KR100667401B1 - Diesel-engine injection-timing control method for improving fuel efficiency - Google Patents

Abstract

A method for controlling the injection time of a diesel engine for improving the fuel economy of the engine is provided to satisfy an exhaust gas regulation and prevent generation of noise by controlling the injection time of the diesel engine. A fuel injection time of a diesel engine is controlled with a correction according to the temperature of sucked air by adding sucked air temperature correction timing to a main timing base map. The sucked air temperature correction timing is obtained by multiplying a value of a sucked air temperature correction map based on the amount of injected fuel and the number of rotations of the engine by a sucked air correction factor determined in a sucked air temperature correction curve based on the sucked air temperature(S1). The sucked air correction map includes a basic sucked air temperature correction map and a fuel ratio improving sucked air temperature correction map. The sucked air temperature correction curve includes a basic sucked air temperature correction curve and a fuel economy improving sucked air temperature correction curve.

Description

DIESEL-ENGINE INJECTION-TIMING CONTROL METHOD FOR IMPROVING FUEL EFFICIENCY}

1 is a diagram showing a conventional diesel engine fuel injection timing determination process;

FIG. 2 is a diagram illustrating a dotted line in FIG. 1 as a separate diagram, in which an intake temperature correction factor is calculated by an intake temperature correction map and an intake temperature correction curve; FIG.

3 is a flowchart illustrating a method of controlling a diesel engine fuel injection timing according to the present invention; And,

4 is a diagram illustrating a process of determining a diesel engine fuel injection timing according to the present invention.

The present invention relates to a method for controlling the injection timing of a diesel engine for improving fuel efficiency, wherein the engine is warmed up above a certain temperature, is not in an alpine region, and the intake air temperature is in an area not included in the EM (engine management) test condition or air conditioner. When it is turned on, the present invention relates to a method for controlling the injection timing of a diesel engine that improves fuel efficiency when driving on the road by applying an intake temperature correction map and an intake temperature correction curve.

Unlike a gasoline engine, a diesel engine is a combustion method by compression and compression, and therefore, the combustion time of the fuel is a major factor in determining the ignition timing of the fuel. The injection timing of the fuel in the diesel engine is finally determined by adding the correction according to the cooling water temperature (engine temperature), the correction according to the engine intake temperature, and the correction according to the atmospheric pressure to the main timing base map. It is preferable that the fuel injection timing be an optimum time within the range that satisfies the emission gas regulation. In addition, the injection timing should be advanced in order to prevent the occurrence of white smoke when the outside air temperature is low temperature (for example, the temperature below 10 ℃), and should be determined in consideration of the high smoke and oscillation.

1 is a diagram illustrating a conventional diesel engine fuel injection timing determination process. Conventionally, as illustrated in FIG. 1, the main timing base map is subjected to correction according to cooling water temperature, intake temperature, atmospheric pressure, and other factors to determine fuel injection timing. Referring to FIG. 1, a water temperature correction map, an intake air temperature correction map, and an atmospheric pressure correction map are determined based on the injection fuel amount and the engine speed, and thus, a water temperature correction curve based on the coolant temperature, an intake temperature correction curve based on the intake temperature, and the atmosphere. Atmospheric pressure correction curves by pressure are multiplied, and the values are reflected in the main timing base map as correction values to determine the fuel injection timing.

FIG. 2 is a diagram illustrating the dotted line of FIG. 1 as a separate diagram, and shows an intake temperature correction factor calculated by the intake temperature correction map and the intake temperature correction curve. 2 shows a process of determining the intake temperature correction timing (b) by multiplying the intake temperature correction map according to the injection fuel amount and the engine speed by the intake temperature correction factor (a) obtained by the intake temperature correction curve based on the intake temperature. Is shown.

According to the fuel injection timing decision as described above, the fuel efficiency (Mode) is good, but the fuel economy on the real road tended to be much lower than the certified fuel economy because there is a part that is not suitable for the real road driving environment. As the number of complaints about actual fuel economy, especially high-speed fuel consumption, is increasing at present, improving fuel efficiency as well as certified fuel efficiency can improve customer competitiveness by minimizing customer complaints and further superior ratings in terms of fuel efficiency. There is a need.

Therefore, the present invention is to solve the conventional problems as described above, by using an improved intake temperature correction map and intake temperature correction curve when the predetermined operating conditions are satisfied diesel engine that improves fuel efficiency as well as certified fuel efficiency. It is an object of the present invention to provide a method for controlling the injection timing of the.

