KR19990028549U - Air-fuel ratio control system according to exhaust gas recirculation amount - Google Patents

Abstract

The present invention relates to an air-fuel ratio control system of a vehicle, in particular, by calculating the fuel injection amount by calculating the EGR amount sucked into the carburetor from the exhaust pipe, the air-fuel ratio according to the exhaust gas recirculation amount to accurately control the injection amount It relates to a control system.

In a conventional vehicle, since the fuel injection amount is corrected by estimating the amount of EGR recycled through the intake pipe from the exhaust pipe, the fuel injection amount injected into the carburetor is not accurate, and thus the air-fuel ratio cannot be accurately controlled.

The present invention calculates the amount of EGR sucked into the carburetor from the exhaust pipe by the basic EGR amount, fuel injection amount and air ratio of the vehicle, and then corrects the fuel injection amount according to the corresponding EGR amount to control the fuel injection amount injected into the carburetor. This optimum air-fuel ratio can be maintained at all times.

Description

Air-fuel ratio control system according to exhaust gas recirculation amount

The present invention relates to an air-fuel ratio control system of a vehicle, in particular, by calculating the fuel injection amount by calculating the EGR amount sucked into the carburetor from the exhaust pipe, the air-fuel ratio according to the exhaust gas recirculation amount to accurately control the injection amount It relates to a control system.

In general, exhaust gas recirculation (EGR) devices draw some of the exhaust gas (up to about 15% of the mixer) from the exhaust pipe below the exhaust manifold and send it back to the intake manifold. Mix with air mixer to get into the combustion chamber. Recirculating the exhaust gas in this way results in a lower filling rate of the new mixer. In addition, the replenished exhaust gas contains a large amount of carbon dioxide gas having a larger heat capacity than nitrogen. In other words, the re-supplied exhaust gas is no longer able to combust, thus lowering the combustion temperature during power administration. When the combustion temperature is lowered, the amount of nitrogen oxides is significantly reduced. However, the amount of hydrocarbons and carbon monoxide in the exhaust gas is not reduced.

On the other hand, the exhaust gas recirculation apparatus is effective as a countermeasure for reducing nitrogen oxides, while the ignition of the mixer is poor and the output of the engine is reduced. And if the EGR rate is not appropriate, the amount of carbon monoxide and hydrocarbons in the exhaust gas increases. For this reason, it is important to select an operating area with a large amount of nitrogen oxide emissions and to recycle the appropriate amount of exhaust gas only in this area.

In addition, the maximum EGR rate is limited by hydrocarbon emissions, fuel consumption rate, engine operation quietness, and the like. Therefore, the exhaust gas is not recycled during idle and turbulent operation. In addition, since it is operated with a rich mixer at all times, the generation of nitrogen oxides is low and the exhaust gas is not recycled because of the basic goal of increasing output.

As shown in FIG. 1, an air-fuel ratio control system of a conventional vehicle includes an EGR valve controller 11 which outputs a control signal for opening and closing the EGR valve 14 according to the throttle valve opening degree, the engine rotation speed, and the coolant temperature; A correction calculation unit 12 which performs calculation for correcting the fuel injection amount supplied to the vaporizer 15 according to the basic fuel injection amount determined in correspondence with the intake air amount and the air ratio from the air ratio sensor, and by the correction calculation unit 12. The fuel injection amount control unit 13 controls the fuel injection duration of the fuel injection device according to the calculated fuel injection amount, and is opened and closed according to the control signal from the purge valve control unit 11, recycled through the intake pipe from the exhaust pipe, and the vaporizer 15. EGR valve 14 which connects or blocks the flow of exhaust gas sucked into the exhaust gas) and the fuel and exhaust pipe injected by the fuel injection device through the intake pipe. And a vaporizer 15 for circulating and inhaling the exhaust gas that is circulated and atomized and mixed with the sucked air. The EGR valve control unit 11 predicts the amount of EGR according to the opening of the throttle valve and the engine rotation speed and the coolant temperature. Outputs a control signal to the EGR valve 14 to allow the corresponding exhaust gas to be sucked into the vaporizer 15 and at the same time, according to the basic fuel injection amount determined in correspondence with the intake air amount and the air ratio from the air ratio sensor, The fuel injection amount injected into the vaporizer 15 is calculated, and the fuel injection duration of the fuel injection device is controlled according to the fuel injection amount calculated by the fuel injection amount control unit 13 so that fuel is injected into the vaporizer 15. Therefore, in the conventional vehicle, the fuel injection amount is corrected by estimating the EGR amount recirculated through the intake pipe from the exhaust pipe and sucked into the vaporizer 15, so that the fuel injection amount injected into the vaporizer 15 is not accurate, so that the air-fuel ratio can be accurately controlled. There was no.

In the conventional vehicle as described above, since the fuel injection amount is corrected by estimating the amount of EGR recycled through the intake pipe from the exhaust pipe, the fuel injection amount injected into the vaporizer 15 is not accurate, and thus the air-fuel ratio cannot be accurately controlled.

The present invention is to solve the problems as described above, the purpose is to calculate the amount of fuel injected into the carburetor from the exhaust pipe by the basic EGR amount, fuel injection amount and air ratio of the vehicle, the fuel injection amount according to the corresponding EGR amount By correcting, the fuel injection amount injected into the carburetor is precisely controlled so that the vehicle can always maintain the optimum air-fuel ratio.

