JPH05248323A - High pressure fuel feeder for fuel injection engine - Google Patents

Abstract

PURPOSE:To prevent splashing of a fuel from a vapor separator located in a fuel feeding system by preventing the reverse stream of compressed air to the fuel feeding system. CONSTITUTION:An air path 59 of an injector 42 for air and a fuel path 59 of an injector 45 for fuel are confluent with one another, and the fuel is supplied to an engine 17 main body along with high pressure air, by a high pressure fuel feeder for fuel injection engine. A first air regulator 131 is provided in the device, by which the compressed air in a delivery tube path 44 for air is discharged when the pressure of a fuel pump is lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure fuel supply system for a fuel injection engine suitable for use in an outboard motor or the like.

[0002]

2. Description of the Related Art The applicant of the present invention has filed Japanese Patent Application No. 3-297696.
The compressed air sent by the air compressor is supplied from the air delivery conduit to the air injector, the fuel in the fuel tank is guided to the vapor separator, and the fuel in the vapor separator is injected from the fuel delivery conduit by the fuel pump. A high-pressure fuel supply device for a fuel injection engine, which supplies the fuel to the engine body together with the high-pressure air by merging the air passage of the air injector with the fuel passage of the fuel injector.

[0003]

However, in the above-mentioned prior art, there is no check valve in the fuel passage of the fuel injector, or even if there is only a check valve having a backflow prevention pressure lower than the pressure of the compressed air. ..

Therefore, when the fuel pump stops abnormally and the pump pressure drops, the compressed air pumped into the air passage of the air injector intrudes into the fuel passage of the fuel injector, and then the delivery line for fuel, It flows back to the vapor separator through the fuel pump. As a result, the fuel in the vapor separator may be explosively scattered by the backflow compressed air.

According to the present invention, in a high-pressure fuel supply system for a fuel injection engine, when the air passage of the air injector and the fuel passage of the fuel injector are merged and the compressed air pressure is used for fuel injection, the compressed air fuel is supplied. It is an object of the present invention to prevent backflow into the system and prevent fuel from scattering from the vapor separator located in the fuel supply system.

[0006]

SUMMARY OF THE INVENTION According to the present invention, compressed air sent by an air compressor is supplied from an air delivery pipe to an air injector, and fuel in a fuel tank is introduced to a vapor separator so that the fuel in the vapor separator is discharged. A fuel injection engine for supplying fuel to a fuel injector from a fuel delivery pipe by a fuel pump, and further joining the air passage of the air injector and the fuel passage of the fuel injector to supply fuel with high-pressure air to the engine body. The high-pressure fuel supply device for a vehicle is provided with high-pressure air discharging means for discharging the compressed air in the air delivery pipeline when the fuel pump pressure decreases.

[0007]

When the pressure of the fuel pump is reduced, the compressed air in the air delivery conduit is immediately discharged by the high pressure air discharge means. For this reason, the compressed air is stopped from being pressure-fed from the air delivery pipeline to the air passage of the air injector, and the compressed air may enter the fuel passage of the fuel injector and flow back to the fuel supply system. Absent. Therefore, the fuel in the vapor separator is not explosively scattered by the backflow compressed air.

[0008]

1 is a schematic view showing an outboard motor, FIG. 2 is a schematic view showing an engine, FIG. 3 is a front view showing the engine, FIG. 4 is a schematic view seen from the IV direction in FIG. 3, and FIG. FIG. 7 is a schematic view seen from the direction V in FIG. 3, FIG. 6 is a schematic view showing a fuel supply unit, and FIG.
Is a cross-sectional view showing an air regulator and a fuel regulator,
8 is a circuit diagram showing an air regulator and a fuel regulator, FIG. 9 is a sectional view showing an injector, FIG. 10 is a sectional view showing a fuel injector, and FIG. 11 is a flow chart showing a fuel supply system.

The outboard motor 10 has a hull 11 as shown in FIG.
The clamp bracket 12 can be attached to the swivel bracket 14, which is tiltably supported by the clamp bracket 12 via the tilt shaft 13, and the propulsion unit 15 is steerably supported by the swivel bracket 14. 16 is a clamp bracket 1
The tilting cylinder is interposed between the swivel bracket 14 and the swivel bracket 14. The outboard motor 10 outputs the output of the engine 17 mounted on the upper portion of the propulsion unit 15 to the propeller 1
8 to enable the hull 11 to move forward, stop, and reverse. A cowling 19 covers the engine 17.

