KR20020058690A - Method for controlling warm-up system by using crossed exhaust axle in diesel engine - Google Patents

Abstract

PURPOSE: A white smoke is reduced in a cold weather by applying an exhaust shaft and an air heater to preheating plug of a hot heating system. CONSTITUTION: A method for controlling hot heating system comprises a step of deciding whether a coolant temperature detected in a coolant temperature sensor does not reach to a first critical temperature when an engine starts in a diesel engine. If then, an engine control member operates an exhaust shaft of the hot heating system to shut a shutter valve of an exhaust brake. Then, the engine control member adjusts fuel amount by the engine load to put the coolant temperature over a predetermined second critical temperature.

Description

TECHNICAL FOR CONTROLLING WARM-UP SYSTEM BY USING CROSSED EXHAUST AXLE IN DIESEL ENGINE}

The present invention relates to a method for controlling a warm air system using exhaust throttling of a diesel engine, and more particularly, in order to reduce white smoke discharged from a cold engine in a diesel engine, exhaust throttling and air heaters are provided in a glow plug of the warming system. The present invention relates to a method of controlling an air turbulence system using an exhaust throttle of a diesel engine to suppress an increase in combustion temperature and generation of unburned gas in a combustion chamber by applying an air heater.

Diesel engines generally have a warming system for preheating cold air during cold. This warming system includes a glow plug to preheat the cool air to improve the ignition of the fuel injected into the cylinder chamber.

However, in diesel engines, the temperature of the compressed air is low during cold cooling, causing ignition delays, thereby generating exhaust gases including white mist due to abnormal combustion.

The white haze is mainly generated by CO 2, SO 2, SO 3, NO 2, and the like, and the exhaust gases generated by fuel combustion of a diesel engine include carbon monoxide, hydrocarbons, and nitrogen oxides.

Therefore, diesel engines use a glow plug, a glow system, to reduce the white fumes emitted during cold chills.

Figure 1 illustrates a white mist test cycle according to the glow plug operating mode of such a diesel engine warming system.

According to Fig. 1, the operating mode of the glow plug is started after switching the ignition key to the start position 28 seconds after the warm-up.

Subsequent heat-up of the glow plug then proceeds for 60 seconds, with the engine speed slow.

When the postheating time of the glow plug expires, the glow plug remains off. In this case, the cycle of white mist test cycle is on for 10 seconds and 50 seconds is off.

If the white mist test cycle is maintained for 10 cycles, it takes 10 minutes.

However, the related art described above has a problem in that a large amount of white mist is discharged even after 25 minutes of repeated 10 cycles after the start of the test cycle when the warm plug is operated as a warming system.

Large amounts of white fumes may cause a decrease in the merchandise of the vehicle. That is, there is a problem that does not satisfy the requirements of domestic and foreign cold cold specifications and military environmental conditions (cold mobility / white haze discharge) requirements.

Preferably, after repeating 4 to 7 cycles, it is possible to determine that an engine or a vehicle equipped with such an engine is excellent in terms of merchandise in which white haze is rapidly reduced and extinguished.

The present invention has been made to solve the above-mentioned conventional problems, an object of the present invention is to reduce the white smoke discharged during cold cooling in a diesel engine (exhaust exhaust plug and air heater in the warm plug of the warming system ( The present invention provides a method of controlling an air turbulence system using an exhaust throttle of a diesel engine to suppress an increase in combustion temperature and generation of unburned gas in a combustion chamber by applying an air heater.

1 is an illustration of a white haze test cycle according to the glow plug operating mode of a typical diesel engine warm-up system.

2 is a block diagram of an engine control system to which the present invention is applied.

3 is a flow chart of a method for controlling a warm air system using an exhaust bridge of a diesel engine according to an embodiment of the present invention.

Fig. 4a is a block diagram showing the operation of the warming system according to Fig. 3;

FIG. 4B is an operation related block diagram of the exhaust shaft in FIG. 4A; FIG.

5 is an exemplary operation mode of the air heater according to FIG.

6 illustrates an operation mode of the warming system according to FIG. 3;

Explanation of symbols on the main parts of the drawings

20: detection means 21: start key

22: coolant temperature sensor 23: vehicle speed sensor

24: engine speed sensor 30: ECU

41: air heater 42: exhaust brake

43: fuel pump

In order to achieve the above object, a method for controlling a warm air system using an exhaust bridge of a diesel engine according to the present invention includes a method in which a cooling water temperature detected by a water temperature sensor is set when an engine is started in a diesel engine equipped with a warm air system; Determining whether the temperature falls below the 1 threshold water temperature value; When the cooling water temperature is lower than the first critical water temperature value, the engine control means turns on and operates the exhaust bridge of the warming system to close the shutter valve of the exhaust brake, and adjusts the fuel amount according to the engine load to adjust the cooling water temperature. It characterized in that it comprises a step to be equal to or more than the set second threshold water temperature value.

