JP2002138920A - Fuel feeder in outboard motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel feeder for an outboard motor, capable of dispensing with a low-pressure fuel pump while keeping a function of separating paper from fuel and jetting fuel by a high-pressure fuel pump. SOLUTION: Fuel in a multi-shaft tank T is increased in pressure by a high pressure fuel pump PH and regulated to constant pressure by a pressure regulator R to be supplied from a fuel injection valve J to an engine. A closed paper separator V is divided into a first chamber and a second chamber 1B by a partition wall 3. The paper separator V is provided with an air vent passage 7 connected to the atmosphere, when the pressure in the paper separator V exceeds a fixed value, the passage is opened by a pressure operating valve G. A constant liquid level control mechanism C for opening and closing a valve seat 10 is disposed in the second chamber, the valve seat 10 is connected to a downstream fuel suction passage F3 connected to the suction passage P1 by a second fuel suction passage F4, and a return fuel passage 17 of the pressure regulator R is connected to the first chamber 1A of the paper separator V.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system for an outboard motor, and more particularly to a fuel injection system for injecting fuel in a fuel tank pressurized by a fuel pump into an engine through a fuel injection valve. Related to the device.

[0002]

2. Description of the Related Art A conventional fuel supply system for an outboard motor will be described with reference to FIG. E is an engine, and an intake pipe 20 is connected to each cylinder constituting the engine. A throttle body 22 having a throttle valve 21 is arranged upstream of the intake pipe 20. V is a vapor separator which is maintained at the atmospheric pressure through the air vent passage 23 and is disposed in the cowling of the engine.
And a float valve 26 that rotates in accordance with the liquid level formed in the vapor separator V, and a float valve 26 that moves in synchronization with the float 25 to open and close the valve seat 24. A constant liquid level control mechanism C is provided. T is a separately installed fuel tank disposed at a lower position away from the vapor separator V. Fuel stored in the fuel tank T (hereinafter simply referred to as fuel tank T) is a mechanical fuel driven by a cam of the engine. pump,
Alternatively, fuel sucked in a low-pressure fuel pump PL such as a diaphragm-type fuel pump driven by a pulsating pressure generated in the engine, and then the fuel whose pressure has been raised to a relatively low fuel pressure is supplied toward the valve seat 24. The fuel supplied into the vapor separator V through the valve seat 24 gradually accumulates in the vapor separator V and raises its fuel level. The float valve 26 constituting the mechanism C closes the valve seat 24, so that a constant fuel level is maintained in the vapor separator V. The fuel stored in the vapor separator V is pressurized to a high pressure (for example, 3.8 kg / cm ² ) by an electric high-pressure fuel pump PH (for example, a Wesco pump) disposed in the vapor separator V. Is supplied to the fuel distribution pipe D. The fuel distribution pipe D is provided with a fuel injection valve J whose tip is disposed facing the inside of the intake pipe 20 and is connected to a pressure regulator R. Pressure regulator R is high pressure fuel pump PH
Is supplied to the fuel injection valve J by controlling the high-pressure fuel supplied from the fuel tank to a desired constant fuel pressure, and the fuel having a pressure exceeding the constant fuel pressure is supplied again through the return fuel passage 25 into the vapor separator V. Refluxed to According to the above, the fuel in the fuel tank T is supplied to the low-pressure fuel pump PL.
The fuel pressure is increased to a low fuel pressure and supplied to the vapor separator V via the valve seat 24, and a constant fuel level is formed and held in the vapor separator V by the constant liquid level control mechanism C. The fuel in the vapor separator V is pressurized and discharged by the high-pressure fuel pump PH, and the fuel regulated to a desired constant high-pressure fuel by the pressure regulator R is supplied to the intake pipe 2 through the fuel distribution pipe D and the fuel injection valve J.
It is injected and supplied within 0. On the other hand, fuel exceeding a certain pressure of the pressure regulator R is returned to the vapor separator V via the return fuel passage 25.