A fuel tank 20 is placed inside the hull 11, and a primary pump 21 is installed in the fuel tank 20.
Is connected to the fuel supply pipe 22.

The engine 17 is a cylinder injection type two-cycle V
As shown in FIG. 2 and FIG. 3, the crankshaft 23A is vertically arranged at a substantially central portion where the cylinder bodies 23 of the left and right banks intersect each other.
A piston (not shown) is connected to the cylinder, and a combustion chamber 25 is formed between the piston and the cylinder head 24 (see FIG. 9). Incidentally, 26 is a spark plug.

The engine 17 is provided in a crank chamber (not shown) on the opposite side of the cylinder head 24 via a reed valve type check valve 28 provided in an intake manifold 27 corresponding to each cylinder arranged vertically. , The throttle body 29 is connected, and the throttle valve 3 is provided in each throttle body 29.
It has 0. An intake silencer 31 is arranged on the upstream side of the throttle body 29. The air introduced into the crank chamber through the check valve 28 of the intake manifold 27 is pre-compressed in the crank chamber and supplied to the combustion chamber 25 through the scavenging passage 23B of each cylinder opened and closed by the reciprocating movement of the piston. To be done.

As a result, the air taken in from the air intake opening of the cowling 19 becomes the intake silencer 31, the throttle valve 30, the intake manifold 27, as shown in FIG.
Through the check valve 28, the crank chamber, and the scavenging passage, the combustion chamber 2
An intake air supply system that is supplied to the unit 5 is configured.

The engine 17 includes a cylinder head 24 of each of the left and right banks, a delivery unit 32 for each cylinder,
32 are extended.

The delivery unit 32 has a set of injection nozzles 41, a high-pressure air injector 42, and a fuel injector 43 for each cylinder, and the injection nozzle 41 is projected into the combustion chamber 25 of each cylinder. ..

The delivery unit 32 extends vertically through the high pressure air delivery pipe line 44, and the air compressor 61, which will be described later, pressurizes the high pressure air delivery pipe line 44 so that the air flowing downward from above the high pressure air delivery pipe line 44 is discharged. It is supplied to each high-pressure air injector 42. Further, the delivery unit 32 extends the fuel delivery pipe line 45 in the up-down direction, and the high-pressure fuel pump 72 described later pressure-feeds the fuel flowing through the fuel delivery pipe line 45 from below to above. Supply to.

As shown in FIG. 9, the injection nozzle 41 of each cylinder is connected to a high pressure air injector 42. The component including the air injector 42 and the injection nozzle 41 is attached to the delivery unit 32 via O-rings 46A and 46B, respectively. An on-off valve 47 that opens and closes its mouth is provided in the injection nozzle 41, and its valve rod 48 extends to the upper portion of the air injector 42. A stopper 49 and a movable member 50 are fixed to the upper portion of the valve rod 48, and a coil spring 51 that is compacted urges the valve rod 48 upward through the movable member 50, thereby closing the opening / closing valve 47. Is urged to. Reference numeral 52 is a solenoid coil, and when the solenoid coil 52 is excited via the connector 53, the movable member 50 is moved to the coil spring 51.
9 is moved to the lower side of FIG.
Open. Reference numeral 54 is an inlet for high-pressure air, which communicates with the delivery conduit 44 for high-pressure air.

A throttle portion 55 is formed at a substantially central portion of the valve rod 48, and a fuel port 56 which opens facing the throttle portion 55.
A fuel nozzle 57 of the fuel injector 43 is open so as to communicate with the fuel injector 43. This fuel injector 43 is also attached to the delivery unit 32 via an O-ring 58.

With this configuration of the delivery unit 32,
So-called air-assisted fuel injection is performed on the combustion chamber 25. That is, the solenoid coil 52 is energized, the movable member 50 moves against the urging force of the coil spring 51, and the opening / closing valve 47 is opened, so that the pressurized air from the inlet 54 passes through the throttle portion 55 and the passage. Introduced in 59. At the same time, the high-pressure fuel injected from the fuel nozzle 57 of the fuel injector 43 is smoothly introduced into the passage 59 from the throttle portion 55 whose pressure is reduced by the passage of the pressurized air, and joins with the air. As a result, fuel is injected from the position of the opening / closing valve 47 into the combustion chamber 25 together with the high pressure air.

