JPH0932677A - Steam separator in fuel injection system of two-cycle ship engine - Google Patents

Abstract

(57) [Summary] [Purpose] Uniformly mix oil and fuel well in a steam separator. [Constitution] In the liquid storage tank 3 of the vapor separator V, the fuel level X
A fuel stirring chamber 23 having a collision surface E facing the fuel return passage 17 is formed, and the fuel stirring chamber 23 is connected to the liquid storage tank 3 with a gap S. The fuel return passage 17 of the pressure regulator R opens to face the collision surface E of the fuel stirring chamber 23, and the oil discharge passage 24 opens to the inside of the fuel stirring chamber 23. The oil is mixed with the return fuel that is stirred in the fuel stirring chamber 23, and is discharged into the liquid storage tank 3 through the gap S.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil for a two-cycle engine (generally referred to as a two-cycle ship engine) used on water such as an inboard motor, an outboard motor, a watercraft motorcycle, etc., through a fuel injection valve. Related to a fuel injection device in a two-cycle marine engine for injecting and supplying fuel including
The bubbles contained in the fuel supplied from the first fuel pump are separated inside, and the oil supplied from the oil pump is mixed inside, and the fuel containing the oil separated from the bubbles is supplied to the second electric fuel. The present invention relates to a vapor separator that serves to supply a pump.

[0002]

2. Description of the Related Art In a marine engine, "the outside of an engine unit integrally formed with the marine engine,
Do not form a pressurized fuel flow path through which highly pressurized fuel will pass. There is a safety regulation. For this reason, the second electric fuel pump and the steam separator are integrally mounted near the unit of the marine engine. Then, the fuel in the fuel tank is supplied into the vapor separator through the filter and the first fuel pump, while the fuel in the vapor separator is separated into the second fuel.
Fuel that is sucked in by the electric fuel pump and is largely pressurized is injected and supplied from the fuel injection valve toward the marine engine.
The fuel injection device and steam separator of this marine engine are shown in Japanese Utility Model Laid-Open No. 2-74565. The vapor separator forms a fuel liquid level in the vapor separator by the cooperation of the float, the float valve, and the valve seat, and separates bubbles contained in the fuel supplied from the first fuel pump and does not contain bubbles. Fuel is supplied to the second electric fuel pump.

On the other hand, in a marine engine, a two-cycle engine is often used, and the oil supplied to the engine is mixed with the fuel in the steam separator, and the fuel containing this oil is the second fuel as described above. It is supplied to a two-cycle marine engine via an electric fuel pump.

[0004]

In such a conventional vapor separator for a fuel injection device for a two-cycle ship engine, the oil in the oil tank is pressurized by an oil pump, and this oil is applied to the side wall of the vapor separator or the fuel. It is supplied from the bottom of the liquid surface into the liquid storage tank of the vapor separator. In the case where oil is supplied to the side wall of the vapor separator, the oil travels down the side wall and mixes with the fuel in the liquid storage tank, so it takes time for the oil to contact the fuel. It is necessary to partially mix with the fuel first, and this gradually mixes into the fuel in the liquid storage tank to mix, so it may not be possible to immediately obtain a good mixed state of oil and fuel. . Also, in the case where the oil is supplied to the bottom of the fuel level, the oil is discharged directly into the fuel, but the viscosity of the oil and the fuel (gasoline) is greatly different, Moreover, it is impossible to uniformly mix the oil with the entire fuel in the liquid storage tank.

The present invention has been made in view of the above problems, and the mixing of the oil and the fuel in the vapor separator is made uniform over the entire fuel in the liquid storage tank without any time delay and the mixing is excellent. It is an object of the present invention to provide a vapor separator in a fuel injection device for a two-cycle engine that can be used.

[0006]

According to the present invention, the above-mentioned object is to supply the fuel in the fuel tank into the vapor separator via the first fuel pump and to supply the oil in the oil tank to the oil pump. Through the second electric fuel pump into the fuel distribution pipe via the second electric fuel pump, and the fuel below the liquid surface of the fuel containing the oil formed in the vapor separator is supplied through the second electric fuel pump. In a fuel injection device for a two-cycle marine engine that supplies fuel to a marine engine via a fuel injection valve mounted on a fuel agitator chamber, the vapor separator has at least a collision surface facing a fuel return passage of a pressure regulator. The fuel return passage of the pressure regulator and the oil discharge passage communicating with the oil pump are opened in the fuel stirring chamber and mixed in the fuel stirring chamber. The mixed fuel of the return fuel and oil to be achieved by draining the liquid storage tank of the steam separator.

