JP4152039B2 - LPG engine fuel supply system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an LPG engine fuel supply apparatus characterized in that the LPG fuel supply system is improved from a suction system using a mixer to an LPG fuel pressure injection system.
[0002]
[Prior art]
Recently, in Europe, vehicles using LPG fuel, which is a generic term for liquefied petroleum gas such as propane, propylene, butane and butylene, are being developed in order to reduce pollution and fuel consumption. The reason is that even if the specific gravity of LPG fuel is smaller than that of gasoline fuel and the calorie per unit amount is smaller, the fuel consumption can be increased by nearly 10% by sending high pressure LPG into the engine. Moreover, it is known that the amount of exhaust of harmful substances such as nitrogen oxides and hydrocarbons is reduced. For this reason, for example, fuel tanks are provided as two tanks for LPG fuel and gasoline fuel, and usually run with LPG fuel. By switching to gasoline fuel on the way and using it, you can run with confidence even if there are few LPG fuel filling stations. A fuel supply apparatus having the advantages described above has been proposed. However, the conventional LPG engine fuel supply device that normally runs on LPG fuel and switches to gasoline fuel on the way is still rarely developed in Japan.
[0003]
In addition, in an LPG fuel vehicle in Europe, a device has been developed in which a pressurization device is provided in an LPG tank mounted in a vehicle trunk, and the LPG fuel is pressurized once and supplied to the engine in a high pressure state. However, in the case of applying a pressurization device in the LPG tank like this LPG fuel vehicle in Japan, it is regarded as dangerous because it is regarded as a high-pressure gas production act of the High-Pressure Gas Safety Act. Therefore, a safety distance of about 8 meters or more around the vehicle is required, and it is virtually impossible to run.
[0004]
On the other hand, when LPG fuel is directly supplied to the engine, the latent heat of vaporization, that is, a large amount of heat necessary for vaporizing the LPG fuel, is taken away from the surroundings, so that the LPG fuel supply port to the engine is cooled and the engine does not operate. . Therefore, as shown in FIG. 2, for example, a fuel supply device using a suction system using an LPG fuel mixer has been proposed. That is, high pressure liquid fuel is vaporized from an LPG high pressure gas container 100 storing LPG fuel through a high pressure pipe 101, a filter 102, and a solenoid valve 104 that can be opened and closed by an ignition switch 103 that can be freely started from the driver's seat. The cooling water (heated by cooling) of the engine 107 is sent to the vaporizer 105 through the cooling water guide conduit 108. Then, the primary diaphragm of the vaporizer 105 is elastically deformed by evaporating the high-pressure liquid fuel using the cooling water as a heat source, and the vaporized fuel is adjusted to a pressure higher than the atmospheric pressure, and the adjusted high-pressure vaporized fuel is introduced. By doing so, the secondary diaphragm of the vaporizer 105 is elastically deformed. At this time, the high-pressure vaporized fuel that has flowed into the secondary chamber of the vaporizer 105 is set to a pressure higher than the atmospheric pressure, but the pressure is adjusted to be lower than the internal pressure of the primary chamber, and the high-pressure vaporized fuel regulated in the secondary chamber is reduced to a low pressure. The engine-side mixer 110 is sucked through the hose 109 and using the internal pressure of the secondary chamber of the vaporizer 105.
[0005]
[Problems to be solved by the invention]
That is, this is to supply the LPG fuel by a suction system from a vaporizer by a mixer. However, the conventional LPG engine fuel supply apparatus using this suction system feeds the high-pressure vaporized fuel regulated by the vaporizer 105 to the mixer on the engine 107 side as it is using the low-pressure hose using only its internal pressure. Therefore, stable supply of LPG fuel is maintained from the cold time to the high temperature of the engine 107, but fine control is impossible and the speed is equivalent to that of a vehicle using current gasoline fuel. It was impossible to bring out the driving performance. In addition, there are problems such as that it is very difficult to control the future regulation of exhaust gas.
