KR100774725B1 - Fuel injection apparatus for gosoline engine and injection method thereof - Google Patents

Abstract

A fuel injection apparatus of a gasoline engine and an injection method thereof are provided to maintain a uniform amount of gasoline evaporation gas which is generated in a fuel tank and sprayed with intake air to a cylinder of the engine. A fuel injection apparatus of a gasoline engine includes a main air passage(111) through which intake air moves to be injected into a cylinder of the engine, a flow rate sensor(115) measuring the flow rate of the intake air moving through the main air passage, an auxiliary air passage(113) through which a portion of air branched from the intake air moves, a first solenoid valve(116) branching out intake air into the auxiliary air passage, a canister(120) collecting evaporation gas generated in a fuel tank, an evaporation gas tube(124) transferring the evaporation gas collected in the canister to the auxiliary air passage, a gas mixing/compression unit(140) connected to the auxiliary air passage and receiving the intake air and the evaporation gas moved to the auxiliary air passage and mixing/compressing the intake air and the evaporation gas, a concentration sensor(142) measuring concentration of the evaporation gas received in the gas mixing/compression unit, a second solenoid valve(143) injecting the intake air and the evaporation gas into an injector, an ECU(160) receiving the concentration of the evaporation gas measured by the concentration sensor and calculating the amount of the evaporation gas, an injector(150) connected to the gas mixing/compression unit and spraying the intake air and the evaporation gas to the cylinder of the engine.

Description

FUEL INJECTION APPARATUS FOR GOSOLINE ENGINE AND INJECTION METHOD

1 is a view schematically showing a fuel injection device of a conventional gasoline engine.

2 is a view showing a connection portion between a fuel injection device and an engine of a conventional gasoline engine.

3 is a view showing a part of a fuel injection device of a gasoline engine according to an embodiment of the present invention.

4 is a flowchart illustrating a fuel injection method of a gasoline engine according to an exemplary embodiment of the present invention.

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

10 fuel tank 12 first gasoline evaporative gas pipe

20, 120: canister 24: second gasoline evaporation gas pipe

30: actuator 52: surge tank

55 cylinder 111 main air passage

113: auxiliary air passage 115: flow rate sensor

116: first solenoid valve 124: gasoline evaporative gas pipe

140: gas mixing and compression unit 142: concentration detection sensor

143: second solenoid valve 150: injector

160: ECU

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injector, and more particularly, to a fuel injector for a gasoline engine and an injection method thereof capable of constantly controlling the amount of gasoline evaporated gas generated in a fuel tank and injected into the cylinder of the engine together with intake air. will be.

1 is a view schematically showing a fuel injection device of a conventional gasoline engine.

Referring to FIG. 1, a fuel injection device of a conventional gasoline engine includes a fuel tank 10 in which gasoline is stored, a canister 20 in which gasoline boil-off gas generated in the fuel tank 10 is collected, and a canister ( And an actuator 30 for injecting the gasoline evaporated gas collected in 20) into the engine. In addition, the fuel injection device of the conventional gasoline engine includes a first gasoline boil-off gas tube 12 between the fuel tank 10 and the canister 20, and a second gasoline boil-off gas tube between the canister 20 and the actuator 30 ( 24) is further provided.

In the fuel injection device of the conventional gasoline engine, when gasoline evaporation gas is generated in the fuel tank 10 and its capacity exceeds a predetermined level, the generated gasoline evaporation gas is transferred to the canister 20 through the first gasoline evaporation gas pipe 12. Move to collect in the canister (20). When gasoline evaporated gas is collected in the canister 20 by a predetermined capacity or more, the gasoline evaporated gas collected in the canister 20 is moved to the second gasoline evaporated gas pipe 24 by a difference from the atmospheric pressure. Then, the actuator 30 injects the gasoline boil-off gas moved to the second gasoline boil-off gas pipe 24 to the engine. At this time, the actuator 30 receives a control signal from the ECU (Electronics Control Unit) of the vehicle and injects the amount of gasoline evaporated gas required by the engine to the engine. As the actuator 30, a purge control solenoid valve (P.C.S.V) is used.

