|
(11) | EP 1 154 148 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 158(3) EPC |
|
|
|
|
||||||||||||||||
| (54) | MARINE ENGINE FUEL INJECTION DEVICE |
| (57) A high-pressure fuel pump, high-pressure fuel filter and fuel pressure regulator
are housed inside a case having resistance to corrosion and rust caused by salt water
damage, shielded from the outside atmosphere. A position above a fuel level of a fuel
tank is connected to a the atmosphere by way of a atmosphere connecting pipe. Mid
way along the atmosphere connecting pipe, there are provided a fuel check valve at
a side lose to the fuel tank, and an air check valve at a side close to the atmosphere.
The position of the fuel check valve in the atmosphere connecting pipe, and the position
of the air check valve are connected by a second ventilation pipe connected to inner
parts of the case. Thus, the inner parts of the case are not directly connected to
the atmosphere, and are only connected to the atmosphere connecting pipe for connecting
the atmosphere (downstream side of an air cleaner for an intake passage of the engine)
and the fuel tank. Since the inner parts of the case are not directly connected to
the atmosphere, the occurrence of rust on the high-pressure fuel components such as
the high-pressure fuel pump, the high-pressure fuel filter and the fuel pressure regulator
is prevented. |
Technical Field
[0001] The present invention relates to a fuel injector for a marine engine, and particularly to a fuel injector for a marine engine that handles fuel leakage from a high-pressure fuel component.
Description of Related Art
[0002] Conventionally, a fuel injector used in a marine engine such as an outboard motor, water motorcycle (PWC Personal Water Craft) or jet boat etc. has a different fuel system to a fuel injector of an automobile engine. A conventional fuel system used in an outboard motor is shown in Fig. 7. A fuel tank 10 is provided on the side of the boat body, and a vapor separator is provided in the outboard motor. Fuel is supplied from the fuel tank 10 through a fuel supply pipe 14 to the vapor separator 12. Mid way along the fuel supply pipe 14 there are provided a manual fuel feed valve 16, a low-pressure fuel pump 18 and a low-pressure fuel filter 20.
[0003] The vapor separator 12 is for separating fuel and vapor internally, and vapor inside the vapor separator 12 passes through a pipe 22 connecting to the atmosphere and is introduced to a downstream side of an air cleaner of an engine intake pipe. On the other hand, fuel inside the vapor separator 12 is introduced to a high-pressure fuel pump 24 provided externally to the vapor separator 12.
[0004] The high-pressure fuel pump 26 is linked to a delivery pipe 32 provided with a plurality of injectors 30, via high-pressure fuel connecting pipes 28 having a high-pressure fuel filter 24 provided between them. A fuel pressure regulator is connected to the delivery pipe 32, and surplus fuel in the delivery pipe 32 is returned from the fuel pressure regulator to the vapor separator, via a low-pressure fuel return pipe 36.
[0005] With the conventional fuel system shown in Fig. 7, the main high-pressure fuel components (high-pressure fuel pump 26, high-pressure fuel filter 24, fuel pressure regulator 34) used in a fuel injector for a marine engine are all exposed to the atmosphere. Nevertheless, there are no countermeasures to deal with the case of fuel leakage from these high-pressure fuel components. Neither is there any protection to prevent salt damage and corrosion to these high-pressure fuel components. Accordingly, there is a need to either carry out surface treatment on the high-pressure fuel components or to use corrosion-resistant materials, which brings about the disadvantage of cost increases. Countermeasures against fuel leakage and related art technology for protecting high-pressure fuel components from salt damage have been proposed in Japanese Utility Model Laid-open No. Hei. 7-55327 and USP 5103793. These related art techniques have a fuel pump housed inside the vapor separator, with the intention of reducing the overall size and improving safety. However, among the high-pressure fuel components, these related art techniques only have a fuel pump housed inside a fuel tank, and countermeasures against fuel leakage from the high-pressure fuel filter or the fuel pressure regulator, and for preventing corrosion of these parts, are inadequate.
[0006] It has also been considered to not use a high-pressure fuel filter in a fuel injector. However, in this case, there are likely to be situations where the fuel injector invites seating defects of the injector or the fuel pressure regulator due to foreign matter such as brush powder coming out from the low-pressure pump or the high-pressure fuel pump. Accordingly, currently a high-pressure fuel filter 26 is nearly always used in a fuel injector.
