KR20120090209A - Apparatus and method for controlling fuel feed of automobile using both gasoline and lpg - Google Patents

Abstract

PURPOSE: A device and method for controlling a fuel supply for gasoline/LPG vehicles are provided to collect surplus LPG fuel to a fuel tank, and to prevent gasoline and LPG from mixing. CONSTITUTION: A device and method for controlling a fuel supply for gasoline/LPG vehicles comprises a gasoline supply unit(10), a LPG supply unit(20), a high pressure pump(30), a delivery pipe(40), an electric control unit(50), and a controller(60). The gasoline supply unit comprises a first shut up valve(13). The first shut up valve is installed in a gasoline supply line which supplies gasoline to the high pressure pump, and selectively shuts down the gasoline. The LPG supply unit comprises a second shut up valve(24). . The second shut up valve is installed in a LPG supply line which supplies LPG to the high pressure pump, and selectively shuts down the LPG.

Description

Fuel supply control device and control method for gasoline and LPI combined vehicle {APPARATUS AND METHOD FOR CONTROLLING FUEL FEED OF AUTOMOBILE USING BOTH GASOLINE AND LPG}

The present invention relates to a fuel supply control device and a control method of a vehicle combined with gasoline and liquefied petroleum gas (hereinafter referred to as 'Elphi'), and more specifically, by using a single high-pressure pump to control gasoline and LPG fuel. The present invention relates to a fuel supply control device and a control method for a gasoline and LPG combined vehicle that pressurizes the engine at high pressure and directly sprays the engine to improve the power performance of the vehicle, reduce fuel consumption, and reduce the amount of carbon generated.

In general, among the fuels used in the vehicle, the LLP fuel is used in some passenger cars and vans because it has the advantage of high octane number, excellent heat resistance, and low fuel cost, and is expected to be applied to large vehicles.

When the LPI fuel supplied to the engine of the vehicle is liquid and vaporized, it has a good mixing property with air, and thus has good flammability. Therefore, knocking is less likely to occur than gasoline and diesel. Vapor-Lock or percolation and Since the same phenomenon can be prevented, its application range is gradually increasing as an alternative fuel of gasoline or diesel fuel.

Therefore, gasoline and elpgi combined vehicles have an electronic control unit that controls gasoline fuel tanks, vaporizers and mixers, elbow fuel tanks, solenoid valves and solenoid valves that control the supply of Elpig fuel. ) Is essentially provided.

Recently, in order to improve the engine output and reduce the emission of pollutants, the direct injection gasoline engine that injects and compresses only air into the engine and injects gasoline fuel and the liquefaction that directly injects liquid LPG fuel into the engine. Elpiai engines have been developed using the Liquefied Petroleum Injection (hereinafter referred to as Elpiai) engine.

Therefore, in order to simultaneously achieve two objectives of increasing environmental protection and fuel economy, the development of fuel supply control apparatus for a gasoline and LPG combined vehicle using a direct injection method is in progress.

An example of a technology for controlling fuel supply of a gasoline and LPG combined vehicle using the direct injection method is disclosed in Korean Patent Registration No. 10-0770802 (registered on October 22, 2007, hereinafter referred to as 'Patent Document 1'). have.

1 is a block diagram of an Elpia-type Elpig supply device according to Patent Literature 1 and the combined Elpig gasoline vehicle using the same.

As shown in FIG. 1, the LLP gasoline combined vehicle according to Patent Literature 1 is provided with a gasoline supply system 1 for supplying gasoline fuel to an engine and an LPI supply system 2 for supplying Elpgi fuel at the same time.

The gasoline supply system 1 includes a gasoline injector 3 mounted on a gasoline tank, a gasoline pump, a filter, a back pressure regulator and an intake pipe of an intake manifold.

The LLP supply system 2 includes an LLP tank 4 in which LLP fuel is stored, an LLP pump 5 for forcibly feeding LLP fuel, and an ELPI type fuel supply device 6.

The ELPI type fuel supply device 6 is a housing 6b in which the liquid LLP fuel is supplied through the supply pipe S and the supply pipe S connected to the LLP pump 5, and the LPI injector 6a is built therein. It includes a tube (6c) drawn out from (6b) and penetrated into the intake pipe (7) of the intake manifold, and a recovery pipe (R) for connecting the housing (6b) and the elbow tank (4).

The ELPI type fuel supply device 6 having such a configuration sucks the liquid LLP fuel, which is pumped into the housing 6b through the supply pipe R, from the LLP injector 6a through the tube 6c as it is in the liquid state. It moves to the engine 7 and injects into the intake valve front end of the combustion chamber 8.

