KR20020000245A - Method for protecting a shock at returning the fuel cut - Google Patents

Abstract

PURPOSE: A shock preventive method when restoring from fuel cut is provided to prevent a shock phenomenon according to a sudden rise of rotational frequency and to promote driving efficiency by preventing the occurrence of hunting. CONSTITUTION: A shock preventive method when restoring from fuel cut comprises the steps of: starting an engine of a car; deciding whether the car is running or not on the basis of a speed of 2.5 kilometers an hour; if the car runs at over 2.5 kilometers an hour, deciding whether an idler is running or not with an idle switch on and off; if the idle switch is on, deciding to be fuel cut among driving conditions; if the car is in a condition of fuel cut, measuring the quantity of fuel required for restoring; if the quantity of fuel required for restoring is measured, calculating the measured quantity of fuel in a time function and percentage and spraying as much as the appointed quantity of fuel.

Description

METHODS FOR PROTECTING A SHOCK AT RETURNING THE FUEL CUT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of preventing shock when returning a fuel cut, and more particularly, to a method of preventing shock when returning to a fuel cut to prevent the shock generated when the fuel cut is returned after the fuel cut.

The fuel cut is to stop the fuel supply to the engine, that is, to cut off the fuel so that the speed does not increase when the speed rises above a certain speed.

This stops gasoline supply to the main line at the same time as the throttle valve is closed and the intake pressure rises, saving fuel that is not needed in the meantime until the natural supply is stopped and at the same time preventing the catalyst from rising in temperature due to excess HC. .

On the other hand, as described above, when the vehicle is stopped while the vehicle is running, the vehicle with the manual transmission is operated, the fuel cut for reducing fuel consumption is applied, and the fuel is returned at a time according to the engine conditions at that time.

However, since the fuel amount is applied at the time of the fuel cut release, a sudden increase in the rotational speed may be generated, thereby causing shunting and hunting due to a decrease in the actual rotational speed relative to the target rotational speed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a method of preventing a fuel cut upon returning to prevent a phenomenon that occurs due to a sudden increase in the number of revolutions when the fuel cut returns during driving.

1 is a schematic flow chart sequentially illustrating a method of preventing splash upon returning to a fuel cut according to the present invention.

In order to achieve the above object, the method for preventing the fuel cut upon returning the fuel cut includes: (a) starting a vehicle; (b) determining whether the vehicle is driven at a vehicle speed of 2.5 km / h; (c) determining the idle switch on and off based on whether the vehicle is idle when the vehicle speed is determined to be 2.5 km / h in the step (b); (d) in the step (c), in the case where the idle switch is turned on and idling, determining a fuel cut among driving conditions; (e) in step (d), if the driving condition is determined to be a fuel cut, measuring a return fuel amount; (f) in step (d), if the return fuel amount is measured, calculating the measured fuel amount as a function of time and as a percentage to inject a predetermined amount of fuel.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flow chart schematically showing a method for preventing a splash upon returning to a fuel cut according to the present invention.

As shown, in the fuel cut return prevention method according to the present invention, first, the vehicle is started. (Step 10) That is, this logic process proceeds while driving.

Then, it is determined whether the vehicle is driven at a vehicle speed of 2.5 km / h. (Step 20) That is, it is determined whether the vehicle is running at a speed signal of 2.5 km / h or more.

Subsequently, when it is determined in step 20 that the vehicle speed is 2.5 km / h, it is determined whether the idle switch is on or off (driving on or off). Or judges OFF.

In addition, in step 30, if it is determined that the idle switch is turned on and idle driving, the fuel cut of the driving condition is determined.

In step 40, if the operation condition is determined to be fuel cut, the return fuel amount is measured. (Step 50) This is applied only at the fuel cut. The return fuel amount is measured by checking the current engine state of the fuel cut condition (calculation). It is.

Here, the fuel amount is, for example, 4.70 msec. This assumes that, for example, the fuel amount at 1200 rpm and the intake manifold negative pressure 290 mmHg is 4.70 msec.

In this manner, assuming that the fuel amount is 4.70 msec, the fuel return amount in the current system is injected to 4.7 msec.

When the return fuel amount is measured as in step 50, the measured fuel amount is calculated as a function of time and a percentage to inject a predetermined fuel amount.

