KR20020047554A - Method for controlling engine for prevent of off-idle knock in a vehicle - Google Patents

Abstract

PURPOSE: An off-idle knock is expected beforehand to control fuel amount, thereby stabilizing engine combustion. CONSTITUTION: An engine fuel amount and rpm are detected by a throttle position sensor and a crank position sensor respectively. A voltage value of a throttle position sensing signal of the throttle position sensor is sensed, and rpm of engine is calculated by a crank position sensing signal from the crank position sensor. An off-idle knock is decided if the voltage value of the throttle position sensing signal increases abruptly over a set value and the engine rpm is reduced abruptly compared to an idle rpm. If the off-idle knock is decided, the fuel amount supplied to the engine is increased by a certain value.

Description

Method for controlling engine for prevent of off-idle knock in a vehicle}

The present invention relates to a method for controlling an engine of a vehicle, and more particularly, to prevent off-idle knocks generated from an engine during rapid acceleration of an automatic transmission vehicle so that stable driving of the engine can be achieved. An engine control method for preventing off-idle knocking of a vehicle.

In general, in the case of a gasoline engine applied to a passenger vehicle, when a mixture of gasoline fuel and air is supplied at a predetermined ratio to a cylinder of the engine through a fuel injector, ignition occurs in the ignition coil in the cylinder, The combustion is generated to drive the cylinder piston and the crankshaft, so that it can be transmitted to the wheel of the vehicle through the shift operation through the transmission.

Recently, while maintaining optimum engine performance for such a gasoline engine, the fuel injection amount, injection timing, ignition timing, air volume, etc. according to each operating condition are calculated to properly drive actuators such as fuel injectors and ignition coils. Accordingly, an engine electronic control system for electronically controlling the engine has been developed and commercialized.

In such an engine electronic control system, the fuel amount, the ignition state, the air amount, etc., which have a significant influence on the driving performance, emission gas, fuel economy, etc. of the vehicle are input through various sensors, and then the optimum fuel injection amount is based on such sensor signals. Various fuel, ignition and exhaust systems can be controlled by calculating injection timing, ignition timing and air volume.

On the other hand, the sensor employed for controlling the engine of the vehicle includes a throttle position sensor (TPS) for detecting a mixture of fuel and air in the throttle valve, and a crank position sensor for detecting the rotational speed of the crankshaft of the engine ( Crank Position Sensor (CPS), an oxygen sensor (O ₂ Sensor) for measuring the oxygen concentration in the exhaust gas, and the like.

However, in the engine system of such a vehicle, in particular, in the case of an automatic transmission vehicle, when the driver performs a driving operation for rapid acceleration, abnormal noise is generated while knocking off-idle due to a momentary increase in combustion pressure. When such off-idle knock occurs, a misfire occurs in a cylinder in which combustion is terminated in the immediately preceding cylinder stroke, causing a sudden decrease in engine speed according to the misfire occurrence, and thus unstable driving of the vehicle. There is a problem that is caused.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to predict the occurrence of off-idle knock in advance so that the combustion of the engine can be normally stabilized by adjusting the fuel amount. It is to provide an engine control method for preventing knock.

1 is a block diagram showing a configuration of an engine control apparatus of a vehicle to which an engine control method for preventing off-idle knocking of the present invention is applied;

2A is a graph illustrating an example in which the engine speed is reduced by the occurrence of off-idle knocking;

2B is a graph illustrating an example in which off-idle knocking is prevented according to fuel amount control of an engine according to an exemplary embodiment of the present invention;

3 is a flowchart illustrating an operation of an engine control method for preventing off-idle knocking of a vehicle according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: start detection unit, 20: throttle position sensor,

30: crank position sensor, 40: electronic control unit (ECU),

50: memory, 60: ignition driving unit,

70: ignition plug, 80: throttle valve actuator,

90: throttle valve, 100: fuel injector.

