JP2506051B2 - Outboard motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outboard motor having an internal combustion engine mounted on a main body of an outboard motor covered with a cowling and provided with a fuel pressure pump and a fuel injection device for pumping fuel into the cowling. Is.

[0002]

2. Description of the Related Art An internal combustion engine mounted on an outboard motor main body is covered with a cowling, and a fuel pressure pump and a fuel injection device for pressure-feeding fuel are provided in the cowling, while fuel in a fuel tank is pressure-fed outside the cowling. An outboard motor equipped with a primary pump to be sent to a pump is, for example, Shoukai 58-9036.
It is known as shown in Japanese Patent Publication No.

[0003]

By the way, in the above-mentioned prior art, since the fuel pipe is simply present between the primary pump and the fuel pressure pump, and the fuel reservoir is not provided, the fluctuation of the engine fuel consumption amount is prevented. However, there is a problem in that the fuel pumping state between the fuel pumping pump and the fuel injection device lacks smoothness. In addition, in an outboard motor, the outboard motor often changes its attitude with respect to the hull.In this case, even if a fuel sump is provided in the outboard motor, depending on the arrangement of the fuel sump, the fuel may Fuel in the puddle
It is also possible that the fuel fluctuates greatly and the fuel cannot be held reliably.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce the amount of fuel between the fuel pressure pump and the fuel injection device in response to changes in engine fuel consumption. Even if the outboard motor changes its posture significantly with respect to the hull, the amount of movement of the fuel puddle relative to the hull is small, the fluctuation of the fuel in the fuel puddle is reduced, and the fuel injection device It is intended to provide an outboard motor capable of stably supplying the outboard motor.

[0005]

In order to achieve the above object, the outboard motor according to the present invention is a fuel for introducing fuel in a fuel tank arranged on the hull side into a fuel pressure pump arranged in a cowling. A cylinder head in the cowling, which is provided with an introduction path and a fuel supply path for supplying fuel to be pressure-fed by a fuel pressure feed pump to a fuel injection device, the portion being located inside the outboard motor of the fuel introduction path. Les Rutotomoni, the fuel reservoir is provided fuel reservoir to the hull than
It is characterized in that it is connected to the fuel return path downstream of the regulator .

[0006]

With the above structure, the fuel consumption increases during high-speed operation of the internal combustion engine, the amount of surplus fuel returned to the fuel return path is small, and the amount of fuel to be pumped by the fuel pump is large. Then, the stored fuel in the fuel pool is sucked into the fuel pressure pump. Further, by positioning the fuel pool and the fuel pressure pump inside the outboard motor to shorten the path between the fuel pool and the fuel pressure pump, the fuel pump immediately sucks the stored fuel in the fuel pool. The fuel can be smoothly pumped to and from the fuel injection device with respect to changes in fuel consumption.

Further, since the fuel sump is provided in the cowling on the side of the hull rather than the cylinder head, the amount of movement of the fuel sump with respect to the hull is small even when the outboard motor changes its posture with respect to the hull significantly, and thus the inside of the fuel sump It is possible to reduce the fluctuation of the fuel. Furthermore, this fuel pool is
Since it was connected to the fuel return path of
Low pressure fuel with reduced pressure is returned to the fuel pool
Will be.

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

The outboard motor 10 includes an outboard motor 12 mounted on a hull 11 via a clamp bracket 12 and a swivel bracket 13.
The propulsion unit 14 as a main body is removable.
In addition, the outboard motor 10 has a V-shaped 6 on top of the propulsion unit 14.
A cylinder 4-cycle internal combustion engine 15 is installed. The internal combustion engine 15 can be covered with a cowling 15A, and a piston 16 is provided in each cylinder, and a spark plug 1 is attached to a cylinder head H thereof.
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 the propeller through a drive shaft 23 connected to a crankshaft 22 extending in the vertical direction, a forward / reverse switching device 24, and a propeller shaft 25. The cylinder head H is located on the side opposite to the hull 11 with respect to the crankshaft 22.

The internal combustion engine 15 is of a fuel injection type and is provided with an injector 27 which is an electromagnetic 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 system diagram showing a fuel injection system applicable to the outboard motor according to the present invention. This fuel injection system includes a fuel tank 29 arranged on the hull 11 side.
And a fuel pressure pump 30 which is arranged on the outboard motor 10 side and pressure-feeds the fuel, and the injector 27 of the internal combustion engine 15.
A fuel delivery pipe 31 for delivering the fuel in the fuel tank 29, and an outboard motor 10 side,
A fuel pressure pump 3 for connecting fuel to the fuel delivery pipe 31
Fuel introduction pipe 32 as a fuel introduction route to be introduced into the 0 pump chamber, fuel supply pipe 33 as a fuel supply route for supplying the fuel pumped by the fuel pressure pump 30 to the injector 27, and surplus in the fuel supply pipe 33. The fuel return pipe 34 as a fuel return route for returning the fuel is provided between the end of the fuel supply pipe 33 and the start of the fuel return pipe 34.
Fuel supply pipe 33 when the pressure exceeds a predetermined value higher than the injection pressure of
It has a regulator 35 as a pressure adjusting device capable of transferring the surplus fuel therein to the fuel return pipe 34.

