JP2004340086A - Vapor separator structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor separator structure capable of reducing the amount of occurrence of vapor gas by securing sufficient volume and reducing the volume of a circulation route. <P>SOLUTION: This vapor separator structure comprises a vapor separator tank 25 installed in a fuel route from the fuel tank 20 to an injector 11, a fuel sump amount regulating means 26 and a fuel discharge means 27 stored in the vapor separator tank, a pressure regulator 28 installed on the discharge side of the fuel discharge means 27, vapor release pipes 53a, 54a, and 52 feeding separated gas to an intake pipe 9, and a fuel return pipe 51 returning fuel from the pressure regulator 28 to the vapor separator tank 25. The vapor separator tank 25 comprises a first chamber 45 storing the fuel sump amount regulating means 26 and a second chamber 46 storing the fuel discharge means 27. The first chamber 45 and the second chamber 46 are allowed to communicate with the upper side and the lower side of liquid level. The fuel tank 20 is connected to the first chamber 45, and the fuel return pipe 51 is connected to the second chamber 46. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vapor separator structure for an engine.
[0002]
[Prior art]
In an outboard motor equipped with a fuel injection engine, an engine malfunction is likely to occur due to the vapor gas generated from the fuel system, particularly at the time of idling, trolling, warm-up restart, etc., where the engine consumes less fuel. Conventionally, a vapor separator has been used to separate such a vapor gas in the fuel (see, for example, Patent Document 1).
[0003]
The fuel is supplied from the fuel tank into the vapor separator tank, stored in the tank, and sent from the vapor separator tank to the injector by a high-pressure fuel pump via a pressure regulator. Of the high-pressure fuel discharged from the high-pressure fuel pump, excess fuel not injected by the injector is returned to the vapor separator tank via the pressure regulator. That is, the fuel that is not injected by the injector circulates through the route of the high-pressure fuel pump → the pressure regulator → the vapor separator tank → the high-pressure fuel pump. The amount of vapor gas generated during operation is generated in this circulation path, especially when the fuel consumption is small. Therefore, in order to reduce the amount of vapor gas, it is effective to reduce the volume of this circulation path.
[0004]
On the other hand, the vapor separator tank, which occupies most of the circulation path volume, requires a relatively large volume as a buffer to cope with a sudden change in fuel consumption during operation. Contradicts the requirement to reduce
[0005]
[Patent Document 1]
JP-A-8-4617
[Problems to be solved by the invention]
The present invention has been made in consideration of the above-described conventional technology, and has an object to provide a vapor separator structure in which a sufficient volume as a vapor separator tank is secured and a volume of a vapor gas is reduced by reducing a volume of a circulation path. .
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, there is provided a vapor separator tank provided in the middle of a fuel supply path from a fuel tank to an injector on an intake pipe, a fuel pool adjusting means housed in the vapor separator tank, and a fuel discharge tank. Means, a pressure regulator provided on the discharge side of the fuel discharge means, a vapor relief pipe for sending gas separated in the vapor separator tank to the intake pipe, and fuel for returning fuel from the pressure regulator to the vapor separator tank. In a vapor separator structure provided with a return pipe, the vapor separator tank is constituted by a first chamber accommodating the fuel accumulation amount adjusting means and a second chamber accommodating the fuel discharging means, The second chamber communicates with an upper side and a lower side of a liquid surface, respectively, connects the fuel tank to the first chamber side, and connects to the second chamber side. Providing vapor separator structure, characterized in that connected the fuel return pipe.
[0008]
According to this configuration, the vapor separator tank having a sufficient capacity to cope with the fluctuation of the fuel consumption is constituted by the two chambers of the first chamber and the second chamber, and the first chamber has a fuel pool adjusting means such as a float. The fuel circulation system is accommodated in the second chamber by connecting a fuel return pipe from a pressure regulator to the second chamber. Despite having a vapor separator tank formed from the pressure regulator to the second chamber and having a sufficiently large vapor separator tank as a whole, the volume of the fuel circulation system is reduced, and the amount of generated vapor gas is reduced.
[0009]
In a preferred configuration example, a partition wall that divides the vapor separator tank into a first chamber and a second chamber is provided, and communication holes are provided in upper and lower portions of the partition wall, respectively.
