KR101579680B1 - Gdi engine fuel injection amount control device - Google Patents

Abstract

The present invention discloses a method for controlling a gas fuel injection of a GDI engine. The present invention relates to a method for controlling a gas fuel injection control of a GDI engine by applying a gas dual fuel system configured by an MPI method to a fuel supply system of a GDI engine type, The injection timing and order of the gaseous fuel are controlled through the information sensed by the sensor which determines the injection and ignition of the gaseous fuel in the exhaust stroke of the immediately preceding cylinder so that the fuel supply is performed in the manifold direction (intake valve front end) The GDI engine improves the dual use of the fuel by improving the fuel supply switching of the dual fuel system, the timing of the supply of the gaseous fuel, and the output fluctuation due to the fuel characteristics.

Description

TECHNICAL FIELD [0001] The present invention relates to a GDI engine,

The present invention relates to a gasoline direct injection (GDI) engine of a gasoline direct injection type to which the next generation engine technology is applied, and more particularly to a gasoline direct injection (GDI) To a gas fuel injection control method of a GDI engine that enables to control the injection timing and order of gaseous fuel through information sensed from a sensor that determines injection and ignition of gaseous fuel.

In general, the application of automotive fuel injection systems has been introduced since the 1970s to improve output and atmospheric environmental issues.

Carburetor was used as the initial fuel supply device, but it did not satisfy exhaust gas emission standard by strengthening exhaust gas regulation, and since 1980, fuel control system using electronically controlled injection device has been developed.

It can be divided into SPI (Single Port Injection) and MPI (Multi Port Injection) or PFI (Port Fuel Injection) depending on the fuel supply method.

The SPI is a method of injecting fuel into a throttle body in such a way that fuel is injected in only one position and the mixer is distributed to each cylinder. This method is called Throttle Body Injection (TBI).

In MPI and PFI, separate injectors are installed for each cylinder, and fuel is injected. In the MPI type engine, there is a limit in responsiveness and fuel amount control since the injected fuel is injected into the intake port having low pressure.

On the other hand, the GDI fuel injection system is a clean engine that improves fuel consumption and output at the same time as the MPI system by injecting fuel into the combustion chamber to achieve ultra-lean combustion.

That is, the GDI engine is intended to obtain the maximum output with a minimum amount of fuel in order to increase exhaust gas emission standards by enhancing exhaust gas regulation and to use limited resources efficiently.

The fuel economy improving technology of the GDI engine can significantly reduce the pumping loss during the intake stroke occurring in the low load region and burn in a very lean state, so that the combustion temperature is lowered and the cooling loss is greatly reduced. In addition, This is because the increase of the compression ratio is reflected in the fuel efficiency improvement.

At this time, the GDI engine must satisfy the exhaust gas tolerance standard as compared with the MPI engine. If the temperature of the exhaust gas and the catalyst rises above the set temperature, the MPI engine further increases the fuel amount to lower the temperature of the combustion chamber. Thereby inducing a temperature drop of the gas.

This method of increasing fuel affects the deterioration of high-speed fuel economy and directly affects the increase of exhaust gas. In the GDI engine system, the exhaust gas temperature is lowered by controlling the injection timing and the ignition timing without increasing the fuel.

In the meantime, various operation modes are used in the GDI engine system to enable the optimum mixer to be formed and burned in each operation state.

[Layered mode]

Fuel is injected into the combustion chamber immediately before the ignition timing during the compression stroke. The fuel injected by the vortex generated in the combustion chamber is pushed toward the spark plug in a rolling state and the time interval between ignition is short so that the fuel can not be uniformly mixed with all the air present in the combustion chamber.

[Homogeneous Mixer Mode]

The fuel injection is performed during the intake stroke in the high speed or high torque state or when aiming at high output. There is enough time to allow the fuel / air mixture to ignite.

[Homogeneous lean mode]

Transitional region between superficial mode and homogeneous mixer mode. The fuel consumption rate can be lowered compared with the homogeneous mixture mode.

[Homogeneous-Layer Super Mode]

The mixture is injected during the intake stroke to form a homogeneous and lean mixture, and the remaining amount is injected separately during the compression stroke. The mixer has good flammability and is capable of complete combustion in the combustion chamber.

[Homogeneous - knock prevention mode]

By injecting the fuel in two divided doses at the time of full load, it is not necessary to retard the ignition timing in order to prevent the knock, and self-ignition is prevented.

