JP2640440B2 - Outboard fuel injection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection system for an outboard motor.

[0002]

2. Description of the Related Art A fuel tank disposed on a hull side, a fuel pressure pump disposed on an outboard motor side for pumping fuel, and a fuel injection provided for an internal combustion engine mounted on the outboard motor body. A fuel introduction pipe for introducing the fuel in the fuel tank into the pump chamber of the fuel pump, a fuel supply pipe for supplying the fuel pumped by the fuel pump to the fuel injection device, and a surplus fuel in the fuel supply pipe. A fuel injection system for an outboard motor, comprising: a fuel return pipe for returning fuel; and a pressure adjusting device disposed on the fuel return pipe and capable of transferring surplus fuel from a fuel reservoir to a fuel introduction pipe. The return pipe is directly connected to the portion of the fuel introduction pipe located on the outboard motor side, a fuel reservoir is provided in the middle of the fuel return pipe, and a large amount of fuel from the fuel pump is used for the fuel injection device. Fueled The fuel injection system for an outboard motor which is adapted Ruru are known as shown in JP-Utility Model 58 over 90,364.

[0003]

By the way, in the above prior art, the fuel return pipe and the fuel introduction pipe are directly connected, and the fuel from the fuel tank is guided to the fuel pressure pump through the connection. From the fuel pump, a larger amount of fuel than is used in the fuel injection device is pumped.However, the control of the fuel supply from the fuel tank from the fuel tank to the fuel pump is not limited to the connection. Therefore, there is a possibility that the pumping of the fuel from the fuel pump to the fuel injector lacks smoothness. In addition, since the fuel reservoir is disposed in the high pressure region in the middle of the fuel return pipe on the upstream side of the pressure adjusting device, a pressure-resistant one is required,
There is also a problem that the configuration is not simple.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to smoothly control the state of fuel pumping between a fuel reservoir and a fuel injection device. However, the injection pressure of the fuel injection device is kept at a certain high level.
It is not necessary to return the excess fuel from the fuel injection device to the fuel tank on the hull side, making the fuel pipes on the hull side and the outboard motor side easy and reducing the piping inside the hull. An object of the present invention is to provide a fuel injection system for an outboard motor that can be simplified.

[0005]

In order to achieve the above object, an outboard motor fuel injection system according to the present invention has a booster pump interposed in an intermediate portion of a fuel introduction pipe provided on the outboard motor side. A fuel reservoir is provided downstream of the fuel reservoir, and a control valve for allowing a flow of fuel from a fuel tank in accordance with the amount of fuel in the reservoir is disposed in the fuel reservoir, and a fuel supply piping system is provided.
The fuel return pipe on the downstream side of the pressure adjusting device connected to the fuel injection device in the inside is connected to the fuel reservoir.

[0006]

[Function] A booster pump is interposed in the middle of the fuel introduction pipe disposed on the outboard motor side, and a fuel reservoir is provided downstream thereof.
With placing a control valve that allows the flow of fuel from the fuel tank in accordance with the amount of fuel in reservoir to the fuel in the reservoir, the fuel
Pressure regulator connected to fuel injector in supply piping system
The end of the fuel return pipe on the downstream side is connected to the fuel reservoir, so the injection pressure of the fuel injection device is always maintained at a constant high pressure
However , excess fuel from the fuel injection device is returned to the fuel reservoir from the end of the fuel return pipe via the pressure adjusting device, and is supplied from the fuel reservoir again to the fuel injection device.
The supply of fuel from the fuel tank only has to compensate for the decrease in the excess fuel, the operation of which is controlled by a control valve in the fuel reservoir, and the excess fuel from the fuel injection device is supplied to the fuel tank on the hull side. There is no need to return to. In addition, since the fuel reservoir is located downstream of the pressure adjusting device and upstream of the fuel pump, it is not necessary to provide a particularly pressure-resistant structure.

Further, when the surplus fuel from the fuel injection device is reduced, the fuel is supplied from the fuel tank to the fuel reservoir by the booster pump. At this time, the booster pump is located on the outboard motor side. There is no flow of fuel pressurized by the booster pump in the piping on the hull side.

[0008]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing an outboard motor to which the present invention is applied;
FIG. 2 is a schematic diagram showing an internal combustion engine of the outboard motor.

In the outboard motor 10, a propulsion unit 14 as a main body of the outboard motor is detachably attached to a hull 11 via a clamp bracket 12 and a swivel bracket 13. Further, the outboard motor 10 has a V-type 6-cylinder 4-cycle internal combustion engine 15 mounted on an upper part of the propulsion unit 14. Internal combustion engine 1
5 can be covered with a cowling 15A, a piston 16 is provided in each cylinder, and a spark plug 1 is provided in its cylinder head H.
7, an intake pipe 19 opened and closed by an intake valve 18, an exhaust pipe 21 opened and closed by an exhaust valve 20, and the like. The output of the internal combustion engine 15 can be transmitted to a propeller 26 via a drive shaft 23 connected to a vertically extending crankshaft 22, a forward / reverse switching device 24, and a propeller shaft 25. The cylinder head H is located on the opposite side of the hull 11 with respect to the crankshaft 22.