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

FIG. 2 is a block diagram of an engine control system to which the present invention is applied, FIG. 3 is a flowchart of a method for controlling an air turbulence system using an exhaust bridge of a diesel engine according to an embodiment of the present invention, and FIG. 4A is a warming system according to FIG. Fig. 4B is a block diagram showing the operation of the exhaust shaft in Fig. 4A, Fig. 5 is a view showing an operation mode of the air heater according to Fig. 3, and Fig. 6 is a mode of operation of the warming system according to Fig. 3. It is an illustration.

According to FIG. 2, the engine control system includes a sensing unit 20, an electronic control unit (ECU) 30 that performs engine control by determining an engine operating condition by receiving a signal detected by the sensing unit 20. And an air heater 41, an exhaust brake 42, and a fuel pump 43.

Accordingly, the engine control means of the present invention is preferably implemented by the ECU (30).

In addition, the sensing means 20 includes switching state information of the ignition key 21, cooling water temperature detected by the water temperature sensor 22, vehicle speed detected by the vehicle speed sensor 23, and the engine speed sensor 24. The engine speed detected by the controller is applied to the ECU 30.

Thus, according to FIG. 3, in the diesel engine equipped with the warming system, the ECU 30 applies the detection signal of the water temperature sensor 22 installed in the cooling system when the ignition key 21 is switched to the start position and the engine is started. The cooling water temperature is calculated, and it is determined whether the calculated cooling water temperature is lower than the set first threshold water temperature value (ST21, ST22).

At this time, preferably the first critical water temperature is set to -15 ° C. The first critical water temperature value is used to determine whether it corresponds to cold time.

When the coolant temperature detected in step ST22 falls below the first threshold water temperature value, the ECU 30 may determine whether the engine speed detected by the engine speed sensor 24 falls within the set threshold speed region. (ST23).

In addition, when the coolant temperature detected by the condition determination in step ST22 falls below the first threshold water temperature value or when the engine speed is determined to fall within the critical speed range in step ST23, the ECU 30 activates the exhaust bridge of the warm-up system. . That is, the exhaust throttle may be installed so as to be connected to the displacement degree of the solenoid valve that is duty controlled according to the control signal of the ECU 30, and the operation of the exhaust throttle may be performed by the ECU 30 turning on the solenoid valve (ST24). .

At this time, in addition to the duty control of the solenoid of the exhaust bridge according to the operation of the warming system, the ECU 30 performs preheating and postheating logic.

4A shows an operating relationship diagram of such a warming system.

According to Fig. 4A, the warm-up system is activated to operate the preheat / postheating logic set up. After the preheat / postheating logic is performed, the air heater is activated, followed by chopping.

When the exhaust bridge is operated, the negative pressure of the vacuum pump acts (ST25).

When the negative pressure of the vacuum pump acts by the operation of the exhaust bridge, the shutter valve of the exhaust brake is closed (ST26).

4B shows an operation relationship diagram of the exhaust bridge.

As shown in FIG. 4B, when the exhaust brake valve is closed, the exhaust pressure is increased and the engine load is increased, so that the ECU 30 performs fuel quantity increase correction according to the increase of the engine load. This increases the amount of heat dissipation into the cooling water and improves the preheating properties (ST27, ST28).

In addition, when the exhaust brake valve is closed, combustion gas remains in the cylinder chamber. If residual combustion gas is generated, the temperature in the combustion chamber is increased to work together with the fuel quantity increase correction to increase the combustion temperature. Increasing the combustion temperature then increases the amount of heat dissipation of the cooling water, while suppressing the generation of unburned gas. By suppressing the generation of unburned gas, white mist is reduced.

Subsequently, the ECU 30 detects the cooling water temperature rising by the operation of the exhaust bridge and determines whether or not the set temperature is equal to or higher than the set second threshold water temperature value. Preferably, the second critical water temperature is set to 60 ° C. (ST29).

If it is determined in step ST29 that the cooling water temperature does not exceed the second threshold water temperature value, the ECU 30 returns to step ST24 and repeats steps ST24 to ST29.

Thus, when the cooling water temperature is greater than or equal to the second critical water temperature value in step ST29 or the corresponding determination condition is not satisfied in step ST22 or step ST23, the ECU 30 turns off the solenoid valve of the exhaust bridge (ST30).

After step ST30 is performed, ECU 30 operates the air heater in accordance with the detected coolant temperature (ST31).