[0007] Here, if attention is paid to the general related art with respect to internal combustion engines mainly used in automobiles, a structure where a fuel pump, a fuel filter and a fuel pressure-regulating path etc. are integrated, and this integrated device is housed inside the fuel tank, is common. Structures where the regulator is integrated and this integrated device is housed inside the fuel tank are also commonplace. Examples of such related art are disclosed in Japanese Patent application No. Hei. 8-189444, Japanese Patent application No. Hei. 8-193552, Japanese Patent application No. Hei. 8-210212, and Japanese Patent application No. Hei. 8-277758. However, these related art patents have the objective of making the device compact and reducing assembly costs, and do not deal with salt damage corrosion inherent to marine engines (outboard motors, water motorcycles or jet boats).
[0008] Also, in marine engines, since there is a need to mount all high-pressure fuel components external to the fuel tank, it is not possible to use the related art technology for internal combustion engines mainly used in automobiles without some form of modification. In the case of a water motorcycle as an example, this is for the following two reasons. Firstly, fuel lines for two systems (normal use/emergency use) are switched, and secondly, in an outboard motor, there is a demand to fix the fuel tank as a detachable fixture on the side of the boat body, and the tank itself has various sizes and shapes.
[0009] The present invention has been conceived in view of the above-described problems, and even if fuel leakage occurs in high-pressure fuel components in a fuel injector for a marine engine, that leaking fuel is prevented from getting from specified internal sections to the outside. At the same time, the present invention prevents salt damage corrosion and rust of high-pressure fuel components by cutting off the atmosphere, and makes it possible to use existing high-pressure fuel components in a marine engine. An object of the present invention is to provide a fuel injector for a marine engine that solves the above-described problems.
SUMMARY OF THE INVENTION
[0010] In order to achieve the above described object, the present invention provides a fuel injector for a marine engine provided with a fuel tank and high-pressure fuel components, wherein the high-pressure fuel components are housed inside a case cut off from the atmosphere, and the atmosphere and a space higher up than a fuel level of the fuel tank are connected by an atmosphere connecting pipe. The present invention is provided with an air check valve for guiding only the atmosphere from the atmosphere to a fuel tank side at a midpoint of the atmosphere-connecting pipe. Further, the present invention connects together an intermediate position between a fuel tank inside the atmosphere connecting pipe and the air check valve, and the inside of the case, using a ventilation pipe.
[0011] The present invention also provides a fuel injector for a marine engine provided with a fuel tank and high-pressure fuel components, wherein the high-pressure fuel components are housed inside a case shielded from the atmosphere, and the atmosphere and a space higher up than a fuel level of the fuel tank are connected by an atmosphere connecting pipe. The present invention is provided with an air check valve for guiding only the atmosphere from the atmosphere to a fuel tank side at a midpoint of the atmosphere connecting pipe, and connects the case with the fuel tank using a ventilation pipe.
In addition, the present invention is also provided with a fuel check valve allowing fuel to pass only from the case side to a tank side at a mid point of the ventilation pipe.
[0012] The present invention further provides a fuel injector for a marine engine provided with a fuel tank and high-pressure fuel components, wherein a case is provided for connecting the fuel tank to a fuel supply pipe, and fuel from the fuel tank is introduced into the case through the fuel supply pipe. The present invention has the high-pressure fuel components housed inside the case, and a position above the fuel tanks and a position above the inside of the case are connected by an overflow pipe.
Brief Description of the Drawings
[0013]
Fig. 1 is a system diagram showing one embodiment of a fuel injector for a marine engine of the present invention.
Fig. 2 is a cross sectional drawing of a case used in Fig. 1.
Fig. 3 is a system diagram showing another embodiment of a fuel injector for a marine engine of the present invention.
Fig. 4 is a system diagram showing yet another embodiment of a fuel injector for a marine engine of the present invention.
Fig. 5 is a system diagram showing a still further embodiment of a fuel injector for a marine engine of the present invention.
Fig. 6 is a system diagram showing yet another embodiment of a fuel injector for a marine engine of the present invention.
Fig. 7 is a system diagram showing another embodiment of a fuel injector for a marine engine of the present invention.
Fig. 8 is a cross sectional drawing of a case used in Fig. 7.
Fig. 9 is a system diagram showing a still further embodiment of a fuel injector for a marine engine of the present invention.
Fig. 10 is a system diagram showing yet a further embodiment of a fuel injector for a marine engine of the present invention.
Fig. 11 is a system diagram showing one embodiment of a fuel injector for a marine engine of the related art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0015] Fig. 1 is a system diagram showing one embodiment of a fuel injector for a marine engine of the present invention, and shows application to a water motorcycle. Fig. 2 is a cross sectional drawing of a case used in Fig. 1. In Fig. 1 and Fig. 2, the same reference numerals as used in Fig. 11 represent the same parts
[0016] As shown in Fig. 2, a case 40 is made up of a body 42, a cover 44 for the body 42, and packing for sealing between the body 42 and the cover 44. A high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34, being the principal high-pressure fuel components, are housed inside this case 40 shielded from the outside atmosphere.
