KR100412692B1 - Apparatus for correction exhaust gas recirculation of diesel vehicle and thereof - Google Patents

Abstract

The present invention relates to a method for controlling an EG duty before and after engine tamping to prevent 'NOx' excessive emission in a vehicle equipped with a diesel engine.

The present invention provides correction fuel amount calculation means for calculating a correction fuel amount according to an external condition and an integration distance for controlling an engine of a vehicle; Air amount calculating means for calculating a basic air amount by applying an intake temperature and a pressure value in the intake pipe to a basic map; Valve position calculating means for calculating the position of the EGR valve by calculating an external condition such as engine speed, idle air amount, atmospheric pressure, and the calculated corrected air amount; It characterized in that it comprises a control means for controlling the EGR duty until the end of the taming of the engine by calculating the position of the EGR valve and the value of the basic air amount.

Therefore, the amount of fuel is reduced at the same vehicle speed according to the mileage by applying the taming effect of the diesel engine to the EGR valve position calculation, thereby stabilizing the emission of the initial 'NOx'.

Description

EGAL correction system and method for diesel engines {APPARATUS FOR CORRECTION EXHAUST GAS RECIRCULATION OF DIESEL VEHICLE AND THEREOF}

The present invention relates to an exhaust gas stabilization device, and more particularly, to a method of controlling an EG duty before and after engine break-in to prevent 'NOx' excessive emission in a vehicle equipped with a diesel engine.

In general, 'NOx' is the most important exhaust gas to be reduced due to the characteristics of diesel engines operating in the lean burn area. Therefore, in the engine mapping company, the engine injection parameter is usually optimized to minimize the emission of 'NOx' and to optimize the EGR. The limit value set by the duty control of (Exhaust Gas Recirculation) is met.

However, this is because the engine company that maps the engine meets regulations through tests on vehicles that have been sufficiently tamed, so that the exhaust gas emitted from vehicles immediately after mass production cannot be guaranteed and is recalled. Doing.

This steadily decreases the friction of the vehicle until it is fully tamed at the time of appearance.

Therefore, in order to achieve the same vehicle speed as after being tamed at the time when the break-in of the vehicle is not finished, the amount of fuel must be increased by further stepping on the accelerator pedal, and thus the exhaust gas is further increased due to the following reasons.

The reason for this is firstly the effect of an absolute increase in the amount of fuel injected into the combustion chamber, and secondly at the same vehicle speed due to an increase in the amount of fuel in the engine speed and fuel level maps used in the EGR operation to reduce 'NOx' emissions. It is the case that 'NOx' is increased by increasing the amount of air.

As a way to reduce the emission of NOx, there is no special method at present, except for the absolute level of the emission gas being lower than the regulation level so that it is released below the regulation level immediately after mass production. It is a problem.

In recent years, domestic and foreign emission regulations have become impossible to map vehicles that have reduced absolute emissions, as Korea 2000 and EURO III regulations are applied, and the problem of excessive emissions of 'NOx' in all mass-produced diesel vehicles is regulated. As NO is strengthened, 'NOx' emission immediately after mass production is the most important factor in vehicle production in terms of absolute environmental pollution prevention.

However, the basic map for applying the NOx regulation of exhaust gas in mass production of diesel vehicles is based on the amount of fuel given by the sum of the fuel speed according to the engine speed and the position of the idle air accelerator pedal. The final target air volume is calculated only for external conditions such as temperature, cooling water temperature and EGR correction factor.

Therefore, no corrections are made to the engine being tamed, and the base map for EGR duty control is created for test vehicles that are sufficiently tamed, so that the conditions before and after taming are met. Since it is not considered, there is a problem of releasing 'NOx' which does not satisfy the regulation value.

The present invention has been invented to solve the above problems, the object of which is to calculate the amount of correction fuel in consideration of the mileage of the vehicle and calculate the final target air amount after calculating with the basic map, according to the control of the EGR duty accordingly The engines before and after mass production ensured that the emission of NOx met the regulated value.

1 is a block diagram of a device for correcting the ease of a diesel engine according to the present invention.

FIG. 2 is a detailed configuration diagram of the corrected fuel amount detector shown in FIG. 1. FIG.

3 is a flow diagram of one embodiment for performing easy R correction of a diesel engine in accordance with the present invention.