In order to achieve the above object, the present invention provides an intake temperature correction timing obtained by multiplying the value of the intake temperature correction map based on the injection fuel amount and the engine speed by the intake temperature correction factor determined by the intake temperature correction curve based on the intake temperature. A method of controlling the fuel injection timing of a diesel engine by adding a correction according to the intake temperature, wherein the intake temperature correction map is composed of a basic intake temperature correction map and a fuel efficiency improvement intake temperature correction map. Is composed of basic intake temperature correction curve and fuel efficiency improvement intake temperature correction curve, and when both engine warm-up condition based on coolant temperature and non-alpine area based on atmospheric pressure are satisfied, fuel efficiency improvement intake temperature correction map and fuel efficiency improvement intake temperature correction Conditions where the curve is selected and the engine warm-up condition is based on coolant temperature and is not alpine based on atmospheric pressure If at least one is not satisfied, the basic intake temperature correction map and the basic intake temperature correction curve are selected so that the value of the intake temperature correction map selected by the switch configuration and the intake temperature correction factor of the intake temperature correction curve are multiplied. Let timing be added to the main timing base map.

This control method allows the fuel injection timing to be advanced while avoiding low temperature combustion noise problems and high-pressure smoke.

Here, the fuel efficiency improvement intake temperature correction curve is composed of the first intake temperature correction curve and the second intake temperature correction curve, the first intake temperature correction curve is selected when the air conditioner is not in operation, The intake temperature correction curve may be selected.

This allows the advancement to be made to the most efficient fuel economy by creating a calibration curve that distinguishes the engine combustion surroundings when the air conditioner is in operation and when the air conditioner is not in operation.

In addition, the first intake temperature correction curve may set the intake temperature correction factor to zero when the intake temperature is present between 20 ° C and 40 ° C. Such a configuration may prevent separate intake temperature correction from being performed on the main timing base map when the engine is operated in the EM region.

Here, a ramp switch may be used between the basic intake temperature correction curve and the fuel efficiency improvement intake temperature correction curve to prevent a sudden fluctuation in the intake temperature correction factor.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the injection timing control method of the diesel engine for improving fuel efficiency according to the present invention.

The most efficient way to improve fuel efficiency in terms of engine management system (EMS) is to advance the timing of injection. Advancement of the injection timing has a great effect on improving fuel efficiency, but on the other hand, the degree of advancement is limited because it leads to an increase in combustion noise and an increase in emissions such as NOx and PM. One embodiment according to the present invention is to increase the injection timing for fuel efficiency improvement within the condition that there is no increase in the combustion noise and satisfy the regulation of the exhaust gas, from the region meeting this condition to the optimum injection timing Instead of the conventional intake temperature correction logic (refer to FIG. 2), the fuel efficiency improvement intake temperature correction map and the intake temperature correction curve are applied to improve the fuel efficiency in the area where the conditions are met.

3 is a flowchart illustrating a method of controlling a diesel engine fuel injection time according to the present invention, and FIG. 4 is a diagram illustrating a process of determining a diesel engine fuel injection time according to the present invention.

First, there is no increase in combustion noise and the conditions for satisfying the regulation of emission gas are set as follows.

Conditions 1. The engine will warm up above a certain temperature.

Condition 2. Not Alpine Area

Condition 3-1. When the air conditioner is not in operation, the intake air temperature should be in an area other than the intake air temperature range under the EM test conditions.

Condition 3-2. When the air conditioner is in operation (non-EM area), it is applied regardless of the intake temperature.

The condition that the engine warms up above a certain temperature is a condition for avoiding the combustion sound when the engine is advanced when the engine is cold. Normally, if the temperature of the coolant is above 60 ° C, it can be determined that the engine has warmed up.

The condition that it should not be an alpine region is a condition that is applied because conventional logic already includes injection timing advancement by notification correction, and it is unnecessary to apply injection timing advance correction. Usually, if the atmospheric pressure is lower than 930 hpa, it can be considered as an alpine region.

Since the conventional injection timing determination logic is designed based on the EM region (the region included in the engine management test conditions), it is not an optimal logic in the non-EM region where the air conditioner operates. Therefore, when the air conditioner is in operation, the intake air temperature correction curve for fuel efficiency improvement is designed in consideration of the environment around the engine according to the operation of the air conditioner. In addition, if the air conditioner does not operate and the current intake temperature is present in the EM region, the conventional injection timing determination logic based on the EM region is optimal, so that it is unnecessary to apply a separate fuel efficiency improvement logic. Therefore, when the air conditioner does not operate, the intake air temperature correction curve for improving fuel efficiency is applied considering the current intake temperature outside the EM range. The EM region of intake temperature is between 20 ° C and 40 ° C.