At this time, the surplus of the LLP fuel remaining in the housing 6b is recovered to the LLP tank 4 through the recovery pipe (R).

Accordingly, the ELPI type fuel supply device of the LPG gasoline combined vehicle according to Patent Literature 1 is in a liquid state at the same position as the gasoline injection point of the gasoline injector 3 separately from the gasoline injector 3 mounted on the gasoline vehicle. Stable transfer and injection of LPG fuel.

That is, a gasoline and an LPG combined vehicle according to the prior art, such as an LPG gas combined vehicle including an LPIA fuel supply device according to Patent Literature 1, have a gasoline injector 3, an LPG injector 6a, and an LPG injector 6a embedded therein. And a gasoline supply system 1 and an LLP supply system 2 for supplying fuel to each injector 3 and 6a, respectively.

Accordingly, the combined gasoline and LPG vehicle according to the prior art has a problem that the configuration of the fuel supply device is complicated and the manufacturing cost increases.

If a single injector is used to inject gasoline fuel and LLP fuel, the injector prevents mixing of fuels having different fuel characteristics, and recovers each fuel remaining in the housing after fuel injection. There is a need to develop a technology for preventing the error to be returned to the tank.

Korea Patent Registration No. 10-0770802 (registered October 22, 2007)

The present invention is to solve the problems as described above, an object of the present invention is to provide a fuel supply control device and a control method for a gasoline and Elpgi combined vehicle directly injecting fuel into the engine of the gasoline and Elpgi combined vehicle. .

It is another object of the present invention to provide a fuel supply control apparatus and control method for a gasoline and elpgi combined vehicle that directly injects gasoline fuel and elpig fuel into an engine by mixing one injector.

Still another object of the present invention is to provide a fuel supply control apparatus and control method for a combined gasoline and elpgi vehicle, which prevents mixing of gasoline fuel supplied with a high pressure pump and elpji fuel, and recovers the surplus of the lpage fuel into the lpgi fuel tank. will be.

According to a feature of the present invention for achieving the above object, the present invention in the fuel supply control apparatus for a gasoline and LPG combined vehicle having a gasoline supply unit and the LPG supply unit, the gasoline fuel or the LPG supplied from the gasoline supply unit A high pressure pump for pressurizing the Elpji fuel supplied from the supply unit to a predetermined pressure, a delivery pipe in which the fuel pressurized from the high pressure pump is filled with high pressure, an injector for directly injecting the fuel filled with the high pressure in the delivery pipe into the combustion chamber of the engine, An electronic control unit for generating a control signal for controlling the drive of the LLP supply unit and the injector based on the target RPM of the engine and to control the driving of the gasoline supply unit, the LLP supply unit and the injector based on the control signal of the electronic control unit. Including a controller; The gasoline supply unit includes a first shutdown valve installed on a gasoline supply line for supplying gasoline fuel stored in a gasoline tank to the high pressure pump, and selectively shuts off gasoline fuel. And a second shut-up valve installed on the LLP supply line for supplying the pump to selectively block the LLP fuel.

The LLP supply part is provided on an LLP recovery line for recovering a part of the LLP fuel supplied to the high pressure pump to the bomb, and is installed on the LLP recovery line to reduce the pressure of the LLP fuel recovered from the low pressure part of the high pressure pump to the bomb. And a third shut-off valve to selectively shut off the LP fuel recovered from the pressure regulator and the high pressure pump through the LLP recovery line.

The present invention further includes a mode switch for supplying gasoline fuel to drive an engine and an LPG mode for driving an engine by supplying an LPG fuel, wherein the electronic control unit switches from the gasoline mode to the LPG mode. When the mode switch is operated, the control signal is generated to shut off the first shutdown valve and to open the second and third shutdown valves when a predetermined delay time elapses.

The high-pressure pump is a pressurizing means for generating a suction force and a pressing force of the fuel therein, a damper portion for reducing the pulsation of the fuel, a spill valve installed in the inlet through which the fuel is introduced, and a spill valve for controlling the supply flow rate and the discharge pressure of the fuel, spill valve An inlet side check valve and a outlet side check valve installed at a discharge port through which fuel is discharged, and the remaining excess fuel is supplied to the delivery pipe and the remaining fuel is recovered in the low pressure state through the damper part. Characterized in that the line is transmitted.