[0003]

According to the conventional fuel supply apparatus for an outboard motor, a low-pressure fuel pump PL for supplying the fuel in the fuel tank T toward the vapor separator V is necessarily required. According to this, the whole apparatus is complicated and it is difficult to make it compact. Further, the fuel tank T is arranged at a place considerably away from the cowling where the vapor separator V and the like are arranged, while the low-pressure fuel pump PL is arranged near the fuel tank T. According to the above, the low-pressure fuel pump PL is disposed at a position distant from the engine, and when the low-pressure fuel pump PL is driven by the cam of the engine or when the pulsating pressure of the engine is used, the drive source And low pressure fuel pump PL
Difficult to connect with. On the other hand, the low-pressure fuel pump PL is abolished, and the high-pressure fuel pump PH in the vapor separator V is replaced with a self-priming fuel pump (for example, trochoid).
In this case, it is possible to inhale the fuel inside, but at this time, the air vent passage 23 of the vapor separator V needs to be closed and sealed. According to the above, the function of separating the vapor and the fuel in the vapor separator V is impaired.
As a result, the low-pressure fuel pump PL cannot be eliminated.

[0004] The present invention has been made in view of the above problems,
An object of the present invention is to provide a fuel supply device for an outboard motor that can eliminate a low-pressure fuel pump while maintaining a function of separating a vapor and a fuel of a vapor separator.

[0005]

According to the present invention, there is provided a fuel supply system for an outboard motor according to the present invention, in order to achieve the above object, a separately installed fuel tank arranged at a position distant from an engine; an intake pipe having one end connected to the engine. A fuel distribution pipe provided with a fuel injection valve disposed facing the fuel tank; a fuel flow path connecting the separate fuel tank and the fuel distribution pipe; and a fuel flow path disposed in the fuel flow path and in the separate fuel tank. A high-pressure fuel pump having a self-priming property to supply pressure to the fuel distribution pipe;
A partition having a constant height for dividing into a first chamber and a second chamber;
A pressure-operated valve that opens the air vent passage when the pressure in the housing rises above a certain value, and a pressure-operated valve that closes the air vent passage at a pressure lower than the air vent passage from the housing to the atmosphere, A constant level control mechanism that closes a valve seat that opens to the second chamber when fuel supplied from the first chamber to the second chamber is equal to or lower than a certain level, and opens the valve seat when the fuel level is equal to or higher than a certain level. A separator; and a pressure regulator that regulates a fuel pressure in a fuel discharge passage including a discharge passage of a high-pressure fuel pump and a fuel distribution pipe in the fuel flow passage to a constant pressure;
A first check valve that allows only a fuel flow from the separately provided fuel tank to the high pressure fuel pump is disposed in a fuel intake passage connecting the suction path of the high pressure fuel pump and the separately provided fuel tank in the fuel flow path. A second fuel intake passage connects the downstream fuel intake passage connecting the first check valve and the intake passage of the high-pressure fuel pump with a valve seat, and further connects a return fuel passage of the pressure regulator to a first passage of the vapor separator. The first feature is that the user is in the room.

According to the present invention, in addition to the first feature, a first fuel filter is disposed in an upstream fuel suction passage connecting the first check valve and the separately installed fuel tank in the fuel flow path. A second feature is that a second fuel filter is arranged in the fuel discharge path.

Further, according to the present invention, in addition to the first feature, a diaphragm that divides the pressure-operated valve into a pressure receiving chamber and an atmospheric chamber, and a diaphragm that is contracted into the atmospheric chamber to urge the diaphragm toward the pressure receiving chamber. A spring, a pressure introduction passage opening at one end into the housing and the other end opening at the pressure receiving chamber, an air vent passage opening at one end into the pressure receiving chamber, and the other end opening to the atmosphere, and is formed integrally with the diaphragm. A third feature is that it is formed by a valve body that opens and closes the air vent passage.