[0006]
Therefore, the present invention was created in view of the conventional circumstances as described above, and is a conventional LPG engine fuel supply device using a suction system for a vehicle using LPG fuel, which is a low pollution and low fuel consumption fuel. Compared to gasoline-powered vehicles, it is possible to bring out high driving performance at the same speed as that of a vehicle using gasoline fuel, while avoiding legal regulations that apply to high-pressure gas production under the High-Pressure Gas Safety Law, and exhaust gas, especially nitrogen oxides and carbon dioxide. An object of the present invention is to provide an LPG engine fuel supply apparatus improved to an LPG fuel pressurization and injection system capable of exhibiting sufficient effects for gas reduction, energy saving measures, and the like.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, in the present invention, in the LPG engine fuel supply apparatus in the engine 20 that is driven by switching between the supply of LPG fuel and gasoline fuel, at the start of driving of the engine 20 LPG gas phase supply path P for forcibly injecting LPG gas vaporized in the LPG high-pressure gas container 1 to the engine 20, and LPG liquefied in the LPG high-pressure gas container 1 after the engine 20 is warmed up And an LPG liquid phase supply path Q that is heated and vaporized and forcibly supplied to the engine 20.
A junction pipe 12 connected to the gas phase portion of the LPG high-pressure gas container 1 via the vaporizer 9 and connected to the liquid phase portion via the hot water vaporizer 10 and the decompressor 11, and the junction pipe 12 connected to the engine 20 A plurality of LPG injections 13 provided on the downstream side of the plurality of LPG conduits 16 extended corresponding to the plurality of cylinders arranged, and forcibly injecting and distributing the vaporized LPG inside each cylinder. is there.
A liquid phase part pipe extending from the LPG high pressure gas container 1 by connecting the downstream side of the gas phase part pipe 3 extending from the LPG high pressure gas container 1 to the lower end pipe port via a solenoid valve with filter 5A. 4 is connected to the lower end pipe port of the lower end 4 via the solenoid valve with filter 5B, and the upper end pipe port of the branch pipe 15 is connected via the LPG solenoid valve 8A to reduce the pressure. The hot water vaporizer 10 connected to one end of the junction pipe 12 via the vessel 11 is connected to the upper end of the branch conduit 15 via the LPG solenoid valve 8B and connected to the other end of the junction pipe 12. A vaporizer 9, a plurality of LPG conduits 16 extended to correspond to a plurality of cylinders disposed in the engine 20 in the junction pipe 12, and the LPG A plurality of LPG injections 13 provided on the downstream side of the pipe 16 for forcibly distributing and injecting LPG vaporized inside the cylinders, solenoid valves 5A and 5B with filters, both LPG solenoid valves 8A and 8B, and each LPG An LPG engine fuel supply device having an electronic control device 18 connected to each injection 13 via a driver 6, which opens a solenoid valve with filter 5 </ b> A on the downstream side of the gas-phase part pipe 3, and liquid-phase part pipe 4 By closing the downstream solenoid valve with filter 5B, the gas phase section pipe 3, the branch pipe 15 communicating with the gas phase section pipe 3 via the filter solenoid valve 5A, and the branch pipe 15 Junction pipe 1 through vaporizer 9 connected via LPG solenoid valve 8B LPG vapor phase supply path P for supplying the vaporized LPG to the bottom, and the solenoid valve with filter 5A on the downstream side of the gas phase piping 3 is closed, and the solenoid valve with filter on the downstream side of the liquid phase piping 4 By opening the valve 5B, the liquid phase section pipe 4, the branch pipe 15 communicating with the liquid phase section pipe 4 via a solenoid valve with filter 5B, and the branch pipe 15 connected via the LPG solenoid valve 8A LPG liquid phase part for supplying LPG vaporized to the junction pipe 12 through the hot water vaporizer 10 that is connected to and the decompressor 11 connected to the hot water vaporizer 10 so as to depressurize the high-pressure gas vaporized by the hot water vaporizer 10 The supply path Q is configured.
A check valve 14 may be attached immediately before the solenoid valve with filter 5B on the downstream side of the liquid phase pipe 4.
The driver 6 may include an LPG fuel / gasoline fuel supply changeover switch 7 for manually and instantaneously switching between the LPG fuel use state and the gasoline fuel use state.
[0008]
In the LPG engine fuel supply apparatus according to the present invention configured as described above, an LPG vapor phase supply path P for supplying vaporized LPG is formed when the engine is cold. That is, the solenoid valve with filter 5B on the downstream side of the liquid phase pipe 4 and the LPG solenoid valve 8A on the hot water vaporizer 10 side are closed by the output signal from the electronic control unit 18 via the driver 6 and at the same time the gas phase The solenoid valve with filter 5A on the downstream side of the pipe section 3 and the LPG solenoid valve 8B on the vaporizer 9 side are opened, and the vapor phase LPG in the LPG high-pressure gas container 1 is taken out through the vapor section pipe 3 and vapor is removed. It is sent to the riser 9 where it is vaporized under reduced pressure and then supplied to the junction pipe 12.