The high-pressure fuel pump 24 and the high-pressure fuel filter 26 are connected inside the case 40.
[0017] The body 42 and the cover 44 making up the case 40 are made from materials having resistance to corrosion and rust caused by salt damage. Specifically, the body 42 and the cover 44 are preferably made from corrosion resistant and rust resistant materials such as resin or stainless steel. Alternatively, it is possible to prevent rust using surface treatment, such as plating or painting, to coat the parts with a rust preventing material. It is also possible to prevent corrosion and rusting of the high-pressure fuel components by filling the case 40 with grease or the like.
[0018] A low-pressure fuel inlet pipe 48, a low-pressure fuel outlet pipe 50, a high-pressure fuel outlet pipe 52 and a high-pressure fuel inlet pipe 54 are fixed to the cover 44 of the case 40. The low-pressure fuel inlet pipe 48 communicates with the high-pressure fuel pump 24 through an internal low-pressure inlet pipe 56. Fuel flows in to the high-pressure fuel pump 24 through the low-pressure fuel inlet pipe 48. The low-pressure fuel outlet pipe 50 communicates with the fuel pressure regulator 34 through an internal low-pressure outlet pipe 58. Fuel flows out from the fuel pressure regulator 34 to the outside through this low-pressure fuel outlet pipe 50. The high-pressure fuel outlet pipe 52 communicates with the high-pressure fuel filter 26 through an internal high-pressure outlet pipe 60. Fuel flows out from the high-pressure fuel filter 26 to the outside through this high-pressure fuel outlet pipe 52. The high-pressure fuel inlet pipe 54 communicates with the fuel pressure regulator 34 through an internal high-pressure inlet pipe 62. Fuel flows in to the fuel pressure regulator 34 through this high-pressure fuel inlet pipe 54.
[0019] A fuel tank 10 is provided in a water motorcycle, and the fuel tank 10 and the low-pressure fuel inlet pipe 48 are connected through a low-pressure fuel connecting pipe 64. Mid way along the low-pressure fuel connecting pipe 64, there are provided a fuel line switching valve 66, and a low-pressure fuel filter 20. Specifically, fuel inside the fuel tank 10 flows in to the high-pressure fuel pump 24 through the low-pressure fuel connecting pipe 64 and the low-pressure fuel inlet pipe 48.
[0020] Connection is made between the fuel tank 10 and the fuel line switching valve 66 using an emergency low frequency fuel connecting pipe 68. At the time of an emergency, fuel can be led into the high-pressure fuel pump 21 through the low-pressure fuel connecting pipe 68, by switching the fuel line switching valve 66.
[0021] A connection is made between the high-pressure fuel outlet pipe 52 and the high-pressure fuel inlet pipe 54 provided in the case 40, with the high-pressure fuel connecting pipe 28 having a delivery pipe 32 provided at a midpoint. A plurality of injectors 30 are attached to this delivery pipe 32. Fuel flowing out from the high-pressure fuel connecting pipe 28 to the delivery pipe 32 is injected by the injectors 30. Of the fuel that has flowed out, fuel that has not been injected by the injectors passes through the high-pressure fuel connecting pipe at a downstream side of the delivery tube 32 and is returned to the fuel pressure regulator inside the case 40.
[0022] The low-pressure fuel inlet pipe 50 connected to the fuel pressure regulator 34 is connected to a low-pressure fuel return pipe 36. The low-pressure fuel return pipe 36 is also connected to the fuel tank 10. Specifically, fuel returned to the fuel pressure regulator 34 is connected to the fuel tank 10 through the low-pressure fuel return pipe 36.
[0023] An air chamber 70 is formed in the fuel pressure regulator 34. This air chamber 70 is connected to an engine intake pipe (not shown) via a pressure introduction pipe attached to the cover 44 of the case 40.
[0024] The atmosphere connecting pipe 74 is attached above a fuel surface of the fuel tank 10, and the atmosphere connecting pipe 74 is connected to a downstream side of an air cleaner of an engine intake path 75. Midway along the atmosphere connecting pipe 74, there are provided a fuel check valve 76, and an air check valve 78. The fuel check valve is arranged more towards the fuel tank 10 than the air check valve.
[0025] A first ventilation pipe 80 is attached to the cover 44 of the case 40, and one end of the first ventilation pipe 80 is connected to an inner space of the case 40. The other end of this first ventilation pipe 80 is connected to a second ventilation pipe 82, and this second ventilation pipe 82 connects between a position of the fuel check valve 76 of the atmosphere connecting pipe 74, and the position of the air check valve 78.
