JP2003184687A - Fuel supply device for ship - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve operability and restartability of an engine by restraining generation of fuel vapor discharged from a fuel pump without fuel vapor sucked by the fuel pump, in a fuel supply device using a displacement type pump. <P>SOLUTION: A capacity type pump P is housed in a sealed fuel chamber C, and a sealed sub-chamber S is installed separately from the chamber C. A fuel discharge chamber 32 with a cooling water pipe 30 is arranged above the fuel chamber. A regulator pipe 33 connected with a pressure regulator R, a fuel inflow pipe 34 connected with an discharge hole PB of the pump P, and a fuel outflow pipe 35 connected with a fuel discharge pipe 1J are opened to the fuel discharge chamber 32. A fuel suction pipe 1M connected with a fuel tank T, a return fuel pipe 1D connected with the regulator R, and a vapor releasing pipe 1Q connected with the sub-chamber S are opened to the chamber C. A fixed liquid level controller L comprising a valve seat 17, a float valve 19, and a float 22 is arranged to the sub-chamber S, and a one-way control valve 18 is arranged to a negative pressure introduction pipe 15. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device for an inboard engine in which a fuel supply device for supplying fuel to the engine is arranged in an engine room of the hull, and the fuel supply device is arranged at the rear of the hull together with the engine. A fuel injection system for a ship used as a fuel supply system for an outboard engine, in which fuel in a fuel tank is boosted by a fuel pump, and the boosted fuel is injected and supplied to an engine through a fuel injection valve. Fuel supply device.

[0002]

2. Description of the Related Art A conventional fuel supply system used in a marine engine is shown in FIG. P is a positive displacement fuel pump in which the chamber volume of the pump chamber changes, such as a rotor, a roller,
The positive displacement fuel pump P is a roller type pump including a pump spacer and has a high self-sufficiency performance.
(In the following description, a positive displacement fuel pump is simply referred to as a fuel pump.) Such a fuel pump P has a suction hole PA and a discharge hole PB, and the suction hole PA stores fuel inside through a fuel suction pipe 90. A suction side fuel filter F that is connected to the fuel tank T and removes foreign matters in the fuel flowing from the fuel tank T toward the fuel pump P is disposed in the fuel suction pipe 90. The discharge hole PB of the fuel pump P is connected to a fuel distribution pipe D via a fuel discharge pipe 91, and a fuel injection valve J for injecting fuel into the intake pipe 92 of the engine is connected to the fuel distribution pipe D. Be worn. A pressure regulator R is attached to the fuel distribution pipe D, and the return fuel pipe 93 of the pressure regulator R is connected to the fuel tank T. The fuel discharge pipe 91 is provided with a discharge side fuel filter G for removing foreign matters in the fuel flowing from the fuel pump P to the fuel distribution pipe D.

According to the above-described fuel supply device for a marine engine, when the fuel pump P is driven along with the operation of the engine, the fuel pump P, which is of a positive displacement type and has a self-priming property, removes the fuel in the fuel tank T. The fuel sucked into the pump chamber of the fuel pump P through the fuel suction pipe 90 and the suction hole PA, and the fuel whose pressure is increased in the pump chamber is discharged through the discharge hole PB and the fuel discharge pipe 91.
And is supplied into the fuel distribution pipe D via. On the other hand, the fuel in the fuel distribution pipe D is introduced into the pressure regulator R and regulated to a constant fuel pressure, and the fuel having the predetermined fuel pressure is introduced through the fuel injection valve J into the intake pipe 92. It is injected and supplied inward. In the pressure regulator R, the surplus fuel discharged for pressure regulation is returned into the fuel tank T via the return fuel pipe 93.
Further, the fuel flowing in the fuel suction pipe 90 from the fuel tank T to the fuel pump P has foreign substances removed by the suction side fuel filter F, and the fuel flowing in the fuel discharge pipe 91 from the fuel pump P to the fuel distribution pipe D. The foreign matter is removed by the discharge side fuel filter G.

[0004]

Such a conventional fuel supply device for a marine engine is arranged near an engine in an engine room for an inboard engine, and covers an engine around an outboard motor. It is arranged in the cowling in the vicinity of the engine, and particularly during operation in summer, the temperature of the fuel supply device greatly increases due to the influence of the atmospheric temperature or the radiant heat during combustion of the engine. Here, the fuel pump P has a high self-priming property, so that the fuel is sucked from the fuel tank T into the pump chamber of the fuel pump P, and at this time, the pressure in the fuel suction pipe 90 becomes a negative pressure state. When the negative pressure acts on the fuel flowing in the fuel suction pipe 90, the fuel generates vapor, and this vapor is sucked into the pump chamber of the fuel pump P, which is an effective pump of the fuel pump P. The action is hindered, which causes a problem that the pump discharge amount is reduced or the pressure cannot be increased to a desired pressure. Further, the vapor sucked into the pump chamber of the fuel pump P is the fuel discharge pipe 91, the fuel distribution pipe D,
Is supplied to the fuel injection valve J via the
The vapor generated inside is supplied toward the fuel injection valve J. According to this, the fuel supplied from the fuel injection valve J into the intake pipe 92 becomes intermittent or is injected from the fuel injection valve J. The amount of fuel consumed may be reduced by the amount corresponding to the vapor amount, which hinders good engine operation. Further, after the engine is stopped, the fuel suction pipe 90 is warmed by heat radiation from the engine, so that the fuel suction pipe 90
The fuel inside may be heated to a temperature higher than the boiling point, a large amount of vapor may be generated, and this vapor may return the fuel inside the fuel suction pipe 90 into the fuel tank T. According to this, at the time of restarting the engine, It takes time until the fuel pump P sucks the fuel in the fuel tank T, and there is a drawback that a good engine restart cannot be performed.