The system for supplying high pressure air and fuel to the delivery unit 32 will be described below (see FIGS. 3 to 8).

That is, an air compressor 61 and a fuel supply unit 62 are arranged between the left and right banks of the engine 17. 61A is an air compressor support stay (see FIG. 4).

The fuel supply unit 62 includes an upper case 63A.
The lower case 63B and the lower case 63B are united with each other via a seal 64, and the substantially
Type air separator 6 on the upper side in the vapor separator 63 of the mold
5, an air filter 66 is built in, and a gas-liquid separation chamber 70 and a fuel filter 7 are provided on the lower side inside the vapor separator 63.
1. A high-pressure fuel pump 72 is built in, and a regulator assembly (see FIG. 7) including an air regulator 67 and a fuel regulator 73 is integrated in an L-shaped recess on the outer side of the vapor separator 63. 63C is the lower case 63
It is a drain bolt of the vapor separator 63 screwed to the bottom portion of B. The fuel pump 72 is supported in the cases 63A and 63B of the vapor separator 63 via mount rubbers 165A and 165B described later. And
A spout 76 having an O-ring 75 is provided around the discharge port 74 of the fuel pump 72, and a fuel receiving port 77 of the upper case 63A is provided with a receiving part 79 having an O-ring 78. As a result, when the upper and lower cases 63A and 63B are united, the spigot portion 76 of the fuel pump 72 is placed in the upper case 6
It can be liquid-tightly fitted and assembled to the receiving port 79 of 3A. In FIG. 6, A and B are anode terminals, and C and D are cathode terminals.

In addition, 80 is fixed to the upper case 63A,
It is a holding plate that holds the air filter 66 and the receptacle 79 and has a large number of holes.

The delivery unit 32, the air compressor 61, and the fuel supply unit 62 are housed inside a first cover 81 and a second cover 82 which are phase-coupled as shown in FIG. The covers 81 and 82 cover at least the rear of the engine and the upper and lateral sides around the head of the engine.

The air compressor 61 is connected to the engine 17
The reciprocating motion of the piston driven by
Air sucked from the air intake port 88 of the two filter silencers 87 via the suction side reed valve, and the air in the air intake device 65 built in the upper part of the vapor separator 63 is connected to the air filter 66 and the air outlet 83A. The air is sucked from the suction pipe 83 via the suction side reed valve and discharged from the air discharge pipe 84 via the discharge side reed valve. The air intake 65 has an air intake 85 which is an opening in the upper case 63A.
To the inner space of the covers 81 and 82, and to the air regulator 67 via the excess air return port 86.

In FIG. 2, reference numeral 1 is an air compressor pulley, and the pulley 1 is a drive pulley 2 around a crankshaft 23A.
It is driven by the drive belt 3 wound around.
In addition, 4 is a flywheel magneto cover, 5 is a tension pulley, 6 is a generator, and 7 is a starter (see FIG. 2).

The air compressor 61 includes a lubricating oil supply pipe 9
Lubricating oil supply port 91A to which 1 is connected, lubricating oil discharge pipe 92
Is provided with a lubricating oil discharge port 92A, a cooling water supply pipe 93 connected with a cooling water supply port 93A, and a cooling water discharge pipe 94 connected with a cooling water discharge port 94A. The cooling water supply pipe 93 is provided below the engine 17 and
Of the cooling water jacket, and the cooling water discharge pipe 94 is connected to the pilot water outlet for cooling confirmation.

The air discharge pipe 84 of the air compressor 61 is connected to the left and right delivery units 32, 3 via a T-shaped connector.
The two high pressure air pipes 96, 96 are connected to each other.
Then, each high-pressure air pipe 96 is connected to each delivery unit 3
It is connected to the upper nipple of the second delivery line 44 for high pressure air.

An excess air return pipe 97 is connected to the lower end nipple of the delivery line 44 for high pressure air of each delivery unit 32. The surplus air return pipes 97, 97 connected to the left and right delivery units 32, 32 are connected to the surplus air return pipe 98 by a T-shaped connector, and thus communicated with the air regulator 67. The air regulator 67 is connected to the surplus air return port 86 of the air intake device 65 described above.