[Layered Catalyst - Catalyst Heated Mode]

It is possible to rapidly heat the catalytic converter in the form of two divided injections, and after the mixture is ignited, the fuel is again injected during the explosion stroke to rapidly heat the exhaust.

On the other hand, the gas dual fuel system means a fuel supply system that selectively uses gas fuel such as gasoline fuel, LPG (liquefied petroleum gas), NG (natural gas), shale gas and DME, The internal combustion engine has the same fuel supply configuration as the conventional dual fuel system of a gasoline MPI (intake port fueling system) engine. In the case of compressed natural gas (CNG), a high pressure fuel tank, a fuel pressure reducer, , A gas fuel control device, and a gas state input sensor.

The gas fuel control method of the dual fuel system using the common MPI engine is to calculate the gasoline injection signal which has been calculated and determined by using the internal program of the gas electronic control device to calculate the temperature, And a method of outputting a jetting signal is used.

However, in the system in which the GDI engine is applied, in the mode in which the fuel is injected immediately before ignition in the compression stroke and the fuel is injected twice in the compression stroke, such as a layered supercharger, a knock prevention, It is difficult to construct a dual fuel system using a gasoline injection signal and a mechanical gas injection device has to be constituted in an intake port and it takes a time to mix with the inhaled air and supply it to the combustion chamber by a mixer .

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a gas dual fuel system configured by an MPI system in a fuel supply system of a GDI engine type, The injection timing and the order of the gaseous fuel are controlled through the information sensed by the sensor which determines the injection and ignition of the gaseous fuel in the exhaust stroke of the immediately preceding cylinder so that the fuel supply is performed at the intake valve front end (intake valve front end) The present invention provides a gas fuel injection control method of a GDI engine that improves the dual use performance of a fuel by improving problems such as fuel supply switching of the fuel system, timing of supplying the gaseous fuel, .

The gaseous fuel injection control method of a GDI engine according to the present invention for achieving the above object is characterized in that the dual fuel supply device includes a first detection signal of a cam sensor for detecting a TDC position with respect to a first cylinder, A second detection signal of a crank sensor for detecting the position of the crankshaft and the engine speed, and an ignition signal of the ignition coil for the first cylinder, which is a reference outputted from the GDI electronic control unit (ECU) A first step of analyzing; The dual fuel supply device is a one-cycle four-stroke internal combustion engine in which the ignition sequence is composed of cylinder No. 1, cylinder No. 3, cylinder No. 4 and cylinder No. 2 based on the information analyzed from the first step. A second step of setting fuel injection positions respectively; A second step of determining fuel switching so that the GDI engine is supplied with the gaseous fuel according to the fuel injection positions for the cylinders 1 to 4 which are the one-cycle four-stroke internal combustion engines set from the second step; And the double fuel supply device is configured such that, when the fuel switching is determined from the third step, the one-cycle four-stroke internal combustion engines 1 to 4 of the GDI engine set the supply position of the gaseous fuel to the cylinder, step; .

In addition, in the first step, the double fuel supply device outputs a detection signal of the crank sensor to the ignition signal of the ignition coil for the first cylinder, which is a reference output from the GDI electronic control unit, Synchronizing for a number of cycles and capturing and capturing in the form of a raw signal; When the detection signal of the crank sensor is input, the dual fuel supply device synchronizes the detection signal of the cam sensor and the ignition signal of the ignition coil for the first cylinder, which is a reference output from the GDI electronic control unit, for a few cycles Capturing and storing the original signal form; And the dual fuel supply device supplies the ignition signal of the ignition coil for the first cylinder, which is a reference outputted from the GDI electronic control unit, to the ignition signal of the crank sensor and the cam sensor during several cycles Capturing and storing the signals in the form of a raw signal; As shown in FIG.

The analysis of the detection signals of the cam sensor and the crank sensor and the ignition signal of the ignition coil output from the GDI electronic control unit stored in the dual fuel supply device is based on the ignition signal of the ignition coil for the first cylinder Setting a cycle of the ignition signal of the ignition coil for the first cylinder to be the next reference to one cycle; Repeating a cycle set from the step twice; Comparing a detection signal of the cam sensor synchronously stored within a range of one cycle of the ignition coil with respect to the first reference cylinder to a detection signal of the crank sensor; From the falling edge of the detection signal of the cam sensor generated at the first time after inputting the ignition signal of the ignition coil for the first cylinder which is the reference from the detection signal comparison of the above step, (TDC) position; The detection signal of the cam sensor synchronized within the range of one cycle of the ignition signal of the ignition coil for the first cylinder, which is the reference, in accordance with the TDC position of the first cylinder, Analyzing a detection signal to extract a target wheel shape of the cam sensor and the crank sensor; As shown in FIG.