[0026] The fuel check valve 76 is for preventing a flow of fuel inside the fuel tank 10 through the second ventilation pipe 82 and the first ventilation pipe 80 into the case 40 in the event of capsizing or the like. The fuel check valve 76 also enables fuel or air from the case 40 to flow into the fuel tank 10. The air check valve 78 is the same as is provided in a boat of the related art, and is for preventing negative pressure inside the fuel tank 10 and the case 40. The air check valve is for introducing air at a downstream side of an air cleaner of the engine intake passageway to the side of the fuel tank 10 or case 40, only when the pressure inside the fuel tank 10 or the case 40 is lower than atmospheric pressure (pressure at a downstream side of the air cleaner of the intake passageway 75).
[0027] A vapor pipe 86 provided with a vapor check valve at a mid point is connected to part of the fuel tank 10 above the fuel surface. When the vapor pressure inside the fuel tank 10 becomes high, vapor inside the fuel tank 10 is expelled to the outside through the vapor pipe 86, which prevents the pressure inside the fuel tank 10 becoming high.
[0028] With the present invention constructed as described above, high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34) are housed inside the case 40 shielded from the outside. In this way, even if there is fuel leakage from the high-pressure fuel components, leaked fuel accumulates inside the case 40 and leakage to the outside is prevented.
[0029] In the event that the inside of the case 40 fills up with leaked fuel, the fuel filling up the case 40 is returned to the fuel tank 10 by way of the first ventilation pipe 80, the second ventilation pipe 82 and the atmosphere connecting pipe 74.
[0030] In a state where there is little or no fuel leakage, in the event of the temperature inside the case becoming high and the atmospheric pressure inside the case become higher than the air pressure inside the fuel tank 10, the high-pressure inside the case 40 is vented into the fuel tank 10 by way of the first ventilation pipe 80, the second ventilation pipe 82 and the atmosphere connection pipe 74. As a result, the pressure inside the case 40 does not fluctuate. High-pressure introduced into the fuel tank is expelled to the outside through the vapor pipe 86, which means that there is also no fluctuation of the pressure inside the fuel tank 10.
[0031] Conversely, in the event that the temperature inside the case 40 becomes low and the atmospheric pressure inside the case 40 becomes lower than normal atmospheric pressure, air at a downstream side of an engine intake air cleaner is taken in to the case 40 through the air check valve, and so the pressure inside the case 40 does not fluctuate. In this way, even if there are changes in pressure due to temperature variations inside the case 40, the pressure inside the case 40 is kept constant.
[0032] As described above, with the present invention, by housing high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34) inside the case 40 shielded from the outside, even if there is leakage with respect to the high-pressure fuel components, it is possible to accumulate leaked fuel inside the case 40. Because of this, it is possible to prevent a boat getting soiled by leaked fuel, and to prevent causes of fuel catching fire.
[0033] Also, by housing the high-pressure fuel components inside the case 40, water and salt water do not come into direct contact with the high-pressure fuel components making it possible to prevent corrosion and rust of the high-pressure fuel components. In addition, since it is possible to prevent corrosion and rust, it is possible to put high-pressure fuel components for an automobile engine to use as high-pressure fuel components for a marine engine without modification.
[0034] In the above description, the high-pressure fuel components of the high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34 are housed inside the case 40, but from these high-pressure fuel components, it is also possible to house one or more inside the case 40.
Second Embodiment
[0035] In Fig. 1, the structure is such that the first ventilation pipe 80 is attached to an upper part of the case 40 (the position where the first ventilation pipe 80 is connected to the second ventilation pipe 82 is also at the upper part of the case 40). Further, Fig. 3 corresponds to Fig. 2, and shows a structure where the first ventilation pipe 80 is attached to a lower part of the case 40 (the position where the first ventilation pipe 80 is connected to the second ventilation pipe 82 is also at the lower part of the case 82).
[0036] The second ventilation pipe 82 connecting to the first ventilation pipe 80 at the lower part of the case 40 is provided with a fuel check valve 76 at a mid point. The other end of the second ventilation pipe 82 is connected to part of the fuel tank 10 above the fuel level 10. This fuel check valve 76 allows fuel to pass from the inside of the case 40 to the fuel tank 10, but does not allow passage of fuel in the opposite direction. Part of the fuel tank 10 above the fuel level 10 is connected to a downstream side of an air cleaner of the engine intake passageway 74 by way of the atmosphere connecting pipe 74. An air check valve 78 is provided midway along the atmosphere connecting pipe 74. Also, a vapor pipe 86 provided with a vapor check valve at a mid point is connected to part of the fuel tank 10 above the fuel surface.
[0037] Also with the embodiment shown in Fig. 3, similarly to Fig.1, high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34) are housed inside the case 40 shielded from the outside.