According to another feature of the invention, (a) checking the setting state of the mode switch at start-up, (b) proceeding to the gasoline mode or Elpji mode based on the test result of step (a), (c) Supplying gasoline fuel to a high pressure pump by driving a gasoline supply unit in the gasoline mode, (d) driving an LLP supply unit in the LLP mode to supply an LLP fuel to a high pressure pump, and (e) step (c) or and (d) pressurizing the fuel supplied to the high pressure pump to directly spray the combustion chamber of the engine.

The present invention is characterized in that it further comprises the step of (f) directly injecting into the combustion chamber of the vellum fuel supplied to the high pressure pump in the step (e) and recovering the remaining excess lpgi fuel to the bomb through the lpage recovery line. .

When switching to the LLP mode while performing the gasoline mode in the step (c), the first shut-off valve for opening and closing the gasoline fuel supplied to the high-pressure pump, the first delayed shut-off after closing the shutdown valve After the time elapses, it is characterized in that the second shut-off valve for opening and closing the lpig fuel supplied to the high-pressure pump and the third shut-off valve for opening and closing the lpgi fuel recovered through the lpage recovery line.

As described above, the present invention can selectively supply gasoline fuel and LLP fuel to the high pressure pump, and directly inject the fuel pressurized to the high pressure by mixing one injector into the engine.

Accordingly, the present invention can precisely control the injection amount of the gasoline fuel or the LPG fuel in the high-pressure liquid state to improve the power performance and fuel economy of the vehicle, and reduce the carbon generation amount.

In addition, the present invention can properly maintain the level of the liquid fuel in the cylinder by directly recovering fuel from the low pressure portion of the high pressure pump, and can suppress cavitation by preventing the empty space inside the cylinder from increasing rapidly.

In particular, the present invention can maintain the temperature of the fuel in a low temperature state by recovering the low-pressure Elpig fuel before supplying to the delivery pipe through a high pressure pump, thereby maintaining a constant temperature inside the cylinder, thermal equilibrium inside the cylinder Maintain state.

Accordingly, the present invention can perform the pressurized delivery process of the fuel smoothly to improve the performance of the LLP supply unit to the best.

 In addition, the present invention, when switching from the gasoline mode to the LPG mode, the second shut-off valve for opening and closing the gasoline fuel after the predetermined delay time elapses the second shutdown valve for supplying the LPG fuel and the first recovery of the LPG fuel 3 Open the shutdown valve.

Accordingly, the present invention has the effect of preventing the mixing of gasoline fuel and the LPG fuel in the high pressure pump, and precisely controlling the injection amount of the fuel injected into the combustion chamber of the engine to improve the performance of the engine.

1 is a configuration diagram of an Elpia-type Elpgi supply device according to the prior art and the vehicle combined with the Elpig gasoline using the same.
2 is a block diagram of a fuel supply control apparatus for a gasoline and LPG combined vehicle according to a preferred embodiment of the present invention.
Figure 3 is a flow chart illustrating a step-by-step method of controlling the fuel supply of the combined vehicle gasoline support according to a preferred embodiment of the present invention.

Hereinafter, a fuel supply control apparatus and a control method for a gasoline and LPG combined vehicle according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a fuel supply control apparatus for a combined gasoline and LPG vehicle according to a preferred embodiment of the present invention.

In this embodiment, the fuel supplied through the gasoline supply line GS or the LPG supply line LS by the pumping operation of the gasoline pump 12 or the LPG pump 22 at the start of the engine is initially at a predetermined pressure, for example, about 2 bar. The pressure is delivered to the high pressure pump 30, the fuel pressure supplied at the beginning of the start is referred to as a 'low pressure state'.

In addition, the transfer path for transferring the low-pressure LPG fuel from the inlet of the high-pressure pump 30 to the LPG recovery line LR through the damper is referred to as a 'low pressure part'.

As shown in FIG. 2, a fuel supply control apparatus for a combined gasoline and LPG vehicle according to a preferred embodiment of the present invention includes a gasoline supply unit 10 and a cylinder 21 for supplying gasoline fuel stored in a gasoline tank 11. From the high-pressure pump 30, the high-pressure pump 30 to pressurize the pressure of the gasoline fuel or the LPG fuel supplied from the LLP supply unit 20, the gasoline supply unit 10 or the LPG supply unit 20 for supplying the stored LLP fuel The delivery pipe 40 in which the pressurized fuel is filled at high pressure and the fuel filled at high pressure in the delivery pipe 40 are directly injected into the combustion chamber of the engine based on the target RPM of the injector I and the engine E. And the gasoline pump 12 according to the control signal of the electronic control unit (ECU) 50 and the ECU 50 which generate control signals for controlling the driving of the injector I. ), Elfiji And a controller 60 for controlling the drive of the pump 22 and the injector I.

