle stop, and a vehicle stop time detected by the stop elapsed time measuring means 20d for a predetermined stop time (equivalent to a shift range change delay time at the time of shifting the shift range. (For example, 0.5 seconds), the shift range when the vehicle is stopped is determined to be the travel range or the non-running range based on the shift range detected after the elapsed time is measured. Shift range detecting means 20e for detecting whether the gear is in the range (N range or P range), automatic stop time measuring means 20f for measuring the previous automatic stop time by the automatic stop / restart means 20c, and shift range detecting means Elapsed after restart of the engine, which is one of the automatic stop conditions in the automatic stop / restart means 20c based on the shift range detected by the automatic stop time 20e and the automatic stop time measured by the automatic stop time measuring means 20f. Automatic stop condition setting means 20g for setting a "predetermined elapsed time" for determining whether the time is equal to or longer than a predetermined elapsed time.
The setting of the "predetermined elapsed time" in the automatic stop condition setting means 20g will be described in detail. When the shift range is the travel range, the longest first predetermined elapsed time (for example, 10 seconds) is set, and the non-travel range is set. If the previous automatic stop time is shorter than the predetermined automatic stop time, a second predetermined time (for example, 7 seconds) shorter than the first predetermined elapsed time is set, and the automatic stop in the non-traveling range and the previous automatic stop time is performed. When the time is longer than the predetermined automatic stop time, the shortest third predetermined time (for example, 5 seconds) is set.
[0015]
When the automatic stop / restart means 20c executes the automatic stop, the display control means 20a provides a notification lamp 33 for notifying that the automatic stop is being performed, and the automatic stop condition setting means 20g provides a display lamp after the restart. When the elapsed time is less than the predetermined elapsed time and the execution of the automatic stop is prohibited, the notification lamp 34 for notifying that the automatic stop is prohibited, and when the automatic stop / restart means 20c restarts, A notification lamp 35 for notifying that the engine has been restarted for a predetermined time from the start of the engine is provided based on a signal from the engine control means 20a.
The notification may be made by using a display screen of the navigation device, or by using a sound other than the lamp, in addition to providing a dedicated lamp on the instrument panel.
[0016]
Here, the automatic stop and restart conditions of the automatic stop / restart means 20c will be described in detail with reference to FIG.
First, as shown in FIG. 3A, the automatic stop condition is as follows: when the brake operation amount is equal to or more than a predetermined value a, the brake is depressed; A substantially flat road surface with a road surface gradient equal to or less than a predetermined value a, a state in which the steering angle is equal to or less than a predetermined angle and substantially no steering is performed, and a deviation between the target temperature and the actual temperature even when the air conditioner is turned off or the air conditioner is turned on. Is less than the predetermined value, the air conditioner is not actually operating, and the engine water temperature is more than the predetermined value and the catalyst is almost warmed up. When the engine is stopped, it is considered that there is no adverse effect such that the vehicle retreats or the air conditioner is turned off against the intention of the occupant even if the engine is stopped, and the automatic stop of the engine is permitted.
[0017]
Next, the restart condition will be described.
As shown in FIG. 3B, the restart condition is such that the brake operation amount becomes substantially zero and the brake is completely released, the state where the vehicle speed is equal to or more than a predetermined value continues for a predetermined time, and the turn signal is turned on from off to on. When the brake negative pressure becomes equal to or less than a predetermined value a (in a state where the brake negative pressure decreases and the braking performance decreases), and if any one of the air conditioner switches is turned on, the driver travels. Or the brake performance or cooling performance is reduced, and the vehicle is forcibly restarted.
[0018]
Next, the automatic stop and restart control according to the present embodiment will be described based on the flowchart of FIG.
In step S1 of FIG. 4, it is determined whether or not the automatic stop has already been executed.
When NO is determined in step S1, the process proceeds to step S2, and a predetermined time after the vehicle stops, for example, 0.5 seconds (equivalent to a shift range change delay time at the time of shifting the shift range) after the vehicle speed becomes zero. Is determined.