A fuel supply device for a marine engine according to the present invention is made in view of the above-mentioned problems, and in a fuel supply device in which a positive displacement fuel pump is used as a fuel pump, and in particular, an ambient temperature is arranged in a high temperature state. An object of the present invention is to provide a marine fuel supply device in which the operation of the engine is not hindered by vapor generated in the fuel in the fuel intake pipe and the fuel discharge pipe, and the restartability of the engine is good.

[0006]

In order to achieve the above-mentioned object, a ship fuel supply system according to the present invention boosts the pressure of fuel in a fuel tank by a positive displacement fuel pump, and boosts the boosted fuel. In a ship fuel supply device for supplying to a ship engine via a sealed fuel chamber for housing a positive displacement fuel pump, a fuel inflow path connected to a discharge hole of the fuel pump, and a fuel discharge path connected to a fuel injection valve. And a cooling water pipe for cooling the fuel in the fuel discharge chamber,
A pressure regulator arranged in a regulator pipe branched from the fuel discharge chamber; and a closed sub-chamber, which is formed separately from the fuel chamber and which is provided with a valve seat, a float valve, and a constant liquid level controller including a float, In the chamber, a fuel intake pipe connected to the fuel tank, a return fuel pipe connected to the return valve seat of the pressure regulator, and a vapor vent pipe connected to the subchamber are opened, and a valve seat and an intake pipe opened in the subchamber. The first feature is that the one-way control valve is connected to the negative pressure introducing pipe and the one-way control valve that allows only the flow from the valve seat to the intake pipe is arranged in the negative pressure introducing pipe.

In addition to the first feature of the present invention, the sub-chamber is located above the fuel chamber in the direction of gravity, and the fuel discharge chamber is located above the fuel chamber. The second feature is that the upstream opening of the regulator tube is opened at a position above the fuel discharge chamber in the gravity direction.

In addition to the first feature of the present invention, a plurality of vapor vent pipes are provided, and the upper opening 1Qa1 of one vapor vent pipe 1Qa is opened above the constant liquid level XX of the sub-chamber S. The third feature is that the upper opening 1Qb1 of the other vapor vent pipe 1Qb is opened below the constant liquid level XX.

Further, in addition to the first feature, the present invention is a positive displacement fuel pump P disposed in the fuel chamber.
Of the suction side fuel filter F is disposed so as to surround at least the suction hole PA of the suction side fuel filter F,
The fourth characteristic is that the fuel suction pipe 1M, the return fuel pipe 1D, and the vapor vent pipe 1Q are opened.

Further, in addition to the first feature, the present invention further comprises:
The fuel chamber is formed by a chamber body and a cup body having a bottomed cup arranged below the chamber body.
A fifth feature is that the fuel discharge chamber is formed as an annular chamber by surrounding the outer circumference of the pipe-shaped cooling water pipe, and the fuel discharge chamber including the cooling water pipe is attached to the chamber body.

[0011]

According to the first technique of the fuel supply device for a marine engine according to the present invention, when the fuel pump is driven during operation of the engine, the fuel pump sucks the fuel in the closed fuel chamber. According to this, the pressure in the fuel chamber becomes a negative pressure state, and the fuel in the fuel tank is sucked into the fuel chamber through the fuel suction pipe. Then, the fuel in the fuel chamber is continuously sucked into the pump chamber of the fuel pump and boosted in pressure, the boosted fuel flows into the fuel discharge chamber, and is cooled by the cooling water pipe. The fuel is injected and supplied into the intake pipe through the fuel injection valve attached to the distribution pipe. on the other hand,
During operation of such an engine, the one-way control valve holds the negative pressure introducing passage open by the negative pressure generated in the intake pipe, and the negative pressure in the intake pipe additionally acts on the fuel in the fuel chamber. According to this, a large amount of fuel is sucked into the fuel chamber through the fuel suction pipe, and this fuel is then sucked into the sub chamber. When the liquid level of the fuel in the sub chamber rises to a certain level, the float closes the valve seat via the float valve. On the other hand, during operation of such an engine, the vapor generated in the fuel intake pipe flows into the fuel chamber due to the fuel flow, and this vapor also flows into the sub-chamber through the vapor vent hole. The liquid level of the fuel will decrease in response to the inflow of vapor. When the fuel level in the sub-chamber is lowered, the float valve opens the valve seat, and the vapor accumulated above the fuel level in the sub-chamber is sucked into the intake pipe through the negative pressure introducing pipe. As a result, excess vapor does not accumulate in the sub chamber. Thus, the fuel pump sucks the fuel in the fuel chamber with the vapor separated and supplies the fuel into the fuel discharge chamber. Since the fuel in the fuel discharge chamber is cooled by the cooling water in the cooling water pipe, the generation of vapor is suppressed and the vapor is not mixed into the fuel injected and supplied into the intake pipe.

Further, according to the second feature of the present invention, the vapor flowing into the fuel chamber from the fuel suction pipe or the like moves upward by the buoyancy of the vapor chamber itself, and further into the subchamber located above the vapor chamber. The vapor flows in through the drain pipe, and the vapor can be concentrated in the upper part of the sub-chamber, whereby the fuel liquid level in the sub-chamber can be displaced appropriately, and the vapor from the negative pressure introduction path can be removed. The dischargeability can be improved. Further, when vapor is mixed in the fuel discharged from the fuel pump, this vapor can be collected in the upper part of the fuel discharge chamber, and this vapor can be surely returned to the inside of the fuel chamber via the return fuel pipe. it can.

Further, according to the third feature of the present invention, the vapor can be discharged to a constant liquid level from the upper opening of the one vapor drain pipe, and the upper part located below the constant liquid level of the other vapor drain pipe accordingly. The fuel in the sub-chamber can be discharged to the fuel chamber through the opening, so that the vapor and the fuel in the sub-chamber can be replaced smoothly and immediately.

Further, according to the fourth aspect of the present invention, foreign matter contained in the fuel introduced into the fuel chamber from the fuel suction pipe, the return fuel pipe, and the vapor vent pipe is surely secured by the suction side fuel filter. Therefore, only clean fuel is sucked into the fuel pump. Further, since the vapor contained in the fuel introduced into the fuel chamber through the pipe is blocked by the suction side fuel filter, the vapor is not sucked into the fuel pump.