The gasoline supply unit 10 includes a gasoline tank 11 in which gasoline fuel is stored, a gasoline pump 12 pumping gasoline fuel stored in the gasoline tank 11, and a gasoline fuel pumped from the gasoline pump 12 in a high pressure pump 30. And a first shutdown valve 13 installed on the gasoline supply line GS and gasoline supply line GS for selectively blocking gasoline fuel.

The first shutdown valve 13 opens the gasoline supply line GS to supply gasoline fuel according to a control signal of the ECU 50 transmitted through the controller 60 in the gasoline mode in which gasoline fuel is supplied to the engine and driven. do.

On the other hand, the first shutdown valve 13 closes the gasoline supply line GS so as to stop the supply of gasoline fuel in the Elphi mode, which is driven by supplying the engine with Elpji fuel.

The LLP supply unit 20 is installed in the cylinder 21 in which the LLP fuel is stored, and is installed inside the cylinder 21 to pump the fuel pumped by the LLP pump 22 and the LLP pump 22 to pump the LLP fuel. A multi-valve (23), the agent is installed on the elbow supply line (LS), the elbow supply line (LS) for supplying the LPG fuel sent from the multi-valve 23 to the high-pressure pump (30) to selectively block the LPG fuel 2 shut-up valve 24, the Elpji recovery line (LR) for recovering a portion of the Elbegi fuel supplied to the high pressure pump 30 to the cylinder 21, the installed on the Elpig recovery line (LR) of the high pressure pump 30 A third pressure regulating valve 25 for reducing the pressure of the LPG fuel recovered from the low pressure portion to the cylinder 21 and a third shutdown valve for selectively blocking the LPG fuel recovered from the high pressure pump 30 through the LPG recovery line LR. (26).

The second shut-up valve 24 opens the LLP supply line LR to supply the LLP fuel according to the control signal of the ECU 50 transmitted through the controller 60 in the LLP mode.

On the other hand, the second shut-up valve 24 closes the LLP supply line LR to stop the supply of the LLP fuel in the gasoline mode.

The pressure regulator 25 is a pre-pressurized pressure from the low pressure state (2bar) by the continuous pumping operation of the LLP pump 22, the pressure of the LLP fuel recovered from the low pressure portion of the high pressure pump 30 to the cylinder 21, for example When it is pressurized by Δ5 bar and becomes about 7 bar, an internal valve is opened to deliver the LPG fuel to the cylinder 21.

The pressure regulator 25 closes the valve when the pressure inside the cylinder is lower than about 7 bar as fuel is delivered to the cylinder 21 through the open valve, and then opens when the pressure inside the valve is higher than about 7 bar. Repeat the operation.

The pressurization pressure is a pressure set in advance to pressurize the fuel recovered to the cylinder 21 to achieve thermal equilibrium in the cylinder 21 to prevent vaporization.

Accordingly, in the cylinder 21, thermal equilibrium is achieved by the fuel discharged by the LLP pump 22 and the fuel recovered from the high pressure pump 30.

In detail, in the general Elpia system, fuel in the cylinder is discharged so that the fuel stored in the cylinder maintains the liquid state at the lower inner side, but vaporization occurs at the upper space, thereby lowering the saturated vapor pressure inside the cylinder.

As a result, the internal temperature of the bomb is drastically lowered, and fuel is more easily vaporized, and as the cavitation occurs during the first pumping process, the fuel delivery capacity of the LPG pump is significantly reduced.

On the other hand, in the present invention is to achieve a thermal equilibrium inside the bomb by recovering the appropriate amount of fuel through the LLP recovery line.

That is, the present invention can maintain the level of the liquid fuel in the cylinder properly by immediately recovering fuel from the low pressure portion of the high-pressure pump, and prevents a rapid increase in the empty space inside the cylinder, thereby cavitation (cavitation) ) Can be suppressed.

In particular, the present invention can maintain the temperature of the fuel in a low temperature state by recovering the low-pressure Elpig fuel before supplying to the delivery pipe through the high-pressure pump can maintain a constant temperature inside the bomb.

Accordingly, the inside of the cylinder 21 is to maintain the thermal equilibrium state. As such, when the thermal balance is made in the cylinder 21, the pressure sending process of the fuel may be performed smoothly, and thus the performance of the LLP supply unit 20 may be best exhibited.