A target wheel of the cam sensor is a half-moon type targer wheel with a 1/2 rising waveform and a 1/2 falling waveform during one cycle. The target wheel type of the crank sensor has 58 falling points and 2 It is the target wheel of 60-2 that there is not tooth part.

In the second step, the first cylinder acting as a reference of the one-cycle four-stroke internal combustion engine performs four-stroke one cycle operation in the order of suction-compression-explosion (power) When the rotation angle of the 1-cycle crankshaft of the 1-cycle four-stroke internal combustion engine is 720 ° (2 rotations), the ignition sequence is performed in the order of No. 1 cylinder, No. 3 cylinder, No. 4 cylinder, Setting an ignition position of the first cylinder at a specific point with respect to the detection signal of the crank sensor based on the position of the TDC with respect to the first cylinder of the falling edge in the detection signal of the crank sensor; Setting the ignition position of the third cylinder at a specific point with respect to the detection signal of the crank sensor on the basis of the position of TDC relative to the first cylinder of the falling edge in the detection signal of the cam sensor ; Setting the ignition position of the fourth cylinder at a specific point with respect to the detection signal of the crank sensor on the basis of the position of the TDC with respect to the fourth cylinder of the rising edge in the detection signal of the cam sensor ; And a position ('360') of a top dead center (TDC) with respect to a fourth cylinder of the rising edge in the detection signal of the cam sensor, Setting an ignition position of the ignition switch; .

Further, in the third step, in a state where the gasoline fuel supply to the first cylinder of the GDI engine is completed in the compression stroke at the crankshaft rotation angle of 540 to 720 DEG, the GDI fuel Switching the supply of gasoline fuel to the first cylinder of the GDI engine to a supply of gaseous fuel at an exhaust stroke position where the signal supplied to the injector is blocked / bypassed and the crankshaft rotational angle is 180 to 360 °; At the crankshaft rotation angle 360 to 540 °, the signal supplied to the GDI fuel injector is blocked at 540 to 720 °, at which the explosion (ignition) stroke starts, with the gasoline fuel supply to the second cylinder of the GDI engine being completed. / Diverting and switching the supply of gasoline fuel to the second cylinder of the GDI engine to a supply of gaseous fuel at an exhaust stroke position with a crankshaft rotation angle of 0 to 180 DEG; At the crankshaft rotation angle of 0 to 180 °, the signal supplied to the GDI fuel injector is blocked at 180 to 360 ° at which the explosion (ignition) stroke starts when the gasoline fuel supply to the GDI engine cylinder 3 is completed. / Diverting and switching the supply of gasoline fuel to the third cylinder of the GDI engine to a supply of gaseous fuel at an exhaust stroke position with a crankshaft rotation angle of 360 to 540 DEG; And a signal supplied to the GDI fuel injector at 360 to 540 ° at which the explosion (ignition) stroke starts, with the gasoline fuel being supplied to the cylinder No. 4 of the GDI engine in the compression stroke at a crankshaft rotation angle of 180 to 360 ° And switching the supply of gasoline fuel to the fourth cylinder of the GDI engine to a supply of gaseous fuel at an exhaust stroke position where the crankshaft rotation angle is 540 to 720 DEG; .

Further, the fourth step may include: setting a gas fuel supply position for the first cylinder at an exhaust position of the first cylinder; Setting a gas fuel supply position for the third cylinder at an exhaust position of the third cylinder; Setting a gas fuel supply position for the fourth cylinder at an exhaust position of the fourth cylinder; And setting a gas fuel supply position for the second cylinder at an exhaust position of the second cylinder; .

In addition, since the exhaust position of the first cylinder is the ignition position + 180 ° and the ignition position of the first cylinder is 711 ° in the detection signal of the crank sensor, the exhaust position of the first cylinder is 711 ° + 180 ° = 891 °, and the one-cycle rotation angle of the crankshaft is calculated as 720 ° = 891 ° - 720 ° = 171 °, so that the gas fuel supply position for the first cylinder is 171 ° relative to the detection signal of the crank sensor .

In addition, since the exhaust position of the third cylinder is the ignition position + 180 ° and the ignition position of the third cylinder is 171 ° in the detection signal of the crank sensor, the exhaust position of the third cylinder is 171 ° + 180 ° = 351 °, the gas fuel supply position for the third cylinder is 351 ° relative to the detection signal of the crank sensor.