Further, according to the fifth feature of the present invention, the maintenance of the fuel chamber can be easily performed by removing the cup body from the chamber body. Further, since the fuel discharge chamber is formed as an annular chamber surrounding the outer circumference of the cooling water pipe, it can be easily attached to the chamber body.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a ship fuel supply system according to the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a ship fuel supply device. 2 is a vertical cross-sectional view taken along the line AA of FIG. FIG. 3 is a vertical sectional view taken along the line BB of FIG. Reference numeral 1 denotes a chamber main body formed of an injection molding material such as an aluminum material or a synthetic resin material, which is composed of the following. Referring to FIG. 1, 1A is a chamber body 1
Is a pump housing hole that is formed in a substantially central portion of the pump housing hole and is recessed upward from a flat portion 1B facing downward.
A discharge hole insertion hole 1C is formed in an upper part of A, and the upper side of the discharge hole insertion hole 1C is opened to an upper end 1Y of the chamber body 1 with a fuel inflow passage 1H. 1D is a left side of the pump housing hole 1A in FIG. 1 and FIG. 3, a return fuel pipe having an upper part projecting upward through a joint 1E and opening, and a lower part opening to a flat portion 1B. On the right side of the hole 1A in FIG. 2, a discharge side fuel filter storage recess 1F having a bottom shape is provided. The discharge side fuel filter storage recess 1F is formed on the right side end surface 1 on the side.
It is recessed from G toward the bottom of the pump housing hole 1A side.

Further, the chamber body 1 has a fuel suction pipe 1
M, a sub chamber 1N, and a regulator pipe 1K are formed. In FIG. 2, the fuel suction pipe 1M is formed on the left side of the pump housing hole 1A, the upstream side thereof opens toward the left side of the chamber body 1, and the downstream side thereof opens on the flat portion 1B. The sub-chamber 1N is recessed on the right side of the pump housing hole 1A in FIG. 2, and its upper portion opens toward the upper end 1P. Further, a vapor vent pipe 1Q is formed in the sub-chamber 1N with an opening. The vapor vent pipe 1Q has an upper portion opening into the sub-chamber 1N and a lower portion opening toward the flat portion 1B. In this example, two vapor vent pipes 1Q are provided. One of the vapor vent pipes 1Qa has an upper opening 1Qa1 above the sub-chamber 1N (the upper side is a constant liquid level formed in the sub-chamber 1N described later). To the upper part of),
The upper opening 1Qb1 of the other vapor vent pipe 1Qb opens below the sub-chamber 1N (below the constant liquid level, more specifically, near the bottom of the sub-chamber 1N).

A pressure regulator R and a discharge side fuel filter G are mounted on the chamber body, a sealed sub-chamber S is formed, and a positive displacement fuel pump P is mounted on the chamber body. The pressure regulator R is a known one, and is composed of the following. Reference numeral 2 is a diaphragm that is sandwiched between the regulator body 3 and the cover 4 and divides the fuel chamber 5 and the spring chamber 6. An inflow passage 7 is opened to the side of the fuel chamber 5 and the center of the fuel chamber 5 is opened. A discharge passage 8 opens in the portion via a return valve seat 9. The return valve seat 9 is controlled to open and close by the valve body 10 attached to the diaphragm 2. The pressure regulator R is attached to the left end face 1L of the chamber body 1 in FIG. 3 with a screw or the like, and the inflow passage 7 is connected to the regulator pipe 1K opening to the left end face 1L at this time. On the other hand, the discharge passage 8 is inserted into the joint 1E projecting upward to return the return fuel pipe 1D.
Connected to. The upstream side of the regulator pipe 1K opens upward toward the upper end 1Y of the chamber body 1.
As a result, the pressure regulator R is attached to the chamber body 1. According to this, the regulator pipe 1K is connected to the fuel chamber 5 via the inflow passage 7, and the return valve seat 9 opening to the fuel chamber 5 is connected to the discharge passage 8 , Is connected to the return fuel pipe 1D via the joint 1E.

The discharge side fuel filter G is a known one and is provided with a cylindrical filter member GA, and the discharge side fuel filter G is located in the discharge side fuel filter storage recess 1F from the right end surface 1G of the chamber body 1. After being inserted, the opening of the right end surface 1G of the discharge side fuel filter storage recess 1F is closed by the filter cover 12. A fuel discharge pipe 1J is formed in the center of the filter cover 12 so as to penetrate therethrough. The left side of the filter cover 12 opens into the discharge side fuel filter storage recess 1F, and the right side thereof faces outward. To open. According to the above, the discharge side fuel filter G is disposed in the discharge side fuel filter storage recess 1F sealed by the filter cover 12, and the chamber body 1
The fuel discharge passage 1J provided in the fuel discharge passage 1J is located inside the discharge side fuel filter storage recess 1F and is open to the outside of the filter member GA of the discharge side fuel filter G, and the left side of the fuel discharge pipe 1J provided in the filter cover 12 is The filter member GA opens inside. Reference numeral 13A is a first spring that is contracted in the discharge side fuel filter storage recess 1F and presses and biases the discharge side fuel filter G toward the filter cover 12.
The upstream side of the fuel discharge passage 1J opens at the upper end 1Y of the chamber body 1.