2 is a view showing a connection portion between a fuel injection device and an engine of a conventional gasoline engine.

Referring to FIG. 2, the gasoline boil-off gas injected from the actuator 30 is received in a surge tank 52 before being injected into the engine, and mixed with intake air in the surge tank 52 so that each cylinder of the engine Sprayed inside. However, the gasoline evaporated gas contained in the surge tank 52 and mixed with the intake air is difficult to be evenly mixed with the intake air in the surge tank 52. Therefore, the gasoline evaporated gas contained in the surge tank 52 and mixed with the intake air is not uniformly injected into each cylinder 55 of the engine as shown in FIG. 2. If the gasoline evaporated gas mixed with the intake air is not uniformly injected into each cylinder 55, and the gasoline evaporated gas mixed with the intake air is heavily concentrated in any one cylinder 55, the vehicle has a serious problem that the starting is turned off. Occurs.

Accordingly, an object of the present invention is to provide a fuel injection device for a gasoline engine and an injection method thereof capable of constantly controlling the amount of gasoline evaporated gas generated in the fuel tank and injected into the cylinder of the engine together with the intake air.

In order to achieve the above object, the fuel injection device of a gasoline engine according to an embodiment of the present invention includes a main air passage for moving the intake air to be injected into the cylinder of the engine; An auxiliary air passage in which a portion of the intake air that moves the main air passage branches and moves; A canister for collecting the evaporated gas generated in the fuel tank; An evaporating gas pipe configured to move the evaporated gas collected in the canister to the auxiliary air passage; A gas mixing / compression unit connected to the auxiliary air passage and configured to receive, mix and compress the intake air and the evaporated gas moved to the auxiliary air passage; And an injector connected to the gas mixing / compressing unit and supplied with the intake air and the boil-off gas mixed and compressed with each other in the gas mixing / compressing unit and injecting gasoline into a cylinder of an engine.

The fuel injection device of the gasoline engine includes a flow rate sensor for measuring a flow rate of the intake air moving through the main air passage; A first solenoid valve branching the intake air of the main air passage to the auxiliary air passage; A concentration sensor for measuring a concentration of the evaporated gas contained in the gas mixing / compressing unit; A second solenoid valve for injecting the mixed and compressed intake air and the boil-off gas contained in the gas mixing / compressing unit into the injector; The ECU further receives the concentration of the boil-off gas measured by the concentration sensor and calculates the amount of the boil-off gas.

The ECU receives the flow rate of the intake air moving through the main air passage from the flow rate sensor to calculate the total amount of fuel required by the engine, and calculates the injector based on the calculated total amount of fuel and the amount of evaporated gas. Calculate the amount of gasoline to inject through.

The total fuel amount is the sum of the amount of the boil-off gas and the amount of gasoline.

The gasoline is injected and atomized together with the intake air and the boil-off gas mixed and compressed with each other.

A fuel injection method of a gasoline engine according to an embodiment of the present invention includes the steps of moving the intake air and the evaporated gas into the auxiliary air passage; Receiving the intake air and the boil-off gas moved to the auxiliary air passage in a gas mixing / compression unit; Mixing and compressing the intake air and the boil-off gas contained in the gas mixing / compression unit; Measuring a concentration of the boil-off gas mixed and compressed with the intake air; Determining whether the measured concentration of the boil-off gas exceeds a predetermined concentration; Injecting the evaporated gas and the intake air into the injector by mixing and compressing each other by opening a second solenoid valve when the measured concentration of the evaporated gas is less than a predetermined concentration; Calculating an amount of the boil-off gas according to the measured concentration of the boil-off gas, and calculating an amount of gasoline to be injected into an injector according to the calculated amount of boil-off gas; Injecting the calculated gasoline into the injector; Injecting the intake air, the boil-off gas, and the gasoline mixed and compressed with each other injected into the injector into an engine.