Features of the present invention for achieving the above object, the vaporizer 26 for mixing the inhaled gas atomized by atomizing, atomized by the fuel injected by the fuel injection device and the exhaust gas recycled from the exhaust pipe; An EGR valve 25 which opens and closes according to a control signal, is recycled from the exhaust pipe, and connects or blocks the flow of exhaust gas sucked into the vaporizer 26; An EGR valve controller 21 for outputting a control signal for opening and closing the EGR valve 25 according to the throttle valve opening degree, the engine rotation speed, and the coolant temperature; In the vehicle air-fuel ratio control system provided with a fuel injection amount control unit 24 for controlling the fuel injection duration of the fuel injection device, the basic EGR amount by the EGR valve control unit 21 and the fuel vaporizer by the fuel injection device. An EGR amount calculating section (22) for calculating an actual EGR amount sucked into the vaporizer (26) from an exhaust pipe in accordance with the fuel injection amount injected into the gas 26 and the air ratio from the air ratio sensor; A correction calculation unit 23 for performing calculation for correcting the fuel injection amount supplied to the vaporizer 26 according to the EGR amount calculated by the EGR amount calculation unit 22 and the basic fuel injection amount determined corresponding to the intake air amount. ) Is included.

1 is a configuration block diagram of an air-fuel ratio control system of a conventional vehicle.

2 is a block diagram of an air-fuel ratio control system for a vehicle according to the present invention.

Explanation of symbols on the main parts of the drawings

11, 21: EGR valve control unit 12, 23: correction operation unit

13, 24: fuel injection amount control unit 14, 25: EGR valve

15, 26: carburetor 22: EGR amount calculation unit

Hereinafter, with reference to the accompanying drawings, an embodiment of the present invention in detail as follows.

As shown in FIG. 2, the air-fuel ratio control system for a vehicle according to the present invention includes an EGR valve controller 21 which outputs a control signal for opening and closing the EGR valve 25 according to the throttle valve opening degree, the engine rotation speed, and the coolant temperature. ), The actual EGR sucked into the carburetor 26 from the exhaust pipe according to the basic EGR amount by the corresponding EGR valve control unit 21, the fuel injection amount injected into the vaporizer 26 by the fuel injection device, and the air ratio from the air ratio sensor. The fuel supplied to the carburetor 26 according to the EGR amount calculation part 22 which calculates the quantity, the actual EGR amount computed by the said EGR amount calculation part 22, and the basic fuel injection amount determined corresponding to the intake air amount. A correction calculation unit 23 for performing calculations to correct the injection amount, a fuel injection amount control unit 24 for controlling the fuel injection duration of the fuel injection device in accordance with the fuel injection amount calculated by the correction calculation unit 23, and EG An EGR valve 25 which opens and closes according to a control signal from the R valve control unit 21, is recycled from the exhaust pipe, and connects or blocks the flow of the exhaust gas sucked into the vaporizer 26, and fuel injected by the fuel injection device; And a vaporizer 26 for refining and atomizing the boil-off gas recycled from the exhaust pipe and mixing it with the air sucked in. The EGR valve control unit 21 controls the exhaust gas from the exhaust pipe according to the opening of the throttle valve and the engine rotation speed and the coolant temperature. By estimating the recycled basic EGR amount, the control signal is output to the EGR valve 25 to allow the exhaust gas to be sucked into the vaporizer 26, and the basic EGR amount by the EGR valve control unit 21 and the fuel injection device. Actual E sucked into the carburetor 26 from the exhaust pipe by the EGR amount calculation section 22 according to the fuel injection amount injected into the carburetor 26 by the air and the air ratio from the air ratio sensor. After calculating the GR amount, the fuel supplied to the vaporizer 26 from the correction calculation unit 23 by the actual EGR amount calculated by the corresponding EGR amount calculation unit 22 and the basic fuel injection amount determined corresponding to the intake air amount. The injection amount is calculated and the fuel injection duration of the fuel injection device is controlled according to the fuel injection amount calculated by the fuel injection amount control unit 24 so that fuel is injected into the vaporizer 26. Therefore, the vehicle corrects the fuel injection amount injected into the carburetor 26 by calculating the actual EGR amount sucked into the carburetor 26 from the exhaust pipe, so that the vehicle accurately controls the fuel injection amount injected into the carburetor 26 under all driving conditions. Thus, the air-fuel ratio can be accurately controlled.

As described above, the present invention calculates the amount of EGR sucked into the carburetor 26 from the exhaust pipe by the basic EGR amount, fuel injection amount and air ratio of the vehicle, and then corrects the fuel injection amount according to the corresponding EGR amount to the corresponding carburetor 26. By controlling the fuel injection amount injected into the vehicle, the vehicle can always maintain the optimum air-fuel ratio.

Claims (1)

A vaporizer 26 for refining and atomizing the fuel injected by the fuel injection device and the exhaust gas sucked from the exhaust pipe and mixed with the sucked air; An EGR valve 25 which opens and closes according to a control signal, is recycled from the exhaust pipe, and connects or blocks the flow of exhaust gas sucked into the vaporizer 26; An EGR valve controller 21 for outputting a control signal for opening and closing the EGR valve 25 according to the throttle valve opening degree, the engine rotation speed, and the coolant temperature; In the vehicle air-fuel ratio control system provided with a fuel injection amount control unit 24 for controlling the fuel injection duration of the fuel injection device, The actual EGR amount sucked into the carburetor 26 from the exhaust pipe according to the basic EGR amount by the EGR valve control unit 21, the fuel injection amount injected into the vaporizer 26 by the fuel injection device, and the air ratio from the air ratio sensor. EGR amount calculation unit 22 for calculating the; A correction calculation unit 23 for performing calculation for correcting the fuel injection amount supplied to the vaporizer 26 according to the EGR amount calculated by the EGR amount calculation unit 22 and the basic fuel injection amount determined corresponding to the intake air amount. Air-fuel ratio control system according to the exhaust gas recycle amount, characterized in that it comprises a).