As a result, the air taken in from the air intake opening of the cowling 19 is, as shown in FIG. 11, two silencers 87 with filters, or an air intake 85 and an air intake 65 opened in the upper case 63A. From either of the air intake paths of the air filter 66, the air compressor 6
1. A high pressure air supply system to the injection nozzle 41, which is supplied to the injection nozzle 41 via the delivery line 44 for high pressure air and the injector 42 for high pressure air, is configured. At the same time, from the delivery line 44 for high pressure air to the air regulator 67
A surplus air return system is configured to reach the air intake device 65 via.

On the other hand, the fuel in the fuel tank 20 on the side of the hull 11 is pressure-fed to the fuel supply pipe 22 by the primary pump 21 and is supplied to the filter 102 and the fuel pump 103 in the cowling 19 via the connector 101. From the rubber fuel discharge pipe 104 connected to 103 to the gas-liquid separation chamber 70 in the vapor separator 63 from the needle valve 106 capable of opening and closing the fuel intake passage 105 through the fuel intake passage 105 penetrating the upper case 63A. Is supplied to.
107 is a float for operating the needle valve 106.

The fuel supplied to the gas-liquid separation chamber 70 is sucked from the fuel filter 71 into the suction port 108 of the high-pressure fuel pump 72, and is connected to the fuel pressure supply port 77 communicating with the discharge port 74 of the high-pressure fuel pump 72. The fuel is discharged to the fuel connecting pipe 109. The fuel connecting pipe 109 is connected to the fuel pipes 111, 111 connected to the left and right delivery units 32, 32 via a T-shaped connector. Then, the fuel pipe 111 is connected to the lower end nipple of the fuel delivery pipeline 45 of each delivery unit 32.

An excess fuel return pipe 112 is connected to the upper end nipple of the fuel delivery pipe 45 of each delivery unit 32. The surplus fuel return pipes 112, 112 connected to the left and right delivery units 32, 32 are connected to the surplus fuel return pipe 114 by a T-shaped connector, and thus communicated with the fuel regulator 73. Then, the fuel regulator 73 is connected to the gas-liquid separation chamber 70 from the excess fuel return passage 116 penetrating the upper case 63A of the vapor separator 63 via the excess fuel return pipe 115.

As a result, the fuel tank 20 in the hull 11 is
As shown in FIG. 11, the fuel pumped from the primary pump 21 from the connector 101, the filter 102, the fuel pump 103, the gas-liquid separation chamber 70, the fuel filter 71,
A fuel supply system to the injection nozzle 41, which is supplied to the injection nozzle 41 via the high-pressure fuel pump 72, the fuel delivery pipe 45, and the fuel injector 43, is configured. At the same time, from the fuel delivery line 45 to the fuel regulator 7
A surplus fuel return system that reaches the gas-liquid separation chamber 70 of the vapor separator 63 via 3 is configured. The exhaust gas of the combustion chamber 25 is exhausted to the outside through the exhaust passage 25A.

In the engine 17, however, the following
It has a characteristic configuration as described in (1) to (17).

(1) A high-pressure air delivery pipe 44 for supplying high-pressure air to each high-pressure air injector 42 is arranged vertically, and a high pressure from the air compressor 61 is provided on the upper end side of the high-pressure air delivery pipe 44. An air pipe 96 is connected, and a surplus air return pipe 97 to the air regulator 67 is connected to the lower end side of the delivery line 44 for high pressure air. Therefore, due to some abnormality from the mixing portion of the high pressure air of the high pressure air injector 42 in the injection nozzle 41 and the high pressure fuel of the fuel injector 43, the delivery line 44 for high pressure air is generated.
Even if the high pressure fuel enters the inside, the high pressure fuel can be easily discharged from the lower end portion. This fuel is returned to the gas-liquid separation chamber 70 in the vapor separator 63 together with the surplus air from the air regulator 67 and the surplus air return port 86 via the holding plate 80 having many holes.