In addition, since the exhaust position of the fourth cylinder is the ignition position + 180 ° and the ignition position of the fourth cylinder is 351 ° in the detection signal of the crank sensor, the exhaust position of the fourth cylinder is 351 ° + 180 ° = 531 °, the gaseous fuel supply position for the fourth cylinder is 531 ° relative to the detection signal of the crank sensor.

Also, since the exhaust position of the second cylinder is the ignition position + 180 ° and the ignition position of the second cylinder is 531 ° in the detection signal of the crank sensor, the exhaust position of the second cylinder is 531 ° + 180 ° = 711 °, the gas fuel supply position for the second cylinder is 711 ° relative to the detection signal of the crank sensor.

As described above, according to the present invention, a gas double fuel system constructed in the MPI system is applied to the fuel supply system of the GDI engine type, and the fuel is supplied immediately before the intake manifold direction (intake valve front end) The control means controls the injection timing and order of the gaseous fuel through the information sensed by the sensor which determines the injection and ignition of the gaseous fuel in the exhaust stroke of the cylinder, thereby enabling the GDI engine to switch the fuel supply of the dual- It is possible to expect the effect of improving the dual use performance of the fuel by improving problems such as the timing of the supply and the output fluctuation due to the fuel characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic block diagram of a gaseous fuel injection control apparatus for implementing a gas fuel injection control method of a GDI engine according to an embodiment of the present invention; FIG.
FIG. 2 is a waveform diagram of a synchronization signal of one rotation cycle for a detection signal of a cam sensor and a detection signal of a crank sensor according to an embodiment of the present invention; FIG.
3 is a waveform diagram showing a state in which a detection signal of a one-cycle cam sensor, a detection signal of a crank sensor, and a fuel injection position of a dual fuel supply device are set as an embodiment of the present invention.
4 is a waveform diagram of a detection signal target wheel and a detection signal of a cam sensor according to an embodiment of the present invention;
5 is a view showing a detection signal target wheel of a crank sensor according to an embodiment of the present invention.

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

FIG. 1 is a schematic block diagram of a gaseous fuel injection control apparatus for implementing a method of controlling a gaseous fuel injection of a GDI engine according to an embodiment of the present invention. FIG. 3 is a graph showing the relationship between the detection signal of the one-cycle cam sensor, the detection signal of the crank sensor, and the state of setting the fuel injection position of the dual fuel supply device in the embodiment of the present invention. As shown in FIG.

FIG. 4 is a waveform diagram of a detection signal target wheel and a detection signal of a cam sensor according to an embodiment of the present invention, and FIG. 5 is a diagram showing a detection signal target wheel of a crank sensor according to an embodiment of the present invention.

1 to 5, a method of controlling a gaseous fuel injection of a GDI engine according to an embodiment of the present invention includes, as shown in FIG. 1, the GDI engine control unit 3, A signal line of the crank sensor 2 for detecting the position of the crankshaft and the engine speed, and a signal line of the crankshaft 2 for detecting the position of the crankshaft 2, By connecting the double fuel supply device 5 and the ignition signal line of the first ignition coil 4 output from the control unit 3 in parallel and including the first through fourth steps.

The first step performed by the dual fuel supply device 5 includes a first detection signal of the cam sensor 1 for detecting a top dead center (TDC) position with respect to the first cylinder, which is a reference of the GDI engine, The second detection signal of the crank sensor 2 for detecting the position of the crankshaft and the engine speed and the ignition timing of the ignition coil 4 for the first cylinder which is the reference output from the GDI electronic control unit (ECU) The signal is received, stored and analyzed.

2, when the detection signal of the cam sensor 1 is inputted, the double fuel supply device 5 outputs the detection signal of the crank sensor 2 and the detection signal of the crank sensor 2 to the GDI electronic control unit 3 The ignition signal of the ignition coil 4 for the first cylinder to be outputted is synchronized for several cycles and is captured and stored in the form of the original signal.

2, when the detection signal of the crank sensor 2 is inputted, the double fuel supply device 5 outputs the detection signal of the cam sensor 1 and the output signal of the GDI electronic control unit 3 The ignition signal of the ignition coil 4 for the first cylinder which is a reference to be synchronized for a few cycles is captured and stored in the form of the original signal.

