JP2629243B2 - Fuel-injected outboard motor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fuel injection type outboard motor, and more particularly to a fuel injection type outboard motor having a sub fuel tank.

[Conventional technology]

FIGS. 5 and 6 show a conventional example. The conventional example shown in FIG. 5 is a general example, and includes a delivery pipe 60 and an injector 60A provided in an engine;
A fuel tank 61 provided on the fuel suction side of the delivery pipe 60; a fuel tank 61 for sucking up the fuel in the fuel tank 61;
And a pressure regulator 64 for returning the fuel not consumed by the injector 60A to the fuel tank 61 as shown by the arrow B.

In this case, the portion not consumed by the injector 60A must be returned to the fuel tank. Therefore, in order to use this basic form as it is for an outboard motor, a pipe for returning fuel is required. In the outboard motor, since the fuel tank is fixedly mounted inside the ship, new installation or change of the piping requires much trouble and is not easy.

For this reason, recently, as shown in FIG. 6, an outboard motor equipped with a sub fuel tank has been proposed.

6 is characterized in that a sub fuel tank 80 is provided between the pump 63 for pumping and the filter 62 in the conventional example of FIG. 5 described above.

A sub fuel pump 81 for pumping necessary fuel from the sub fuel tank 80 is provided on the fuel suction side of the filter 62 described above. Further, the fuel not consumed by the injector 60A is sent to the sub fuel tank 80 via the pressure regulator 64.

[Problems to be solved by the invention]

In the conventional example shown in FIG. 5, as described above, there is an inconvenience that laying of a pipe or the like requires much time and labor.

In the conventional example shown in FIG. 6, especially when the fuel consumption is small such as idling at a high temperature, the fuel flows into the sub fuel tank 80 → the pump 81 → the delivery pipe 60 → the pressure regulator 64 → the sub fuel tank 80. And the temperature of the fuel increases, the temperature of the fuel rises, and vapor (gasoline vapor) is generated due to the heat, and the flow of fuel in a fuel passage such as a pipe is blocked, thereby reducing the fuel supply. Or an aborted vapor lock (vapo
ur lock) often occurs, making fuel control difficult. Further, sometimes a situation in which restart from full-open operation cannot be performed has occurred.

On the other hand, to avoid these situations, the sub fuel tank 80
Although it is conceivable to increase the size of the outboard motor in this case, it is inevitably necessary to increase the size of the outboard motor equipped with this, which is not practical.

[Object of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the disadvantages of the prior art, and in particular, to prevent the generation of vapor at high temperatures without increasing the size of the entire apparatus, and to effectively prevent the generation of vapor lock. To provide an external unit.

[Means for solving the problem]

The present invention relates to a sub-fuel tank for temporarily storing fuel fed from a fuel tank disposed on a hull side via a pump for pumping, a delivery pipe and an injector provided with an engine for the fuel in the sub-fuel tank. Water pump for supplying cooling water to the engine through a cooling water pipe having a fuel circulation system formed by a fuel pump for feeding the fuel into the engine and a pressure regulator for returning the fuel remaining in the delivery pipe to the sub fuel tank. Equipped. A fuel cooler is provided in a part of the fuel circulation path, a drain side path is provided in the cooling water pipe, and a part of the engine cooling water is sent from the water pump to the fuel cooler through the drain side path. Further, a configuration is adopted in which the flow control means for sending the cooling water to the drain passage only at the time of low engine rotation is provided on the output side of the water pump, thereby achieving the above-mentioned object.

(Example of the invention)

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

In this embodiment, a sub fuel tank 3 for temporarily storing fuel sent from a fuel tank 1 disposed on a hull 100 side shown in FIG. The fuel pump 6 includes a fuel pump 6 that feeds fuel to a delivery pipe 4 and an injector 5 mounted on the engine 200, and a press regulator 7 that sends fuel remaining in the delivery pipe 4 back to the sub fuel tank 3. A circulation path is formed.

The sub fuel tank 3 is formed by a sealed tank having a sealed structure without a needle valve or the like inside. An air release valve is provided at the upper end of the sub fuel tank 3.
12 are equipped.

After the fuel in the sub fuel tank 3 is pumped out by the fuel pump 6, the fuel is sent to the delivery pipe 4 via the filter 10 and the fuel pulsation damper 11.

The fuel pulsation damper 11 has a function of effectively suppressing upstream fuel pressure pulsation. If the fuel pulsation damper 11 is also provided at the position shown by P in FIG. 2, that is, between the pump 2 and the sub fuel tank 3, the pulsation of the fuel pressure can be suppressed more effectively, which is convenient.

In the present embodiment, a fuel cooler 8 for preventing a rise in fuel temperature is provided between the pressure regulator 7 and a part of the sub fuel tank 3, which constitute a part of the fuel circulation system described above. As shown in FIG. 1, the structure of the fuel cooler 8 is very simple, and comprises a container 8A and a fuel pipe 8B provided inside the container 8A. Here, the lower end of the fuel pipe 8B in FIG. 1 is connected to the above-described fuel passage on the lesser regitator 7 side, and the upper end is connected to the fuel passage on the sub fuel tank 3 side. And
Cooling water such as seawater taken in through a water pump 17 for taking in cooling water of the engine 200 described later is supplied to the container 8A.
By flowing through the internal space water jacket) 8a, the fuel inside the fuel pipe 8B is cooled.