In this way, with the structure having the first ventilation pipe attached to a lower part of the case 40, even if there is fuel leakage from the high-pressure fuel components, leaked fuel accumulates inside the case 40 and there is no leakage of fuel to the outside. Leaked fuel passes from the first ventilation pipe attached to a lower part of the case 40, through the second ventilation pipe 82 and is returned to the inside of the fuel tank 10.
[0038] Here, even if there is variation in the atmospheric pressure inside the case 40 caused by temperature variations inside the case 40, the pressure inside the case 40 can be kept substantially constant by moving fuel inside the first ventilation pipe 80 and the second ventilation pipe 82.
[0039] As described above, high-pressure fuel components are also housed inside the case 40 shielded from the outside with the embodiment having the first ventilation pipe 80 attached to a lower part of the case 40. In this way, even if fuel leakage occurs with the high-pressure fuel components, it is possible to prevent a boat getting soiled by leaked fuel, and to prevent causes of fuel catching fire. It is possible to prevent corrosion and rust to the high-pressure fuel components, and it is possible to put high-pressure fuel components for an automobile engine to use as high-pressure fuel components for a marine engine without modification.
Third Embodiment
[0040] In the first embodiment, description was given for a water motorcycle not using a vapor separator. Next, a description will be given of an outboard motor using a vapor separator, based on Fig. 4. In Fig. 4, the same reference numerals as used in Fig. 1 and Fig. 11 represent the same parts
[0041] With this third embodiment, a vapor separator 12 is provided, and fuel is supplied from a fuel tank 10 through a fuel supply pipe 14 to the vapor separator 12. With this third embodiment also, similarly to the first embodiment, a high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34 are housed inside the case 40. Similarly, a low-pressure fuel inlet pipe 48, a low-pressure fuel outlet pipe 50, a high-pressure fuel outlet pipe 52, a high-pressure fuel inlet pipe 54 and a first ventilation pipe 80, for connecting into and out of the case 40, are attached to the case 40.
[0042] An air chamber 70 of the fuel pressure regulator 34 is connected to an engine intake pipe external to the case 40 in the first embodiment, but in Fig. 4 the air chamber 70 is connected internally to the case 40.
[0043] Among the plurality of pipes provided in the case 40, the low-pressure fuel inlet pipe 48 is connected to a part of the vapor separator below the fuel level via the low-pressure fuel connecting pipe 64. Specifically, fuel flows from the vapor separator 12, through the pressure fuel connecting pipe 64 and the low-pressure fuel inlet pipe 48 to the high-pressure fuel pump inside the case 40. Also, the low-pressure fuel outlet pipe 50 communicates with a space above the fuel level of the vapor separator 12 through a low-pressure fuel return pipe 36. Specifically, fuel is returned to inside of the vapor separator from the fuel pressure regulator 34 through the low-pressure fuel outlet pipe and the low-pressure fuel return pipe 36. Also, the inside of the case 40 and a space above the fuel level of the vapor separator 12 are connected by means of the first ventilation pipe 80 provided in the case 40 and the second ventilation pipe 82 connected to the first ventilation pipe 80.
[0044] The vapor separator 12 is connected to a downstream side of an air cleaner for the intake passage 75 through the atmosphere connecting pipe 22. Also, vapor occurring as a result of temperature rises or decompression of the fuel is expelled from the vapor separator 12 to a downstream side of the air cleaner for the intake passage 75.
[0045] In Fig. 4, the structure is such that the first ventilation pipe 80 is attached to an upper part of the case 40 (the position where the first ventilation pipe 80 is connected to the second ventilation pipe 82 is also at the upper part of the case 40), but it is also possible to have the first ventilation pipe 80 connected to a lower part of the case 40 (with the position where the first ventilation pipe 80 connects to the second ventilation pipe 82 also being below the case 40), corresponding to Fig. 2. As described above, since the inside of the case 40 is connected to a space above the fuel level of the vapor separator 12 in the event that the pressure inside the case 40 becomes higher than the pressure inside the vapor separator12, the high-pressure inside the case 12 can be vented to the inside of the vapor separator.. If the pressure inside the case 40 becomes lower than atmospheric pressure, the pressure inside the vapor separator is vented in to the inside of the case 40. In the event of pressure fluctuations inside the vapor separator 12, the pressure inside the vapor separator 12 is regulated by a space between the vapor separator itself and a downstream side of the air cleaner for the engine intake passage 75 In this way, even if there are changes in pressure due to temperature variations inside the case 40, there are no pressure fluctuations inside the case 40.