The internal combustion engine 15 is of a fuel injection type and has an injector 27 comprising a solenoid valve as a fuel injection device capable of injecting fuel into the combustion chamber of each cylinder. Reference numeral 28 denotes a throttle valve provided in the intake pipe 19 of each cylinder and capable of adjusting the amount of air supplied to the combustion chamber of each cylinder.

FIG. 3 is a piping diagram showing a fuel injection system according to an embodiment of the present invention. The fuel injection system includes a fuel tank 29 disposed on the hull 11 side in front of the outboard motor 10, a fuel pump 30 disposed on the outboard motor 10 side for pumping fuel, and the injector of the internal combustion engine 15. 27, a fuel delivery pipe 31 disposed on the hull 11 side for delivering fuel in the fuel tank 29, and a fuel delivery pipe 31 disposed on the outboard motor 10 side and connected to the fuel delivery pipe 31 for supplying fuel to the fuel pump 30. A fuel introduction pipe 32 as a fuel introduction path to be introduced into the chamber, a fuel supply pipe 33 as a fuel supply path for supplying the fuel pumped by the fuel pump 30 to the injector 27, and a return of excess fuel in the fuel supply pipe 33. A fuel return pipe 34 is provided between the end of the fuel supply pipe 33 and the beginning of the fuel return pipe 34, and the fuel pressure in the fuel supply pipe 33 becomes When exceeding a predetermined value or more injection pressure Ekuta 27, regulator of the excess fuel in the fuel supply pipe 33 as a pressure regulating device capable of transporting the fuel return pipe 34 - and a motor 35.

Here, the fuel delivery pipe 31 and the fuel introduction pipe 32 can be connected to or disconnected from each other at a connection portion 15B provided on the cowling 15A of the outboard motor 10. A manual pump 36 is interposed at an intermediate portion of the fuel delivery pipe 31, and a diaphragm pump 37 constituting a booster pump and an intermediate portion at a fuel reservoir are provided at an intermediate portion of the fuel introduction pipe 32 which is a low-pressure fuel path in the cowling 15 </ b> A. A tank 38 is interposed. The intermediate tank 38 includes a float 3 provided at a swinging end of an arm extending in the front-rear direction.
9 and the floating of the float 39, the fuel introduction pipe 32
Needle valve 4 which is a control valve for opening and closing the intermediate outlet portion 40
1 and a check valve 42 for keeping the internal space of the intermediate tank 38 at atmospheric pressure, so that the left and right width of the intermediate tank 38 can be reduced to reduce the running resistance. Further, on the outlet side of the fuel pump 30 in the fuel supply pipe 33, a damper 43 which can smooth the pulsation of the discharge pressure of the fuel pump 30 and the fuel pump 30 are provided.
A filter 44 that allows the discharged fuel to be filtered is interposed.

An end of the fuel return pipe 34 is connected to an upper space of the intermediate tank 38 interposed at an intermediate portion of the fuel introduction pipe 32, and is connected to the fuel return pipe 33 via the fuel supply pipe 33 through the regulator 35. The surplus fuel transferred to the intermediate tank can be returned to the intermediate tank.

The internal combustion engine 15 includes a crank angle sensor 45, a throttle angle sensor 46, a water temperature sensor 47, an intake air temperature sensor 48, an atmospheric pressure sensor 49, and the like. The crank angle sensor 45 detects a compression point of the piston 16,
The ejection timing of the injector 27 can be determined.
The throttle angle sensor 46 detects the opening angle of the throttle valve 28, and when the amount of intake air increases, increases the opening time of the injector 27 so that the air-fuel ratio can be optimized. The water temperature sensor 47 detects the cooling water temperature of the internal combustion engine 15 and increases the open time of the injector 27 at the time of cooling to enable a large amount of fuel to be supplied. The intake air temperature sensor 48 detects the intake air temperature and makes it possible to correct the intake air amount. The atmospheric pressure sensor 49 detects the atmospheric pressure and makes the amount of intake air appropriate.

Next, the operation of the above embodiment will be described. In the above-described fuel injection system, by operating the regulator 35, the fuel supply pipe 33 is always filled with high-pressure fuel that is equal to or higher than the injection pressure of the injector 27, so that an appropriate and reliable fuel injection operation by the injector 27 can be obtained. It is possible.