[0008]

According to the feature of the present invention, when the high-pressure fuel pump is driven, the fuel in the fuel tank is sucked into the pump via the first check valve, and the high-pressure fuel is supplied to the fuel distribution pipe. The fuel supplied toward the fuel tank and regulated to a constant fuel pressure by the pressure regulator is injected from the fuel injection valve into the intake pipe. The fuel discharged from the return fuel passage of the pressure regulator into the vapor separator is supplied while gradually increasing the pressure in the vapor separator, and when the fuel exceeds a certain value, the pressure control valve opens the air vent passage and opens the vapor. To achieve the function of separating fuel and fuel. On the other hand, the fuel that has risen beyond the partition in the vapor separator is stored in the second chamber, and when the fuel level in the second chamber reaches a certain level, the valve seat is opened, and the fuel in the second chamber is pumped by the high-pressure fuel pump. Sucked by

[0009]

FIG. 1 shows an embodiment of a fuel supply system for an outboard motor according to the present invention. Outboard engine E
Is connected to an intake pipe 20, and a throttle body having a throttle valve is connected upstream of the intake pipe 20. (The throttle valve and the throttle body are omitted.) D is a fuel distribution pipe having a side flow path, the front end of the fuel injection valve J is disposed facing the intake pipe 20, and the rear end is a fuel distribution pipe D And open to the channel. J is a separately installed fuel tank, which is arranged at a position away from the engine E and a cowling (not shown) surrounding the engine E. F is a fuel passage connecting the fuel tank T and the fuel distribution pipe D, and a high-pressure fuel pump PH having self-priming is arranged in the fuel passage F. High pressure fuel pumps having self-priming properties include, but are not limited to, vane pumps, roller vane pumps, trochoid pumps, gear pumps, plunger pumps, and the like. According to the above description, the fuel flow path F between the suction path P1 of the high-pressure fuel pump PH and the fuel tank T becomes the fuel suction path F1, and the discharge path P of the high-pressure fuel pump PH
The fuel flow path F between the fuel supply pipe 2 and the fuel distribution pipe D is a fuel discharge path F2.
Becomes

The vapor separator V is formed as follows. The vapor separator V is hermetically formed by a bottomed cup-shaped casing 1 and a cover 2 covering the opening thereof, and a partition 3 having a certain height is erected from the bottom of the casing 1. According to the above, the housing 1 is divided into the first chamber 1A on the left side and the second chamber 1B on the right side, and the upper parts of the first chamber 1A and the second chamber 1B communicate with each other at the upper part of the partition wall 3.
A pressure control valve G is arranged on the cover 2 (not blocked by the partition 3). The pressure control valve G includes the following. Reference numeral 4 denotes a diaphragm which divides a pressure receiving chamber 5 from an atmosphere chamber 6 having an atmosphere opening. The pressure receiving chamber 5 has an air vent passage 7 communicating with the atmosphere and a pressure introduction passage 8 communicating with the inside of the housing 1, and further has a diaphragm. 4 is a spring S contracted into the atmosphere chamber 6
Thus, it is pressed toward the pressure receiving chamber 5. 9 is diaphragm 4
The valve body 9 moves in synchronization with the air vent passage 7 and opens and closes the air vent passage 7. When the pressure in the pressure receiving chamber 5 is equal to or lower than a predetermined pressure, the valve body 9 contacts the opening 7A of the air vent passage 7 by the spring force of the spring S. Then, the air vent passage 7 is closed and held. On the other hand, when the pressure in the pressure receiving chamber 5 rises beyond a certain pressure, the diaphragm 4 is displaced toward the atmosphere chamber 6 against the spring force of the spring S, whereby the valve 9 holds the air vent passage 7 open. I do. The air vent passage 7
The opening to the atmosphere side is opened in a throttle body (not shown), and at this time, a canister may be arranged in a passage therebetween.

A constant liquid level control mechanism C is disposed in the second chamber 1B. The constant liquid level control mechanism C includes a valve seat 10, a float valve 11, and a float 12, and the valve seat 10 is formed in the bottom of the second chamber 1B.
The float 12 is displaced according to the liquid level in the second chamber 1B, and the float valve 11 moves in synchronization with the float 12 to open and close the valve seat 10.