In this case, the amount of fuel recovered may be controlled to an amount necessary for thermal balance through appropriate evaluation according to the size of the cylinder 21 and the vehicle displacement.

The third shut-up valve 26 recovers the Elpji to recover a portion of the Elpige fuel supplied to the high pressure pump 30 to the cylinder 21 according to the control signal of the ECU 50 transmitted through the controller 60 in the Elpji mode. Open the line LR.

On the other hand, the third shut-up valve 26 closes the LLP recovery line LR to stop the recovery of the LLP fuel in the gasoline mode.

The high pressure pump 30 is pumped by the gasoline pump or the LPG pump 22 to supply the gasoline fuel or a part of the LPG fuel supplied at a low pressure to a high pressure, for example, about 40 to 150 bar to supply the delivery pipe 40.

And the high pressure pump 30 is supplied to the injector (I) from the vellum fuel supplied to the delivery pipe 40 and to recover the excess lpgi fuel to the cylinder 11 through the lpgi recovery line (LR) from the internal low-pressure portion do.

Although the high-pressure pump 30 is not shown in the drawing, the pressurizing means for generating the suction force and the pressing force of the fuel therein, the damper portion for reducing the pulsation of the fuel, the flow rate of the fuel supply and the discharge of the fuel inlet is installed A spill valve for controlling pressure, an inlet check valve connected to the spill valve, and a discharge side check valve installed at a discharge port through which fuel is discharged.

On the other hand, the gasoline pump 12, the LPG 22 and the high pressure pump 30 is preferably provided as a volumetric pump using a piston, a diaphragm, gears, vanes and the like.

Impeller-type pumps, such as turbine pumps, have a positive pressurizing capacity in the pressurization process using two pumps, but gasoline pumps 12, LLP pumps 12 and high-pressure pumps 30 equipped with volumetric pumps pressurize fuel. This is because the effect of the pressurization capability multiplied by the pumping capability of the visual pumps 12, 22 and 30 can be exhibited.

According to the test result, the high pressure pump 30 is pumped by the LLP pump 22 to supply about 95% of the LLP fuel in the idle of the engine E among the fuel supplied to the high pressure pump 30. Through (LR) to recover to the cylinder 21, and during the normal operation of the engine (E) to recover about 60% of the fuel to the cylinder 21.

First and second pressure sensors for detecting the fuel pressure so as to check the moving fuel pressure in the front of the high-pressure pump 30 of the LP feed line (LS) and the rear of the high-pressure pump (30) of the LPG recovery line (LR) Not shown) is preferably installed, the delivery pipe 40 is preferably provided with a third pressure sensor (not shown).

The ECU 50 calculates the target RPM of the engine E, and selectively controls the gasoline supply unit 10 or the Elpji supply unit 20 to supply the gasoline fuel or the LLP fuel according to the calculated RPM.

To this end, the ECU 50 enters the gasoline mode or the LPG mode according to an operation of a mode switch (not shown) or a pre-programmed fuel supply method to selectively drive the gasoline supply unit 10 or the LPG supply unit 20. Control the supply of the fuel.

 For example, when the mode switch is set to the gasoline mode, or when the vehicle is started in the automatic mode or at high speed, the ECU 50 enters the gasoline mode to drive the gasoline supply unit 10 to supply gasoline fuel to the engine E. To control.

On the other hand, when the mode switch is set to the Elpji mode or the low-speed driving in the automatic mode state, the ECU 50 enters the Elpji mode and controls the Elpji fuel supply to the engine by driving the Elpig supply unit 20.

In this case, when the ECU 50 switches from the gasoline mode to the LPG mode, a predetermined delay time elapses after the first shut-off valve 13 is blocked in order to prevent the gasoline fuel and the LPG fuel from mixing in the high pressure pump 30. The second and third shutdown valves 24 and 26 are controlled to open.

The delay time is preferably set to less than about 0.5 seconds.

Meanwhile, the ECU 50 may set a delay time even when switching from the LPG mode to the gasoline mode. The ECU 50 may shut off the second and third shutdown valves 24 and 26 without setting the delay time, and the first shutdown valve ( 13) may be controlled simultaneously to open.

According to the present invention, a gasoline fuel and an LPG fuel are selectively supplied to a high pressure pump, and a single injector is mixed to directly inject the fuel pressurized to a high pressure into the engine.

