KR100354081B1 - Method for controlling an amount of a fuel jet when an automobile starts - Google Patents

Abstract

According to the present invention, the calibration time for each section is shortened in the relationship between the time during engine start and the engine speed, and the start failure is prevented even when noise is generated from various input signals such as the engine speed. A fuel injection amount control method at start-up of a vehicle has a fuel injection amount control method comprising: detecting a rotational speed and a coolant temperature of an engine at start-up; Correcting the fuel injection value according to the engine speed in accordance with the coolant temperature and the absorption time when the engine is stored in the memory; Detecting a start time of an engine started by the fuel injection corrected according to the correction value; Designating a start time rank of the start time detected by the start time length, and calculating a new fuel correction value at engine start with the specified start time rank; Updating the fuel correction value stored in the memory by having the new fuel correction value calculated at engine startup for use of the next engine.

Description

Method for controlling an amount of a fuel jet when an automobile starts}

The present invention relates to a method for controlling fuel injection amount of a vehicle, and more particularly, to a method for controlling fuel injection amount during start-up of a vehicle, which prevents a starting failure of the vehicle due to the generation of noise during starting of the vehicle, and has a simple starting logic.

In the fuel injection amount control method of a conventional vehicle, the amount of fuel injected during the start-up of the engine is determined by outputting a pulse having a fixed pulse width to a predetermined fuel injector irrespective of the amount of intake air to the cylinder of the engine. Therefore, a pulse having a fixed pulse width was corrected by estimating the intake air to the cylinder by the engine water temperature and the engine speed, and the engine should be set to a value capable of starting the engine under all conditions.

1 is a view schematically showing an internal combustion engine including a conventional fuel injection electronic control apparatus.

In FIG. 1, the intake air to the engine main body 7 flows in from the inlet 2 of the air cleaner 1, and the hot air flow meter 3, the duct 4, and the throttle controlling the air amount detect the amount of intake air. It is conveyed to the collector 6 via the throttle body 5 which has a valve. In the collector 6 air is distributed to each intake pipe 8 which leads directly to the engine 97 and is supplied to each cylinder. Fuel is sucked from the fuel tank 9 by the fuel pump 10 and injected from the injector 13 provided in each intake pipe 8 through the fuel damper 11 and the fuel filter 12.

On the other hand, it is built in the distributor 16 which detects the output signal Qa from the hot air flow meter, the output signal Tw of the water temperature sensor 19 provided in the engine 7, and the engine speed in order to detect temperature. Signals indicating the operating state of the engine 7 such as the output signal from the crank angle sensor and the output signal Q of the throttle sensor 18 installed on the throttle body for detecting the opening degree of the throttle valve are controlled. It is inputted by (15).

The control device 15 calculates the fuel injection device to obtain the fuel injection value by controlling the valve opening pressure time of the injector.

2 shows the internal configuration of the control device 15 and the main processor unit 100 (MPU) is fuel injection value and ignition timing by various input signals sent from the I / O LSI 103 connected via the bus 104. Is processed, and is connected via the bus 104 to the ROM 101 which stores the processing order and the fixed information necessary for the processing.

The RAM 102 is a read / write LSI that stores various information processed in the MPU 100 and is always supplied with power even when the ignition key is turned off to maintain the memory contents.

The I / O LSI 103 converts the analog signals from the hot air flow meter 3, the O ₂ sensor, the water temperature sensor 19, the battery voltage detector and the throttle sensor 18 into digital signals. Built-in A / D converter is sent.

On and off signals from the crank angle sensor, idle switch and starter switch are also processed in the I / O LSI 103. Meanwhile, the I / O LSI 103 functions to receive fuel injection information processed by the MPU 100 and to send a valve open signal to the injector 13.

In the operating state detecting means (LSI) of the vehicle, the operating state of the engine 7 is detected by processing input signals from a plurality of sensors as described above, and the injection valve calculating means (not shown) is detected in the above means. The fuel injection value supplied to each cylinder of the engine 7 is calculated through the fuel injector 13 with reference to a predetermined calculation expression according to the operating state of the engine.

The fuel injection value calculated by the fuel injection value calculating means is corrected by the correction means (not shown) by the correction value input to the memory, and the correction value from the correction means is the fuel of the fuel injection pulse generating means (not shown). In the injector 13 is converted into a pulse signal which opens the valve and supplied to the fuel injector.

On the other hand, in the engine start time detecting means (not shown), the start time of the engine is obtained with reference to the full width judgment rotation speed N2 and the predetermined time T _{delay as} shown in FIG. The full width judgment rotation speed N2 is set to a value at which the engine 7 can rotate by magnetic force without the help of a starter motor.

In the above means, the time t at which the engine rotation during start-up exceeds the full width determining rotation speed N2 is stored, and after the predetermined time T _delay has elapsed, the engine speed exceeds the full width determining rotation speed N2. If it still remains, the means determines the full width, and determines the memory time t1 as the start time, and the predetermined time T _delay determines the engine speed by chance at the time of the initial burst as shown in FIG. 4 where t3 is the start time. It is used to prevent erroneous detection of the starting time, such as determining t1 or t2 as the starting time when the rotation speed N2 is exceeded.