With this embodiment also, by housing high-pressure fuel components inside the case 40, even if there is fuel leakage from the high-pressure fuel components, leaked fuel accumulates inside the case 40 and there is no leakage of fuel to the outside. It is also possible to prevent corrosion or rusting of the high-pressure fuel components. As well as this, since it is possible to prevent corrosion and rust, it is possible use high-pressure fuel components for an automobile engine without modification.
Fourth Embodiment
[0046] Another embodiment of the present invention is shown in Fig. 5. With the first embodiment, a high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34 are all housed inside the case 40. However, with the fourth embodiment, the high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34 are each housed in individual cases. Specifically, the high-pressure fuel pump 24 is housed in a first case 88, the high-pressure fuel filter 26 is housed in a second case 90, and the fuel pressure regulator 34 is housed in a third case 92.
[0047] The first case 88, second case 90 and third case 92 are made of a salt damage resistant and rust proof material, or can be protected from rust due to being subjected to surface treatment to coat on plating or paint on a rust preventing oil. It is also possible to prevent corrosion and rusting of the high-pressure fuel components by filling the cases 88, 90 and 92 with grease or the like. Using the first case 88, second case 90 and third case 92, water or salt water does not come into direct contact with the high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34) preventing corrosion and rust to the high-pressure fuel components.
[0048] A low-pressure fuel inlet pipe 48, and a high-pressure fuel outlet pipe 52 are provided in the first case 88 housing the high-pressure fuel pump 24. Fuel from the fuel tank 10 is fed into the high-pressure fuel pump 24 through the low-pressure fuel inlet pipe 48 and the low-pressure fuel connecting pipe 64 connected to the low-pressure fuel inlet pipe 48. The high-pressure fuel outlet pipe 52 communicates with the high-pressure fuel filter 26 housed in the second case 90 through a high-pressure fuel connecting pipe 28.
[0049] A high-pressure fuel inlet pipe 54 and a high-pressure fuel outlet pipe 52 are provided in the second case 90 housing the high-pressure fuel filter 26. The high-pressure fuel inlet pipe 54 is connected to a high-pressure fuel pump 24 side high-pressure fuel connecting pipe 28, while the high-pressure fuel outlet pipe 52 is connected to a delivery pipe 32 side high-pressure fuel connecting pipe 28.
[0050] A high-pressure fuel inlet pipe 54 and a low-pressure fuel outlet pipe 50 are provided in the third case 92 housing the fuel pressure regulator 34. The high-pressure fuel inlet pipe 54 is connected to a delivery pipe 32 side high-pressure fuel connecting pipe 28, while the low-pressure fuel outlet pipe 50 is connected to a fuel tank 10 side low-pressure fuel return pipe 36.
[0051] Respective first ventilation pipes 80 are provided in the first case 88, second case 90 and third case 92. The first ventilation pipes 80 are connected to a second ventilation pipe 82, and this second ventilation pipe 82 connects to the atmosphere connecting pipe 74, similarly to Fig. 1.
[0052] As described above, with the present invention, by respectively shielding the high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34 using the first case 88, second case 90 and third case 92, even if there is leakage from the high-pressure fuel components, leaked fuel accumulates inside the cases 88, 90 and 92 and there is no leakage of fuel to the outside.. Also, since the high-pressure fuel components are housed inside the cases 88, 90 and 92, it is possible to prevent corrosion or rust. As well as this, since it is possible to prevent corrosion and rust to the high-pressure fuel components, it is possible to make use of high-pressure fuel components for an automobile engine without modification.
[0053] In the case of housing the fuel pressure regulator 34 inside the case 40 or the second case 90, it is necessary to introduce air pressure into the air chamber 70. At this time, it is acceptable to adopt either of the case of introducing intake pipe pressure as shown in Fig. 1, introducing the internal pressure of the case 40 as shown in Fig. 4, or introducing atmospheric pressure as shown in Fig. 5, or besides any of these methods, to introduce air pressure or hydraulic pressure using an external pressure source.
Fifth Embodiment
[0054] In Fig. 5, the attachment positions for the first ventilation pipes 80 on the cases 88, 90 and 92 is at an upper part of each of the cases 88, 90 and 92 (with the connection positions for the second ventilation pipe 82 also being at an upper part of the cases 88, 90 and 92). With this embodiment, as shown in Fig. 6, the attachment positions for the first ventilation pipes 80 on the cases 88, 90 and 92 is at a lower part of each of the cases 88, 90 and 92.
The first ventilation pipes 80 of each of the cases 88, 90 and 92 are connected to a second ventilation pipe 82, and the other end of this second ventilation pipe 82 is connected to the fuel tank 10 above the fuel level. The second ventilation pipe 82 is provided with a fuel check valve 76 close to the fuel tank 10. This fuel check valve 76 allows fuel to pass from the inside of the cases 88, 90 and 92 to the fuel tank 10, but does not allow passage of fuel in the opposite direction.