[0010]
According to this configuration, the vapor separator tank is divided into the first chamber and the second chamber by the partition wall, and the upper part and the lower part of the liquid surface communicate with each other, so that one large-capacity vapor separator tank is constituted as a whole. On the other hand, in the fuel circulation system, the fuel can be circulated by using the divided second small chamber.
[0011]
In a preferred configuration example, the vapor relief pipe is connected to two locations separated from each other on the upper surface of the first chamber.
[0012]
According to this configuration, the upper portions of the first chamber and the second chamber communicate with each other, and the vapor release pipe is connected to the first chamber, so that the vapor gas in the entire tank is smoothly returned to the intake pipe. In this case, since the vapor release pipes are connected to the two places separated from each other, even if, for example, the tank is greatly inclined and one of the vapor release pipes is closed, the vapor gas can be reliably released.
[0013]
In a preferred configuration example, the second chamber is further divided into a fuel discharge chamber accommodating the fuel discharge means and a fuel return chamber to which the fuel return pipe is connected.
[0014]
According to this configuration, the fuel returning from the pressure regulator to the second chamber is once returned to the fuel return chamber of the second chamber, and flows into the fuel discharge chamber from the fuel return chamber. Flows into the fuel stored in the fuel return chamber, whereby its kinetic energy is absorbed and the momentum is reduced, and then discharged again from the fuel discharge chamber at a high pressure. Therefore, generation of vapor gas in the second chamber is reduced.
[0015]
By applying the vapor separator structure of the present invention to the engine of the outboard motor, the generation of vapor gas is suppressed, and the problem of engine malfunction during idling and trolling, which is a problem particularly with the outboard motor, is avoided, so that it is always stable. A highly reliable engine rotation operation can be obtained.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a side view of an outboard motor to which the present invention is applied, and FIG. 2 is a horizontal sectional view of an upper cowl portion.
[0017]
The outboard motor 1 is covered on the outside by an upper cowl 2, a lower cowl 3, an upper casing 5 connected via a lower guide exhaust 4, and a lower casing 6 therebelow. A V-type six-cylinder engine 7 is housed in the upper cowl 2. An intake silencer 8 is provided at the front of the engine 7, and three intake pipes 9 are provided from the intake silencer 8 on each of the left and right sides, and communicate with each cylinder of the cylinder head 10. An injector 11 is provided in the middle of each intake pipe 9.
[0018]
A drive shaft 13 is connected to a lower end of a crankshaft 12 of the engine 7. The drive shaft 13 is connected to a propeller shaft 15 via a bevel gear 14 in the lower casing 6 and drives a propeller 16. The outboard motor 1 is mounted on a transom 18 of a hull via a mounting bracket 17.
[0019]
A vapor separator tank 19 is provided in the middle of a fuel supply pipe (not shown) for connecting a fuel tank (not shown) and the injector 11 in the hull.
[0020]
FIG. 3 is an overall configuration diagram of the fuel cooling structure according to the embodiment of the present invention.
Fuel is supplied from a fuel tank 20 provided in the ship to a vapor separator tank 25 of a vapor separator 24 through a fuel pipe (hose) 23 through a filter 22 by a low-pressure fuel pump 21. The vapor separator 24 includes a vapor separator tank 25 for storing fuel, a float 26 provided in the vapor separator tank 25, a high-pressure fuel pump 27, and a pressure regulator 28.
[0021]
The intake pipe 9 is provided with a throttle valve 29, and the injector 11 is provided downstream thereof. High-pressure fuel is supplied from the high-pressure fuel pump 27 to the injector 11 through the fuel supply pipe 56 via the pressure regulator 28. Excess high pressure fuel is returned from the pressure regulator 28 to the vapor separator tank 25 via the fuel return pipe 51.
[0022]
The vapor gas separated in the vapor separator tank 25 is sucked and sent into the suction pipe 9 by the suction negative pressure through the vapor release pipe 52.
[0023]
The vapor separator tank 25 is divided by a partition wall 44 into two chambers, a first chamber 45 and a second chamber 46. The partition wall 44 has communication holes 47 and 48 in the upper part (above the liquid level) and the lower part (below the liquid level), and the first chamber 45 is provided on both the upper gas side and the lower liquid side in the tank. And the second chambers 46 are communicated with each other.