When the ignition signal of the ignition coil 4 for the first cylinder, which is the reference output from the GDI electronic control unit 3, is input to the dual fuel supply device 5, the double fuel supply device 5 outputs the detection signal of the crank sensor 2 And the detection signals of the cam sensor 1 are synchronized for several cycles and captured and stored in the form of a raw signal.

On the other hand, the double fuel supply device 5 analyzes the detection signals of the stored cam sensor 1 and the crank sensor 2 and the ignition signal of the ignition coil 4 outputted from the GDI electronic control unit 3, In the analysis, the cycle of the ignition signal of the ignition coil 4 for the first cylinder and the ignition signal of the ignition coil 4 for the first cylinder, which is the next reference, is set to one cycle After that, one set cycle is repeated twice.

2) of the cam sensor 1 synchronously stored in the range of one cycle of the ignition coil 4 for the first reference cylinder as shown in Fig. 2 and the detection signal (A in Fig. 2) of the cam sensor 1, 2) of the detection signal of the cam sensor 1 generated first after inputting the ignition signal of the ignition coil 4 for the reference cylinder No. 1 by comparing the detection signal (FIG. 2B) It is possible to detect the TDC position (C in Fig. 2) of the first cylinder as a reference from the point (Falling Edge) (Fig. 2B).

Next, the cam sensor 1 synchronized within one cycle of the ignition signal of the ignition coil 4 for the first cylinder, which is the reference, according to the detected TDC position of the first cylinder, The target wheel shape of the cam sensor 1 and the crank sensor 2 is determined by analyzing the detection signal of the crank sensor 2 (FIG. 2B) .

In this case, the target wheel of the cam sensor 1 is a half-moon type targer wheel with a 1/2 rising waveform and a 1/2 falling waveform during the cycle as shown in FIG. 4, As shown in Fig. 5, the number of descending points is 58, and there is a portion without two toot, which is a target wheel of 60-2.

As a second step, the double fuel supply device 5 is configured to perform a four-cycle four-stroke cycle in which the ignition order is one cylinder, three cylinders, four cylinders, and two cylinders on the basis of the information analyzed from the first step And the fuel injection position of the gas injection device configured in the intake port is set as the internal combustion engine.

That is, the GDI engine operates in the order of four strokes in one cycle in the order of suction-compression-explosion (power) -exhaust, while cylinder No. 1, which is the reference of the one cycle four- stroke internal combustion engine, Cylinder, cylinder No. 3, cylinder No. 4, cylinder No. 2, and the rotation angle of the 1-cycle crankshaft of the 1-cycle four-stroke internal combustion engine is 720 ° (2 rotations)

The position (TDC) of the top dead center (TDC) of the double fuel supply device 5 with respect to the first cylinder of the falling edge in the detection signal (B in FIG. 2) of the cam sensor 1 is The ignition position of the first cylinder (D in FIG. 3) is set at a specific point (for example, 711 ° position) with respect to the detection signal (A in FIG. 2) of the crank sensor 2 .

Next, the double fuel supply device 5 detects the position of the TDC position relative to the third cylinder of the falling edge at the detection signal (B in Fig. 2) of the cam sensor 1 (E in Fig. 3) at a specific point (e.g., 171 [deg.] Point) with respect to the detection signal (A in Fig. 2) of the crank sensor 2, .

Next, the double fuel supply device 5 detects the position of the top dead center (TDC) relative to the fourth cylinder of the rising edge at the detection signal (B in Fig. 2) of the cam sensor 1 The ignition position of the cylinder No. 4 (F in FIG. 3) at a specific point (for example, 351 ° position) with respect to the detection signal (A in FIG. 2) of the crank sensor 2, .

Next, the double fuel supply device 5 detects the position of the top dead center (TDC) relative to the fourth cylinder of the rising edge at the detection signal (B in Fig. 2) of the cam sensor 1 3) of the cylinder # 2 at a specific point (e.g., 531 [deg.] Point) relative to the detection signal (A in Figure 2) of the crank sensor 2, ).

In the next step 3, the dual fuel supply device 5 is arranged to supply fuel to the GDI engine in accordance with the fuel injection positions for the cylinders 1 to 4, which are the one-cycle four-stroke internal combustion engines set up from the second step, You decide to switch.