[0055] Also with the embodiment shown in Fig. 6, similarly to Fig.5, high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 34 and fuel pressure regulator 34) are housed inside the cases 88, 90 and 92 shielded from the outside. In this way, with the structure having the first ventilation pipes attached to a lower parts of the cases 88, 90 and 92, even if there is fuel leakage from the high-pressure fuel components inside the cases 88, 90 and 92, leaked fuel accumulates inside the cases 88, 90 and 92 and there is no leakage of fuel to the outside. Leaked fuel passes from the first ventilation pipes 80 attached to lower parts of the cases 88, 90 and 92, through the second ventilation pipe 82 and is returned to the inside of the fuel tank 10.
[0056] As described above, high-pressure fuel components are also housed inside the cases 88, 90 and 92 shielded from the outside with the embodiment having the first ventilation pipes 80 attached to lower parts of the cases 88, 90 and 92. In this way, even if fuel leakage occurs with the high-pressure fuel components, it is possible to prevent a boat getting soiled by leaked fuel, and to prevent causes of fuel catching fire. It is possible to prevent corrosion and rust to the high-pressure fuel components, and it is possible to put high-pressure fuel components for an automobile engine to use as high-pressure fuel components for a marine engine without modification.
Sixth Embodiment
[0057] Another embodiment of a fuel injector for a marine engine of the present invention is shown in Fig. 7. Fig. 7 shows application to a water motorcycle. Fig. 8 is a cross sectional drawing of a case used in Fig. 7. In Fig. 7 and Fig. 8, the same reference numerals as used in Fig. 1 to Fig. 6, and Fig. 11, represent the same parts
[0058] As shown in Fig. 8, a case 100 is made up of a body 102, a cover 104 for the body 102, and packing 106 for sealing between the body 102 and the cover 104. A high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34, being the principal high-pressure fuel components, are housed inside this case 100 shielded from the outside atmosphere.
[0059] The body 102 and the cover 104 making up the case 100 are made from materials having resistance to corrosion and rust caused by salt damage. Specifically, the body 102 and the cover 104 are preferably made from corrosion resistant and rust resistant materials such as resin or stainless steel. Alternatively, it is possible to prevent rust using surface treatment, such as plating or painting, to coat the parts with a rust preventing material.
[0060] With this case 100, the cover 104 is attached to an upper part of the body 102, and the inside of the body 102 is capable of containing fuel. To the cover 104 there are attached a low-pressure fuel inlet pipe 48 connecting to a fuel supply pipe 14 for inflow of fuel, a high-pressure fuel outlet pipe 52 for outflow of fuel from a high-pressure fuel filter 26, a high-pressure fuel inlet pipe 54 for returning fuel from a delivery pipe 32 to the fuel pressure regulator 34, a pressure introduction pipe 72 for connecting an air chamber 70 of the fuel pressure regulator to the outside, and an overflow connecting pipe 108 for outflow of fuel overflowing inside the case 100 to the outside.
[0061] As shown in Fig. 7, the fuel tank 10 and the case 100 are connected by the fuel supply pipe 14. A low-pressure fuel pump 18 is provided mid-way along the fuel supply pipe 14. A fuel solenoid 110 is provided at a point of connection between the fuel supply pipe 14 and the low-pressure fuel inlet pipe 48 attached to the cover 102 of the case 100. A liquid level sensor 112 for detecting the height of the fuel level is attached to the case 100. A controller 114 is provided externally to the case 100, and this controller is input with a signal from the liquid level sensor 112 to cause operation of the fuel solenoid 110. If the fuel level inside the case 100 is below a specified level, the low-pressure fuel pump 18 is activated to introduce fuel from the fuel supply pipe 14 to the inside of the case 100. On the other hand, if the fuel level inside the case 100 is higher than the specified level, this is detected by the liquid level sensor 112 and a signal is sent to the controller 114, causing the fuel supply pipe 14 to be closed by the fuel solenoid 110, and stopping the low-pressure fuel pump 18. Specifically, fuel at a constant height of fuel level is contained inside the case 100, using means for keeping the height of fuel level constant, such as the fuel solenoid 110, the liquid level sensor 112 and the controller 114. It is also possible to use other well-known means as means for keeping the height of fuel level constant inside the case 100.
[0062] In Fig. 7, the low-pressure fuel pump 18 is provided mid-way along the fuel supply pipe 14 connecting between the fuel tank 10 and the case 100. It is also possible to arrange the fuel tank 10 at a position higher up than the case 100 and to omit the low-pressure fuel pump midway along the fuel connecting pipe 14, to supply fuel from the tank 10 to the case 100 utilizing a head difference.