In order to achieve the above object, according to the present invention, by detecting the fuel amount and the number of revolutions of the engine by the throttle position detection signal from the throttle position sensor and the crank position detection signal from the crank position sensor to efficiently control the driving of the engine A method of controlling an engine of a vehicle, the method comprising: detecting a voltage value of a throttle position detection signal from the throttle position sensor, calculating a rotation speed of the engine based on a crank position detection signal from the crank position sensor, and throttle position When the voltage value of the detection signal rises sharply above a predetermined value and the engine speed is sharply lowered compared to the idle speed, determining the off-idle knock and determining the off-idle knock state. Increase the amount of fuel supplied according to the preset setting And returning the engine speed detected by the crank position sensor to the normal state, and returning the fuel amount supplied to the engine to the normal fuel amount. Is provided.

Hereinafter, the present invention configured as described above will be described in detail with reference to the accompanying drawings.

That is, FIG. 1 is a block diagram illustrating a configuration of an engine control apparatus of a vehicle to which an engine control method for preventing off-idle knocking of the present invention is applied.

As shown in FIG. 1, an engine control apparatus of a vehicle to which the method of the present invention is applied includes a start detector 10, a throttle position sensor 20, a crank position sensor 30, and an electronic control unit 40; ECU), a memory 50, an ignition driver 60, a spark plug 70, a throttle valve actuator 80, a throttle valve 90, and a fuel injector 100.

In the figure, the start detection unit 10 is for generating a start detection signal by detecting a state in which the start key is operated by the driver to the start position.

In addition, the throttle position sensor 20 is installed on the throttle body side in which the throttle valve 90 is installed, and detects the opening value of the throttle valve 90 according to the driver's accelerator pedal operation. The crank position sensor 30 is installed near the crankshaft axis to generate a crank position detection signal that detects the engine speed (RPM) and the stroke of the cylinder by determining the position of the corresponding crank. do.

In the same figure, the electronic control unit 40 controls the engine to be started by operating a start generator (not shown) when the start detection signal is input from the start detection unit 10, and controls the fuel amount and ignition timing of the engine. In order to control the vehicle to run normally by controlling the exhaust state and the like.

Here, the electronic control unit 40 receives the throttle position detection signal from the throttle position sensor 20 and the crank position detection signal from the crank position sensor 30, and the voltage of the throttle position detection signal. If the value rises sharply (i.e., rapidly rises to about 10V from the normal state where 0 to 0.1V is generated), and the state in which the engine speed is rapidly decreased is determined, the off-idle knock phenomenon occurs. By judging, control is performed to increase and adjust the amount of fuel supplied to the engine in accordance with the fuel amount setting data stored in the memory 50.

On the other hand, the memory 50 stores the fuel amount setting data for the information of the fuel amount to be increased at the off-idle knock, as well as the information on the optimum fuel amount in the steady state.

In addition, the ignition driving unit 60 is controlled by the electronic control unit 40 to drive the ignition of the spark plug 70, the throttle valve actuator 80 is the electronic control unit 80 It is controlled by the control to perform the drive to adjust the opening degree of the throttle valve 90, thereby adjusting the injection amount of the fuel-air mixed mixer.

In addition, the fuel injector 100 is controlled by the electronic control unit 40 to adjust the injection timing of the fuel injected into the cylinder.

Here, when the rapid acceleration of the vehicle proceeds by the driver's operation in the idle state of the engine, as shown in Fig. 2a, a misfire occurs in the cylinder in which the combustion is completed, the engine speed is drastically reduced to off-idle knock You can see what is happening.

On the other hand, when the fuel supply amount is increased in a section in which the rapid acceleration of the vehicle is progressed according to the fuel amount control of the electronic control unit 40, as shown in Figure 2b the combustion in the cylinder stroke is rapidly increased, the engine rotation It can be seen that it proceeds to the steady state which is steadily increasing in response to the rapid acceleration state without a decrease in the number.

Next, the operation of the present invention made as described above will be described in detail with reference to the flowchart of FIG. 3.