The junction pipe 12 feeds the vaporized LPG to the LPG injection 13 side inside the plurality of cylinders disposed in the engine 20 via the plurality of LPG conduits 16 and amplifies the electronic control device 18 by the driver 6. The engine 20 is started by forcibly distributing the vaporized LPG into the cylinder through the LPG injection 13 based on the injection signal for the gasoline engine.
After that, when the warm-up operation is performed and the temperature reaches a constant temperature, an LPG liquid phase part supply path Q for supplying liquefied LPG is formed. That is, the solenoid valve with filter 5A on the downstream side of the gas phase section pipe 3 is closed and the solenoid valve with filter 5B on the downstream side of the liquid phase section pipe 4 is opened to switch to the LPG liquid phase supply state. When the temperature further rises, the LPG solenoid valve 8A is opened by an output signal from the electronic control unit 18 via the driver 6 to open a passage to the hot water vaporizer 10, and the LPG decompressed by the decompressor 11 is connected to the junction pipe 12. Let's add to.
At this time, the check valve 14 disposed immediately before the solenoid valve with filter 5B on the downstream side of the liquid phase pipe 4 prevents the high pressure LPG from flowing back from the liquid phase pipe 4 into the LPG high pressure gas container 1. The LPG return gas is returned into the LPG high-pressure gas container 1 through the gas phase pipe 3.
The LPG fuel / gasoline fuel supply changeover switch 7 that switches between the LPG fuel use state and gasoline fuel use state, which are arranged in the driver 6, is instantaneously switched between the LPG use state and gasoline use state of the engine as needed. Switch to.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1. Reference numeral 1 shown in the figure denotes propane, propylene, butane in an LPG engine fuel supply apparatus mounted in a vehicle trunk as an injection engine. This is an LPG high-pressure gas container in which LPG fuel, which is a generic name for liquefied petroleum gas such as butylene, is stored and filled in a high-pressure state compressed to about 1/250 of the gas state via the filling conduit 2. The LPG high-pressure gas container 1 has a gas-phase part pipe 3 extending outside through an inverted U-shaped supply pipe 3A facing the gas-phase side inside the container, and a container in parallel with the gas-phase part pipe 3 The liquid phase part piping 4 is extended outside through the supply nozzle 4A immersed in the liquid phase side inside.
[0010]
When the LPG high-pressure gas container 1 side is the upstream side and the junction pipe 12 side, which will be described later, is the downstream side, the downstream side of the gas phase section pipe 3 is connected to a filter-equipped solenoid valve 5A, for example, an H type The lower end of the branch pipe 15 formed in the pipe is connected to the lower end of the pipe, while the downstream side of the liquid phase pipe 4 is connected to the lower end of the branch pipe 15 via the filter-equipped solenoid valve 5B. It is.
[0011]
The upper one end of the branch conduit 15 is connected to the hot water vaporizer 10 via the LPG solenoid valve 8 </ b> A, and this hot water vaporizer 10 is connected to one end of the junction pipe 12 via the decompressor 11. On the other hand, the upper other end pipe port of the branch conduit 15 is connected to a small vaporizer 9 via an LPG solenoid valve 8B, and this vaporizer 9 is connected to the other end of the junction pipe 12. The vaporizer 9 adjusts the pressure of the high-pressure liquid fuel from the LPG high-pressure gas container 1 to a high-pressure vaporized fuel having a constant pressure slightly higher than the atmospheric pressure. The LPG fuel taken out from the phase pipe 3 is vaporized under reduced pressure and supplied to the junction pipe 12. Further, the vaporizer 9 and the hot water vaporizer 10 circulate the water on the radiator side of the engine 20 through a cooling water guide member (not shown), whereby the LPG fuel supplied from the liquid phase part can be obtained by the engine. While being heated and vaporized by warm water such as a radiator, the LPG fuel that has become high pressure due to vaporization is decompressed by the decompressor 11 and then supplied to the junction pipe 12.
[0012]
A check valve 14 is attached immediately before the solenoid valve 5B with a filter on the downstream side of the liquid phase pipe 4 and, for example, LPG expands due to high-temperature water and becomes a high-pressure state during continuous running on a highway or the like, so that it temporarily In order to prevent the flow of the LPG fuel from flowing backward and stopping the high-speed operation performance, the high-pressure return gas is returned to the LPG high-pressure gas container 1 via the gas phase pipe 3.