The calculating of the amount of gasoline to be injected into the injector includes measuring a flow rate of intake air moving through the main air passage through a flow rate sensor; Calculating a total amount of fuel to be supplied to the engine based on the measured flow rate; Calculating by subtracting the calculated amount of the boil-off gas from the total fuel amount.

Closing the second solenoid valve if the measured concentration of the boil-off gas does not exceed a predetermined concentration in the step of determining whether the measured concentration of the boil-off gas exceeds a predetermined concentration; Injecting said gasoline to said injector equal to said total fuel amount.

The moving of the intake air and the boil-off gas into the auxiliary air passage may include moving some intake air of the intake air into the auxiliary air passage in a main air passage through which the intake air to be injected into the cylinder of the engine moves. Wow; Moving the boil-off gas into the auxiliary air passage from the canister in which the boil-off gas generated in the fuel tank is collected.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 and 4.

3 is a diagram illustrating a part of a fuel injection device of a gasoline engine according to an exemplary embodiment of the present invention.

Referring to FIG. 3, a fuel injection device of a gasoline engine according to an embodiment of the present invention includes a main air passage 111 through which intake air to be injected into a cylinder of the engine moves, and an intake air moving through the main air passage 111. The auxiliary air passage 113 in which some of the branches diverge, the canister 120 in which gasoline evaporated gas generated in the fuel tank (not shown) is collected, and the gasoline evaporated gas collected in the canister 120 are stored in the auxiliary air passage 113. Gas mixing / compression unit which receives and mixes and compresses the gasoline evaporating gas pipe 124, which is a passage that moves to the side), and the intake air and gasoline evaporating gas which are connected to the auxiliary air passage 113 and moved to the auxiliary air passage 113. An injector 150 connected to the gas mixing / compressing unit 140 and supplied with the intake air and gasoline evaporation gas mixed and compressed in the gas mixing / compressing unit 140 and injected into the cylinder of the engine together with the gasoline. Sphere The.

In addition, the fuel injection device of the gasoline engine of the present invention includes a flow rate sensor 115 for measuring the flow rate of intake air moving through the main air passage 111, and the intake air of the main air passage 111 to the auxiliary air passage ( Housed in the first solenoid valve 116 branching to 113, the concentration sensor 142 for measuring the concentration of the gasoline evaporated gas contained in the gas mixing / compressing unit 140, and the gas mixing / compressing unit 140. And a second solenoid valve 143 for injecting the mixed and compressed intake air and gasoline evaporated gas into the injector 150.

In addition, the fuel injection device of the gasoline engine of the present invention receives the concentration of the gasoline evaporated gas measured from the concentration sensor 142 and calculates the amount of gasoline evaporated gas according to the concentration of the gasoline evaporated gas received, the calculated gasoline The ECU 160 calculates the amount of gasoline to be injected through the injector 150 according to the amount of the evaporated gas. The amount of gasoline to be injected through the injector 150 is calculated by subtracting the calculated amount of gasoline evaporated gas from the total amount of fuel required by the engine. At this time, the total amount of fuel required by the engine is obtained by the ECU 160 using the flow rate of intake air moving through the main air passage 111 measured through the flow rate sensor 115. The ECU 160 calculates the total amount of fuel required by the engine based on the correlation between the intake air measured by the flow rate sensor 115 and the total amount of fuel required by the engine (eg, the flow rate sensor 115). Intake air, measured through): total fuel required by the engine = 14: 1).

Referring to the fuel injection method of the gasoline engine according to the embodiment of the present invention using the fuel injection device of the gasoline engine of the present invention as follows.