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 provided in the middle of the fuel delivery pipe 31, and a diaphragm pump 37 and an intermediate tank 38 as a fuel reservoir are provided in the middle of the fuel introduction pipe 32, which is a low-pressure fuel passage in the cowling 15A. ing. The intermediate tank 38 includes a float 39 and an intermediate outlet 40 of the fuel introduction pipe 32 due to the floating of the float 39.
And a check valve 42 for maintaining the internal space of the intermediate tank 38 at atmospheric pressure. In addition, the fuel pressure pump 3 in the fuel supply pipe 33
On the outlet side of 0, a damper 43 for smoothing the pulsation of the discharge pressure of the fuel pressure pump 30 and a filter 44 for filtering the fuel discharged by the fuel pressure pump 30 are interposed.

However, in this embodiment, the end of the fuel return pipe 34 is connected to the upper space of the intermediate tank 38 which is interposed in the intermediate portion of the fuel introduction pipe 32, and the regulator from the fuel supply pipe 33. The surplus fuel transferred to the fuel return pipe 34 via 35 can be returned to the intermediate tank 38.

The internal combustion engine 15 is provided with 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.

Then, as shown in FIG.
7 is attached to the cylinder head H, and as shown in FIG. 3, the intermediate tank 38, which is a fuel reservoir, is on the hull side of the injector 27, and the intermediate tank 38, which is a fuel reservoir, is located in the middle of the fuel introduction pipe 32. 1 to 3, the intermediate tank 38, which is a fuel reservoir, is a portion of the fuel introduction path 32 located inside the outboard motor, and the cylinder head H in the cowling 15A.
It can be understood that it is on the side of the hull.

Next, the operation of the above embodiment will be described. By the operation of the regulator 35, the fuel supply pipe 33
It is possible to constantly fill the inside with high-pressure fuel that is equal to or higher than the injection pressure of the injector 27 and obtain a proper and reliable fuel injection operation by the injector 27.

Here, during low speed operation of the internal combustion engine 15,
The amount of surplus fuel transferred 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 with the fuel return pipe 34 only on the outboard motor 10 side.
It is possible to return the surplus fuel inside to the fuel introduction path 32, and it is possible to obtain a proper and reliable fuel injection operation under the condition that the piping 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 transferred 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. Further, during high-speed operation, the stored fuel in the intermediate tank 38 is immediately sucked into the fuel pressure pump 30 so that the fuel pressure pump 30 can ensure sufficient fuel pressure supply. Therefore, it is possible to smooth the pressure-feeding state and the fuel-returning state of the fuel with respect to the fuel injection device with respect to changes in the engine fuel consumption amount.

FIG. 4 is a piping system diagram showing another fuel injection system applicable to the outboard motor according to the present invention. The difference from this embodiment of this fuel injection system is that an accumulator 51, which is a fuel reservoir, is provided in the vicinity of the terminal connection part of the fuel return pipe 34 in the fuel introduction pipe 32, which is the fuel low-pressure passage in the cowling 15A. Especially.

In this case, when the internal combustion engine 15 is operating at a low speed, the amount of surplus fuel transferred to the fuel return pipe 34 is large, and the amount of fuel temporarily stored in the accumulator 51 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 accumulator 51 is small.

Also in the case of this embodiment, the fuel supply pipe 33
The fuel return pipe 34 for returning the surplus fuel in the outboard motor 10
It can be provided only on the side to simplify the piping structure. In addition, during low speed operation, a large amount of surplus fuel transferred to the fuel return pipe 34 is immediately stored in the accumulator 51, so that smooth pressure adjustment by the regulator 35 can be maintained. Also, during high speed operation, the accumulator 51
The stored fuel inside is immediately sucked into the fuel pressure pump 30,
It is possible to ensure sufficient fuel pressure feeding by the fuel pressure feeding pump 30. Therefore, it is possible to smooth the pressure-feeding state and the fuel-returning state of the fuel with respect to the fuel injection device with respect to changes in the engine fuel consumption amount.

FIG. 5 is a piping system diagram showing still another fuel injection system applicable to the outboard motor according to the present invention.
The difference from the first embodiment of this fuel injection system is that
The diaphragm type storage chamber 61, which is a fuel reservoir, is provided in the vicinity of the terminal connection portion of the fuel return pipe 34 in the fuel introduction pipe 32, which is the low-pressure fuel passage in the cowling 15A.

In this case, when the internal combustion engine 15 operates at a low speed, the amount of surplus fuel transferred to the fuel return pipe 34 is large, and the diaphragm 62 of the diaphragm type storage chamber 61 is pushed up against the elastic force of the spring 63. As a result, the amount of fuel temporarily stored in the storage chamber 61 increases. During high-speed operation of the internal combustion engine 15, the amount of surplus fuel transferred to the fuel return pipe 34 is small, the diaphragm 62 descends, and the amount of fuel temporarily stored in the storage chamber 61 is small.