(2) The surplus fuel that has passed through the fuel regulator 73 is returned from the surplus fuel return pipe 115 and the surplus fuel return passage 116 to the gas-liquid separation chamber 70, and at the same time, the air intake device disposed above the gas-liquid separation chamber 70. 65 and the upper part of the gas-liquid separation chamber 70 are connected via a holding plate 80 having many holes, and the air intake device 65 and the air compressor 61 are connected by an air suction pipe 83. Therefore, the vapor (vaporized component of the fuel) generated in the fuel delivery pipe 45 arranged in the vertical direction.
Can be discharged from the upper end of the fuel delivery pipeline 45, and can be smoothly returned together with the surplus fuel dropped by gravity through the fuel regulator 73 to the gas-liquid separation chamber 70 below the fuel regulator 73. That is, the fuel vapor generated in the fuel delivery conduit 45 can be recirculated and burned in the air supply system.

(3) The vapor separator 63 is substantially L-shaped, and an air intake device 65 projecting like a bowler hat is provided on the upper part of the vapor separator 63.
A gas-liquid separation chamber 70 was provided in the lower portion, and a regulator assembly including an air regulator 67 and a fuel regulator 73 was provided in an L-shaped recess on the outer side. Therefore, the overall shape of the fuel supply unit 62 becomes compact, and the space around the engine can be saved. In addition, since the pipe for connecting the air intake device 65 and the gas-liquid separation chamber 70 is not required, the pipe arrangement is simple and the device configuration is simple.

(4) An air filter 66 is attached to the air intake device 65 provided in the upper space of the gas-liquid separation chamber 70 so as to clean the air to the air compressor 61.

(5) The air intake 85 of the air intake 65 is
The air was opened to the atmosphere at a portion corresponding to the upper portion of the air filter 66. Therefore, even if the fuel oil level in the gas-liquid separation chamber 70 sways during the tilt-up cruise, the fuel does not leak out from the air intake 85. Further, since the pipe-shaped air intake 85 projects into the vapor separator, when the outboard motor 10 is detached from the ship and the starboard side is placed on the ground,
The oil level is as shown by R in FIG. 6, and the fuel is the air intake 85
Never leaks out. Similarly, when the outboard motor 10 is laid so that the port side is placed on the ground, the oil level becomes L and fuel does not leak.

(6) The intake of air into the air compressor 61 is
Silencer 87 with two filters and air intake 65
2 of the air intake 85. Therefore, the amount of air can be increased.

(7) The air compressor 6 is provided above the air intake 65.
The air suction pipe 83 connected to the air outlet 83A to 1 is provided. Therefore, the air intake device 65 performs a gas-liquid separation function of fuel and air. That is, fuel does not enter the air compressor 61 during trim-up traveling. Even when the outboard motor 10 is laid down, the suction side reed valve of the air compressor 61 blocks entry of the fuel into the compression chamber, and the fuel merely accumulates in the air suction pipe 83. The accumulated fuel returns to the gas-liquid separation chamber 70 when the outboard motor 10 is attached to the hull.

(8) An excess air return port 86 from the air regulator 67 is opened in the air intake 65, that is, in the upper part of the vapor separator 63. Therefore, the fuel mixed in the return air returns to the fuel pool in the gas-liquid separation chamber 70 below the vapor separator 63 by direct gravity.

(9) The gas-liquid separation chamber 70 is disposed below the fuel regulator 73, and the fuel is discharged from the fuel regulator 73 to the upper space inside the gas-liquid separation chamber 70. Therefore,
Along with the fact that the fuel oil surfaces of the gas-liquid separation chamber 70 are controlled by the float, the fuel regulator 73 is connected to the fuel regulator 73 from the gas-liquid separation chamber.
Backflow of fuel into the

(10) In the fuel supply unit 62, the integrated air regulator 76 and fuel regulator 73 are
The vapor separator 63 was integrally attached to the upper case 63A. Therefore, the overall shape of the fuel supply unit 62 becomes compact, and the space around the engine can be saved. In addition, the air regulator 67 and the vapor separator 63, the fuel regulator 73 and the vapor separator 63
Since the pipes for communicating with each other can be eliminated or can be extremely shortened, the pipes can be easily handled and the device configuration can be simplified.