In FIG. 3, section A is a section that is ignored in order to prevent inflow of noise and the like at the initial start of a vehicle, section B is a section inducing ultra-wide width through well wetting, and section C is Start up section.

In the graph of FIG. 3, the fuel amount for each section is determined as follows:

That is, in interval B, 2T _LSES * Z _YLZA * F _SESM ,

In segment (C), 2T _LST * F _KSN * F _KSU * F _KSM * Z _YLZA * T _VUB

In the section C of the predetermined time T _delay , 2T _LST * F _KSM * Z _YLZA * T _VUB .

Where T _LSES = T _LST is a constant, Z _YLZA is the number of cylinders in the engine (7), F _SESM is a weight variable, T _VUB is a battery calibration value, and F _KSM is a fuel level damping constant for engine speed. , F _KSU is the fuel attenuation constant for engine speed, and F _KSM is the cooling water temperature correction constant.

However, the conventional fuel injection amount control device as described above takes a lot of time for calibration for each section in the relationship between the time during engine start and the engine speed, and the control logic at the start of the vehicle is complicated. In addition, there is a problem that a start failure occurs when noise occurs in various input signals such as the engine speed in each section.

Accordingly, an object of the present invention is to shorten the calibration time for each section in the relationship between the time during engine start and the engine speed, and to prevent starting failure even when noise is generated from various input signals such as the engine speed, In addition, the present invention provides a fuel injection amount control method for starting a vehicle having simple control logic.

1 is a schematic diagram of an automotive engine system used in a fuel injection amount control method when starting a vehicle;

FIG. 2 is a block diagram of a control device for performing a fuel injection amount control method when starting a vehicle shown in FIG. 1.

3 and 4 are graphs showing the relationship between the time during engine start and the engine speed.

5 is a schematic block diagram for performing a fuel control method when starting an engine according to the present invention.

Figure 6 is a flow chart for performing a fuel control method when starting the engine according to the present invention.

7 is a graph showing the relationship between time during engine start time and engine speed in accordance with the present invention.

(Explanation of symbols for the main parts of the drawing)

1: control device 2: coolant temperature sensor

3: start switch 4: injector

5: memory

The object as described above comprises the steps of detecting the engine speed and the coolant temperature of the engine at start-up; Correcting the fuel injection value according to the engine speed in accordance with the coolant temperature and the absorption time when the engine is stored in the memory; Detecting a start time of an engine started by the fuel injection corrected according to the correction value; Designating a start time rank of the start time detected by the start time length, and calculating a new fuel correction value at engine start with the specified start time rank; Updating the fuel correction value stored in the memory by having a new fuel correction value calculated at engine startup for use of the next engine. Is achieved.

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

5 is a schematic block diagram for performing a fuel control method when starting the engine according to the present invention, Figure 6 is a flow chart for performing a fuel control method when starting the engine according to the present invention.

5 and 6, first, when the start switch 3 is turned on, the coolant temperature is detected by the coolant temperature sensor 2 of the engine, and the rotation speed of the engine is detected so that the control device 1 Is input (S1). The control apparatus 1 determines whether the input engine speed RPM is a full width speed (S2), and determines that it is a full width when the engine speed is a full speed speed (S7).

However, when the engine speed is not the full speed, the fuel injection value corresponding to the engine speed is corrected according to the cooling water temperature and the absorption time at the start of the engine stored in the memory 5 (S3). Then, the start time of the engine started by the fuel injection corrected according to the value corrected in the above step is detected (S4). Next, a start time rank of the start time detected by the start time length is specified, and a new fuel correction value is calculated at engine start by the specified start time rank (S5), and the engine start calculation for new use of the engine is performed. The fuel correction value stored in the memory 5 is updated by having the new fuel correction value.

7 is a graph showing a relationship between time during engine start time and engine speed according to the present invention.

In the graph of FIG. 7, section a is a section that is ignored in order to prevent inflow of noise and the like at the initial stage of starting of the vehicle, and section b is a starting section.

The fuel amount calculation of the starting section b is obtained by the following equation.

Interval (b) = F _KTIM * F _KTIN * F _KTIU * T _UVB

Here, F _KTIM is a map consisting of coolant temperature and absorption time at start-up, F _KTIN is a mass variable according to engine speed input, F _KTIU is a mass variable according to elapsed start time, and T _UVB is a battery correction factor. .

According to the present invention as described above, the calibration time for each section is shortened in the relationship between the time during engine start and the engine speed, and prevents starting failure even when noise is generated from various input signals such as engine speed. It also has simple control logic.

Claims (1)

Detecting engine speed and coolant temperature at start-up; Correcting the fuel injection value according to the engine speed in accordance with the coolant temperature and the absorption time when the engine is stored in the memory; Detecting a start time of an engine started by the fuel injection corrected according to the correction value; Designating a start time rank of the start time detected by the start time length, and calculating a new fuel correction value at engine start with the specified start time rank; And updating the fuel correction value stored in the memory by having a new fuel correction value calculated at engine startup for use of the next engine.