Also in the case of this embodiment, the fuel supply pipe 33
The fuel return pipe 34 for returning the surplus fuel in the outboard motor 10
It can be provided only on the side to simplify the piping structure. In addition, during low speed operation, a large amount of excess fuel transferred to the fuel return pipe 34 is immediately stored in the storage chamber 61, and smooth pressure adjustment by the regulator 35 can be maintained. Further, during high-speed operation, the stored fuel in the storage chamber 61 is immediately sucked by the fuel pressure pump 30 to ensure sufficient fuel pressure supply by the fuel pressure pump 30. Therefore,
It is possible to smooth the pressure-feeding state and the fuel-returning state of the fuel with respect to the fuel injection device with respect to changes in the engine fuel consumption.

In any of the above embodiments,
The intermediate tank 38, which is a fuel reservoir, the accumulator 51, or the diaphragm-type storage chamber 61 is provided in the fuel introduction path 32.
Which is located in the outboard motor of the cowling 15A
Since it is inside the cylinder head H and closer to the hull, the amount of movement of the fuel pool with respect to the hull is small even when the outboard motor changes its posture with respect to the hull, and the fluctuation of the fuel in the fuel pool can be reduced. it can. Also, this fuel puddle
Since it was connected to the fuel return path downstream of the
The low-pressure fuel whose pressure has been reduced by the
The fuel pool is pressure resistant because it will be returned to the inside
Is needed, and therefore the thickness of the fuel puddle
It is possible to make it thinner, resulting in a smaller cowling
Can be converted.

[0026]

According to the present invention described in detail above, the fuel consumption increases during high speed operation of the internal combustion engine, the amount of surplus fuel returned to the fuel return path is small, and the fuel pressure pump pumps the fuel. When the amount of fuel to be consumed increases, the stored fuel in the fuel reservoir is sucked into the fuel pressure pump, and at that time, the fuel reservoir and the fuel pressure pump are positioned inside the outboard motor to shorten the path between the fuel reservoir and the fuel pressure pump. By doing so, the stored fuel in the fuel sump is immediately sucked by the pressure feed pump, so that the outboard motor has a smooth fuel feed state with the fuel injection device in response to changes in engine fuel consumption. .

Further, since the fuel pool is provided in the cowling on the side of the hull rather than the cylinder head, the amount of movement of the fuel pool with respect to the hull is small even when the outboard motor changes its posture with respect to the hull significantly, and the inside of the fuel pool is small. It is possible to reduce the fluctuation of the fuel in the fuel injection device and to stably supply the fuel to the fuel injection device. Also, use this fuel sump under the regulator.
Since it is connected to the fuel return path of the flow,
Low pressure fuel with reduced pressure is returned to this fuel reservoir.
Therefore, the fuel pool will not have much pressure resistance.
Not required and therefore the fuel puddle can be made thinner.
It is possible to reduce the size of the cowling as a result.
Can also.

[Brief description of 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.

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

FIG. 4 is a piping system diagram showing another fuel injection system that can be applied to the outboard motor according to the present invention.

FIG. 5 is a piping system diagram showing still another fuel injection system that can be applied to the outboard motor according to the present invention.

[Explanation of symbols]

 10 Outboard Motor 11 Hull 15 Internal Combustion Engine 15A Cowling 22 Crankshaft 27 Fuel Injection Device 30 Fuel Pressure Pump 29 Fuel Tank 32 Fuel Introduction Route 33 Fuel Supply Route 34 Fuel Return Route 35 Pressure Regulator 38, 51, 61 Fuel Reservoir H Cylinder head

Claims (1)

(57) [Claims] 1. A fuel pump for covering an internal combustion engine mounted on a main body of an outboard motor with a cowling, the fuel pump being arranged in the cowling to pump fuel, a fuel injection device provided in the internal combustion engine, and a hull side. A fuel introduction path for introducing the fuel in the fuel tank disposed in the fuel pump to the fuel pressure pump, a fuel supply path for supplying the fuel to be pumped by the fuel pressure pump to the fuel injection device, and a surplus fuel in the fuel supply path for returning the fuel. The internal combustion engine includes a fuel return path, a regulator that is arranged between the fuel supply path and the fuel return path, and adjusts the pressure in the fuel supply path, and the internal combustion engine includes a crankshaft that extends in the vertical direction, and Ri Na has a cylinder head located on the opposite side of the hull with respect to the crankshaft, clamp bracket, swivel
In the outboard motor that is attached to the hull via the Le bracket, a portion located outboard motor fuel introduction path,
Rutotomoni provided fuel reservoir to the hull of the cylinder head in the cowling, the fuel reservoir the regulation
An outboard motor characterized by being connected to a fuel return path downstream of the engine.