JP2007023779A - Fuel vapor processing control device for idle stop vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel vapor processing control device of an idle stop vehicle capable of efficiently increasing a purge flow rate. <P>SOLUTION: This fuel vapor processing control device has an idle stop device 19 automatically stopping an engine 1 when a predetermined idle stop condition is realized and a fuel vapor processing system 8 purging fuel vapor gas generated in a fuel tank 5 to an intake passage 2 of the engine 1 by temporarily adsorbing the fuel vapor gas to a canister 10. Idle stop time T up to restarting from an idle stop of the engine 1 is measured, and purge introduction prohibiting time (t) after restarting the engine is shortened in response to shortness of this idle stop time T. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel vapor processing control device for an idle stop vehicle.

  In general, since the fuel vapor gas generated from the fuel tank causes air pollution, the vehicle is provided with a fuel vapor processing control device for preventing the fuel vapor gas from being discharged into the atmosphere. In this type of fuel vapor processing control device, the fuel tank and the engine intake system are connected by a purge line equipped with a canister, and the fuel vapor gas generated in the fuel tank is adsorbed by the activated carbon in the canister, The fuel vapor gas in the activated carbon is purged into the engine intake system in accordance with the intake negative pressure and burned with fresh air.

  Such a conventional fuel vapor processing control device is disclosed in Patent Document 1, for example.

JP-A-7-301158

  Generally, when purging the fuel vapor gas adsorbed in the canister, the purge is not performed until a predetermined period after the engine is started, that is, until the warm-up is completed. This is because the engine immediately after start-up is in a cold state, the fuel is difficult to vaporize and the combustion is likely to become unstable, and further purging the fuel vapor gas in such a state is an air-fuel ratio. This makes it difficult to properly control the engine and hinders smooth engine operation.

  In recent years, in order to improve fuel economy and reduce exhaust gas emissions, the engine is automatically stopped when the vehicle is idling after stopping at a signal after starting the engine, and the engine is automatically started when the vehicle restarts. Stop vehicles are in practical use. That is, in such an idle stop vehicle having a high restart frequency and a short stop period, if the purge of the fuel vapor gas is prohibited during a predetermined period after the restart, the vehicle is idle stopped within the predetermined period. Therefore, there is a possibility that the purge is not performed and the purge flow rate cannot be obtained sufficiently.

  On the other hand, in the conventional fuel vapor processing control device described above, the time from the stop of the engine to the start is measured, and if the measured elapsed time is shorter than a predetermined value, the fuel vapor adsorbed on the canister Judging that the amount of gas is small, the rising rate of the purge rate after starting the engine is set large. However, even when such a conventional fuel vapor processing control device control method is applied to an idle stop vehicle, the purge flow rate is reduced for a system with a short engine stop time and a high restart frequency such as an idle stop vehicle. It is difficult to get enough and there is room for improvement.

  Accordingly, an object of the present invention is to provide a fuel vapor processing control device for an idle stop vehicle that can efficiently increase the purge flow rate.

A fuel vapor treatment control device for an idle stop vehicle according to a first aspect of the present invention for solving the above-described problem is provided.
An idle stop device that automatically stops the engine when a predetermined idle stop condition is satisfied;
A fuel vapor processing device that temporarily adsorbs the fuel vapor gas generated in the fuel tank to the adsorption means and purges the fuel vapor gas adsorbed by the adsorption means to the intake system of the engine;
A start-time purge prohibiting means for prohibiting purging of the fuel vapor processing device for a predetermined period after the engine is started;
Time measuring means for measuring an elapsed time from idle stop to restart of the engine;
And a start-up purge prohibition adjusting means for shortening the predetermined period according to the shortness of the elapsed time.

A fuel vapor processing control device for an idle stop vehicle according to a second invention that solves the above-described problem,
In the fuel vapor processing control apparatus for an idle stop vehicle according to the first invention,
The start time purge prohibition adjusting means sets the predetermined period to zero when the elapsed time is shorter than a specified time.

  According to the fuel vapor processing control apparatus for an idle stop vehicle according to the first aspect of the invention, an idle stop device that automatically stops the engine when a predetermined idle stop condition is satisfied, and a fuel vapor gas generated in the fuel tank are temporarily adsorbed. A fuel vapor processing apparatus that purges the fuel vapor gas adsorbed to the adsorption means into the intake system of the engine and a purge prohibition at start-up that prohibits the purge of the fuel vapor processing apparatus for a predetermined period after the engine is started Means for measuring an elapsed time from idle stop to restart of the engine, and a start-time purge prohibition adjusting means for shortening the predetermined period according to a shortness of the elapsed time. When the stop time is short, purge can be introduced early after engine startup, so the purge flow rate is efficient. It can be increased to.