The closed sub-chamber S is formed by the following. To describe with reference to FIG. 1, 14 is a sub-chamber cover that closes the opening to the upper end 1P of the sub-chamber 1N, and a negative pressure introducing pipe 15 opens upward in the sub-chamber cover 14 to introduce a negative pressure. The lower portion of the pipe 15 opens below the sub-chamber cover 14 via the first valve seat 16 and the valve seat 17. The first valve seat 16
Is formed so as to face upward in the figure.
The valve seat 16 is opened and closed by a one-way control valve 18. That is, the one-way control valve 18 is arranged so as to be movable in the vertical direction in the figure, and in the state where no force acts on the one-way control valve 18, the one-way control valve 18 moves downward due to its own gravity. Then, the first valve seat 16 is held closed. The valve seat 17 is formed so as to face downward in the drawing, and the valve seat 17 is opened and closed by a float valve 19. A constant liquid level control device L is formed on the sub chamber cover 14 by the valve seat 17, the float valve 19 and a float described later. That is, 20 is a float arm that is rotatably supported by a shaft 21 that is erected on the sub-chamber cover 14, a float 22 is integrally attached to the tip of the float arm, and the upper surface of the tongue portion 20A is the float valve 19. It is placed facing the bottom edge of. According to the above constant liquid level control device L, when the float 22 rotates clockwise in the drawing, the tongue portion 20A moves the float valve 19 upward to close the valve seat 17, and the float 21 moves counterclockwise in the drawing. When rotated in the direction, the tongue portion 20A moves the float valve 19 downward to open the valve seat 17. Then, by the sub-chamber cover 14 including the constant liquid level control device L, the upper end 1 of the chamber body 1 is
The sub-chamber 1N opening to P is closed. According to the above, the sub-chamber 1N is formed as a closed sub-chamber S, the float 21 is arranged in the sub-chamber S, and the one vapor vent pipe 1Qa and the other vapor vent pipe 1Qb described above are provided in the sub chamber S.
And open.

Further, a fuel pump P is attached to the chamber body 1. Referring to FIG. 2, the upper portion of the fuel pump P is inserted and arranged in the pump housing hole 1A, and the discharge hole PB protruding upward at this time is an O-ring in the discharge hole insertion hole 1C of the chamber body 1. The fuel pump P is inserted and arranged in a liquid-tight manner via U, and the upper step PC of the fuel pump P is inserted and arranged into the step 1R of the pump housing hole 1A via an O-ring U. Reference numeral 23 is a tubular pump support member, and an annular upper flange portion 23A extending laterally is formed on the upper side, and a lower flange portion 23B facing the lower step portion PD of the fuel pump P and directed inward is formed on the lower side. Is formed. A mounting hole 23C is formed in the upper collar portion 23A. An annular member 24 is integrally fixed to the upper outer circumference of the pump support member 23 by welding or the like, and a male screw is formed on the outer circumference. Then, the fuel pump P is attached to the chamber body 1 as follows. From the lower side of the fuel pump P toward the outer periphery of the fuel pump P, the upper flange portion 23A of the pump support member 23
Is inserted and arranged. At this time, the pump support member 23
The upper flange portion 23A of the pump support member 23 is disposed in contact with the flat portion 1B of the chamber main body 1, and the lower flange portion 23B of the pump support member 23 is O.
It is arranged so as to face the lower step portion PD of the fuel pump P via the ring U. Then, in such a state, the upper flange portion 23A of the pump support member 23 is screwed and fixed to the chamber body 1 with a screw through the mounting hole 23C. According to the above, the fuel pump P is fixedly sandwiched and supported between the step portion 1R of the chamber body 1 and the lower flange portion 23B of the pump support member 23 via the O-ring U.

Reference numeral 26 denotes a shaft portion 2 which is screwed to a male screw of an annular member 24 fixed to the pump supporting member 23 through a female screw.
6A and an annular plate portion 2 extending laterally from the upper end of the shaft portion 26A
A plurality of through holes 26C are formed by penetrating the annular plate portion 26B. Also, the annular plate portion 26B
On the outer periphery of the upper end of the plate, a thin plate annular mounting piece 26
D is fixedly arranged, and a ring groove 26E facing upward is provided in the center of the mounting piece 26D. The mounting piece 26D is a through hole 2 formed in the annular plate portion 26B.
It does not block 6C. Further, F is a suction side fuel filter, an annular filtering member FC is arranged between the lower plate FA and the upper plate FB, and a cylinder inserted into the outer periphery of the shaft portion 26A of the support portion 26 in the upper plate FB. The part FD and the flange part FE extending outward from the upper end of the tubular part FD are integrally formed. And fuel chamber C
A bottomed cup-shaped cup body 25 is prepared and is formed by the following. First, the coil-shaped second spring BB is arranged in the cup body 25 from the upper opening of the cup body 25, and the suction side fuel filter F is arranged. Further, toward the opening of the cup body 25, the shaft portion 26A and the annular plate are arranged. Part 26B,
The support portion 26 including the attachment piece 26D is arranged, and in this state, the outer periphery of the attachment piece 26D is caulked toward the upper end of the cup body 25, whereby the support portion 26 is fixedly arranged in the upper opening of the cup body 25. According to the above, the cylinder portion FD of the upper plate FB of the intake side fuel filter F arranged in the cup body 25 is centeringly supported on the outer periphery of the shaft portion 26A of the support portion 26, and the collar portion EF is the spring of the second spring 13B. It is pressed and supported by the force toward the annular plate portion 26B of the support portion 26 via the elastic ring V. That is, the suction side fuel filter F is pressed and housed inside the cup body 25.

The cup body 25 having the above-described intake side fuel filter F is mounted from below the chamber body 1 toward the flat portion 1B, which is located inside the shaft portion 26A of the support portion 26. This is performed by screwing the female screw formed on the male screw toward the male screw of the annular member 24. According to the above, the support portion 26 of the cup body 25 is screwed to the annular member 24, and at this time, the elastic ring V arranged in the ring groove 26E of the mounting piece 26D is arranged in pressure contact toward the flat portion 1B. The fuel chamber C having a hermetically sealed structure including a cup body 25 below the chamber body 1
Is formed.