[0013]
Both solenoid valves with filters 5A and 5B, both LPG solenoid valves 8A and 8B, and each LPG injection 13 are LPG fuel / gasoline fuel supply switching for instantaneously switching between LPG fuel use state and gasoline fuel use state manually. A switch 7 and an LPG switch 17 for manual ON / OFF switching operation in the LPG fuel usage state are connected to a driver 6. The driver 6 is connected to an electric control unit (ECU) 18 through one contact of an ignition switch 19, and both filters are attached by an electric signal output from the electric control unit 18 through the driver 6. The solenoid valves 5A and 5B and both LPG solenoid valves 8A and 8B are opened and closed, and the driver 6 amplifies the gasoline injection signal to the LPG injection 13 to operate the LPG injector.
[0014]
On the other hand, the other contact point of the ignition switch 19 is connected to the electric control device 18 and the gasoline injector 21 on the engine 20 side. The fuel injection time of the engine 20 is determined by the electric control device 18 and a drive signal corresponding to the fuel injection time is determined. The fuel is injected. The electric control device 18 is connected to an O ₂ sensor 22 disposed on the exhaust manifold on the engine 20 side, detects the oxygen concentration in the exhaust gas, sends the output voltage to the electric control device 18, and the combustion injection time of the engine 20 Is controlled to obtain the stoichiometric air-fuel ratio.
[0015]
A plurality of LPG conduits 16 are extended on the side surfaces of the junction pipe 12 corresponding to the plurality of cylinders arranged in the engine 20, and the LPG vaporized inside each cylinder is forcibly injected and distributed to each cylinder. A plurality of corresponding LPG injections 13 are provided. The LPG injection 13 is vaporized by determining the LPG fuel injection time of the engine 20 at the time of start-up based on an output signal from the electric control device 18 via the driver 6 and injecting LPG fuel with a drive signal corresponding to the LPG fuel injection time. The LPG vapor phase supply path P through which the LPG fuel thus supplied is configured.
[0016]
Further, when the warm-air operation reaches a certain temperature, the solenoid valve with filter 5A on the downstream side of the gas phase pipe 3 is closed, and the solenoid valve 5B with filter on the downstream side of the liquid phase pipe 4 is opened to open the LPG fuel. When the temperature is further increased, the LPG solenoid valve 8A is opened by an output signal from the electric control device 18 via the driver 6 to open the passage to the hot water vaporizer 10, The LPG fuel depressurized by the decompressor 11 is supplied to the junction pipe 12 so as to be in a normal operation mode, thereby constituting the LPG liquid phase supply path Q for supplying the vaporized LPG fuel. is there.
[0017]
Reference numeral 30 in the drawing denotes a gasoline supply pipe connected to the gasoline injector 21 for supplying gasoline fuel to the engine 20.
[0018]
Next, an example of use and operation of the embodiment configured as described above will be described. First, as shown in the figure, when the engine is cold, the LPG switch 17 is manually turned on to use LPG fuel. At the same time, the solenoid valve with filter 5B on the downstream side of the liquid phase piping 4 and the LPG solenoid valve 8A on the hot water vaporizer 10 side are closed by the output signal from the electric control device 18 via the driver 6, The solenoid valve with filter 5A on the downstream side of the gas phase pipe 3 and the LPG solenoid valve 8B on the vaporizer 9 side are opened. At this time, the gas phase LPG fuel in the LPG high pressure gas container 1 is taken out via the gas phase pipe 3 and sent to the vaporizer 9 where it is vaporized under reduced pressure and then supplied to the junction pipe 12. Then, an injection signal for a gasoline engine is supplied to the LPG injection 13 side inside the plurality of cylinders arranged in the engine 20 through the plurality of LPG conduits 16 of the junction pipe 12 and amplified by the driver 6 for the gasoline engine. Based on this, the vaporized LPG fuel is forcibly injected and distributed into the cylinder through the LPG injection 13 to start the engine 20.