(11) The fuel regulator 73 is shown in FIGS.
As shown in FIG. 4, the excess fuel return pipe 114 communicates with the valve chamber 12
The valve seat 122 in 1 can be opened and closed by the valve body 123. The valve body 123 is attached to the diaphragm plate 124 via a spherical pair with the caulking plate, and has good adhesion to the valve seat 122.

At this time, in the valve element 123, the fuel pressure in the surplus fuel return pipe 114 is applied to the rear surface of the diaphragm plate 124 via the control air pipe 127, and the air pressure in the surplus air return pipe 98 and the spring 125. The valve chamber 121 is opened when the spring force is larger than the spring force of (1) to connect the valve chamber 121 to the excess fuel return passage 116. The spring force of the spring 125 can be adjusted by the adjusting screw 126.

That is, the relief pressure of the fuel regulator 73 is variable by the adjusting screw 126, and the relief pressure increases as the pressure of the air system increases. Thereby, the high pressure air of the air injector 42 and the fuel injector 4
The pressure difference between the high pressure fuel and the high pressure fuel can be maintained in a predetermined relationship, and the high pressure air is prevented from entering the fuel delivery pipeline 45 at the mixing portion of the high pressure air and the high pressure fuel.

Since the air regulator 67 and the fuel regulator 73 are integrated, the control air pipe 127 described above can be handled reliably and easily.

(12) The air regulator 67 is shown in FIGS.
As shown in, it has a first air regulator 131 and a second air regulator 132.

The first air regulator 131 can open and close the valve seat 134 in the valve chamber 133, which communicates with the surplus air return pipe 98, by the valve element 135. The valve body 135 is attached to the diaphragm plate 136 via a spherical pair with the caulking plate, and has good adhesion to the valve seat 134.

At this time, in the valve element 135, the air pressure in the surplus air return pipe 98 is the fuel pressure in the surplus fuel return pipe 114 applied to the back surface of the diaphragm plate 136, and the spring 1.
The valve chamber 133 is opened when it is larger than the spring force of 37 so that the valve chamber 133 is communicated with the atmosphere opening port 138. The diaphragm plate 13
The back chamber 6 is a part of the fuel passage from the surplus fuel return pipe 114 to the valve chamber 121 of the fuel regulator 73. And the air regulator 67 and the fuel regulator 7
Since 3 is integrated with each other, a separate pipe for connecting the back chamber of the diaphragm plate 136 and the valve chamber 121 of the fuel regulator 73 is not required, and the device configuration is simplified.

On the other hand, the second air regulator 132 has a valve seat 144 in the valve chamber 143 with which the surplus air return pipe 98 communicates.
Can be opened and closed by the valve body 145. Disc 145
Is a diaphragm plate 14 through a spherical pair with a caulking plate.
6 and has good adhesion to the valve seat 144.

At this time, the valve body 145 opens when the air pressure in the excess air return pipe 98 is larger than the spring force of the spring 147 applied to the back surface of the diaphragm plate 146,
The valve chamber 143 is provided with the excess air return path 8 to the excess air return port 86.
Connect to 6A. The spring force of the spring 147 is the adjusting screw 1
It can be adjusted by 48.

That is, the relief pressure of the second air regulator 132 is variable by the adjusting screw 148, and this relief pressure is (a) higher than the relief pressure of the first air regulator 131 when the pump pressure of the fuel pump 72 drops, and ) When the fuel pump 72 is operating, it is lower than the relief pressure of the first air regulator 131.

Therefore, even if the air compressor 61 is operating during operation due to some abnormality and the pump pressure of the fuel pump 72 drops, the first air regulator 131
The compressed air in the air delivery conduit 44 is immediately discharged from the atmosphere opening port 138. Therefore, the compressed air flows from the air delivery conduit 44 to the air injector 42.
Of the fuel supply system (fuel delivery pipeline 4). As a result, the compressed air enters the fuel passage of the fuel injector 43 as shown in FIG.
5. There is no backflow to the fuel pump 72). Therefore,
The fuel in the vapor separator 63 is not explosively scattered by the backflow compressed air.

(13) The upper and lower cases 63A and 63B constituting the fuel supply unit 62 are attached to the cylinder body 23 by the bolt 153 via the mount rubber 152 having a damper function which is engaged with the attachment holes 151 of the upper and lower cases. Be done. Therefore, it is possible to prevent the springs 125, 137, 147 in the air regulator 67 and the fuel regulator 73 from dancing due to engine vibration and causing an error in their relief pressures.