Reference numeral 30 denotes a pipe-shaped cooling water pipe, and 3
Reference numeral 1 denotes a fuel pipe which is arranged on the outer circumference of the cooling water pipe 30 with a gap and whose both ends are fixedly arranged with a reduced diameter on the outer circumference of the cooling water pipe 30.
An annular fuel discharge chamber 32 is formed by 1 and 1.
A regulator pipe 33, a fuel inflow pipe 34, and a fuel discharge pipe 35 are formed in the fuel discharge chamber 32 so as to protrude downward. The regulator pipe 33 has a lower protruding end that opens to the upper end 1Y of the chamber body 1 1K.
The upstream opening 33A is inserted into the fuel discharge chamber 32.
Is curved so as to open above. The fuel inflow pipe 34 (which is well shown in FIG. 3) is inserted into the fuel inflow passage 1H whose lower projecting end opens to the upper end 1Y of the chamber body 1, and whose upper part opens to the bottom of the fuel discharge chamber 32. To do. The lower end of the fuel discharge pipe 35 is inserted into the fuel discharge passage 1J opening at the upper end 1Y of the chamber body 1, and the upper end thereof opens at the bottom of the fuel discharge chamber 32. A fuel pipe 31 having a cooling water pipe 30 inside and a regulator pipe 33, a fuel inflow pipe 34, and a fuel discharge pipe 35 toward the outside is arranged on the chamber body 1. At this time, As described above, the regulator pipe 33 is inserted into the regulator pipe 1K, the fuel inflow pipe 34 is inserted into the fuel inflow passage 34, and the fuel discharge pipe 35 is inserted into the fuel discharge passage 1J. Then, in such a state, the U-shaped mounting band 36 is arranged on the outer circumference of the fuel pipe 31, and the flange 36 extending laterally from the end of the mounting band 36.
A is screwed and fixed to the chamber body 1 via the screw 37.

Summarizing the above, the chamber body 1
Of the fuel suction pipe 1M, one vapor vent hole 1Qa, the other vapor vent hole 1Qb, and the return fuel pipe 1D, which are open to the flat portion 1B of the support member 26, through the through hole 26C provided in the annular plate portion 26B of the support portion 26. To open in the closed fuel chamber C on the outer periphery of the filter member FC of the suction side fuel filter F. On the other hand, the fuel pump P projecting below the flat portion 1B of the chamber body 1 is arranged inside the fuel chamber C and inside the intake side fuel filter F, and the intake hole PA is also located in the intake side fuel filter F. The filter member FC opens inside. Further, a fuel discharge chamber 32 having a cooling water pipe 30 is arranged at the upper end of the chamber body 1, the fuel discharge chamber 32 and the regulator pipe 1K are connected by a regulator pipe 33, and the fuel discharge chamber 32 and the fuel inflow passage 1H are connected to each other. The fuel inflow pipe 34 communicates with each other, and the fuel discharge chamber 32 and the fuel discharge passage 1J connected to the fuel discharge pipe 1J communicate with each other through a fuel outflow pipe 35. The fuel supply system for ships consisting of the above is
As shown in FIG. 4, the pipes are connected. FIG. 4 is a simplified pipe connection diagram. The negative pressure introducing pipe 15 is connected to the intake pipe K, and the outward fuel discharge pipe 1J (specifically, the fuel discharge pipe 1J provided on the filter cover 12) is connected to the fuel distribution pipe D including the fuel injection valve J. Connected, fuel intake pipe 1M
Is connected to the fuel tank T.

Next, the operation will be described. To explain the stopped state of the engine, in this state, the fuel is retained and retained in the fuel chamber C, the sub-chamber S is empty, the float valve 19 holds the valve seat 17 open, and the one-way control is performed. The valve 18 is the first valve seat 16
Hold closed. Here, when the engine is stopped, the fuel remains in the fuel chamber C because the fuel in the fuel chamber C is not completely consumed in the stopped state after the engine is once operated. . The float valve 19 holds the valve seat 17 open because the subchamber S is empty and the float 22 is rotated in the most counterclockwise direction. The reason why the valve 16 is kept closed is that the negative pressure in the intake pipe K does not act on the one-way control valve 18.

In this state, when the engine is started and the fuel pump P is driven, the fuel pump P sucks the fuel in the fuel chamber C and discharges it. The pressure in the chamber C becomes a negative pressure state. On the other hand, when the engine start is started,
The negative pressure generated in the intake pipe K acts toward the one-way control valve 18 via the negative pressure introduction pipe 15, whereby the one-way control valve 18 holds the first valve seat 16 open, and the intake pipe K is opened. The negative pressure inside is the valve seat 17 in an open state, the sub-chamber S in which fuel is not stored, the vapor vent pipe 1Qa, 1
It is introduced into the fuel chamber C via Qb. According to the above, in the fuel chamber C, the negative pressure generated by the driving of the fuel pump P and the negative pressure in the intake pipe K act, and the negative pressure causes the fuel in the fuel tank T to move. Is sucked into and stored in the fuel chamber C through the fuel chamber C, and this fuel is sucked into the pump chamber (not shown) of the fuel pump P from the suction hole PA of the fuel pump P, and the fuel pressurized in the pump chamber is Fuel inflow path 1 from the discharge hole PB
H is discharged toward the fuel discharge chamber 32 through the H and fuel inflow pipes 34. Here, the fuel discharged into the fuel discharge chamber 32 includes the regulator pipe 33, the regulator pipe 1K, and the inflow passage 7.
Is introduced into the fuel chamber 5 of the pressure regulator R via the pressure regulator R, the diaphragm 2 is pushed up to the spring chamber 6 side, the valve body 10 opens the return valve seat 9, and the spring is compressed in the spring chamber 6 at a set pressure. It is balanced with the spring force of 13C, so that the fuel pressure in the fuel discharge chamber 32 can be adjusted to a predetermined constant fuel pressure. On the other hand, the surplus fuel flowing into the return fuel pipe 1D from the return valve seat 9 through the discharge passage 8 and the joint 1E is returned to the fuel chamber C again. According to the above, the fuel having a constant fuel pressure flowing in the fuel discharge chamber 32 is discharged into the fuel discharge pipe 3
5. The foreign matter is removed by the discharge side fuel filter G through the fuel discharge passage 1J and into the discharge side fuel filter housing recess 1F, and the clean fuel is the fuel discharge pipe 1J.
The fuel is further supplied to the fuel distribution pipe D, and this fuel is further supplied to the engine via the fuel injection valve J.