Referring to FIG. 4, in the fuel injection method of a gasoline engine according to an exemplary embodiment of the present invention, gasoline evaporated gas is first generated in a fuel tank, and the generated gasoline evaporated gas is collected in the canister 120. In addition, the gasoline evaporated gas collected in the canister 120 is moved to the auxiliary air passage 113 by a difference from the atmospheric pressure, and some of the intake air that moves the main air passage 111 is the auxiliary air passage 113. Move to (S110). Then, the gasoline evaporated gas and the intake air moved to the auxiliary air passage 113 are accommodated in the gas mixing / compression unit 140 (S120) and mixed and compressed with each other (S130).

Then, the fuel injection method of the gasoline engine of the present invention is accommodated in the gas mixing / compressing unit 140 through the concentration sensor 142 (S120) and the gasoline evaporation gas from the intake air and gasoline evaporation gas mixed and compressed with each other Measure the concentration of (S140), the measured concentration of the gasoline evaporated gas is a certain concentration (wherein the constant concentration is about 13 to 15% as the concentration of the gasoline evaporated gas is injected into the engine by the actuator in the prior art) It is determined whether it exceeds (S150). The ECU 160 opens the second solenoid valve 143 when the measured concentration of the gasoline evaporated gas exceeds a predetermined concentration (S160). And ECU 160 calculates the amount of gasoline to be injected into injector 150 (S170). Here, the amount of gasoline to be injected into the injector 150 calculated by the ECU 160 is an amount obtained by subtracting the amount of gasoline evaporated gas calculated according to the concentration of the gasoline evaporated gas measured from the total amount of fuel required by the engine. To this end, the ECU 160 measures the flow rate of intake air that moves the main air passage 111 through the flow rate sensor 115 (S162), and the total amount of fuel to be supplied to the engine through the measured intake air flow rate. To calculate (S164).

Subsequently, in the fuel injection method of the gasoline engine of the present invention, when the amount of gasoline to be injected into the injector 150 is calculated, the calculated amount of gasoline is injected into the injector 150 (S180). Then, the injector 150 injects the gasoline boil-off gas mixed and compressed with the injected gasoline and intake air to the engine. In addition, in the fuel injection method of the gasoline engine of the present invention, when the concentration of the gasoline evaporated gas measured in step S150 does not exceed a predetermined concentration, the second solenoid valve 143 is closed (S165), and the gasoline to be injected into the injector 150 is performed. Calculate the amount of (S170). At this time, the amount of gasoline to be injected into the injector 150 is equal to the total amount of fuel required by the engine.

As such, the fuel injection device and the injection method of the gasoline engine according to the embodiment of the present invention includes a gas mixing / compression unit 140 for mixing and compressing some of the intake air and the gasoline boil-off gas. Then, the gas mixture / compressor 140 mixes and compresses gasoline evaporated gas with a part of the intake air, and injects the mixed and compressed intake air and gasoline evaporated gas into the injector 150 to supply each cylinder of the engine. do. Therefore, the fuel injection device and method of the gasoline engine of the present invention can constantly control the amount of gasoline evaporated gas generated in the fuel tank and injected into the cylinder of the engine together with the intake air.

In addition, the fuel injection device and the injection method of the gasoline engine according to the embodiment of the present invention gasoline boiled gas mixed with a portion of the intake air through the gas mixing / compression unit 140 and compressed gasoline through the injector 150 To each cylinder of the engine. Fossil fuels are characterized by atomization when mixed with air. Accordingly, the fuel injection device and method of the gasoline engine of the present invention may be atomized by injecting gasoline with intake air compressed and compressed with gasoline evaporative gas.

As described above, the fuel injection device and the injection method of the gasoline engine according to an embodiment of the present invention includes a gas mixing / compression unit for mixing and compressing some of the intake air and gasoline evaporated gas, and through the gas mixing / compression unit The gasoline evaporated gas is mixed and compressed with a part of the intake air, and the mixed and compressed intake air and gasoline evaporated gas are injected into the injector and supplied to each cylinder of the engine. Therefore, the fuel injection device and method of the gasoline engine of the present invention can constantly control the amount of gasoline evaporated gas generated in the fuel tank and injected into the cylinder of the engine together with the intake air.