Crankshaft
Rotation angle

1 turn

2 rotations
0 ° to 180 °

180 ° to 360 °

360 ° to 540 °

540 ° to 720 °
 Cylinder No    One    explosion     exhaust      inhale      compression    2    exhaust     inhale      compression      explosion    3    compression     explosion      exhaust      inhale    4    inhale     compression      explosion      exhaust

That is, as shown in [Table 1], the double fuel supply device 5 is configured such that when the gasoline fuel supply to the No. 1 cylinder of the GDI engine is completed in the compression stroke with the crankshaft rotation angle of 540 to 720 degrees, The supply of gasoline fuel to the cylinder No. 1 of the GDI engine at the exhaust stroke position where the crankshaft rotation angle is 180 to 360 ° is interrupted / bypassed and the signal supplied to the GDI fuel injection device is switched from 0 to 180 ° at which the stroke starts, As shown in FIG.

Next, the double fuel supply device 5 is operated in a state where the gasoline fuel supply to the cylinder No. 2 of the GDI engine is completed in the compression stroke of the crankshaft rotation angle of 360 to 540 °, ° to the GDI fuel injector and divert the gasoline fuel supply to the second cylinder of the GDI engine to the supply of gaseous fuel at the exhaust stroke position where the crankshaft rotation angle is 0 to 180 °.

Next, in the double fuel feed device 5, in the state where the gasoline fuel supply to the No. 3 cylinder of the GDI engine is completed in the compression stroke of the crankshaft rotation angle of 0 to 180 DEG, the explosion (ignition) ° to the GDI fuel injector and switches the gasoline fuel supply to the third cylinder of the GDI engine to the supply of gaseous fuel at an exhaust stroke position of 360 to 540 ° of the crankshaft rotation angle.

Next, in the double fuel feed device 5, when the gasoline fuel supply to the cylinder No. 4 of the GDI engine is completed in the compression stroke of the crankshaft rotation angle of 180 to 360 °, the explosion (ignition) ° to the GDI fuel injector and switches the gasoline fuel supply to the fourth cylinder of the GDI engine to the supply of gaseous fuel at the exhaust stroke position where the crankshaft rotation angle is 540 to 720 ° .

In the next step 4, when the fuel switching is determined from the third step, the double-fuel supply device 5 determines that the one-cycle four-stroke internal combustion engines 1 to 4 of the GDI engine supply the gas fuel supply position to the cylinder Thereby supplying the gaseous fuel.

That is, the double fuel supply device 5 sets the gas fuel supply position for the first cylinder at the exhaust position of the first cylinder.

3) of the crank sensor 2 is 711 DEG in the detection signal (FIG. 2A) of the crank sensor 2, and the ignition position of the first cylinder The exhaust position of the first cylinder is calculated as 711 ° + 180 ° = 891 °, and the one-cycle rotation angle of the crankshaft is calculated as 720 °, ie, 891 ° - 720 ° = 171 °. The gas fuel supply position is set at 171 ° relative to the detection signal (A in Fig. 2) of the crank sensor 2.

Next, the double fuel supply device 5 sets the gas fuel supply position for the third cylinder at the exhaust position of the third cylinder.

3), the ignition position of the third cylinder (E in FIG. 3) is 171 degrees (FIG. 2) in the detection signal (A in FIG. 2) of the crank sensor 2, The exhaust gas position of the third cylinder is calculated as 171 ° + 180 ° = 351 °, and the gas fuel supply position for the third cylinder is 351 (FIG. 2) relative to the detection signal (A in FIG. 2) of the crank sensor 2 Point.

Next, the double fuel supply device 5 sets the gas fuel supply position for the fourth cylinder at the exhaust position of the fourth cylinder.

3), the ignition position of the fourth cylinder (F in FIG. 3) is 351 degrees (FIG. 2) in the detection signal of the crank sensor 2 The exhaust gas position of the fourth cylinder is calculated as 351 ° + 180 ° = 531 °, and the position of the gas fuel supply to the fourth cylinder is calculated as 531 (A) of the detection signal of the crank sensor 2 Point.

Finally, the double fuel supply device 5 sets the gas fuel supply position for the second cylinder at the exhaust position of the second cylinder.

That is, since the exhaust position of the second cylinder is the ignition position + 180 ° and the ignition position (G in FIG. 3) of the second cylinder is 531 ° in the detection signal of the crank sensor 2 (A in FIG. 2) The exhaust gas position of the second cylinder is calculated as 531 ° + 180 ° = 711 °, and the gas fuel supply position for the second cylinder is calculated as 711 ° relative to the detection signal (A in FIG. 2) of the crank sensor 2 .