[0007]

A large amount of return fuel continuously flows into the fuel stirring chamber from the fuel return passage of the pressure regulator when the engine is operating, and this return fuel is stirred in the fuel stirring chamber. On the other hand, since the oil is also supplied into the fuel stirring chamber, the oil is immediately and uniformly mixed with the return fuel in the fuel stirring chamber. Then, the return fuel mixed with this oil is supplied into the liquid storage tank of the vapor separator, and this is supplied to the two-cycle ship engine via the second electric fuel pump.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vapor separator in a fuel injection system for a two-cycle ship engine according to the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a main part of a vapor separator provided with a pressure regulator, FIG. 2 is a longitudinal sectional view taken along the line YY of FIG. 1, and FIG. 3 is a simplified top plan view of FIG. V is a vapor separator consisting of: Reference numeral 1 denotes a bottomed cup-shaped chamber having an open upper portion. The upper opening of the chamber 1 is closed by a lid member 2, and the chamber 1 and the lid member 2 form a liquid storage tank 3. A channel 4 is formed in the lid member 2, and the downstream side of the channel 4 opens into the liquid storage tank 3 via a valve seat 5. Reference numeral 6 denotes a float valve which is arranged in the valve seat 5 and opens and closes a seat hole 5A of the valve seat 5. Reference numeral 7 denotes a float arm rotatably supported on the axis G. The first arm 7 of the float arm 7 is
A extends to the left side and its upper surface is arranged to face the float valve 6, and the second arm 7B has a float 8
Is attached. When the float 8 is in the liquid storage tank 3 and there is no fuel in the liquid storage tank 3, the float 8 is rotated in the counterclockwise direction and is thereby positioned.
Holds the seat hole 5A of the valve seat 5 open. When the fuel is supplied from the flow path 4, the fuel is supplied to the valve seat 5
Through the sheet hole 5A of the
The fuel is stored inside, and the fuel liquid level in the liquid storage tank 3 is gradually raised. When the fuel level rises, the float 8 gradually rotates clockwise due to its buoyancy. The clockwise rotation of the float 8 causes the float valve 6 to rotate in the clockwise direction. The seat hole 5A of the valve seat 5 is closed. According to the above, the fuel liquid level X-X is formed in the liquid storage tank 3, and the fuel liquid level X-
The atmosphere chamber 9 is formed above -X. Reference numeral 10 denotes an atmosphere opening hole provided in the lid member 2, one end of which is opened to the atmosphere chamber 9, and the other end of which is connected to an intake pipe, a throttle body, a fuel tank, which will be described later, or the atmosphere.

Reference numeral R denotes a pressure regulator arranged on the lid member 2 for keeping the fuel pressure constant against atmospheric pressure or negative pressure in the intake pipe, which is made of a metal housing and whose inside is made of rubber. The spring 11 and the fuel chamber 13 are separated by the diaphragm 11, and the fuel supplied from the fuel distribution pipe enters through the inlet 14 and the fuel chamber 1
3, the valve 15 is pushed up via the diaphragm 11 and is balanced with the spring force of the spring 16 at a set pressure, after which the fuel is returned to the atmosphere chamber 9 of the vapor separator V via the fuel return passage 17. . The spring chamber 12 of the pressure regulator R and the intake pipe are connected to each other through the negative pressure introducing passage D, so that a constant set pressure is maintained with respect to the negative pressure in the intake pipe. The valve seat 5 and the fuel return passage 17 open into the atmosphere chamber 9 of the chamber 1. P is a second electric fuel pump arranged in the vapor separator V, and is sandwiched between the lid member 2 and the step portion 1C of the chamber 1 via an O-ring 18 and a flat rubber 19. A fuel inflow pipe 20 is opened below the fuel inflow pipe 20 and penetrates the lid member 2 above the fuel inflow pipe 20.
1 opens. Then, the fuel inflow pipe 20 of the second electric fuel pump P opens below the fuel liquid level XX in the liquid storage tank 3 via the strainer 22.

A fuel stirring chamber 23 is formed in the lid member 2 as follows. The fuel stirring chamber 23 is formed from a lower surface 2B of the upper bottom portion 2A of the lid member 2 with a standing wall 23A having a U-shaped cross section protruding downward by H. The U-shaped open end 23B of each standing wall 23A forms a gap S continuous in the vertical direction with respect to the inner circumference 2C of the lid member 2, and the lower end of the fuel stirring chamber 23 faces downward. To make an opening 23C. This opening 23C is a standing wall 23A.
It was necessary to cast and form the lid integrally with the lid member 2. The opening 23C is closed by the closing plate 23D. According to the above, the fuel stirring chamber 23 has the lid member 2
The fuel stirring chamber 23 is formed by the upper bottom portion 2A of the standing wall 23A, the closing plate 23D facing the upper bottom portion 2A, and the standing wall 23A facing each other.
Is communicated with the atmosphere chamber 9 through a gap S formed by the inner circumference 2C of the. Further, a through hole 23E is formed in the upper bottom portion 2A forming an upper portion of the fuel stirring chamber 23 so as to face the fuel stirring chamber 23, and the through hole 23E is connected to the fuel return passage 17. Further, an oil discharge passage 24 opens on the side of the fuel stirring chamber 23 (specifically, the standing wall 23A). The closing plate 23D is disposed so as to face the opening of the fuel return passage 17, and forms a collision surface E with respect to the fuel return passage 17. According to the above, the fuel return passage 17 opens into the fuel stirring chamber 23 through the through hole 23E, facing the closing plate 23D as the collision surface E of the fuel stirring chamber 23.