  According to the fuel vapor processing control apparatus for an idle stop vehicle according to a second aspect of the present invention, in the fuel vapor processing control apparatus for an idle stop vehicle according to the first aspect of the invention, the start-time purge prohibition adjusting means defines the elapsed time. If the idling stop time is shorter than the specified time by setting the predetermined period to zero when the time is shorter than the specified time, the purge can be introduced very early after the engine is started. Can be increased.

  Hereinafter, a fuel vapor processing control device for an idle stop vehicle according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a fuel vapor processing control device for an idle stop vehicle according to an embodiment of the present invention, FIG. 2 is a flowchart showing a purge introduction control routine, and FIG. 3 is a diagram showing an idle stop time and a purge introduction prohibition time. FIG. 4 is a diagram showing the relationship between the travel time and the vehicle speed or the purge flow rate of the integrated fuel vapor gas.

  As shown in FIG. 1, for example, an intake pipe injection type in-line four-cylinder gasoline engine is applied to the engine 1. A fuel injection valve 3 is provided for each cylinder in the intake passage 2 of the engine 1, and each fuel injection valve 3 is connected to a fuel tank 5 via a fuel line 4. In addition, a fuel pump 6 is provided in the fuel line 4. During operation of the engine 1, the fuel in the fuel tank 5 is pumped up by the electric fuel pump 6 and adjusted to a predetermined pressure by a regulator (not shown). It is supplied to the fuel injection valve 3 via the fuel line 4 later.

  Further, a fuel vapor processing device 8 is connected to the fuel tank 5, and the fuel vapor processing device 8 includes a first purge line 9, a canister 10, a second purge line 11, a bend line 12, and a purge solenoid. 13 and bend solenoid 14. That is, the fuel tank 5 is connected to the canister (adsorption means) 9 filled with activated carbon via the first purge line 9, and the canister 10 is connected to the intake path 2 via the second purge line 11. At the same time, it is open to the atmosphere via the vent pipe line 11. A purge solenoid 13 is provided in the second purge line 11, and the inside of the canister 10 is communicated with or cut off from the intake passage 2 according to the opening and closing of the purge solenoid 13. On the other hand, a bend solenoid 14 is provided in the bend pipe line 12, and the inside of the canister 10 is communicated with or cut off from the atmosphere according to the opening and closing of the bend solenoid 14.

  That is, the purge solenoid 13 is closed and the bend solenoid 14 is opened, so that it is cut off from the intake negative pressure of the engine 1 and is released to the atmosphere, so that the fuel vapor gas generated from the fuel tank 5 is removed from the canister. 10 can be adsorbed. On the other hand, when the purge solenoid 13 is opened and the bend solenoid 14 is opened, the intake negative pressure of the engine 1 is applied to the canister 10, so that the fuel vapor gas adsorbed by the canister 10 enters the intake passage 2. Can be purged.

  The intake air introduced from the air cleaner (not shown) into the intake passage 2 is adjusted in flow rate by the throttle valve 15 and then injected with the fuel injected from the fuel injection valve 3 or with the fuel injected from the fuel injection valve 3 and the second. It is mixed with a fuel mixture with fuel vapor gas purged from the purge line 11 and introduced into the combustion chamber 16 as an air-fuel mixture when an intake valve (not shown) is opened. Thereafter, the ignition plug 17 is ignited at a predetermined timing, and the exhaust gas after combustion is discharged from the combustion chamber 16 into the exhaust passage 18 and is discharged to the outside through a catalyst, a silencer, etc. (not shown).

  An idle stop device 19 is provided on the side of the engine 1, and the idle stop device 19 includes a starter generator 20, a pulley 21, a water pump pulley 22, an idler pulley 23, a crank pulley 24, and a belt 25. Has been. The starter generator 20 integrates the starter (motor) function and the generator (alternator or generator) function of the engine 1. The pulley 21 of the starter generator 20 includes a water pump pulley 22, an idler pulley 23, and the engine 1. The crank pulley 24 is connected by a belt 25.