Here, the engine is continuously operated, the negative pressure generated by the fuel pump P is accumulated in the fuel chamber C, and the negative pressure is continuously introduced from the negative pressure introducing pipe 15. The fuel level in the fuel chamber C gradually rises due to the fact that the fuel is continuously returned from the return fuel pipe 1D, and this fuel is introduced into the sub chamber S through the vapor vent pipe 1Q. It flows in and stores fuel in the sub-chamber S. When the fuel level in the sub-chamber S gradually rises, the float 22 rotates clockwise in synchronization with the rise of the liquid level, and the fuel level in the sub-chamber S is constant. As soon as the surface XX is reached, the tongue piece 20A moves the float valve 19 upward to close the valve seat 17, thereby preventing the introduction of the negative pressure from the negative pressure introducing pipe 15 into the sub-chamber S. . At this time, the sub chamber S
There will be a closed air chamber above the constant liquid level XX. In addition, a constant liquid level X-
In the state where X is formed, the fuel in the fuel chamber C is consumed by driving the fuel pump P, and when the constant liquid level XX in the sub-chamber S decreases, the float 22 rotates counterclockwise. Then, the float valve 19 opens the valve seat 17, and the negative pressure is again introduced into the sub-chamber C from the negative pressure introducing pipe 15 to increase the negative pressure in the fuel chamber C to suck the fuel from the fuel tank T. The constant liquid level XX can be formed again in the sub-chamber C.

According to the fuel supply system for a ship according to the present invention, a positive displacement fuel pump having a high self-priming property is arranged in the fuel chamber C as the fuel pump P, and the negative pressure in the fuel chamber C is converted into the fuel. Since the fuel in the fuel tank T is sucked into the fuel chamber C by acting on the suction pipe 1M,
Although vapor is generated in the fuel suction pipe 1M, such vapor is not sucked into the fuel pump P by the following. That is, while the engine is operating,
The vapor generated in the fuel suction pipe 1M connected to the fuel tank T flows into the fuel chamber C together with the fuel flow. The vapor stays in the upper part of the fuel chamber C due to its own buoyancy, and then the vapor vent pipe. 1
It flows into the sub-chamber S through Q and stays on the constant liquid level XX of the sub-chamber S. When the amount of vapor flowing into the sub-chamber S increases, the liquid level formed in the sub-chamber S decreases according to the amount of vapor. Due to this decrease in the liquid level, the float 22 moves counterclockwise. Rotating in the direction, the float valve 19 opens the valve seat 17. According to the above, the vapor staying above the sub-chamber S is in the open state.
The gas is sucked out of the valve seat 16 at once through the negative pressure introducing passage 15 into the intake pipe K and discharged. And such valve seat 1
In the opened state of 7, the negative pressure in the intake pipe K is the negative pressure introduction path 1
5 is further introduced into the sub-chamber S through 5, and the negative pressure in the fuel chamber C can be increased to further suck the fuel in the fuel tank T from the fuel suction pipe 1M,
Thereby, the fuel liquid level in the sub-chamber S can be restored to the original constant liquid level XX, and the valve seat 17 can be closed and held by the float valve 19 again. Therefore, the vapor which is sucked into the fuel chamber C from the fuel suction pipe 1M due to the repeated opening and closing operations of the valve seat 17 by the float valve does not remain accumulated in the sub-chamber S, and a certain amount of vapor is kept. Is discharged toward the intake pipe K in the state of being accumulated, the vapor sucked into the fuel chamber C is not discharged through the fuel pump P, and the discharged fuel contains vapor. It is possible to completely solve the problems caused by the fuel injection, that is, the fuel is intermittently injected, the fuel cannot be accurately metered, and the pump performance of the fuel pump is deteriorated.

Further, since the fuel supply system for a ship is arranged in the vicinity of the engine, the fuel discharge pipe 1J is easily warmed by the heat of injection of the engine. It is possible to suppress the generation of vapor inside. That is, the fuel discharged from the fuel pump P is supplied to the engine via the fuel discharge chamber 32, and the fuel in the fuel discharge chamber 32 is constantly cooled by the cooling water circulating in the cooling water pipe 30. Therefore, the fuel discharge pipe 1
Since the fuel temperature from J to the fuel distribution pipe D can be lowered, even if the fuel discharge pipe 1J is warmed, it is possible to effectively suppress the generation of vapor from the fuel flowing in the fuel discharge pipe 1J.

Further, even if vapor is mixed in the fuel discharged from the fuel pump P into the fuel discharge chamber 32, the vapor is prevented from flowing toward the fuel discharge pipe 1J. That is, the vapor that has flowed into the fuel discharge chamber 32 is buoyant to the vapor discharge chamber 3.
2 moves upward, and this vapor flows into the regulator pipe 33 through the upper opening 33A of the regulator pipe 33 that is opened at a position above the fuel discharge chamber 32, and the vapor flows through the regulator pipe 33, the regulator pipe 1K, and the inflow passage 7. It is introduced into the pressure regulator R via the return fuel pipe R and discharged into the fuel chamber C via the return fuel pipe 1D.
The vapor contained in the fuel flowing from the return fuel pipe 1D toward the fuel chamber C also flows into the fuel chamber C and then flows into the sub-chamber S via the vapor vent pipe 1Q to pass through the valve seat 17. Since it is discharged from the negative pressure introducing pipe 15 into the intake pipe K, the vapor is also not sucked into the fuel pump P.