More specifically, first, the elapsed time after the fuel cut is determined. (Step 61) In this case, when the elapsed time after the fuel cut is determined to be 0.5 s or less, the amount of fuel measured in the step 50 (4.7 msec) is determined. (Step 62) The injection amount is 0.47 msec.

This is injected as a result obtained by multiplying the fuel amount measured in step 50 by 10%. That is, within 0.5 seconds, only 10% of the fuel amount is injected. In other words, adjust the injection time to 10%.

Subsequently, the elapsed time after the fuel cut is determined. (Step 71) At this time, when it is determined that the elapsed time after the fuel cut is 1.0 s or less, only 25% of the fuel amount measured in the step 50 is injected. 72. Accordingly, the injection amount is 1.175 msec.

This is injected as a result of multiplying 25% by the amount of fuel measured in the step 50. That is, within 1.0 second, only 25% of the fuel amount is injected. In other words, the injection time is adjusted to 25%.

Then, the elapsed time after the fuel cut is determined. (Step 81) At this time, if it is determined that the elapsed time after the fuel cut is 1.5 s or less, only 50% of the fuel amount measured in the step 50 is injected. Thus, the injection amount is 2.35 msec.

This is injected as a result of multiplying 50% by the amount of fuel measured in the step 50. That is, within 1.5 seconds, only 50% of the fuel amount is injected. In other words, the injection time is adjusted to 50%.

Next, the elapsed time after the fuel cut is determined. (Step 91) At this time, when it is determined that the elapsed time after the fuel cut is 2.0 s or less, 100% of the fuel amount measured in the step 50 is injected. Thus, the injection amount is 4.70 msec.

This is injected as a result of multiplying the fuel amount measured in step 50 by 100%. That is, within 2.0 seconds, 100% of the fuel amount is injected. In other words, the injection time is 100%.

In this way, the return fuel amount calculated in step 50 is divided for a predetermined time (2s) and then gradually injected. This can be summarized as shown in Table 1 below.

Time (s) 0.5 1.0 1.5 2.0 ratio(%) 10 25 50 100 Fuel amount (msec) 0.47 1.175 2.35 4.7

4.70msec, which is calculated as the return fuel amount, increases the fuel amount, that is, the fuel injection time, according to the elapsed time since the fuel cut, thereby preventing a sudden increase in rotational speed.

On the other hand, in the step 20, 30, or 40, if it is determined that each step is negative of the above, it is to be repeated from the step 20.

As described above, in the fuel cut return prevention method according to the present invention, the fuel cut condition is judged while driving, and the sudden increase in rotation speed is prevented by gradual injection of the return fuel amount over time.

As described above, the method of preventing shock when returning to a fuel cut according to the present invention has the effect of preventing the phenomenon caused by a sudden increase in the number of revolutions when returning after the fuel cut while driving and preventing hunting from occurring, thereby improving operability.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (6)

(a) starting the vehicle; (b) determining whether the vehicle is driven at a vehicle speed of 2.5 km / h; (c) determining the idle switch on and off based on whether the vehicle is idle when the vehicle speed is determined to be 2.5 km / h in the step (b); (d) in the step (c), in the case where the idle switch is turned on and idling, determining a fuel cut among driving conditions; (e) in step (d), if the driving condition is determined to be a fuel cut, measuring a return fuel amount; (f) in step (d), if the return fuel amount is measured, calculating the measured fuel amount as a function of time and as a percentage, and injecting a predetermined amount of fuel. The method of claim 1, wherein in step (b), (c), or (d), If it is determined that each step is negative, it is to be performed again from the step (b) characterized in that the fuel cut back when the prevention method. The method of claim 1, wherein in step (f), If it is determined that the elapsed time since the fuel cut is 0.5 s or less, only 10% of the fuel amount measured in the step (e) is injected. The method of claim 1, wherein in step (f), If it is determined that the elapsed time since the fuel cut is 1.0 s or less, only 25% of the fuel amount measured in the step (e) is injected. The method of claim 1, wherein in step (f), If it is determined that the elapsed time since the fuel cut is 1.5s or less, only 50% of the fuel amount measured in the step (e) is injected. The method of claim 1, wherein in step (f), And when the elapsed time since the fuel cut is determined to be 2.0 s or less, injecting 100% of the fuel amount measured in the step (e).