[0024]
The first chamber 45 accommodates a fuel pool amount (liquid level) adjusting means such as the float 26. In addition, other than the float, a valve or the like that detects the liquid level and opens and closes according to the liquid level can be used as the fuel pool amount adjusting means.
[0025]
The second chamber 46 houses fuel discharging means such as the high-pressure fuel pump 27. The second chamber 46 is further divided by a partition wall 49 into a fuel discharge chamber 46a and a fuel return chamber 46b. The partition wall 49 connects the fuel discharge chamber 46a and the fuel return chamber 46b at the upper part, and connects the fuel discharge chamber 46a and the fuel return chamber 46b through the communication hole 50 at the lower part.
[0026]
The high pressure fuel pump 27 is housed in the fuel discharge chamber 46a, and the fuel return pipe 51 from the pressure regulator 28 is connected to the fuel return chamber 46b. As a result, the fuel returning from the pressure regulator 28 to the second chamber 46 is once returned to the fuel return chamber 46b of the second chamber 46 and flows into the fuel discharge chamber 46a from the fuel return chamber 46b. When the returned fuel flows into the fuel accumulated in the fuel return chamber 46b, its kinetic energy is absorbed and the momentum is reduced, and thereafter, the fuel is discharged again from the fuel discharge chamber 46a at a high pressure. Therefore, generation of vapor gas in the second chamber 46 is reduced.
[0027]
A gas vent port 53 is provided near the upper corner of the first chamber 45. Further, a gas vent communication passage 57 communicating with the upper part of the first chamber 45 is formed, and a gas vent port 54 is provided at an end of the gas vent communication passage 57. These gas vent ports 53 and 54 are desirably provided at opposing positions separated from each other, such as corners opposing each other diagonally in plan view (top view) of the upper surface of the vapor separator tank 25. This is because even when the vapor separator tank 25 is inclined and one port is closed with the liquid fuel, the gas can be reliably vented from the other port.
[0028]
Vapor release pipes 53a and 54a are connected to the gas vent ports 53 and 54, respectively. Both the vapor removal pipes 53a and 54a join and communicate with a vapor relief pipe 52 that communicates with the intake pipe 9. One of the vapor release pipes 53a is once spirally wound and then connected to the other vapor release pipe 54a. This can prevent the fuel from flowing out due to the siphon phenomenon when the hull rolls over.
[0029]
FIG. 4 is a configuration diagram of the vapor separator according to the embodiment of the present invention. (A) is a horizontal cross-sectional configuration diagram near the upper end of the vapor separator tank, (B) is a horizontal cross-sectional configuration diagram of a lower portion of the vapor separator tank, and (C) is a vertical cross-sectional view of the vapor separator.
[0030]
As described above (FIG. 3), the vapor separator tank 25 is divided into the first chamber 45 and the second chamber 46 by the partition wall 44 having the communication holes 47 and 48 at the top and bottom. The second chamber 46 is divided by a partition 49 into a fuel discharge chamber 46a and a fuel return chamber 46b. In this example, a communication hole 55 is formed in the upper part of the partition wall 49, and connects the fuel discharge chamber 46a and the fuel return chamber 46b above the liquid level L. Gas vent ports 53 and 54 are provided at substantially diagonally opposite corners of the upper surface of the vapor separator tank 25. As described above (FIG. 3), one gas vent port 53 is provided near a corner on the upper surface of the first chamber 45, and the other gas vent port 54 is a gas vent communicating with the upper part of the first chamber 45. It is provided at the end of the communication path 57. Fuel is supplied to the injector 11 (FIG. 3) through the fuel supply pipe 30 by the high-pressure fuel pump 27, and excess fuel is supplied from the pressure regulator 28 (FIG. 3) through the fuel return pipe 51 to the fuel return chamber of the second chamber 46. 46b. 56 is a sealing material.
[0031]
【The invention's effect】
As described above, the vapor separator tank having a sufficient capacity to cope with the fluctuation of the fuel consumption is constituted by the two chambers of the first chamber and the second chamber, and the first chamber has a fuel pool adjusting means such as a float. The fuel circulation system is accommodated in the second chamber by connecting a fuel return pipe from a pressure regulator to the second chamber. Despite having a vapor separator tank formed from the pressure regulator to the second chamber and having a sufficiently large vapor separator tank as a whole, the volume of the fuel circulation system is reduced, and the amount of generated vapor gas is reduced.