Further, the fuel chamber C is provided with the fuel pump P inside thereof, and further accommodates the suction side fuel filter F surrounding the outer periphery thereof, so that the fuel chamber C is apt to receive heat from the outside in the marine engine. Although vapor is likely to be generated in the fuel chamber C, since the vapor is discharged into the intake pipe K through the sub chamber S and the negative pressure introducing pipe 15, it is generated in the fuel chamber C. Problems caused by vapor are eliminated. Further, after the engine is stopped, the fuel suction pipe 1M is heated by the heat radiation from the engine, so that the fuel in the fuel suction pipe 1M is heated to a temperature higher than the boiling point and a large amount of vapor is generated. Fuel in 1M is fuel tank T
The fuel suction pipe 1M may be returned to the inside, and the fuel suction pipe 1M may become empty. When the engine is restarted in such a state, the fuel pump P immediately supplies the fuel accumulated in the fuel chamber C to the engine. Therefore, good startability of the engine can be obtained without time delay. Then, after the engine is started, the fuel in the fuel tank T is sucked into the fuel chamber C through the fuel suction pipe 1M.

The sub-chamber S is a fuel chamber C.
By arranging the vapor in the upper position in the direction of gravity, the vapor in the fuel chamber C can immediately flow into the sub-chamber S due to the buoyancy of the vapor chamber itself, and the vapor stays in the fuel chamber C. Be deterred. Further, since the fuel discharge chamber 32 is arranged above the sub-chamber S and the upstream opening of the regulator tube is opened above the fuel discharge chamber 32, the vapor flowing into the fuel discharge chamber 32 is not transferred to the fuel discharge chamber 32. The vapor can be collected upward, and the vapor can be reliably discharged into the fuel chamber through the regulator tube.

Further, a plurality of vapor vent pipes 1Q are provided,
The upper opening 1Qa1 of one vapor vent pipe 1Qa is opened above the constant liquid level XX of the sub-chamber S, and the upper opening 1Qb1 of the other vapor vent pipe 1Qb is held at the constant liquid level XX.
Due to the opening to the lower side, the vapor remaining in the fuel chamber C is caused to flow onto the constant liquid level XX through the one vapor drain pipe 1Qa, and the fuel corresponding to this inflow is drained from the other vapor. It can be returned to the inside of the fuel chamber C through the pipe 1Qb, which can improve the replaceability of the vapor and the fuel in the sub-chamber S, and the flowability of the vapor from the fuel chamber C into the sub-chamber S can be improved. It can be greatly improved.

Further, a suction side fuel filter F is arranged so as to surround at least the suction hole PA of the positive displacement fuel pump P arranged in the fuel chamber C, and the fuel suction pipe 1M is provided around the suction side fuel filter. , Return fuel pipe 1D,
By opening the vapor vent pipe 1Q, all the foreign matters contained in the fuel flowing from the fuel chamber C to the suction hole PA of the fuel pump P can be removed by the suction side fuel filter F, and the foreign matters are pumped by the fuel pump. Never inhaled to P. Further, the vapor contained in the fuel flowing into the fuel chamber C from the fuel suction pipe 1M and the return fuel pipe 1D may go to the suction hole PA along with the fuel flow, but at this time, the vapor is sucked into the fuel filter F. The filter member FC prevents the fuel from entering the fuel pump P and is not sucked into the fuel pump P.

Further, the fuel chamber C is the chamber body 1
And the cup body 25, and the cup body is removably arranged in the chamber body 1, the maintainability of the suction side fuel filter F and the fuel pump P formed inside the fuel chamber C is improved. Can be improved. Further, as a fuel supply device, a suction side fuel filter F,
By arranging the fuel pump P inside the cup body 25, the appearance can be neatly arranged, which is preferable. or,
Since the fuel discharge chamber 32 is integrally formed so as to surround the cooling water pipe 30 and the fuel discharge chamber 32 is attached to the chamber body 1, the fuel discharge chamber 32 including the cooling water pipe 30 can be easily installed. You can

Further, since the fuel suction pipe 1M, the vapor vent pipe 1Q, and the return fuel pipe 1D are opened in the flat portion 1B of the chamber body 1, the vapor generated in the pipe is located above the fuel chamber C. Since it is easy to collect the vapor, it is possible to improve the dischargeability of the vapor into the sub-chamber S from the vapor vent pipe 1Q.

The pipe of the fuel supply device is the fuel suction pipe 1.
M is connected to the fuel tank T, the fuel discharge pipe 1J is connected to the fuel distribution pipe D, and the negative pressure introduction pipe 15 is connected to the intake pipe K.
Is completed and the cooling water pipe 30 is connected to the cooling pipe of the engine W. Therefore, a very simple connection pipe can be used and the design freedom of the pipe can be greatly improved. The form of this piping is well shown in FIG.

[0039]

As described above, according to the fuel supply system for a ship of the present invention, a closed fuel chamber for accommodating a positive displacement fuel pump, a fuel inflow passage communicating with a discharge hole of the fuel pump, and a fuel injection valve are provided. A fuel discharge chamber having a fuel discharge passage continuous with, a cooling water pipe for cooling the fuel in the fuel discharge chamber,
A pressure regulator arranged in a regulator pipe branched from the fuel discharge chamber; and a closed sub-chamber, which is formed separately from the fuel chamber and which is provided with a valve seat, a float valve, and a constant liquid level controller including a float, In the chamber, a fuel intake pipe connected to the fuel tank, a return fuel pipe connected to the return valve seat of the pressure regulator, and a vapor vent pipe connected to the subchamber are opened, and a valve seat and an intake pipe opened in the subchamber. Is connected by a negative pressure introduction pipe, and a one-way control valve that allows only the flow from the valve seat to the intake pipe is arranged in the negative pressure introduction pipe, so that the fuel supply device has a high self-priming capacity. Of pump discharge due to vapor in the fuel intake passage that occurs when using a type fuel pump It can suppress the decrease in pump efficiency, such decrease of the pump discharge pressure. Further, the vapor contained in the fuel intake passage and the return fuel pipe was separated in the fuel chamber, and this vapor was automatically discharged to the outside through the constant liquid level control device of the subchamber. The vapor does not stay and the fuel containing the vapor is not supplied from the fuel pump to the engine. or,
Since the fuel in the fuel discharge chamber is cooled by the cooling water pipe, the temperature of the fuel in the fuel discharge pipe that goes from the fuel discharge chamber to the fuel distribution pipe can be lowered, which causes vapor in the fuel supplied to the fuel distribution pipe. Occurrence is suppressed. Therefore, stable and accurate fuel supply can be achieved, and the operability of the engine can be greatly improved. Further, even when the engine is restarted, the fuel pump sucks the fuel stored in the fuel chamber, so that a good restartability of the engine can be obtained.