First, when the start detecting unit 10 detects a state in which the start key is operated to the start position, the electronic control unit 40 operates the start generator to drive the throttle valve actuator 80 to drive the throttle valve 90. The opening degree of the vehicle is adjusted, and the spark plug 70 is ignited by driving the ignition driving unit 60 to start the engine. When the driver operates the accelerator pedal, the vehicle is driven according to the operation amount. This is done (step S10).

In this state, the electronic control unit 40 receives a throttle position detection signal detecting the opening value of the throttle valve 90 from the throttle position sensor 20, and the crankshaft rotational speed from the crank position sensor 30. When the crank position detection signal is detected (S11), the throttle position detection signal from the throttle position sensor 20 determines whether the engine is in the idle state, and the crank position sensor 30 The crank position detection signal from) is input to calculate the engine speed (RPM) (step S12).

On the other hand, the electronic control unit 40 determines whether the engine is in the idle state by the throttle position detection signal from the throttle position sensor 20 and the crank position detection signal from the crank position sensor 30. (Step S13).

As a result of the determination, the electronic control unit 40 has an idling speed of about 700 to 800 RPM with the engine speed calculated by the crank position detection signal being about 0 to 0.1 V where the throttle position detection signal is in an idle state. If it is determined that the corresponding to the, by the throttle position detection signal detected again from the throttle position sensor 20 and the crank position detection signal detected again by the crank position sensor 30, the driver excels for rapid acceleration It is determined whether or not the operation is performed (step S14).

As a result of the determination, the electronic control unit 40 rapidly increases the voltage value of the throttle position detection signal, for example, about 10V, and the engine speed calculated by the crank position detection signal is suddenly higher than the engine speed in the idle state. If it is determined that rapid acceleration of the vehicle proceeds by detecting the drop, the opening degree of the throttle valve 90 is controlled by driving control of the throttle valve actuator 80 based on the fuel amount setting data stored in the memory 50. By adjusting the fuel injection amount, the fuel injector 100 is controlled to adjust the fuel injection timing, thereby increasing the fuel supply amount from the subsequent stroke of the engine cylinder (step S15).

In that state, the electronic control unit 40 determines whether or not the engine speed calculated in accordance with the crank position detection signal from the crank position sensor 30 returns to the normal state (step S16).

As a result of the determination, when it is determined that the engine speed is returned to the normal state, the electronic control unit 40 controls the throttle valve actuator 80 so that the throttle valve 90 is adjusted to the normal opening value. The fuel injection period for the fuel injector 100 is also returned to the normal state (step S17).

It is a matter of course that the present invention having the above-described embodiments can be embodied in various modifications without departing from the spirit and scope of the embodiments.

According to the present invention as described above, when detecting the condition that the off-idle knock occurs according to the rapid acceleration of the vehicle, it is possible to prevent abnormal combustion phenomenon such as off-idle knock by increasing the amount of fuel supplied to the engine. As a result, the off-idle knock does not generate abnormal noise of the vehicle, and thus, it is possible to induce fuel atomization and to induce uniform distribution, thereby enabling stable driving of the vehicle.

Claims (2)

In the engine control method of a vehicle for efficiently controlling the driving of the engine by detecting the fuel amount and the number of revolutions of the engine by the throttle position detection signal from the throttle position sensor and the crank position detection signal from the crank position sensor, Detecting the voltage value of the throttle position detection signal from the throttle position sensor, and calculating the rotation speed of the engine based on the crank position detection signal from the crank position sensor; Determining an off-idle knock by detecting a state in which the voltage value of the throttle position detection signal rises sharply above a predetermined value and the engine speed drops sharply relative to the idle speed; Upon determining the off-idle knock state, increasing the amount of fuel supplied to the engine according to a preset setting value; And when the engine speed detected by the crank position sensor returns to a normal state, restoring an amount of fuel supplied to the engine to a normal fuel amount. 2. An engine control for off-idle knock prevention of a vehicle according to claim 1, wherein the step of increasing the amount of fuel supplied to the engine is made to increase the amount of fuel from the cylinder stroke after the off-idle knock state is determined. Way.