In FIG. 1, a water pump 17 is driven by an engine 200 via a shaft 15 together with a propulsion blade 18. The water pump 17 takes in seawater or the like from a cooling water inlet 19 and the discharge port of the water pump 17 and the engine 20.
The engine 200 is sent to the water jacket 202 of the engine 200 through the cooling water pipe 20 connecting the water jacket 202 of the engine 200 to cool the engine 200. In this embodiment, the cooling water line 2
The drain side channel 21 is provided at 0, and furthermore, the drain side channel 21 is provided with a control valve 9 as flow control means.

The control valve 9 has a structure as shown in FIGS. 3 (1) and 3 (2).
Pushes the valve 32 to open the drain side passage 21, and part of the water sent from the water pump 17 to the water jacket 202 is released on the way to reduce the amount of cooling water of the engine 200 (see FIG. 3 (1)). During high-speed operation, the valve 32 retreats against the spring 31 due to the high flow rate and water pressure, the opening 32a is closed by the seat 33, and the drainage is shut off during the operation so that the entire flow rate acts on the cooling of the engine 200 ( (See FIG. 3 (2)).

The opposite side of the drain side passage 21 provided from the control valve 9 is connected to the fuel cooler 8 so that when the amount of water and the water pressure are low, that is, when the engine is in a low rotation range, the water pump 17 and the water jacket 202 are used. The fuel in the fuel pipe 8B in the fuel cooler 8 is cooled by a part of the cooling water that escapes on the way to the fuel cell. Conversely, when the amount of water and the water pressure are high, that is, in a high engine speed range, all the cooling water from the water pump 17 is sent to the engine 200 by the operation of the control valve 9, and the engine 200 is sufficiently cooled at the high speed. It has become.

As described above, in this embodiment, the cooling water pipe 20 is provided with the drain side passage 21, and further, the drain valve 21 is provided with the control valve 9, and the control valve 9 is controlled by the rotation speed of the water pump 17 driven by the engine 200. At the time of low speed operation, the amount of cooling water of the engine 200 is reduced by controlling the amount of water and the water pressure in accordance with the amount of water, and the amount of cooling water is sent to the fuel cooler 8 to cool the fuel. Is achieved well, and there is an advantage that it can be obtained at low cost without failure.

In the above embodiment, the case where the control valve is used as the flow control means is exemplified. However, the present invention is not limited to this, and a thermostat is provided to switch the cooling water passage as shown in FIG. You may be comprised so that it may perform. In this case, the thermostat may be provided on the water jacket 202 of the engine 200, or may be provided on the water jacket 8 (the internal space 8a) in the fuel cooler 8. And
When the engine is running at a low speed (when the water temperature is low), the thermostat works to open and supply water to both the engine 200 and the fuel cooler 8 when the engine is at a high speed (when the water temperature is high).
May be set so that only the fuel cooler 8 side is closed by the action of the thermostat.

In the above-described embodiment, the fuel cooler is disposed downstream of the delivery pipe 4. However, in the above-described fuel circulation path from the sub fuel tank 3 to the sub fuel tank 3 via the delivery pipe 4, It may be arranged.

〔The invention's effect〕

Since the present invention is configured and functions as described above, according to this, at the time of low engine rotation, a part of the engine cooling water is sent from the water pump to the fuel cooler through the drain passage by the action of the flow control means. For this reason, it is possible to suppress an increase in the fuel temperature in a low engine speed region (when the fuel cost is small) at the time of idling at a high temperature or the like, thereby reducing the generation of vapor due to heat.

Moreover, the flow rate of the cooling water is controlled by the flow rate control means,
Since the structure is such that cooling water is supplied to the engine and the fuel cooler, there is no need to increase the capacity of the water pump.

Accordingly, there is provided an unprecedented excellent fuel-injection type outboard motor capable of effectively preventing the occurrence of vapor lock at high temperatures and easily performing fuel control without increasing the size of the entire apparatus. Can be done.

[Brief description of the drawings]

FIG. 1 is a structural view showing a main part of an embodiment of the present invention, FIG. 2 is an overall explanatory view showing an arrangement of the fuel cooler of FIG. 1, and FIGS. 3 (1) and (2) are FIG. FIG. 4 is an explanatory view showing the structure and operation of the control valve, FIG. 4 is a conceptual view when a thermostat is used as a flow control means, and FIGS. 5 and 6 are explanatory views showing a conventional example. DESCRIPTION OF SYMBOLS 1 ... Fuel tank, 2 ... Pumping pump, 3 ... Sub fuel tank, 4 ... Delivery pipe, 5 ... Injector, 6 ... Fuel pump, 7 ... Pressure regulator, 8 ... Fuel cooler, 9 Control valve as flow control means, 17 Water pump, 20 Cooling water pipe, 21
... the drain side, 100 ... the hull, 200 ... the engine.

Claims (1)

(57) [Claims] 1. A sub-fuel tank for temporarily storing fuel fed from a fuel tank disposed on a hull side via a pump for pumping, a delivery pipe mounted on an engine and a fuel in the sub-fuel tank. A fuel pump that feeds fuel into the injector and a pressure regulator that returns fuel remaining in the delivery pipe to the sub-fuel tank; In a fuel injection type outboard motor equipped with a water pump, a fuel cooler is provided in a part of the fuel circulation system, a drain side is provided in the cooling water pipe, and the water is provided through the drain side. A pump sends a part of engine cooling water to the fuel cooler, and supplies the cooling water only when the engine is running at a low speed. Fuel injected outboard motor, characterized in that the flow control means equipped on the output side of the water pump for feeding.