The present invention for achieving the above object is a correction fuel amount calculation means for calculating the correction fuel amount in accordance with the external conditions and integration distance for the engine control of the vehicle; Air amount calculating means for calculating a basic air amount by applying an intake temperature and a pressure value in the intake pipe to a basic map; Valve position calculating means for calculating the position of the EGR valve by calculating an external condition such as engine speed, idle air amount, atmospheric pressure, and the calculated corrected air amount; It characterized in that it comprises a control means for controlling the EGR duty until the end of the taming of the engine by calculating the position of the EGR valve and the value of the basic air amount.

The corrected fuel amount calculating means includes: a first calculation unit configured to calculate an idle air amount and an accelerator pedal position; A first map table in which a fuel amount corresponding to the engine speed and the injected fuel amount is set; A second map table for setting a weighting value for each integration distance by dividing the integration distance in stages until the stable pollutant is discharged, and outputting an air quantity value corresponding to the current integration distance detected; A second calculation unit which multiplies the fuel amount value output from the first map table and the air amount value output from the second map table; And a third operation unit configured to calculate a correction fuel amount in consideration of the integration distance by performing a difference operation between the value calculated by the first operation unit and the value calculated by the second operation unit.

In addition, when the driving is started, the process of determining whether the driving distance is more than the set reference distance by reading the driving integration distance; Entering an EGR correction mode and performing an EGR duty control based on a fuel amount according to a driving distance when the driving distance is not greater than the reference distance set; Determining whether the current air amount is more than a minimum air amount for reducing soot when the amount of fuel injected while the EGR duty control is performed at the fuel amount according to the driving distance is equal to or greater than the idle fuel amount; If the current air amount is more than the minimum air amount for reducing the soot, characterized in that it comprises the step of performing the intake air amount control with the EGR controlled reduced air amount when the fuel temperature is above the reference temperature.

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

As can be seen in FIG. 1, the EGR correction apparatus for a diesel vehicle according to the present invention includes a correction fuel amount detection unit 10, a valve position calculating unit 20, an air amount calculating unit 30, and a control unit 40. The detection unit 10 calculates the map value for the current driving distance from the map value calculated by the amount of fuel according to the engine speed and the position of the accelerator pedal and the distance traveled, that is, the accumulated distance from which stable pollutants are discharged. After calculating the two map values, the calculated result is calculated by calculating the calculated air amount with external conditions for engine control such as idle air amount and accelerator pedal position.

The air amount calculating unit 20 calculates the basic air amount by applying values such as the intake air temperature and the pressure inside the intake pipe to the base map and then outputs the calculated amount of air to the control unit 40.

The valve position calculating unit 30 calculates the position of the EGR valve by calculating external conditions for engine control such as engine speed, idle air amount, atmospheric pressure, and the calculated correction air amount.

The controller 40 calculates the position of the EGR valve and the value of the basic air amount, calculates the EGR duty until the engine is tamed, and then outputs an EGR control duty signal.

As shown in FIG. 2, the corrected fuel amount detection unit 10 outputs a first calculation unit 11 for calculating an idle air amount and an accelerator pedal position, and a fuel amount value corresponding to the engine speed and the injected fuel amount. The first map table 12 is divided into the integration distances by stages to discharge the stable pollutants, and the weights for each integration distances are set, and the corresponding air volume values are output according to the current integration distances detected. A second operation unit 14 and a first operation unit 11 which multiply the fuel amount value output from the second map table 13 and the first map table 12 and the air amount value output from the second map table 13; The third operation unit 15 calculates a corrected fuel amount in consideration of the integration distance by calculating a difference between the value calculated in step 2) and the value calculated in the second operation unit 14.

In the above-described first map table 12, the change in fuel amount of the taming is set as a map of the reduced fuel amount before and after taming at the corresponding point for the engine speed and the required fuel amount, based on the result of the process of taming the engine. do.

In addition, the second map table 13 sets the initial mass production to '0' for the integration distance input up to the point where there is no change in the exhaust gas emission while taming the actual vehicle, and after the taming is completed, '1'. It is set to have each value for each mileage with the linearized map.

In the configuration of the present invention including the function as described above, the operation of performing the EGR duty correction for 'NOx' stabilization is as follows.

When the vehicle starts to operate, the corrected fuel amount detector 10 calculates the corrected fuel amount by calculating the idle air amount for the accelerator pedal position, the injected fuel amount for the engine speed, and the air amount according to the driving distance, and then the valve position calculator 30. When applied, the valve position calculating unit 30 determines the position of the EGR valve in consideration of conditions such as engine speed, idle air amount, atmospheric pressure, etc., which are external conditions to the corrected fuel amount, and applies it to the control unit 40.