Accordingly, the present invention can precisely control the injection amount of the gasoline fuel or the LPG fuel in the high-pressure liquid state to improve the power performance and fuel economy of the vehicle, and reduce the carbon generation amount.

Next, with reference to Figure 3 will be described in detail the fuel supply control method of a gasoline and LPG combined vehicle according to an embodiment of the present invention.

3 is a flowchart illustrating a step-by-step method for controlling fuel supply of a gasoline-eligible combined vehicle according to a preferred embodiment of the present invention.

In the present embodiment, for convenience of description, the gasoline mode and the LLP mode will be described. However, the present invention is not necessarily limited thereto. That is, it should be noted that the present invention can be equally applied to the automatic mode in which the mode is switched according to the driving state of the vehicle.

When the ignition key (not shown) is operated to supply power (S10), the ECU 50 checks the setting state of the mode switch (not shown), and enters the gasoline mode or the LPG mode according to the set mode ( S11).

That is, when the mode switch is set to the gasoline mode as a result of the inspection in step S11 (S12), the ECU 50 controls the gasoline supply unit 10 to supply gasoline fuel to the engine E (S13).

In detail, the ECU 50 generates a control signal to open the first shut-off valve 13 and drive the gasoline pump 12 with the second and third shut-off valves 24 and 26 shut off. .

Then, the controller 60 transmits the control signal transmitted from the ECU 50 to the first to third shutdown valves 13, 24, 26 and the gasoline pump 12 to open the first shutdown valve 13. Control to drive the gasoline pump 12 (S14).

Thus, the gasoline fuel stored in the gasoline tank 11 is pumped by the gasoline pump 12 and transferred to the high pressure pump 30 via the gasoline supply line GS.

The high pressure pump 30 pressurizes the gasoline fuel to a high pressure, for example, about 40 to 150 bar and supplies it to the delivery pipe 40.

Therefore, as the high-pressure gasoline fuel is filled in the delivery pipe 40, the injector I directly injects gasoline fuel into the combustion chamber of the engine E according to the control signal of the ECU 50, and the spark plug The engine E is driven while the gasoline fuel is burned by igniting the injected gasoline fuel (S15).

If the mode switch is operated to switch to the LPI mode while driving the engine E in the gasoline mode (S16), the ECU 50 shuts off the first shutdown valve 13 and after a preset delay time has elapsed. A control signal is generated to open the second and third shutdown valves 24 and 26.

Then, the first shut-off valve 13 is cut off according to the control signal transmitted through the controller 60, and the second and third shut-up valves 24 and 26 are operated to open the LLP fuel to the high pressure pump 30. Supply (S17).

The high pressure pump 30 is driven using the driving force of the engine E in conjunction with the camshaft of the engine E, and a portion of the LLP fuel supplied through the second shut-up valve 24 to high pressure, for example, about 40 to 150 bar. Pressurized and supplied to the delivery pipe 40 (S18), and the remaining surplus fuel is delivered to the cylinder 21 through the Elpji recovery line (LR) from the low pressure portion (S19).

At this time, as the valve inside the pressure regulator 25 is opened and closed, fuel pressurized by about Δ5 bar, which is a pressurized pressure, is recovered to the cylinder 21 through the Elpji recovery line LR.

Accordingly, in the cylinder 21, thermal equilibrium is achieved between the Elpji fuel that is pumped and discharged by the Elpge pump 22 and the Elpji fuel that is pressurized and recovered by the pressure regulator 25.

On the other hand, according to the control signal of the ECU 50, as the high-pressure liquid state of the Elpji fuel is injected directly into the combustion chamber of the engine (E), the high-pressure high-molecular fuel as much as the amount of fuel injected into the combustion chamber is It is supplied to the delivery pipe 15.

As such, the delivery pipe 40 maintains a high pressure at all times, and thus, the elbow fuel in the delivery pipe 40 may be continuously maintained in a liquid state.

In addition, the ECU 50 precisely controls the injection amount of the high-pressure liquid Ellipse fuel injected into the combustion chamber of the engine E to improve the power performance and fuel economy of the vehicle, similar to the direct injection method of gasoline fuel, and the amount of carbon generated. Can be reduced.

On the other hand, when the inspection result of step S11, when the mode switch is set to the Elpji mode (S20), the ECU 50 controls to supply the Elpji fuel to the engine (E) by driving the Elpge supply unit 10 (S21). ).

In detail, the ECU 50 generates a control signal to open the second and third shutdown valves 24 and 26 and drive the elbow pump 22 while the first shutdown valve 13 is shut off. .