Claims (10)

A main air passage through which intake air to be injected into the cylinder of the engine moves; A flow rate sensor for measuring a flow rate of the intake air moving through the main air passage; An auxiliary air passage in which a portion of the intake air that moves the main air passage branches and moves; A first solenoid valve branching the intake air of the main air passage to the auxiliary air passage; A canister for collecting the evaporated gas generated in the fuel tank; An evaporating gas pipe configured to move the evaporated gas collected in the canister to the auxiliary air passage; A gas mixing / compression unit connected to the auxiliary air passage and configured to receive, mix and compress the intake air and the evaporated gas moved to the auxiliary air passage; A concentration sensor for measuring a concentration of the boil-off gas contained in the gas mixing / compression unit; A second solenoid valve for injecting the mixed and compressed intake air and the boil-off gas contained in the gas mixing / compressing unit into the injector; An ECU configured to calculate the amount of the boil-off gas by receiving the concentration of the boil-off gas measured from the concentration sensor; And an injector connected to the gas mixing / compressing unit and receiving the intake air and the evaporative gas mixed and compressed with each other in the gas mixing / compressing unit and injecting the gas mixture into the cylinder of the engine. Fuel injector. delete The method of claim 1, The ECU receives the flow rate of intake air moving through the main air passage from the flow rate sensor to calculate the total amount of fuel required by the engine, And calculating the amount of gasoline to be injected through the injector based on the calculated total fuel amount and the amount of the boil-off gas. The method of claim 3, wherein The total fuel amount is a fuel injection device of the gasoline engine, characterized in that the sum of the amount of the evaporated gas and the amount of the gasoline. The method of claim 1, And the gasoline is injected and atomized together with the intake air and the boil-off gas mixed and compressed with each other. Moving the intake air and the evaporated gas into the auxiliary air passage; Receiving the intake air and the boil-off gas moved to the auxiliary air passage in a gas mixing / compression unit; Mixing and compressing the intake air and the boil-off gas contained in the gas mixing / compression unit; Measuring a concentration of the boil-off gas mixed and compressed with the intake air; Determining whether the measured concentration of the boil-off gas exceeds a predetermined concentration; Injecting the evaporated gas and the intake air into the injector by mixing and compressing each other by opening a second solenoid valve when the measured concentration of the evaporated gas is less than a predetermined concentration; Calculating the amount of the boil-off gas according to the measured concentration of the boil-off gas, and calculating the amount of gasoline to be injected into the injector according to the calculated amount of the boil-off gas; Injecting the calculated gasoline into the injector; And injecting the intake air, the boil-off gas, and the gasoline, which are mixed and compressed with each other, injected into the injector, to the engine. The method of claim 6, Calculating the amount of gasoline to be injected into the injector, Measuring a flow rate of intake air moving through the main air passage through a flow rate sensor; Calculating a total amount of fuel to be supplied to the engine based on the measured flow rate; And subtracting the calculated amount of the boil-off gas from the total amount of fuel. The method of claim 7, wherein In the step of determining whether the measured concentration of the boil-off gas exceeds a certain concentration, if the measured concentration of the boil-off gas does not exceed a predetermined concentration, Closing the second solenoid valve; And injecting the gasoline into the injector equal to the total fuel amount. The method of claim 6, The moving of the intake air and the boil-off gas into the auxiliary air passage, Moving some of the intake air from the intake air to the auxiliary air passage in the main air passage through which the intake air to be injected into the cylinder of the engine moves; Moving the boil-off gas into the auxiliary air passage from the canister in which the boil-off gas generated in the fuel tank is collected. The method of claim 6, And the gasoline is injected and atomized together with the intake air and the boil-off gas mixed and compressed with each other.

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