The sub-chamber is arranged above the fuel chamber in the direction of gravity, the fuel discharge chamber is arranged above the fuel chamber, and the upstream opening of the regulator tube of the pressure regulator is arranged in the direction of gravity of the fuel discharge chamber. By opening in the upper position, it is possible to improve the dischargeability of the vapor entering the fuel chamber into the sub chamber and the dischargeability of the vapor entering the fuel discharge chamber to the fuel chamber.

Further, a plurality of vapor vent pipes are provided, one vapor vent pipe has an upper opening opened above the constant liquid level of the sub-chamber, and the other vapor vent pipe has an upper opening opened below the constant liquid level. It is possible to improve the ability of the vapor to flow from the fuel chamber into the sub-chamber in the sub-chamber and to flow out the fuel from the sub-chamber into the fuel chamber, thereby improving the ability to replace the vapor with the fuel. It is possible to improve the dischargeability of vapor into the chamber.

Further, a suction side fuel filter F is disposed so as to surround at least the suction hole PA of the positive displacement fuel pump P arranged in the fuel chamber, and the fuel suction pipe 1M is provided around the suction side fuel filter. , Return fuel pipe 1D,
By opening the vapor vent pipe 1Q, foreign matters contained in the fuel flowing into the fuel chamber from the fuel intake pipe, the return fuel pipe, and the vapor vent pipe can be completely removed, and the fuel intake pipe and the return fuel pipe can be removed. The vapor flowing into the fuel chamber together with the fuel is prevented from being sucked into the fuel pump by the resistance of the suction side fuel filter.

Further, the fuel chamber is formed by a chamber body and a cup body having a bottomed cup disposed below the chamber body, and the fuel discharge chamber is an annular chamber surrounding the outer periphery of a pipe-shaped cooling water pipe. Since the fuel discharge chamber including the cooling water pipe is attached to the chamber body, the maintainability of the fuel pump and the suction side fuel filter arranged in the fuel chamber can be improved, and the fuel discharge chamber including the cooling water pipe can be improved. Can be easily installed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a ship fuel supply device according to the present invention.

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

FIG. 3 is a vertical cross-sectional view taken along the line BB of FIG.

FIG. 4 is a schematic piping diagram in which the fuel supply device of the present invention is incorporated in an engine.

FIG. 5 is a schematic piping diagram of a fuel supply device in a conventional ship engine.

[Explanation of symbols]

1 chamber body 1D return fuel pipe 1J fuel discharge pipe 1K regulator piping 1M fuel intake pipe 1Q vapor vent tube 30 cooling water pipe 32 Fuel discharge chamber C fuel chamber D Fuel distribution pipe F Intake side fuel filter G Discharge side fuel filter J fuel injection valve K intake pipe P fuel pump R Pressure Regulator S sub chamber

Claims (5)

[Claims] 1. A ship-type fuel supply system for boosting the pressure of fuel in a fuel tank by a positive displacement fuel pump and supplying the boosted fuel to a marine engine via a fuel injection valve. A fuel discharge chamber 32 having a closed fuel chamber C for accommodating a fuel, a fuel inflow passage 1H connected to a discharge hole PB of a fuel pump P, and a fuel discharge passage 1J connected to a fuel injection valve J, and a fuel discharge chamber 32. The cooling water pipe 30 for cooling the fuel, the pressure regulator R arranged in the regulator pipe 1K branched from the fuel discharge chamber 32, and the fuel chamber C are formed separately from each other, and are constituted by a valve seat 17, a float valve 19, and a float 22. A closed sub-chamber S provided with a liquid level control device L, and a fuel suction pipe 1M connected to a fuel tank T in the fuel chamber; The return fuel pipe 1D connected to the return valve seat 9 of the pressure regulator R and the vapor vent pipe 1Q connected to the sub chamber S open, and the valve seat 17 and the intake pipe K opening in the sub chamber S introduce a negative pressure. A one-way control valve 18 connected to the pipe 15 and allowing only the flow from the valve seat 17 to the intake pipe K is arranged in the negative pressure introduction pipe. 2. The sub-chamber is a fuel chamber C.
The fuel discharge chamber 32 is disposed above the fuel chamber C, and the upstream opening 33A of the regulator tube 33 of the pressure regulator R is located above the fuel discharge chamber 32 in the gravity direction. The fuel supply device for a ship according to claim 1, wherein the fuel supply device for a ship is opened at 3. A plurality of vapor vent pipes are provided, an upper opening 1Qa1 of one vapor vent pipe 1Qa is opened on a constant liquid level XX of the sub-chamber S, and an upper opening 1Qb1 of the other vapor vent pipe 1Qb. 2. The fuel supply system for a ship according to claim 1, wherein the tank is opened below the constant liquid level XX. 4. A positive displacement fuel pump P disposed in the fuel chamber is surrounded by at least an intake hole PA,
A suction side fuel filter F is disposed, and a fuel suction pipe 1M and a return fuel pipe 1 are provided around the suction side fuel filter.
2. The fuel supply device for a ship according to claim 1, wherein D and a vapor vent pipe 1Q are opened. 5. The fuel chamber comprises a chamber body 1 and a cup body 2 having a bottomed cup and disposed below the chamber body 1.
5, the fuel discharge chamber 32 is formed as an annular chamber surrounding the outer circumference of the pipe-shaped cooling water pipe 30,
The fuel discharge chamber 32 including the cooling water pipe is attached to the chamber body 1
The fuel supply device for a ship according to claim 1, wherein the fuel supply device is attached to the ship.