When YES is determined in the step S2, that is, when it can be considered that the shift range after the vehicle is stopped is determined, the processes of the steps S3 to S7 are thereafter executed to restart the engine which is one of the automatic stop conditions. A "predetermined elapsed time" is set for determining whether or not the subsequent elapsed time is equal to or longer than the predetermined elapsed time.
First, in step S3, it is determined whether or not the shift range is a non-traveling range (N range or P range).
If NO is determined in step S3, that is, if the driving range is selected and it can be considered that the driver intends to drive, the process proceeds to step S4, and the longest predetermined elapsed time T is set to, for example, 10 seconds. .
If YES is determined in the step S3, the process proceeds to a step S5 to determine whether or not the previous automatic stop time is shorter than the predetermined automatic stop time.
If NO is determined in step S5, that is, if the previous automatic stop time is short and the degree of congestion can be considered to be small in the non-traveling range, the process proceeds to step S6, where the shortest predetermined elapsed time T is, for example, Set 5 seconds.
If YES is determined in step S5, that is, if the previous automatic stop time is short and the degree of congestion can be considered to be large in the non-traveling range, the process proceeds to step S7, and the predetermined time set in step S6 is set. A time longer than the time T, for example, 7 seconds is set.
Subsequently, in step S8, it is determined whether or not the automatic stop condition shown in FIG. 3A has been satisfied. If the determination is YES, the process proceeds to step S9.
In step S9, it is determined whether or not the elapsed time from the restart is equal to or longer than the predetermined elapsed time T set in steps S4, S6, and S7.
When YES is determined in step S9, the process proceeds to step S10, in which the fuel injection by the fuel injection valve 8 is stopped, the ignition by the spark plug 9 is prohibited, the engine is automatically stopped, and the engine is automatically stopped. Is turned on, and the notification lamp 34 for notifying that the automatic stop is prohibited and the notification lamp 35 for notifying the restart are turned off.
In step S12, the counting is started in step S17 described later, and the count of the elapsed time timer for counting the elapsed time from the restart is reset. In step S13, the automatic stop time timer for counting the automatic stop time is reset. Start counting.
If NO is determined in step S9, the process proceeds to step S11, in which the notification lamp 34 for notifying that the automatic stop is prohibited, the notification lamp 33 for notifying that the automatic stop is being performed, and the The notification lamp 35 for notifying the start is turned off.
When YES is determined in step S1, that is, when the automatic stop is already executed, the process proceeds to step S14.
In step S14, it is determined whether or not the restart condition shown in FIG.
When YES is determined in the step S14, the process proceeds to a step S15, in which the fuel injection from the fuel injection valve 8 is restarted, the ignition by the spark plug 9 is restarted, and the engine is restarted. The notification lamp 35 for notifying the fact is turned on for a predetermined time, and the notification lamp 33 for notifying that the automatic stop is being performed and the notification lamp 34 for notifying that the automatic stop is prohibited are turned off.
In the following step S16, the counting of the automatic stop time timer started in step S13 is stopped, and the counter value is stored, and then the counter is reset. Here, this counter value is a value indicating the previous automatic stop time, and is used in the determination in step S5 described above.
In step S17, counting of the above-mentioned elapsed time timer is started.
[0019]
As described above, according to the present embodiment, as shown in the time chart of FIG. 5, when the non-traveling range in which the driver does not intend to travel is selected, the predetermined elapsed time T before the automatic stop starts is selected. Is set to 5 seconds or 7 seconds, which is short, and it is allowed to automatically stop early. Therefore, while improving fuel efficiency, if the driving range that the driver is willing to drive is selected, the automatic The predetermined elapsed time T up to the start of the stop is set to a long 10 seconds, and it is possible to suppress a sense of discomfort due to frequent automatic stop and restart.
Further, the predetermined elapsed time T under the automatic stop condition is set based on the shift range detected after the vehicle stop time has elapsed after the predetermined stop time has elapsed, and therefore, based on the shift range determined after the vehicle stops. The predetermined elapsed time T under the automatic stop condition can be set.