Here, when the internal combustion engine 15 is operated at a low speed,
The amount of surplus fuel returned from the fuel supply pipe 33 to the fuel return pipe 34 via the regulator 35 is large, and the amount of fuel temporarily stored in the intermediate tank 38 is large.
During high-speed operation of the internal combustion engine 15, the amount of surplus fuel transferred to the fuel return pipe 34 is small, and the amount of fuel temporarily stored in the intermediate tank 38 is small.

According to this embodiment, the fuel supply pipe 33 is provided only in the side of the outboard motor 10 where the fuel return pipe 34 is provided.
It is possible to return the excess fuel in the fuel supply pipe 32 to the fuel introduction pipe 32, and to obtain a proper and reliable fuel injection operation in a state where the pipe structure is simplified. Further, it is not necessary to provide a connection port for a fuel return path in the fuel tank 29. During low-speed operation, a large amount of surplus fuel returned to the fuel return pipe 34 is immediately stored in the intermediate tank 38, and the regulator 3
5 enables smooth pressure adjustment to be maintained. In addition, during high-speed operation, the fuel stored in the intermediate tank 38 is immediately sucked into the fuel pump 30 to ensure sufficient fuel pumping by the fuel pump 30. Therefore, the state of pumping fuel and the state of returning fuel to and from the fuel injection device can be smoothed with respect to fluctuations in engine fuel consumption.

[0018]

As described above, according to the present invention, a booster pump is provided at an intermediate portion of a fuel introduction pipe provided on the outboard motor side, and a fuel reservoir is provided downstream thereof. A control valve that allows the flow of fuel from the fuel tank according to the amount of fuel in the reservoir is arranged, and the fuel in the fuel supply piping system is
Since the end of the fuel return pipe downstream of the pressure adjusting device connected to the fuel injection device was connected to the fuel reservoir,
Can maintain a constant high injection pressure at all times and
Fuel from surplus fuel is returned to the fuel reservoir from the end of the fuel return pipe via a pressure regulating device, from being re-supplied fuel injector from the fuel reservoir, fuel tank and from the fuel injection device can readiness to The supply of the fuel may be compensated for the decrease in the excess fuel, and the operation thereof is controlled by a control valve in the fuel reservoir, so that the state of pumping the fuel between the fuel reservoir and the fuel injection device can be smoothly performed, and Since there is no need to return excess fuel from the fuel injection device to the fuel tank on the hull side, the fuel pipes on both the hull side and the outboard motor side become extremely easy. Further, since the fuel reservoir is arranged in the low pressure region on the downstream side of the pressure adjusting device, it is not necessary to have a particularly pressure-resistant structure.

While the above-mentioned effects are exhibited, the reduced amount of surplus fuel in the fuel reservoir is supplied from the fuel tank on the hull side to the fuel reservoir by the booster pump on the outboard motor side. The supply of fuel to the hull is also performed smoothly, and the pressurized fuel does not flow from the fuel tank on the hull side to the booster pump on the outboard motor side, so that the piping in the hull can be further simplified.

[Brief description of the drawings]

FIG. 1 is a side view showing an outboard motor to which the present invention is applied.

FIG. 2 is a schematic view showing an internal combustion engine of the outboard motor.

FIG. 3 is a piping diagram showing a fuel injection system applicable to the outboard motor according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 outboard motor 11 hull 15 internal combustion engine 27 fuel injection device 29 fuel tank 30 fuel pressure pump 31 fuel delivery pipe 32 fuel introduction pipe 33 fuel supply pipe 34 fuel return pipe 35 pressure regulator 37 booster pump 38 fuel reservoir 41 control valve

Claims (1)

(57) [Claims] 1. A fuel tank disposed on a hull side, a fuel pump for pumping fuel disposed on an outboard motor side, and a fuel injection device provided in an internal combustion engine mounted on the outboard motor main body. A fuel delivery pipe for delivering fuel in the fuel tank to the outboard motor side; and a fuel introduction pipe connected to the fuel delivery pipe and located on the outboard motor side for introducing fuel into a pump chamber of the fuel pressure pump. A fuel supply pipe for supplying fuel pumped by a fuel pump to the fuel injection device, a fuel return pipe for returning excess fuel in the fuel supply pipe, and a fuel supply pipe and a fuel return pipe. A pressure adjusting device for transferring excess fuel in the fuel supply pipe to the fuel return pipe when the fuel pressure in the fuel supply pipe exceeds a predetermined value equal to or higher than the injection pressure of the fuel injection device. Machine fuel injection system A booster pump is interposed at an intermediate portion of the fuel introduction pipe disposed on the outboard motor side, and a fuel reservoir is provided downstream thereof, and a fuel reservoir is provided in the fuel reservoir according to the amount of fuel in the reservoir. A control valve that allows the flow of fuel is arranged , and a fuel injection device in the fuel supply piping system is provided.
A fuel injection system for an outboard motor, wherein an end of the fuel return pipe on the downstream side of the pressure regulator connected in series is connected to the fuel reservoir.