Therefore, when the gas fuel supply positions for the first cylinder, the third cylinder, and the fourth cylinder and the second cylinder are set as described above, the double fuel supply device 5 is configured to supply the gasoline fuel to the GDI engine The gaseous fuel injected in the intake stroke is sequentially injected in accordance with the gas fuel supply position set in each cylinder in the exhaust stroke during the stroke of the GDI engine, Homogeneous mixing can be performed.

Although the description of the gas fuel injection control method of the GDI engine of the present invention has been described above with reference to the accompanying drawings, it is to be understood that the present invention is by no means intended to limit the present invention.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined by the appended claims. It is to be understood that such changes and modifications are within the scope of the claims.

One ; Cam sensor 2; Crank sensor
3; GDI electronic control unit 4; Ignition coil
5; Dual fuel supply

Claims (11)

The dual fuel supply device includes a first detection signal of a cam sensor for detecting a top dead center (TDC) position for a first cylinder which is a reference of a GDI engine, a second detection signal of a second sensor of a crankshaft A first step of receiving, storing and analyzing a detection signal and an ignition signal of an ignition coil for a first cylinder which is a reference outputted from the GDI electronic control unit (ECU); The dual fuel supply device is a one-cycle four-stroke internal combustion engine in which the ignition sequence is composed of cylinder No. 1, cylinder No. 3, cylinder No. 4 and cylinder No. 2 based on the information analyzed from the first step. A second step of setting fuel injection positions respectively; A second step of determining fuel switching so that the GDI engine is supplied with the gaseous fuel according to the fuel injection positions for the cylinders 1 to 4 which are the one-cycle four-stroke internal combustion engines set from the second step; And the double fuel supply device is configured such that, when the fuel switching is determined from the third step, the one-cycle four-stroke internal combustion engines 1 to 4 of the GDI engine set the supply position of the gaseous fuel to the cylinder, step; Lt; / RTI >
In the second step, the first cylinder acting as a reference of the one-cycle four-stroke internal combustion engine performs four-stroke one cycle operation in the order of suction-compression-explosion (power) (2 rotations) of the 1 cycle crankshaft of the 1-cycle 4-stroke internal combustion engine is made in the order of No. 1 cylinder, No. 3 cylinder, No. 4 cylinder and No. 2 cylinder. Setting the ignition position of the first cylinder at a specific point with respect to the detection signal of the crank sensor, based on the position of the TDC with respect to the first cylinder of the falling edge of the signal; Setting the ignition position of the third cylinder at a specific point with respect to the detection signal of the crank sensor on the basis of the position of TDC relative to the first cylinder of the falling edge in the detection signal of the cam sensor ; Setting the ignition position of the fourth cylinder at a specific point with respect to the detection signal of the crank sensor on the basis of the position of the TDC with respect to the fourth cylinder of the rising edge in the detection signal of the cam sensor ; And the ignition position of the second cylinder at a specific point with respect to the detection signal of the crank sensor is set on the basis of the position of the top dead center (TDC) relative to the fourth cylinder of the rising edge in the detection signal of the cam sensor ; / RTI >
In the third step, in the state where the gasoline fuel supply to the first cylinder of the GDI engine is completed in the compression stroke at the crankshaft rotation angle of 540 to 720 DEG, the GDI fuel injection device And switching the supply of gasoline fuel to the first cylinder of the GDI engine to a supply of gaseous fuel at an exhaust stroke position where the crankshaft rotation angle is 180 to 360 DEG; At the crankshaft rotation angle 360 to 540 °, the signal supplied to the GDI fuel injector is blocked at 540 to 720 °, at which the explosion (ignition) stroke starts, with the gasoline fuel supply to the second cylinder of the GDI engine being completed. / Diverting and switching the supply of gasoline fuel to the second cylinder of the GDI engine to a supply of gaseous fuel at an exhaust stroke position with a crankshaft rotation angle of 0 to 180 DEG; At the crankshaft rotation angle of 0 to 180 °, the signal supplied to the GDI fuel injector is blocked at 180 to 360 ° at which the explosion (ignition) stroke starts when the gasoline fuel supply to the GDI engine cylinder 3 is completed. / Diverting and switching the supply of gasoline fuel to the third cylinder of the GDI engine to a supply of gaseous fuel at an exhaust stroke position with a crankshaft rotation angle of 360 to 540 DEG; And a signal supplied to the GDI fuel injector at 360 to 540 ° at which the explosion (ignition) stroke starts, with the gasoline fuel being supplied to the cylinder No. 4 of the GDI engine in the compression stroke at a crankshaft rotation angle of 180 to 360 ° And switching the supply of gasoline fuel to the fourth cylinder of the GDI engine to a supply of gaseous fuel at an exhaust stroke position where the crankshaft rotation angle is 540 to 720 DEG; Wherein the gas fuel injection control method of the GDI engine comprises: 2. The method according to claim 1, wherein in the first step,