Also, even in the non-running range, if the previous automatic stop time is short and the degree of congestion can be considered to be large, the case where the previous automatic stop time is long and the degree of congestion is considered to be small is set Since the predetermined elapsed time T is set to 7 seconds, which is long, it is possible to suppress a sense of discomfort due to frequent repetition of automatic stop / restart when the degree of congestion is large.
Further, the predetermined elapsed time T in the automatic stop / restart means is set before the automatic stop condition is satisfied (step S8 in FIG. 4), and is always set in accordance with the latest shift range. It is possible to determine whether or not to execute the automatic stop based on a predetermined elapsed time T set corresponding to the latest shift range at the time of the switching, and after the vehicle stops, the shift range changes from the travel range to the non-travel range. Even if it is switched to, automatic stop can be performed immediately.
[0020]
In the present embodiment, an example is shown in which the present invention is applied to a direct injection gasoline engine. However, the present invention may be applied to a port injection gasoline engine that injects fuel into an intake port or a diesel engine.
Further, the automatic stop condition and the restart condition described in the present embodiment are merely examples, and other conditions such as a throttle opening degree may be added or any of the conditions described in the embodiment may be deleted. Can be set.
Further, in the present embodiment, an example has been shown in which the automatic stop can be immediately executed when the driving range is switched from the driving range to the non-driving range by setting the predetermined elapsed time T in correspondence with the latest driving range. Is switched from the traveling range to the non-traveling range, a predetermined elapsed time T set corresponding to the non-traveling range is compared with the time measured up to the time of the switching, and the measured time is When the predetermined elapsed time T set in accordance with the travel range has elapsed, the automatic stop may be immediately executed.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an engine according to an embodiment.
FIG. 2 is a system block diagram according to the embodiment;
FIG. 3 is a table showing automatic stop conditions and restart conditions according to the first embodiment.
FIG. 4 is a control flowchart according to the embodiment.
FIG. 5 is a time chart according to the embodiment;
[Explanation of symbols]
1: In-cylinder gasoline engine body 8: Fuel injection valve 9: Spark plug 13: High pressure fuel pump 17: Relief valve 18: Relief passage 19: Fuel pressure sensor 20: Control unit 20a: Engine control unit 20c: Automatic stop / restart Starting means 20d: stopping time measuring means 20e: shift range detecting means 20f: automatic stopping time measuring means 20g: automatic stopping condition setting means

Claims (4)

The engine is automatically stopped when predetermined preset automatic stop conditions including at least that the vehicle is stopped and the elapsed time from the restart of the engine is equal to or longer than a predetermined elapsed time are satisfied, and the engine is automatically stopped. In an engine control device for a vehicle having automatic stop / restart means for restarting the engine when a preset restart condition is satisfied during
Shift range detecting means for detecting a shift range of a transmission mounted on the vehicle;
An automatic stop condition setting means for setting a predetermined elapsed time in the automatic stop condition shorter than when the travel range is detected, when the shift range detected when the vehicle is stopped is detected by the shift range detection means; An engine control device for a vehicle, comprising: Equipped with stop time measuring means for measuring the elapsed time from the start of vehicle stop,
The automatic stop condition setting means is configured to determine whether or not a predetermined time has elapsed in the automatic stop condition based on a shift range detected by the shift range detecting means after the stop time measuring means has measured that a predetermined stop time has elapsed. The vehicle engine control apparatus according to claim 1, wherein the apparatus is configured to set a time. An automatic stop time measuring means for measuring an automatic stop time by the automatic stop / restart means,
When the previous automatic stop time measured by the automatic stop / restart means is equal to or shorter than a predetermined automatic stop time, the automatic stop condition setting means corrects the predetermined elapsed time in the non-traveling range so as to increase the elapsed time. The vehicle engine control device according to claim 1 or 2, wherein The automatic stop / restart means, when it is detected that the shift range has been switched from the traveling range to the non-traveling range when the vehicle is stopped, the elapsed time from the restart at the time of the switching corresponds to the non-traveling range. The vehicle engine control device according to any one of claims 1 to 3, wherein the automatic stop is immediately executed when a predetermined elapsed time set as a predetermined time has elapsed.

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