Then, the controller 60 transmits the control signal transmitted from the ECU 50 to the first to third shutdown valves 13, 24, 26 and the LPG pump 22 so that the second and third shutdown valves 24, Open 26, and controls to drive the LLP pump 22 (S22).

Accordingly, the LLP fuel stored in the cylinder 21 is pumped by the LLP pump 22 and transferred to the high pressure pump 30 through the LLP supply line LS.

The high pressure pump 30 is driven using the driving force of the engine E in conjunction with the camshaft of the engine E, and a portion of the LLP fuel supplied through the second shut-up valve 24 to high pressure, for example, about 40 to 150 bar. It is pressurized and supplied to the delivery pipe 40.

Accordingly, since the delivery pipe 40 is filled with high-pressure vellum fuel, the injector I is driven in accordance with the control signal of the ECU 50 to directly inject the lipid fuel into the engine (S23). The engine E is driven while the LLP fuel is combusted by the spark generated from the plug.

That is, according to the control signal of the ECU 50, the high pressure liquid oil is injected directly into the combustion chamber of the engine E in the injector I, so that the high pressure liquid oil is equal to the amount of fuel injected into the combustion chamber. The delivery pipe 40 is supplied.

Thus, the delivery pipe 40 always maintains a high pressure.

In addition, the ECU 50 may precisely control the injection amount of the high-pressure liquid LLP fuel injected into the combustion chamber of the engine E to improve the power performance and fuel economy of the vehicle and reduce the carbon generation amount.

In step S23, the high-pressure pump 30 supplies the delivery pipe 40 to deliver the surplus of the vellum fuel to the cylinder 21 from the low pressure portion through the lpage recovery line (LR).

At this time, as the valve inside the pressure regulator 25 is opened and closed, the fuel pressurized by about Δ5 bar, which is the pressurized pressure, is recovered to the cylinder 21 through the LLP recovery line LR (S24).

Accordingly, in the cylinder 21, thermal equilibrium is achieved between the Elpji fuel that is pumped and discharged by the Elpge pump 22 and the Elpji fuel that is pressurized and recovered by the pressure regulator 25.

On the other hand, according to the control signal of the ECU 50, as the high-pressure liquid state of the Elpji fuel is injected directly into the combustion chamber of the engine (E), the high-pressure high-molecular fuel as much as the amount of fuel injected into the combustion chamber is It is supplied to the delivery pipe 15.

As such, the delivery pipe 40 maintains a high pressure at all times, and thus, the elbow fuel in the delivery pipe 40 may be continuously maintained in a liquid state.

In addition, the ECU 50 precisely controls the injection amount of the high-pressure liquid Ellipse fuel injected into the combustion chamber of the engine E to improve the power performance and fuel economy of the vehicle, similar to the direct injection method of gasoline fuel, and the amount of carbon generated. Can be reduced.

If the mode switch is operated to switch to the gasoline mode while driving the engine in the Elphi mode (S25), the ECU 50 shuts off the second and third shutdown valves 24 and 26 and the first shutdown valve 13 To generate a control signal.

Then, the second and third shutdown valves 24 and 26 are cut off according to the control signal transmitted through the controller 60, and the first shutdown valve 13 is opened to supply gasoline fuel to the high pressure pump ( S26).

The high pressure pump 30 pressurizes the gasoline fuel supplied through the first shut-up valve 13 to a high pressure, for example, about 40 to 150 bar and supplies the gas to the delivery pipe 40, and the injector I supplies the gasoline fuel of high pressure to the engine. Direct injection into the combustion chamber of (E) (S27).

At this time, the gasoline fuel of a high pressure equivalent to the amount of fuel injected into the combustion chamber from the injector I is supplied to the delivery pipe 40.

The ECU 50 can precisely control the injection amount of the high-pressure gasoline fuel injected into the combustion chamber of the engine E to improve the power performance and fuel economy of the vehicle and reduce the carbon generation amount.

Through the above process, the present invention pressurizes the gasoline fuel or the LPG fuel supplied from the gasoline supply unit or the LPG supply unit at a high pressure pump to a high pressure and is directly injected into the engine through a single injector.

The scope of the present invention is not limited to the embodiments described above, but is defined by the claims, and various changes and modifications can be made by those skilled in the art within the scope of the claims. It is self evident.

In the above-described embodiment, only the gasoline mode and the LLP mode have been described. However, the present invention provides a second method when a predetermined delay time elapses after the first shut-off valve is shut off in the process of mode switching according to the driving state of the vehicle when the automatic mode is set. And controlling the opening of the third shutdown valve to prevent the gasoline fuel and the LPG fuel from mixing with each other.