When the detection signal of the cam sensor is inputted, it is synchronized with the detection signal of the crank sensor and the ignition signal of the ignition coil for the first cylinder, which is a reference outputted from the GDI electronic control unit, for a cycle, Capturing and storing; When the detection signal of the crank sensor is inputted, it is synchronized with the detection signal of the cam sensor and the ignition signal of the ignition coil for the first cylinder, which is a reference for outputting from the GDI electronic control unit, for a cycle, Capturing and storing the image; And when the ignition signal of the ignition coil for the first cylinder, which is the reference outputted from the GDI electronic control unit, is inputted, the detection signal of the crank sensor and the detection signal of the cam sensor are synchronized for several cycles, Capturing and storing the data; The method of claim 1, further comprising the step of: 3. The method according to claim 2, wherein, in the first step,
Further comprising the step of analyzing a detection signal of a cam sensor and a crank sensor stored in the dual fuel supply unit and an ignition signal of an ignition coil output from the GDI electronic control unit, Setting a cycle of an ignition signal of the ignition coil and an ignition signal of the ignition coil for the first cylinder as a next reference to a cycle; Repeating a cycle set from the step twice; Comparing a detection signal of the cam sensor synchronously stored within a range of one cycle of the ignition coil with respect to the first reference cylinder to a detection signal of the crank sensor; From the falling edge of the detection signal of the cam sensor generated at the first time after inputting the ignition signal of the ignition coil for the first cylinder which is the reference from the detection signal comparison of the above step, (TDC) position; The detection signal of the cam sensor synchronized within the range of one cycle of the ignition signal of the ignition coil for the first cylinder, which is the reference, in accordance with the TDC position of the first cylinder, Analyzing a detection signal to extract a target wheel shape of the cam sensor and the crank sensor; The method of claim 1, further comprising the step of: 4. The crank angle sensor according to claim 3, wherein the target wheel of the cam sensor is a half-moon type targer wheel with a 1/2 rising waveform and a 1/2 falling waveform for one cycle, and the target wheel type of the crank sensor has a number of falling points 58 is a target wheel and 60-2 is a target wheel in which there are two no tooth parts. delete delete The method as claimed in claim 1,
Setting a gas fuel supply position for the first cylinder at an exhaust position of the first cylinder; Setting a gas fuel supply position for the third cylinder at an exhaust position of the third cylinder; Setting a gas fuel supply position for the fourth cylinder at an exhaust position of the fourth cylinder; And setting a gas fuel supply position for the second cylinder at an exhaust position of the second cylinder; The method according to claim 1, wherein the gas fuel injection control method further comprises: The ignition position sensor according to claim 7, wherein the exhaust position of the first cylinder is an ignition position + 180 ° and the ignition position of the first cylinder is 711 ° in the detection signal of the crank sensor, 180 ° = 891 °, and the one cycle rotation angle of the crankshaft is 720 °, which is calculated as 891 ° - 720 ° = 171 °. Therefore, the gas fuel supply position for the first cylinder is 171 Wherein the gas fuel injection control point of the GDI engine is a point. 9. The method as claimed in claim 8, wherein the exhaust position of the third cylinder is the ignition position + 180 占 and the ignition position of the third cylinder is 171 占 in the detection signal of the crank sensor, 180 ° = 351 °, so that the gas fuel supply position for the third cylinder is 351 ° relative to the detection signal of the crank sensor. 10. The method according to claim 9, wherein the exhaust position of the fourth cylinder is an ignition position + 180 占 and the ignition position of the fourth cylinder is 351 占 in the detection signal of the crank sensor, 180 ° = 531 °, so that the gas fuel supply position for the fourth cylinder is 531 ° relative to the detection signal of the crank sensor. 11. The method according to claim 10, wherein the exhaust position of the second cylinder is the ignition position + 180 占 and the ignition position of the second cylinder is 531 占 in the detection signal of the crank sensor, 180 ° = 711 °, so that the gas fuel supply position for the second cylinder is 711 ° relative to the detection signal of the crank sensor.

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