Then, the vapor separator V is assembled in the fuel injection device as follows. Explaining with reference to FIG. 4, F is a two-cycle ship engine, and an area of an intake passage 32 is variably controlled upstream of an intake pipe 30 connected to the two-cycle ship engine F by a throttle valve 31 operated by a driver. A throttle body 33 is connected, and the upstream side of the intake passage 32 opens to the atmosphere side. Reference numeral 34 is a fuel distribution pipe in which a fuel distribution passage 35 is bored and which holds and holds a fuel injection valve J. The fuel in the fuel distribution passage 35 is
The fuel is injected and supplied into the intake pipe 30 via the fuel injection valve J. In addition, 36 is a pulsation damper.

Further, the flow path 4 of the vapor separator V is connected to the fuel tank T, and the fuel in the fuel tank T is strainer 5
0, and is supplied to the flow path 4 via the first fuel pump 51.
The first fuel pump 51 is preferably a pulsating pressure drive type diaphragm pump that performs a pumping action by reciprocating the diaphragm with the pulsating pressure generated in the intake pipe 30. Further, the oil in the oil tank 60 is pressurized and measured by the oil pump 61, and this oil is discharged into the fuel stirring chamber 23 via the oil discharge passage 24. Furthermore, the inlet 14 of the pressure regulator R is connected to the flow path 7
The fuel distribution line 35 of the fuel distribution pipe 34 is connected via 0.

Next, the operation will be described. When the two-cycle ship engine F is operated, the fuel in the fuel tank T passes through the strainer 50, the first fuel pump 51, the flow path 4, and the seat hole 5A of the valve seat 5 and the storage tank of the vapor separator V. 3 is supplied. In the liquid storage tank 3, the fuel level in the liquid storage tank 3 gradually rises due to the supply of fuel from the seat hole 5A. When the fuel level rises, the float 8 rotates clockwise in synchronism with the rise of the liquid level, and when the desired fuel level XX is reached, the float valve 6 closes the seat hole 5A of the valve seat 5. Therefore, the fuel liquid level XX is formed in the liquid storage tank 3.

On the other hand, in the second electric fuel pump P,
The fuel in the liquid storage tank 3 is sucked into the second electric fuel pump P from the fuel inflow pipe 20 through the strainer 22, and the fuel whose pressure is increased in the second electric fuel pump P is passed through the fuel discharge passage 21. It is supplied into the fuel distribution passage 35 of the fuel distribution pipe 34. Then, the fuel in the fuel distribution pipe 34 is injected and supplied through the fuel injection valve J into the intake pipe 30 connected to the two-cycle ship engine F. The fuel supplied from the first fuel pump 51 into the liquid storage tank 3 contains bubbles due to vibration pressure, temperature conditions, etc., and the fuel containing the bubbles passes through the seat hole 5A of the valve seat 5. Although it is discharged into the liquid storage tank 3, the bubbles in the liquid storage tank 3 rise due to the buoyancy of the liquid storage tank 3 to reach the inside of the atmosphere chamber 9 and are discharged from the atmosphere opening hole 10 to the outside of the vapor separator V. . Therefore, the second electric fuel pump P
The fuel supplied from the fuel injection valve J to the fuel injection valve J does not contain bubbles.

Further, in the pressure regulator R, the fuel in the fuel distribution passage 35 is introduced into the fuel chamber 13 through the inlet 14, and the fuel is constant with respect to the atmospheric pressure or the negative pressure in the intake pipe 30. The valve 15 operates in balance with the spring force of the spring 16 so that the pressure is increased, and excess fuel is supplied to the fuel stirring chamber 23 through the fuel return passage 17 and the through hole 23E.
It is discharged inside. Then, the fuel in the fuel stirring chamber 23 is recirculated into the liquid storage tank 3 of the vapor separator V through the gap S again.