[0019]
Thereafter, when the warm-up operation reaches a certain temperature, the solenoid valve with filter 5A on the downstream side of the gas phase section pipe 3 is closed, and the solenoid valve with filter 5B on the downstream side of the liquid phase section pipe 4 is opened to open the LPG. Switch to the liquid phase supply state of the fuel. When the temperature further rises, an LPG solenoid valve 8A is opened by an output signal from the electric control device 18 via the driver 6 to open a passage to the hot water vaporizer 10, and the LPG fuel vaporized and pressurized by the hot water vaporizer 10 Is decompressed by the decompressor 11 and the decompressed LPG fuel is supplied to the junction pipe 12 to enter the normal operation mode. At this time, in the case of continuous operation on an expressway or the like, the LPG fuel expands and becomes high pressure due to high temperature water, and reversely flows temporarily to stop the flow. The back flow of the high pressure LPG fuel into the high pressure gas container 1 is prevented, and the return gas of the high pressure LPG fuel is returned into the LPG high pressure gas container 1 via the gas phase pipe 3. Then, the LPG fuel / gasoline fuel supply changeover switch 7 may instantaneously switch between the LPG fuel use state and the gasoline fuel use state of the engine as necessary.
[0020]
【The invention's effect】
As described above, according to the present invention, in the LPG engine fuel supply apparatus in the engine 20 driven by switching the supply between the LPG fuel and the gasoline fuel, the LPG high-pressure gas container at the start of driving of the engine 20 LPG vapor phase supply path P for forcibly injecting the LPG gas vaporized in the engine 20 to the engine 20, and the LPG in the LPG high-pressure gas container 1 is heated and vaporized after the engine 20 is warmed up LPG liquid phase supply path Q forcibly supplying the engine 20 to the engine 20 is used, so that the vehicle using LPG fuel, which is a low-pollution and fuel-efficient fuel, can use gasoline fuel as much as possible. Legal regulations for high-pressure gas production activities under the High-Pressure Gas Safety Act, which can bring out high driving performance at the same speed as vehicles. It is possible to avoid, it is possible to exhibit a sufficient effect on the exhaust gases, in particular reduction of nitrogen oxides and carbon dioxide gas, energy saving, carbon dioxide decreased, or the like.
[0021]
A junction pipe 12 connected to the gas phase portion of the LPG high-pressure gas container 1 via the vaporizer 9 and connected to the liquid phase portion via the hot water vaporizer 10 and the decompressor 11, and the junction pipe 12 connected to the engine 20 A plurality of LPG injections 13 provided on the downstream side of a plurality of LPG conduits 16 extended corresponding to the plurality of cylinders arranged, and forcibly injecting and distributing the vaporized LPG inside each cylinder; As a result, it is possible to bring out a large traveling performance at the same speed as that of a vehicle using gasoline fuel, and to avoid the legal regulation corresponding to the high-pressure gas manufacturing act of the High-Pressure Gas Safety Law.
[0022]
By opening the solenoid valve with filter 5A downstream of the gas phase pipe 3 and closing the solenoid valve 5B with filter downstream of the liquid phase pipe 4, the gas phase pipe 3 and the gas phase pipe LPG gas phase for supplying vaporized LPG fuel to the junction pipe 12 through a branch conduit 15 that communicates with 3 through a solenoid valve with filter 5A and a vaporizer 9 that connects to this branch conduit 15 through an LPG solenoid valve 8B. The liquid phase section pipe is constructed by forming the section supply path P, closing the solenoid valve with filter 5A on the downstream side of the gas phase section pipe 3, and opening the solenoid valve with filter 5B on the downstream side of the liquid phase section pipe 4. 4, a branch conduit 15 communicating with the liquid phase pipe 4 through a solenoid valve 5B with a filter, and an LP in the branch conduit 15 The hot water vaporizer 10 for vaporizing and pressurizing the liquid in the LPG liquid phase connected via the solenoid valve 8A, and the vaporized LPG fuel is supplied to the junction pipe 12 through the decompressor 11 connected to the hot water vaporizer 10. Since the LPG liquid phase part supply path Q is configured, the LPG gas phase part supply path P and the LPG liquid phase part supply path Q are switched to each other so as to be distributed to the engine 20 from the cold air operation to the warm air operation of the vehicle. The forced high pressure injection of LPG fuel into the plurality of cylinders can be performed efficiently and continuously, and both the liquid phase portion and the gas phase portion of the LPG high pressure gas container 1 can be used without waste.
[0023]
A check valve 14 is attached immediately before the solenoid valve 5B with a filter on the downstream side of the liquid phase pipe 4 so that the backflow of the high pressure LPG from the liquid phase pipe 4 into the LPG high pressure gas container 1 can be prevented. The LPG return gas can be efficiently returned into the LPG high-pressure gas container 1 via the gas phase pipe 3, and a reduction in high-speed operation performance can be prevented.