At the same time, the air amount calculating unit 20 calculates the intake air amount from the conditions such as the intake temperature and the intake pressure and applies it to the control unit 40. The control unit 40 calculates the duty control signal of the EGR valve according to the determined position and air amount of the EGR valve. The EGR duty control is performed with the calculated value.

Therefore, the amount of fuel fed back to the EGR basic map is reduced in a direction of reducing the amount of fuel fed back to the time when the break-in of the engine is not completed, thereby reducing the amount of air corresponding to the required amount of fuel, thereby stabilizing the emission of NOx exhaust gas.

This will be described with reference to FIG. 3.

When the operation is started, the driving integration distance to the present time is read (S101), and it is determined whether the vehicle has traveled more than the reference integration distance, that is, the distance after the completion of engine tampering without further change of exhaust gas emission (S102).

If it is determined that the vehicle does not travel more than the reference integration distance, the EGR correction mode is entered (S103), and the EGR duty control is performed using the fuel amount having a value corresponding to the current driving integration distance from the second map table 13 ( S104) It is determined whether the current fuel amount is more than the idle fuel amount (S105).

If it is determined that the current fuel amount is more than the idle fuel amount, it is determined whether the current air amount maintains the minimum air amount for reducing the smoke (S106). It is determined whether to maintain the temperature, preferably 80 ° C. or higher (S107).

When it is determined that the fuel temperature is maintained above the set reference temperature, it is determined that the current engine is in a warm-up state, and the intake air amount is controlled by the reduced air amount considering the integration distance through the control of the EGR duty, thereby controlling the 'NOx'. Stabilize the exhaust gas.

Therefore, the amount of fuel input to the EGR map in the diesel engine is input to a value smaller than the amount of fuel actually injected from the injector until the break-in is completed, thereby reducing the amount of EGR air, so that the emission of 'NOx' is stabilized.

As described above, the present invention reduces the fuel amount at the same vehicle speed according to the mileage by applying the taming effect of a diesel engine to the duty calculation for positioning the EGR valve, thereby stabilizing the emission of 'NOx' of the initial production engine. do.

Claims (6)

Correction fuel amount calculating means for calculating a correction fuel amount according to an external condition and an integration distance for controlling the engine of the vehicle; Air amount calculating means for calculating a basic air amount by applying an intake temperature and a pressure value in the intake pipe to a basic map; Valve position calculating means for calculating the position of the EGR valve by calculating an external condition such as engine speed, idle air amount, atmospheric pressure, and the calculated corrected air amount; And a control means for controlling the EGR duty until the engine is tamed by calculating the position of the EGR valve and the value of the basic air quantity. The method of claim 1, The corrected fuel amount calculating means includes: a first calculation unit configured to calculate an idle air amount and an accelerator pedal position; A first map table in which a fuel amount corresponding to the engine speed and the injected fuel amount is set; A second map table for setting a weighting value for each integration distance by dividing the integration distance in stages until the stable pollutant is discharged, and outputting an air quantity value corresponding to the current integration distance detected; A second operation unit which multiplies the fuel amount value output from the first map table and the air amount value output from the second map table; And a third calculation unit configured to calculate a corrected fuel amount in consideration of the integration distance by calculating a difference between the value calculated in the first operation unit and the value calculated in the second operation unit. The method of claim 2, The first map table is made of a fuel amount reduced before and after taming at a corresponding point of the engine speed and the required fuel amount as a map based on the result of the process of taming the engine. Easy to correct the diesel engine. The method of claim 2, The second map table sets the initial mass production to '0' for the integration distance input to the point of time when there is no change in the exhaust gas emission while taming the actual vehicle, and linearizes it after the break-in is set to '1'. EEG correction device for a diesel engine, characterized in that the set to have a value for each mileage in the map. When the driving is started, determining whether the driving distance is greater than the set reference distance by reading the driving integration distance; Performing an EGR duty control on the amount of fuel according to the driving distance by entering the EGR correction mode when the driving distance is not equal to or higher than the reference distance set; Determining whether the current air amount is more than a minimum air amount for reducing soot when the amount of fuel injected while the EGR duty control is performed at the fuel amount according to the driving distance is equal to or greater than the idle fuel amount; And controlling the intake air amount with the EGR controlled reduced air amount when the current air amount is equal to or greater than the minimum air amount for reducing smoke. The method of claim 5, And the set reference distance is set to a point in time at which there is no change in exhaust gas emissions.