10: gasoline supply unit 11: gasoline tank
12: gasoline pump 13: first shutdown valve
20: LPI supply 21: Bombe
22: LPG pump 23: multi-valve
24: second shutdown valve 25: pressure regulator
26: third shutdown valve 30: high pressure pump
40: delivery pipe 50: electronic control unit
60: controller I: injector
GS: Gasoline Supply Line LS: LPI Supply Line
LR: Elpig Recovery Line

Claims (7)

In the fuel supply control apparatus for a gasoline and LPG combined vehicle having a gasoline supply unit and an LPG supply unit,
A high pressure pump for pressurizing the gasoline fuel supplied from the gasoline supply unit or the LPG fuel supplied from the LPG supply unit to a preset pressure;
A delivery pipe in which the fuel pressurized from the high pressure pump is filled with high pressure,
An injector for directly injecting fuel filled at high pressure into the delivery pipe into a combustion chamber of an engine;
An electronic control unit for generating a control signal for controlling driving of the LLP supply unit and the injector based on the target RPM of the engine;
A controller for controlling the driving of the gasoline supply unit, the LPG supply unit, and the injector based on the control signal of the electronic control unit,
The gasoline supply unit includes a first shutdown valve installed on the gasoline supply line for supplying the gasoline fuel stored in the gasoline tank to the high pressure pump, and selectively shut off the gasoline fuel,
The LPG supply unit is a fuel supply control of the gasoline and LPG combined vehicle, characterized in that it comprises a second shut-up valve is installed on the LPG supply line for supplying the LPG fuel stored in the cylinder to the high-pressure pump to selectively block the LPG fuel Device. The method of claim 1, wherein the LLP supply unit
An Elpji recovery line for recovering a part of the Elpgi fuel supplied to the high pressure pump to the bomb,
A pressure regulator installed on the LLP recovery line and reducing the pressure of the LLP fuel recovered from the low pressure part of the high pressure pump to the cylinder;
And a third shutdown valve for selectively shutting off the LP fuel recovered from the high pressure pump through the LP pump recovery line. The method of claim 2,
And a mode switch for selecting a gasoline mode for supplying gasoline fuel to drive an engine and an Elpji mode for supplying an Elpji fuel to drive an engine,
The electronic control unit, when the mode switch is operated to switch from the gasoline mode to the LPG mode, the control signal to shut off the first shutdown valve and open the second and third shutdown valve when a predetermined delay time has elapsed. Fuel supply control device for a combined gasoline and LPG vehicle, characterized in that to generate a. According to any one of claims 1 to 3, wherein the high pressure pump
Pressing means for generating the suction force and the pressing force of the fuel therein,
Damper section for reducing the pulsation of fuel,
A spill valve installed at an inlet through which fuel enters and controlling a supply flow rate and a discharge pressure of the fuel;
Inlet check valve connected to spill valve and
A discharge side check valve provided at a discharge port through which fuel is discharged,
The fuel supply control device for a gasoline and LPG combined vehicle, characterized in that the remaining excess fuel is supplied to the delivery pipe and the remaining surplus fuel is transferred to the Elpji recovery line through the damper portion in the low pressure state. (a) checking the setting state of the mode switch at start-up,
(b) proceeding to the gasoline mode or the LPG mode based on the test result of step (a),
(c) driving a gasoline supply unit in the gasoline mode to supply gasoline fuel to a high pressure pump,
(d) driving an Elpage supply unit in the Elpji mode to supply an Elpgi fuel to a high pressure pump; and
(e) pressurizing the fuel supplied to the high pressure pump in step (c) or step (d) to directly spray the fuel in the combustion chamber of the engine. 6. The method of claim 5,
(F) the gasoline and the LPG further comprises the step of directly injecting into the combustion chamber of the LPG fuel supplied to the high-pressure pump in the step (e) and recovering the remaining surplus of the LPG fuel to the bomb through the LPG recovery line Fuel supply control method for combined vehicle. The method of claim 6, wherein in step (c)
When switching to the LPG mode while performing the gasoline mode, the first shut-off valve for opening and closing the gasoline fuel supplied to the high-pressure pump is cut off, after the predetermined delay time elapses after the first shut-off valve is shut off And a second shut-off valve for opening and closing the LLP fuel supplied to the high pressure pump and a third shut-off valve for opening and closing the LLP fuel recovered through the LLP recovery line.

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