The pressure regulator R is formed as follows. The pressure regulator R is divided into a spring chamber 14 and a fuel chamber 15 by a diaphragm 13. A fuel introduction path 16 and a return fuel path 17 are opened in the fuel chamber 15, and the return fuel path 17 moves synchronously with the diaphragm 10. The opening of the valve body 18 is controlled. The return fuel passage 17 is opened and connected to the first chamber 1A of the vapor separator V. Note that S
Reference numeral 1 denotes a spring that presses the diaphragm 13 toward the fuel chamber 15.

Reference numeral 19 denotes a first check valve disposed in the fuel suction passage F1 of the fuel flow passage F. The first check valve 19 allows a fuel flow from the fuel tank T to the high-pressure fuel pump PH. The fuel flow from the high-pressure fuel pump PH to the fuel tank T is blocked. According to the above, the fuel intake passage F1 is
A downstream fuel suction passage F3 is formed between the check valve 19 and the suction passage P1 of the high-pressure fuel pump PH.

The valve seat 10 of the vapor separator V is connected to the downstream fuel suction passage F3 via a second fuel suction passage F4.

L1 is a first fuel filter disposed in a fuel suction passage F1 upstream of the first check valve 19;
L2 is a second fuel filter arranged in the fuel discharge path F2.

Next, the operation will be described. When the high-pressure fuel pump PH is driven during the operation of the engine E, since the high-pressure fuel pump PH has a self-priming property, the inside of the fuel suction passage F1 is brought into a negative pressure state and the first check valve 19 is opened. Then, the fuel in the fuel tank T located at a lower position away is sucked into the pump via the fuel suction passage F1, and the sufficiently pressurized fuel is supplied to the fuel distribution pipe D via the fuel discharge passage F2. You. In the above, the reason why the inside of the fuel suction passage F1 can be maintained in the negative pressure state is that the fuel is not yet stored in the second chamber 1B, the float 12 is at the lower position, the float valve 11 closes the valve seat 10, and the second This is because the fuel suction passage F4 is held closed. On the other hand, the fuel supplied into the fuel distribution pipe D immediately reaches the fuel chamber 15 of the pressure regulator R via the fuel introduction path 16, and according to this, the fuel in the fuel chamber 15 received by the front surface of the diaphragm 13 The position of the diaphragm 13 is determined in a state where the fuel pressure and the spring force of the spring S1 on the rear surface of the diaphragm 13 are balanced, and the opening of the return fuel passage 17 is controlled by the valve element 18. According to the above, the fuel having a high fuel pressure introduced from the fuel introduction passage 16 into the fuel chamber 15 is discharged from the return fuel passage 17 into the first chamber 1A of the vapor separator V, thereby including the fuel discharge passage F2. The fuel pressure in the fuel distribution pipe D can be adjusted to a desired constant pressure. Fuel having this constant pressure is injected into the intake pipe 20 via the fuel injection valve J, and the engine is operated.

Here, paying attention to the initial empty state of the vapor separator V, the valve body 9 of the pressure control valve G is
Float 2 is closed by its own weight while float valve 11 closes and holds valve seat 10. When the fuel suction passage F1 is in a negative pressure state, the valve seat 10 is closed by the float valve 11, so that even if the second fuel suction passage F4 has a negative pressure, the second fuel 1B is discharged from the second chamber 1B. No fuel or air flows toward the suction path F4.