The oil in the oil tank 60, which is measured and discharged by the oil pump 61, is discharged from the oil discharge passage 24 into the fuel stirring chamber 23.
On the other hand, as for the amount of return fuel discharged from the fuel return passage 17 of the pressure regulator R into the fuel stirring chamber 23 through the through hole 23E, a large amount of fuel is returned during the operation. For example, the displacement of a 2-cycle ship engine is 30
In the case of 00cc, the pump discharge amount of the second electric fuel pump P is 150L / H, and 135L / H of fuel is in the fuel return passage 17 and the through hole 23E at the time of idling operation that is the minimum rotation of the engine. Is discharged to the inside of the fuel stirring chamber 23 via the engine, while 30 L / H of fuel is discharged into the fuel stirring chamber 23 during high-speed operation when the fuel consumption of the engine is maximum.
It is discharged inside.

As described above, since a large amount of the return fuel is discharged from the fuel return passage 17 into the fuel stirring chamber 23, the return fuel is the fuel return passage 1
7 (including the through hole 23E), the collision surface (the closing plate 2)
3), which collides with 3) at a high speed, whereby the return fuel is largely stirred in the fuel stirring chamber 23.

On the other hand, the oil is discharged from the oil discharge passage 24 toward the inside of the fuel stirring chamber 23 as described above, and this oil is surely the return fuel that is largely stirred in the fuel stirring chamber 23. Mixed. Then, the return fuel mixed with the oil is discharged into the liquid storage tank 3 through the gap S and is well mixed with the fuel in the liquid storage tank 3. This is because the oil discharged from the fuel stirring chamber 23 into the liquid storage tank 3 has already been sufficiently and uniformly mixed with the fuel in the fuel stirring chamber 23, so that the liquid storage tank 3
Immediately mix with fuel in. Then, the fuel in which the oil in the liquid storage tank 3 is made to be good and uniformly mixed is injected and supplied from the second electric fuel pump P through the fuel injection valve J toward the two-cycle ship engine.

The shape of the fuel stirring chamber 23 is not limited to the above-mentioned embodiment, and at least the collision surface facing the fuel return passage, the side wall surrounding the collision surface,
Also, any material having a gap that opens into the liquid storage tank may be used. Further, the fuel stirring chamber 23 may be provided in the pressure regulator itself or in the chamber. Further, since the fuel agitating chamber 23 is connected to the atmospheric chamber 9 with a gap S, the fuel agitating chamber 23 is maintained at the atmospheric pressure state. Therefore, the opening end of the oil discharge passage 24 can be maintained at the atmospheric pressure, and the oil discharge is not hindered.

[0020]

As described above, according to the vapor separator in the fuel injection device for a two-cycle ship engine according to the present invention, the return fuel of the pressure regulator is discharged into the fuel stirring chamber and the oil discharged from the oil discharge passage is discharged. Since the fuel agitated in the fuel agitating chamber was positively mixed, the oil and the fuel could be mixed extremely well and uniformly, and the operability of the engine could be significantly improved. Further, in the mixing, since the flow velocity of the return fuel itself is used, it is not necessary to prepare special energy. Further, since the opening of the oil discharge passage is always flushed with the return fuel, the oil discharge passage having a relatively small diameter is not solidified by oil or blocked by foreign matter, and stable oil can be supplied for a long period of time.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a vapor separator in a fuel injection device for a two-cycle ship engine according to the present invention.

FIG. 2 is a vertical sectional view taken along the line YY of FIG.

3 is a simplified top plan view of FIG.

FIG. 4 is a system diagram showing a fuel injection device for a two-cycle ship engine according to the present invention.

[Explanation of symbols]

 V Steam Separator R Pressure Regulator F 2 Cycle Ship Engine P 2nd Electric Fuel Pump T Fuel Tank 3 Storage Tank 23 Fuel Stirring Chamber 24 Oil Discharge Path E Collision Surface of Fuel Stirring Chamber

Claims (1)

[Claims] 1. A fuel in a fuel tank is supplied to a steam separator via a first fuel pump, and an oil in an oil tank is supplied to a steam separator via an oil pump, thereby The fuel below the liquid surface containing the oil formed in the fuel is supplied into the fuel distribution pipe through the second electric fuel pump, and the fuel is directed to the marine engine through the fuel injection valve mounted in the fuel distribution pipe. In a fuel injection device for a two-cycle ship engine that supplies and injects by injection, a fuel agitator chamber 23 having at least a collision surface E facing the fuel return passage 17 of the pressure regulator R is formed in the vapor separator V, and the fuel of the pressure regulator R is also formed. A return passage 17 and an oil discharge passage 24 communicating with the oil pump 61 are opened in the fuel agitation chamber, and the mixture is mixed in the fuel agitation chamber. A steam separator in a fuel injection device for a two-cycle ship engine, wherein a mixed fuel of a fuel and an oil is discharged into a liquid storage tank 3 of a steam separator V.