In the following, the air conditioner does not operate and the intake air temperature correction curve applied when the air intake temperature is out of the EM region is applied to the first intake air temperature correction curve, and the intake air temperature correction curve applied when the air conditioner is operating. The second intake temperature correction curve, the intake air temperature correction map applied when the above conditions presupposed in the embodiment are satisfied is called a fuel efficiency improvement intake air temperature correction map, and the intake air temperature correction map of the related art (refer to FIG. The map and the conventional intake temperature correction curve will be described as a basic intake temperature correction curve.

Hereinafter, an intake temperature correction map and an intake temperature correction curve are applied according to the current engine operating conditions.

If the cooling water temperature does not exceed 60 ℃ (condition 1 dissatisfaction), it can be determined that the engine is not yet warmed up stage, and when the advanced injection in the non-warm up stage, combustion noise problem occurs, the conventional intake temperature compensation as in the prior art The intake temperature correction curve is performed by multiplying the map with the intake temperature correction curve, that is, the basic intake temperature correction map and the basic intake temperature correction curve (S4).

If the cooling water temperature exceeds 60 ℃ but the atmospheric pressure does not exceed 930 hpa (condition 2 dissatisfaction), it can be determined that the alpine zone, and the advanced altitude is already advanced injection by conventional logic, so the basic intake The intake temperature correction is performed by multiplying the on-correction map by the basic intake temperature correction curve (S4).

If the coolant temperature is above 60 ° C and atmospheric pressure is above 930hpa but the air conditioner is off and the intake temperature is between 20 ° C and 40 ° C (condition 3 unsatisfactory), the engine operating environment is consistent with the EM test area. Since the main timing base map, which is the basis, is designed based on the EM test conditions, when the engine operating environment coincides with the EM test condition region, no additional intake air temperature correction is performed (S3).

If the cooling water temperature exceeds 60 ℃, the atmospheric pressure exceeds 930hpa, the air conditioner is off, and the intake temperature is in the range other than 20 ℃ and 40 ℃ (satisfied with condition 3-1), it is based on EM test condition. Since the intake air temperature correction logic (see FIG. 2) is inappropriate, the intake air temperature correction is performed by multiplying the fuel efficiency improvement intake air temperature correction map by the first intake air temperature temperature correction curve (S2).

If the coolant temperature exceeds 60 ° C, atmospheric pressure exceeds 930 hpa, and the air conditioner is on (satisfying condition 3-2), the conventional intake temperature correction logic designed based on EM test conditions (see Fig. 2) is inadequate. The intake air temperature correction map is multiplied by the improved intake air temperature correction map and the second intake air temperature correction curve (S1).

The logic for performing such condition determination and intake air temperature correction for each condition is as shown in FIG. 4. Compared with FIG. 2, it is easy to see which logic is additionally designed to the conventional intake temperature correction logic in the embodiment.

Part of the conventional intake temperature correction map (basic intake temperature correction map) part (Fig. 2) is an additional design of the intake temperature correction map for improving fuel efficiency in parallel (Fig. 4), the conventional intake temperature correction curve (basic intake temperature correction curve) In the portion (FIG. 2), the first intake temperature correction curve and the second intake temperature correction curve were additionally designed in parallel (FIG. 4). In addition, the logic for determining the engine warm-up condition and the alpine condition was additionally designed (FIG. 4).

Here, the first intake temperature correction curve and the second intake temperature correction curve are alternatively shorted by the air conditioner switch input signal. That is, when the air conditioner switch input signal is 0 (off), the switch e3 is connected upward to connect the first intake temperature correction curve, and when the air conditioner switch input signal is 1 (on), the switch e3 is connected downward. The second intake temperature correction curve is connected.

If the coolant temperature satisfies the engine warm-up condition (cooling water temperature> 60 ℃) (c1 = 1) and the atmospheric pressure does not satisfy the high-altitude conditions (atmospheric pressure> 930hpa) (c2 = 1), d becomes 1 (e1, e2) are connected downwards, and in other cases (c1 = 0 or c2 = 0), d becomes 0 and switches (e1, e2) are connected upwards. In particular, a ramp switch e4 is formed at the rear of the switch e2 so that the correction value is drastically changed when there is a change between the basic intake temperature correction curve and the first or second intake temperature correction curve. It prevented sudden fluctuations.