The valve body 9 of the pressure control valve G closes the air vent passage 7, the float valve 11 closes the valve seat 10, and the inside of the casing 1 of the vapor separator V is in a sealed state. Return fuel is supplied into the first chamber 1A from the return fuel passage 17 of the pressure regulator R by driving the pump PH, and the return fuel is gradually stored in the first chamber 1A. And the fuel in the sealed state in the first chamber 1A is supplied to the high-pressure fuel pump P
The temperature gradually rises due to the heat generated by the motor of H or the radiant heat of the engine. As a result, the pressure in the housing 1 gradually increases and exceeds a certain pressure. And
The increased pressure is introduced into the pressure receiving chamber 5 through the pressure introducing passage 8 of the pressure actuating valve G, whereby the diaphragm 4 moves upward against the spring force of the spring S, and the valve body 9 Opens the opening 7A and holds the air vent passage 7 open. According to the above, the vapor generated in the first chamber 1A is opened to the atmosphere through the air vent passage 7, and the vapor generated in the fuel piping system such as the fuel flow path F and the inside of the casing 1 are heated. Is completely separated from the fuel, and only the vapor is discharged through the air vent passage 7. This is because, during operation of the engine, the pressure-operated valve G senses the pressure in the housing 1 and, when the pressure in the housing 1 exceeds a certain value, opens the air vent passage 7 and discharges the vapor. In addition, the pressure in the housing 1 does not exceed a predetermined value and is not continuously maintained.

On the other hand, when the return fuel is continuously supplied from the return fuel passage 17 of the pressure regulator R into the first chamber 1A, the fuel level in the first chamber 1A gradually rises. The fuel that has reached the upper part of the partition 3 flows into the second chamber 1B over the upper part of the partition 3, and
Fuel is stored in the empty second chamber 1B. Then, the fuel liquid level formed in the second chamber 1B gradually starts rising. When the fuel liquid level in the second chamber 1B reaches a certain height, the float 12 is displaced upward, and the float valve 11
Opens the valve seat 10. According to the above, the negative pressure generated in the fuel suction passage F3 on the downstream side by the driving of the high-pressure fuel pump PH acts on the valve seat 10 via the second fuel inflow passage F4. Is sucked into the high-pressure fuel pump PH via the second fuel inflow passage F4 and the downstream fuel suction passage F3.
Therefore, the fuel stored in the second chamber 1B is sucked into the high-pressure fuel pump PH and consumed, so that the fuel level in the second chamber 1B decreases again, and the float valve 11 moves downward to move the float valve 11 down. Close the valve seat 10 again,
The next flow of fuel from the first chamber 1A into the second chamber 1B can be prepared. Valve seat 1 in the second chamber
Opening and closing 0 is during operation of engine E (during operation of high-pressure fuel pump)
This is performed continuously, so that the inside of the vapor separator V is not filled with fuel or overflows from the vapor separator V. When the valve seat 10 is closed by the float valve 11 (the state in which the fuel level in the second chamber 1B does not reach a certain level), the first check valve 19 is connected to the downstream fuel intake passage. The passage is opened by receiving the negative pressure of F3, and the fuel in the fuel tank T is sucked into the high-pressure fuel pump PH via the fuel suction passage F1. In the state where the valve seat 10 is opened by the float valve 11 in the above, the valve seat 10 and the first check valve 1
9, there is a large head difference, the first check valve 19
Causes the fuel suction passage F1 connected to the fuel tank T to be closed due to the head difference, but the fuel in the second chamber 1B is supplied to the high-pressure fuel pump PH via the second fuel suction passage F4. Also, the fuel in the second chamber 1B is consumed and the valve seat 1
As soon as 0 is closed by the float valve 11, the negative pressure in the downstream fuel suction passage F3 acts on the first check valve 19 to open the fuel suction passage F1, and the fuel in the fuel tank T Since the high-pressure fuel pump PH is sucked into the high-pressure fuel pump PH through the fuel suction passage F1, the fuel is continuously sucked into the high-pressure fuel pump PH.

A first fuel filter L is provided in an upstream fuel suction passage F5 connecting the first check valve 19 and the fuel tank T.
1 and a second fuel filter L in a fuel discharge passage F2 connecting the high pressure fuel pump PH and the fuel distribution pipe D.
According to the arrangement of 2, the first fuel filter L1 can improve the closeability of the first check valve 19 and can effectively remove foreign substances contained in the fuel sucked into the high-pressure fuel pump PH. In addition, foreign substances contained in the fuel discharged from the high-pressure fuel pump PH can be effectively removed by the second fuel filter L2, and the stability of performance and quality can be improved.