(14) The air suction pipe 83 is a rubber pipe, and the surplus air return pipe 97, the fuel pipe 111, and the surplus fuel return pipe 112
Is a flexible tube. As a result, as described in (13) above, the fuel supply unit 62 is rubber-mounted, and the positional relationship between the fuel supply unit 62 and the injector rail of the cylinder head 24 changes due to engine vibration, but the flexible piping Vibration can be absorbed by displacement.

(15) Flexible excess air return pipe 97,
A coupling 161 which can be attached and detached to the fuel supply unit 62 side connection portion of the fuel pipe 111 and the surplus fuel return pipe 112,
162 and 163 are provided. Accordingly, if the couplings 161 to 163 are removed, the tubes 97, 111, 112
In addition to being flexible, the fuel supply unit 62 can be easily attached and detached. At this time, the fuel pump 10
It is necessary to remove the rubber fuel discharge pipe 104 from No. 3 from the fuel intake passage 105, and remove the rubber air suction pipe 83 to the air compressor 61 from the air intake device 65.

The excess air return pipe 98 and the fuel connecting pipe 10
9, the surplus fuel return pipe 114, the upper and lower cases 63A, 6
It is held by a stay 164 bolted to 3B (see FIG. 5).

(16) As described above, the fuel pump 72 is not mounted in the upper and lower cases 63A and 63B and the upper and lower mount rubbers 16 are provided.
It is supported by 5A and 165B. This improves the vibration resistance of the fuel pump 72.

(17) The left and right high-pressure air pipes 96 connected to the air discharge pipes 84, which are the passages of air to the left and right banks, are branched at the central portion, and the left pipe 96 and the right pipe 96 have substantially the same length.

The left and right fuel pipes 111 connected to the fuel connecting pipes 109, which are the passages of fuel to the left and right banks, are branched at the central portion, and the left pipe 111 and the right pipe 11 have substantially the same length.

As a result, the high-pressure air pipe 96 and the fuel pipe 111 have the same conduit resistance on the left and right sides, so that the left bank and the right bank do not affect the change in performance.

[0065]

As described above, according to the present invention, in the high-pressure fuel supply system for a fuel injection engine, the air passage of the air injector and the fuel passage of the fuel injector are merged and the compressed air pressure is used for fuel injection. In doing so, it is possible to prevent backflow of compressed air into the fuel supply system and prevent fuel from scattering from the vapor separator located in the fuel supply system.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an outboard motor.

FIG. 2 is a schematic diagram showing an engine.

FIG. 3 is a front view showing an engine.

FIG. 4 is a schematic view seen from the IV direction in FIG.

5 is a schematic view seen from the V direction in FIG.

FIG. 6 is a schematic diagram showing a fuel supply unit.

FIG. 7 is a cross-sectional view showing an air regulator and a fuel regulator.

FIG. 8 is a circuit diagram showing an air regulator and a fuel regulator.

FIG. 9 is a cross-sectional view showing an injector.

FIG. 10 is a cross-sectional view showing a fuel injector.

FIG. 11 is a flowchart showing a fuel supply system.

[Explanation of symbols]

 17 Engine 20 Fuel Tank 42 Air Injector 43 Fuel Injector 44 Air Delivery Pipeline 45 Fuel Delivery Pipeline 59 Passage (Air Passage, Fuel Passage) 61 Air Compressor 62 Fuel Supply Unit 70 Vapor Separator 72 Fuel Pump 131st 1 air regulator (high-pressure air exhaust means)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area // B63H 21/26 Z

Claims (1)

[Claims] 1. A compressed air sent by an air compressor is supplied from an air delivery pipe line to an air injector, and fuel in a fuel tank is led to a vapor separator, and fuel in the vapor separator is delivered by a fuel pump to the fuel delivery pipe. A fuel injector for supplying fuel to the fuel injector from the passage, and further joining the air passage of the air injector and the fuel passage of the fuel injector to supply the fuel together with the high-pressure air to the engine body. A high-pressure fuel supply device for a fuel injection engine, comprising high-pressure air discharge means for discharging compressed air in the delivery pipe for air when the pump pressure decreases.