Therefore, as long as conditions 1 and 2 are not satisfied at the same time, the switches e1 and e2 are set upward, so the intake temperature correction timing B is determined by the product of the basic intake temperature correction map and the basic intake temperature correction curve.

On the other hand, when conditions 1 and 2 are satisfied at the same time, the switches e1 and e2 are set downward.

When the air conditioner is turned on, since the switch e3 is set downward, the intake air temperature correction timing B is determined by the product of the fuel efficiency improvement intake air temperature correction map and the second intake air temperature temperature correction curve. At this time, since the switch e4 is configured as a lamp switch, the intake temperature correction factor A gradually changes from the basic intake temperature correction curve to the second intake temperature correction curve.

On the other hand, when the air conditioner is turned off, since the switch e3 is set upward, the intake air temperature correction timing B is determined by the product of the fuel efficiency improvement intake correction map and the first intake temperature correction curve. In this case, too, the switch e2 is configured as a lamp switch so that the intake temperature correction factor A gradually changes from the basic intake temperature correction curve to the first intake temperature correction curve. If the intake temperature is between 20 ° C and 40 ° C, the coolant temperature, atmospheric pressure, and intake temperature are all present in the EM area, so that no additional intake temperature correction is necessary, so that a separate intake temperature correction is not applied to the main timing base map. And, if the intake air temperature is less than 20 ℃ or greater than 40 ℃ can be configured in a form that is applied to improve the fuel economy. In an embodiment of the present invention, the first intake temperature correction curve is set to 0 between 20 ° C and 40 ° C so that the intake temperature correction timing B, which is multiplied by 0, is zero. It is set so that a separate intake temperature correction is not applied and the factor exists in other areas. This first intake temperature correction curve setting has the same effect as the condition determination for the intake air temperature is made. However, unlike the embodiment of the present invention, it is obvious that the condition determination for the intake air temperature can be formed separately, such as an engine warm-up condition or an alpine condition.

As described above, the method for controlling the injection timing of the diesel engine for improving fuel efficiency of the present invention satisfies the exhaust gas regulation in the region other than the EM condition, and advances the injection timing so that noise does not occur. Can improve.

The present invention is not limited to the described embodiments, and various modifications and changes can be made to those skilled in the art without departing from the spirit and scope of the present invention. Such modifications or modifications may be made to the present invention. It belongs to the claims of the.

Claims (4)

By adding the intake temperature correction timing multiplied by the intake temperature correction factor determined by the intake temperature correction curve based on the intake temperature to the main timing base map, the correction according to the intake temperature is corrected. To control the fuel injection timing of the diesel engine, The intake air temperature correction map is composed of a basic intake air temperature correction map and a fuel efficiency improvement intake air temperature correction map, The intake air temperature correction curve is composed of a basic intake air temperature correction curve and fuel efficiency improvement intake air temperature correction curve, When the engine warm-up condition based on coolant temperature and the condition that is not altitude based on atmospheric pressure are satisfied, fuel economy improvement intake temperature correction map and fuel economy improvement intake temperature correction curve are selected, and engine warm up condition based on coolant temperature and atmospheric pressure based If one or more of the conditions that are not alpine are not satisfied, the default intake temperature correction map and the default intake temperature correction curve are selected. A method of controlling the fuel injection timing of a diesel engine, characterized by adding an intake temperature correction timing multiplied by the value of the intake temperature correction map selected by the switch configuration and the intake temperature correction factor of the intake temperature correction curve to the main timing base map. The method of claim 1, The fuel efficiency improvement intake temperature correction curve is composed of a first intake temperature correction curve and a second intake temperature correction curve, The first intake temperature correction curve is selected when the air conditioner is not in operation, and the second intake temperature correction curve is selected when the air conditioner is in operation. The method of claim 2, The first intake temperature correction curve is a fuel injection timing control method of a diesel engine, characterized in that the intake temperature correction factor is set to 0 when the intake temperature is present between 20 ℃ and 40 ℃. The method according to any one of claims 1 to 3, And a ramp switch between the basic intake temperature correction curve and the fuel efficiency improvement intake temperature correction curve to prevent a sudden fluctuation in the intake temperature correction factor.

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