[0032]
Further, according to the configuration in which the partition wall that divides the vapor separator tank into the first chamber and the second chamber is provided, and the communication holes are provided in the upper part and the lower part of the partition wall, respectively, the vapor separator tank is formed by the partition wall. Since the upper and lower liquid surfaces communicate with each other, the fuel circulation system is divided into a small capacity and a small capacity while forming one large capacity vapor separator tank as a whole. The fuel can be circulated using the changed second chamber.
[0033]
Further, according to the configuration in which the vapor relief pipe is connected to both the first chamber and the second chamber, the upper parts of the first chamber and the second chamber communicate with each other, and the vapor relief pipe is connected to both chambers. In order to return the vapor gas to the intake pipe, even if the tank is greatly inclined and either the first chamber or the second chamber is inclined upward, for example, the vapor gas generated from both chambers is surely provided. Can be missed.
[0034]
Further, according to the configuration in which the second chamber is further divided into a fuel discharge chamber accommodating the fuel discharge means and a fuel return chamber to which the fuel return pipe is connected, the fuel returned from the pressure regulator to the second chamber is provided. Is returned to the fuel return chamber of the second chamber and flows into the fuel discharge chamber from this fuel return chamber. The kinetic energy is absorbed, the momentum is reduced, and then the fuel is discharged again from the fuel discharge chamber at a high pressure. Therefore, generation of vapor gas in the second chamber is reduced.
[Brief description of the drawings]
FIG. 1 is a side view of an outboard motor to which the present invention is applied.
FIG. 2 is a horizontal sectional view of an upper cowl portion of the outboard motor of FIG.
FIG. 3 is a configuration diagram of an embodiment of the present invention.
FIG. 4 is a configuration diagram of a vapor separator according to the embodiment of the present invention.
[Explanation of symbols]
1: Outboard motor, 2: Upper cowl, 3: Lower cowl, 4: Guide exhaust,
5: upper casing, 6: lower casing, 7: engine,
8: intake silencer, 9: intake pipe, 10: cylinder head,
11: injector, 12: crankshaft, 13: drive shaft,
14: bevel gear, 15: propeller shaft, 16: propeller,
17: mounting bracket, 18: transom, 19: vapor separator tank,
20: fuel tank, 21: low pressure fuel pump, 22: filter,
23: fuel pipe, 24: vapor separator, 25: vapor separator tank,
26: float, 27: high pressure fuel pump, 28: pressure regulator,
29: throttle valve, 30: fuel pipe, 44: partition wall, 45: first chamber,
46: second chamber, 46a: fuel discharge chamber,
46b: fuel return chamber, 47: communication hole, 48: communication hole, 49: partition,
50: communication hole, 51: fuel return pipe, 52: vapor release pipe,
53: gas vent port, 54: gas vent port, 55: communication hole,
56: sealing material, 57: gas vent communication passage.

Claims (5)

A vapor separator tank provided in the fuel supply path from the fuel tank to the injector on the intake pipe,
Fuel pool amount adjusting means and fuel discharging means housed in the vapor separator tank,
A pressure regulator provided on the discharge side of the fuel discharge means,
A vapor relief pipe for sending the gas separated in the vapor separator tank to the intake pipe,
A fuel return pipe for returning fuel from the pressure regulator to the vapor separator tank,
The vapor separator tank includes a first chamber that houses the fuel pool amount adjustment unit and a second chamber that houses the fuel discharge unit,
The first chamber and the second chamber communicate with each other above and below the liquid level,
Connecting the fuel tank to the first chamber side,
A vapor separator structure, wherein the fuel return pipe is connected to the second chamber. The vapor separator structure according to claim 1, wherein a partition wall for dividing the vapor separator tank into a first chamber and a second chamber is provided, and communication holes are provided in upper and lower portions of the partition wall, respectively. 3. The vapor separator structure according to claim 1, wherein the vapor relief pipe is connected to two locations separated from each other on an upper surface of the first chamber. 4. The vapor according to claim 1, 2 or 3, wherein the second chamber is further divided into a fuel discharge chamber accommodating the fuel discharge means and a fuel return chamber to which the fuel return pipe is connected. Separator structure. An outboard motor comprising the vapor separator structure according to claim 1.

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