[0024]
The driver 6 has an LPG fuel / gasoline fuel supply changeover switch 7 for manually switching between the LPG fuel use state and the gasoline fuel use state, so that the LPG fuel use state / gasoline fuel use state of the engine as necessary. Can be switched instantaneously, and the performance can be maximized by using either LPG fuel or gasoline fuel.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram according to an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram showing a conventional example.
[Explanation of symbols]
P ... LPG gas phase supply path Q ... LPG liquid phase supply path 1 ... LPG high pressure gas container 2 ... Filling hose 3 ... Gas phase pipe 3A ... Reverse U-shaped supply pipe 4 ... Liquid phase pipe 4A ... Supply nozzle 5A, 5B ... Solenoid valve with filter 6 ... Driver 7 ... LPG fuel / gasoline fuel supply selector switch 8A, 8B ... LPG solenoid valve 9 ... Vaporizer 10 ... Hot water vaporizer 11 ... Pressure reducer 12 ... Junction pipe 13 ... LPG injection 14 ... Check valve 15 ... Branch pipe 16 ... LPG pipe 17 ... LPG switch 18 ... Electronic control unit (ECU) 19 ... Ignition switch 20 ... Engine 21 ... Gasoline injector 22 ... O ₂ sensor 30 ... Gasoline supply pipe 100 ... LPG high pressure gas Container 101 ... High-pressure pipe 102 ... Filter 103 ... Ignit Switch 104 ... solenoid valve 105 ... vaporizer 106 ... suction conduit 107 ... engine 108 ... cooling water guide conduit 109 ... low pressure hose 110 ... mixer

Claims (2)

  In an LPG engine fuel supply apparatus in a vehicle engine that is driven by switching between supply of LPG fuel and gasoline fuel, the LPG gas vaporized in the LPG tank is forced to the engine at the start of engine driving. An LPG vapor phase supply path for injecting and supplying, and an LPG liquid phase supply path for forcibly supplying the LPG in the LPG tank by heating and vaporizing after the engine is warmed, Connect the downstream side of the gas-phase part pipe extended from the LPG high-pressure gas container to the lower one end through the solenoid valve with filter, and connect the downstream side of the liquid-phase part pipe extended from the LPG high-pressure gas container A branch conduit connected to the lower other end pipe port via a solenoid valve with a filter, and an upper one end pipe port of this branch conduit are connected to an LPG solenoid. A hot water vaporizer connected to one end of a junction pipe via a pressure reducer and an upper other end of the branch pipe are connected via an LPG solenoid valve to the other end of the junction pipe. The connected vaporizer, a plurality of LPG conduits extended corresponding to the plurality of cylinders arranged in the engine on the junction pipe, and the LPG vaporized inside each cylinder provided on the downstream side of the LPG conduits A plurality of LPG injections forcibly distributing and injecting, both solenoid valves with filters, both LPG solenoid valves, and an electronic control unit connected to each LPG injection via a driver; Open solenoid valve with filter, and solenoid with filter on the downstream side of the liquid phase piping By closing the valve, the junction pipe passes through the gas phase pipe, the branch pipe communicating with the gas phase pipe via a solenoid valve with a filter, and the vaporizer connected to the branch pipe via the LPG solenoid valve. LPG vapor phase supply path for supplying the vaporized LPG to the gas phase, and the solenoid valve with filter on the downstream side of the gas phase pipe is closed, and the solenoid valve with filter on the downstream side of the liquid phase pipe is opened. A liquid phase pipe, a branch conduit communicating with the liquid phase pipe via a solenoid valve with a filter, a hot water vaporizer connected to the branch pipe via an LPG solenoid valve, and the hot water vaporizer And a decompressor connected to the hot water vaporizer to depressurize the LPG high-pressure gas vaporized by the The LPG liquid phase supply path for supplying the LPG vaporized to the engine is configured, and the driver has an LPG fuel / gasoline fuel supply changeover switch for manually switching between the LPG fuel use state and the gasoline fuel use state instantaneously. An LPG engine fuel supply device provided.   The LPG engine fuel supply apparatus according to claim 1, wherein a check valve is attached immediately before the solenoid valve with a filter on the downstream side of the liquid phase pipe.

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