[0021]

As described above, according to the fuel supply system for an outboard motor according to the present invention, the conventional combination of the vapor separator having the pressure-operated valve and the constant liquid level control mechanism and the high-pressure fuel pump provides The low-pressure fuel pump was abolished and the fuel could be supplied only with the high-pressure fuel pump. According to this, the fuel supply device in the outboard motor could be provided without impairing the function of separating the fuel and vapor in the vapor separator. The degree of freedom of arrangement was greatly improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a fuel supply device in an outboard motor of the present invention.

FIG. 2 is a configuration diagram showing a fuel supply device in a conventional outboard motor.

[Explanation of symbols]

 E Engine T Separate fuel tank J Fuel injector V Vapor separator R Pressure regulator D Fuel distribution pipe PH High pressure fuel pump 1 Housing 1A First chamber 1B Second chamber 10 Valve seat

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F02M 55/00 F02M 55/00 C 55/02 350P 55/02 350 350U B63H 21/26 K 69/00 F02M 69/00 320J

Claims (3)

[Claims] A separate fuel tank disposed at a position distant from the engine; a fuel distribution pipe having a fuel injection valve disposed at one end facing an intake pipe connected to the engine;
A fuel flow path F that connects the separately installed fuel tank T and the fuel distribution pipe D; and a fuel that is arranged in the fuel flow path F and is pressurized toward the fuel distribution pipe D in the separately installed fuel tank T. A high-pressure fuel pump PH having a self-priming property; a partition 3 having a constant height for dividing the inside of the casing 1 into a first chamber 1A and a second chamber 1B; A pressure-operated valve G that opens the air vent passage 7 when the pressure in the housing 1 rises above a certain value and that closes the air vent passage 7 at a pressure lower than the predetermined value; The fuel supplied from the first chamber 1A into the second chamber 1B via the valve closes the valve seat 10 opening to the second chamber 1B at a certain liquid level or lower, and opens the valve seat 10 at a certain liquid level or higher. A vapor separator V including a liquid level control mechanism C; Fuel discharge passage F including a discharge passage P2 and the fuel distribution pipe D of the high-pressure fuel pump PH in the fuel flow path
A pressure regulator R for regulating the fuel pressure in the fuel tank 2 to a constant pressure; and a separate fuel suction passage F1 connecting the suction passage P1 of the high-pressure fuel pump PH and the separate fuel tank T in the fuel flow path. A first check valve 19 that allows only the fuel flow from the fuel tank T to the high-pressure fuel pump PH is disposed, and a downstream-side fuel suction that connects the first check valve 19 and the suction passage P1 of the high-pressure fuel pump PH. An outboard motor characterized in that the path F3 and the valve seat 10 are connected by a second fuel suction path F4, and the return fuel path 17 of the pressure regulator R is connected to the first chamber 1A of the vapor separator V. Fuel supply device. 2. An upstream fuel suction passage F that connects a first check valve 19 and a separately installed fuel tank T in the fuel flow passage.
The fuel supply device for an outboard motor according to claim 1, wherein a first fuel filter (L1) is disposed in the fuel discharge passage (5), and a second fuel filter (L2) is disposed in the fuel discharge path. 3. The pressure-operated valve is connected to a pressure receiving chamber 5 and an atmosphere chamber 6.
And a spring S which is compressed in the atmosphere chamber 6 and urges the diaphragm 4 toward the pressure receiving chamber 5, one end of which is open in the housing 1, and the other end of which is in the pressure receiving chamber 5. A pressure introduction passage 8 that opens, an air vent passage 7 that opens at one end into the pressure receiving chamber 5 and the other end opens to the atmosphere, and a valve body 9 that is formed integrally with the diaphragm 4 and opens and closes the air vent passage 7. The fuel supply device for an outboard motor according to claim 1, wherein the fuel supply device is formed.