  That is, when the starter generator 20 is operated as a starter, electric power charged in a vehicle battery (not shown) is supplied to the starter generator 2 to drive the starter generator 2 and transmit the driving force via the belt 25. Thus, the engine 1 can be started. On the other hand, when the starter generator 20 is operated as a generator, the starter generator 20 is driven by transmitting the driving force of the engine 1 via the belt 25 during engine operation, and power is generated by driving the starter generator 20. Electric power can be supplied to the in-vehicle battery.

  Further, the vehicle interior includes an input / output device (not shown), a storage device (ROM, RAM, BURAM, etc.) used for storing control programs and control maps, a central processing unit (CPU), a timer counter, etc. (Start-up purge prohibiting means, timing means, start-up purge prohibition adjusting means) 24 is provided. On the input side of the ECU 26, a vehicle speed sensor 27 for detecting a vehicle speed, a brake sensor 28 for detecting a brake operation state by a driver, an accelerator sensor 29 for detecting an accelerator operation amount, and a shift for detecting a shift position of a transmission (not shown). A position sensor 30 is connected. Further, the combustion injection valve 3, the fuel pump 6, the purge solenoid 13, the bend solenoid 14, and the spark plug 17 are connected to the output side of the ECU 26.

  Therefore, the ECU 26 can execute various controls for operating the engine 1 including fuel injection control and ignition timing control based on each detection information described above. In addition, while the vehicle is stopped due to traffic light or traffic jams, idle stop control is performed to automatically stop the engine 1 temporarily to improve fuel efficiency and reduce exhaust gas. After restarting the engine, restart the engine. The fuel vapor gas adsorbed by the canister 10 is purged based on the elapsed time until later, and the purge flow rate is controlled to increase efficiently.

  Then, the purge introduction process at the time of engine restart after the idle stop in the ECU 26 will be described with reference to FIGS.

  As shown in FIG. 2, it is determined in step S1 whether or not an idle stop condition is satisfied. Here, the idle stop condition in this embodiment is that the vehicle speed detected by the vehicle speed sensor 27 is 0 km / h, that the brake depressing operation is detected by the brake switch 26, and that the accelerator sensor 29 detects it. The accelerator operation amount is 0, and the shift position detected by the shift position sensor 30 is set to the D (drive) range. When these conditions are all satisfied, the idle stop condition is It is considered to have been established. Here, if yes, measurement of the idle stop time T is started in step S2, and if no, the process is once ended.

  Next, when the vehicle is idle stopped in step S3, it is determined in step S4 whether an engine restart condition is satisfied. Here, as an engine restart condition in this embodiment, the brake switch 26 is not operated to step on the brake, and the shift position detected by the shift position sensor 30 is set to a travel range such as the D range. Therefore, it is considered that the engine restart condition is satisfied when these conditions are satisfied. If yes, the measurement of the idle stop time T is terminated in step S5, and the measured value Tasg of the idle stop time T (elapsed time) is obtained. On the other hand, if no, the process is once processed.

  In step S6, the measured value Tasg of the idle stop time T is stored in the RAM, and based on the measured value Tasg, a preset value is established which has a relationship between the idle step time T and the purge introduction prohibition time t (predetermined period). The actual purge introduction prohibition time tpc is calculated from the map (see FIG. 3). Here, the relationship between the idle stop time T and the purge introduction prohibition time t in the map shown in FIG. 3 is, for example, when the measured value Tasg is (Tasg = 0 sec), the actual purge introduction prohibition time tpc is (tpc = 0 sec). ) When the measured value Tasg is (0 sec <Tas ≦ 100 sec), the actual purge introduction prohibition time tpc is (tpc = 0 sec), and when the measured value Tasg is (100 sec <Tasg ≦ 200 sec), the actual purge introduction prohibition time When the measured value Tasg is (200 sec <Tas ≦ 300 sec), the actual purge introduction prohibiting time tpc is (tpc = 10 sec), and when the measured value Tasg is (300 sec <Tas ≦ 400 sec). Is the actual purge introduction prohibition time tpc (tpc = 20 sec) and the measured value T sg is (400sec <Tasg ≦ 500sec) actual purge introduced prohibition time tpc in the case of being set to (tpc = 30 sec). When the measured value Tasg is (500 sec <Tasg), the actual purge introduction prohibition time tpc is kept constant (tpc = 30 sec).

  In step S7, the engine 1 is restarted, and in step S8, purging is prohibited during the actual purge introduction prohibition time tpc. Next, purging is started when the actual purge introduction prohibition time tpc has elapsed in step S9. Then, when the purge is started in step S10, the idle stop time T and the purge introduction prohibition time t are reset, and the process is temporarily ended.