Figure 5 shows the white smoke test cycle according to the operation of the air heater.

According to Fig. 5, after the preheating is performed for 20 seconds in the operation mode of the air heater, the start key starts. At this time, the white mist test cycle corresponds to the key start state and gradually increases.

At the end of the key start state, the air heater heats up for 30 seconds, and then maintains a chopping state in which the cycle of turning off for 5 seconds and turning on for 20 seconds is repeated five times. At this time, the engine is low speed during the post-heating time, and then maintains a high speed for 10 seconds and a low speed for 50 seconds from the time when the air heater enters the chopping state.

The operation of the air heater is to increase the temperature in the combustion chamber to reduce the white mist (ST32).

6 shows an operation relationship diagram according to the warm-up system mode as described above.

In the warm-up system mode, the ignition key 11 is turned on after the warm-up time in the on state and then switched to the start to maintain the on state when the engine is started. The heater relay, the preheat lamp, and the air heater are turned on at the end of preheating and maintained for the set time (A). Time A is determined by the cooling water temperature.

The exhaust shutter valve and engine speed are turned on at start-up key start and maintained for the set time B. Time B is set according to the experimentally calculated value.

To illustrate, time A is 20 seconds and interval B is 1 minute.

According to the method of controlling the warm air system using the exhaust combustion of the diesel engine of the present invention, when the diesel engine warming system control logic is changed from the conventional glow plug to the exhaust combustion and the air heater application control logic, the combustion temperature in the combustion chamber is increased and unburned gas. It has the effect of improving the commercialization of diesel engines by improving the white haze / cold startability by suppressing the generation.

In other words, when the test cycle is repeated three cycles after the start key starts in the application of the air heater and the exhaust throttling system, the white mist is rapidly reduced and disappeared and the cold startability is improved.

This can be judged to be effective considering that the engine (vehicle) which is rapidly extinguished after the 4-7 cycle cycles and has been extinguished has been extinguished.

In addition, the oil temperature rise time from -15 ° C. to 60 ° C., which is an engine warming evaluation factor, takes about 4 minutes after starting, thereby improving engine warming performance.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Therefore, the above description does not limit the scope of the following claims.

Claims (5)

(a) the engine control means in the diesel engine equipped with the warming system, when the engine is started, determining whether the coolant temperature detected by the water temperature sensor is lower than a set first threshold water temperature value; (b) if the cooling water temperature is lower than the first critical water temperature value, the engine control means turns on the exhaust bridge of the warm-up system to close the shutter valve of the exhaust brake, and performs fuel amount adjustment according to the engine load. And controlling the cooling water temperature to be equal to or higher than the set second threshold water temperature value. The method of claim 1, wherein step (b) comprises: If the cooling water temperature detected in the step (a) is less than the first threshold water temperature value, the engine control means turning on and off the exhaust bridge of the warm-up system to perform a set preheating and afterheating; When the exhaust bridge is turned on and the negative pressure of the vacuum pump acts to close the shutter valve of the exhaust brake to increase the engine load, the engine control means performs fuel quantity increase correction according to the increase of the engine load to increase the amount of heat radiation to the cooling water. Steps; When the cooling water temperature rises according to the fuel quantity increase correction, the engine control means includes maintaining the on-operation state of the exhaust bridge until the cooling water temperature is equal to or higher than a set second threshold water temperature value. A method of controlling an air turbulence system using an exhaust bridge of a diesel engine. The method of claim 1, wherein step (b) comprises: When the coolant temperature detected in the step (a) is less than the first threshold water temperature value, the engine control means exhausts only if the engine speed detected by the engine speed sensor falls within the set threshold speed range. Turbine system control method using the exhaust shaft of the diesel engine, characterized in that it further comprises the step of turning on the shaft. The method according to claim 1 or 3, The coolant temperature detected in step (a) does not fall below the first threshold water temperature value, or the engine speed detected in step (b1) is not within the critical speed range, or operation of the throttling valve in step (b) The engine control means stops the operation of the throttling valve when the cooling water temperature raised by the temperature exceeds the second critical water temperature value; When the operation of the throttling valve is stopped, the engine control means further comprises the step of operating the air heater in accordance with the detected coolant temperature to cause an increase in the temperature of the combustion chamber warmer using the exhaust throttle of the diesel engine, characterized in that System control method. The method of claim 4, wherein the operation of the air heater, When the start-up key is started by preheating for the set preheating time, the start-up key is started at the time when the key start state is terminated, and the preheating time is set and the chopping state of repeating the set on / off cycle is maintained. Method for controlling turbulence system using exhaust bridge.