  Accordingly, when the vehicle is idle-stopped by performing the purge introduction process as described above, if the idle stop time T is shorter than the specified time (200 sec or less in this embodiment), purging is prohibited as in the prior art. Instead, since the actual purge introduction prohibition time tpc is set to 0 sec and the purge is performed immediately after the engine restart, the purge flow rate can be increased efficiently.

  Further, the lower part of FIG. 4 shows the relationship between the travel time and the vehicle speed, and the upper part shows the purge flow rate of the integrated fuel vapor gas corresponding thereto. The upper solid line I shows the characteristics of the fuel vapor processing control device according to the present invention, the dotted line II shows the characteristics of the conventional fuel vapor processing control device, and the lower solid line shows the respective fuel vapor processing control devices. The traveling state of a vehicle equipped with is shown.

  As shown in FIG. 4, in the conventional fuel vapor processing control apparatus, purging of the fuel vapor gas is prohibited during the purge introduction prohibition time to after the restart, so that it is several times (4 in the figure). The total purge flow rate is only slightly increased when the vehicle is running with repeated idling stops. On the other hand, in the fuel vapor processing control apparatus according to the present invention, by setting the purge introduction prohibition time t to be shorter according to the short idling stop time T, the purge flow rate increases with the running time. The purge flow rate can be increased efficiently.

  In the present embodiment, the relationship between the idle stop time T and the purge introduction prohibition time t is shown in FIG. 3, but the present invention is not limited to this, and the numerical value is appropriately changed depending on the running state. It doesn't matter.

  Therefore, according to the fuel vapor processing control apparatus for an idle stop vehicle according to the present invention, the idle stop device 19 that automatically stops the engine 1 when a predetermined idle stop condition is satisfied, and the fuel vapor gas generated in the fuel tank 5 are temporarily stored. And a fuel vapor processing device 8 that adsorbs to the canister 10 and purges it into the intake passage 2 of the engine 1, measures an idle stop time T from the idle stop to restart of the engine 1, and determines the idle stop time T By setting the purge introduction prohibition time t after the engine restart to be shortened according to the shortness, the purge can be introduced early after the engine start when the idle stop time is short. Can be increased efficiently.

  In addition, when the idle stop time T is shorter than the specified time, the purge introduction prohibiting time t can be set to zero, so that the purge can be introduced early after the engine is started. be able to.

  The present invention can be applied to a vehicle including a fuel vapor processing device that purges fuel vapor gas generated in a fuel tank into an intake system of an engine.

1 is a schematic configuration diagram of a fuel vapor processing control device for an idle stop vehicle according to an embodiment of the present invention. It is a flowchart which shows the control routine of purge introduction. It is an example of the map which showed the relationship between idle stop time and purge introduction prohibition time. It is the figure which showed the relationship between travel time and the purge flow rate of vehicle speed or integrated fuel vapor gas.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Intake passage 3 Fuel injection valve 4 Fuel line 5 Fuel tank 6 Fuel pump 8 Fuel vapor processing apparatus 9 First purge line 10 Canister 11 Second purge line 12 Bend line 13 Purge solenoid 14 Bend solenoid 15 Throttle valve 16 Combustion chamber 17 Spark plug 18 Exhaust passage 19 Idle stop device 20 Starter generator 21 Pulley 22 Water pump pulley 23 Idler pulley 24 Crank pulley 25 Belt 26 ECU
27 Vehicle speed sensor 28 Brake sensor 29 Accelerator sensor 30 Shift position sensor

Claims (2)

An idle stop device that automatically stops the engine when a predetermined idle stop condition is satisfied;
A fuel vapor processing device that temporarily adsorbs the fuel vapor gas generated in the fuel tank to the adsorption means and purges the fuel vapor gas adsorbed by the adsorption means to the intake system of the engine;
A start-time purge prohibiting means for prohibiting purging of the fuel vapor processing device for a predetermined period after the engine is started;
Time measuring means for measuring an elapsed time from idle stop to restart of the engine;
A fuel vapor processing control apparatus for an idling stop vehicle, comprising: a start-time purge prohibition adjusting unit that shortens the predetermined period according to a shortness of the elapsed time. The fuel vapor processing control device for an idle stop vehicle according to claim 1,
The start-up purge prohibition adjusting means sets the predetermined period to zero when the elapsed time is shorter than a specified time.

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