[0063] The overflow pipe 108 is connected above the fuel level of the fuel tank via an overflow pipe 116.
[0064] Inside the case 100, an opening in the high-pressure fuel pump 24 for taking in fuel is arranged below the fuel level. In the case 100, the high-pressure fuel pump 24 is connected to the fuel pressure regulator 34.. Fuel saved in the case 100 arrives from the high-pressure fuel pump at the delivery pipe 32 through the fuel pressure regulator 34, and surplus fuel is returned from the delivery pipe 32 to the fuel pressure regulator 34. Fuel returned to the fuel pressure regulator 34 is returned directly to the inside of the case 100.
[0065] The air chamber 70 of the fuel pressure regulator is connected to an engine intake pipe through a pressure introduction tube 72. The air chamber 70 of the fuel pressure regulator 34 can be connected higher up than the fuel level inside the case 100, instead of the engine intake pipe. Fuel returned to the fuel pressure regulator 34 can also be returned to the fuel tank 10 and not returned to the inside of the case 100.
[0066] With the present invention constructed as described above, even if there is leakage of fuel from high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34) inside the case 100, leaked fuel becomes mixed with the fuel inside the case 100 and there is no leakage problem. Even if the means for keeping the fuel level constant is damaged and the case 100 becomes filled with fuel, this excess fuel is returned to the fuel tank 10 by way of the overflow pipe 116. Also, even in the event that the temperature inside the case 100 becomes high and the air pressure inside the case 100 becomes high, the high-pressure inside the case 100 is returned to the fuel tank 10 by way of the overflow pipe 116.
[0067] Thus, with the present invention, high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34), are housed inside the case 100 shielded from the outside. In this way, even if fuel leakage occurs with the high-pressure fuel components, leaked fuel becomes mixed with fuel inside the case 100 which means that it is possible to prevent a boat getting soiled by leaked fuel, and to prevent causes of fuel catching fire.
[0068] Also, by housing the high-pressure fuel components inside the case 100, water and salt water do not come into direct contact with the high-pressure fuel components making it possible to prevent corrosion and rust of the high-pressure fuel components. As well as this, since it is possible to prevent corrosion and rust, it is possible to put high-pressure fuel components for an automobile engine to use as high-pressure fuel components for a marine engine without modification.
[0069] In the above description, three high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 24 and fuel pressure regulator 26) are housed inside the case 1000, but from these high-pressure fuel components, at least the high-pressure fuel pump 24 is housed inside the case 100. It is also possible to take at least one of the high-pressure fuel filter 26 and the fuel pressure regulator out of the case 100.These high-pressure fuel components may also be housed in separate cases (refer to Fig. 5 and Fig. 6).
Seventh Embodiment
[0070] Fig. 7 shows application to a water motorcycle, but an embodiment of the invention applied to an outboard motor is shown in Fig. 9. There are three points of difference between Fig. 7 and Fig. 9, as described below. First, there is means for keeping the height of the fuel level inside the case 100 constant, and secondly, whereas in Fig. 7 the high-pressure fuel filter 26 and the fuel pressure regulator 34 are not directly connected, in Fig. 9 the high-pressure fuel filter 26 and the fuel pressure regulator 34 are directly connected. Thirdly, whereas in Fig. 7 the delivery pipe 32 is connected to the fuel pressure regulator 34, in Fig. 9 the delivery pipe 32 is not connected to the fuel pressure regulator 34.
[0071] In Fig. 9, the high-pressure fuel filter 26 and a fuel chamber 118 of the fuel pressure regulator 34 are connected. In this way it is possible to omit the high-pressure fuel inlet pipe 54 shown in Fig. 7 for returning fuel from the delivery tube 32 to the fuel pressure regulator 34. However, the points of difference between Fig. 7 and Fig 9 are not important here, and so description of the relationship between the high-pressure fuel filter 26 and the fuel pressure regulator shown in Fig. 9 will be omitted.
[0072] In Fig. 9 also, it is possible to omit the low-pressure fuel pump 18 mid-way along the fuel supply pipe 14, and fuel can be supplied from the fuel tank 10 to the case 100 using a head difference.
[0073] Apart from these points of difference, the embodiment of Fig. 9 and the embodiment of Fig. 7 have the same structure. Specifically, the fuel tank 10 and the case 100 are connected by the fuel supply pipe 14, and the low-pressure fuel pump 18 is provided mid-way along this fuel supply pipe 14. High-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34), are housed inside the case 100 shielded from the outside, and fuel is held in the case 100. With this structure the height of the fuel level inside the case 100 is kept constant by means for keeping the height of fuel level constant. An upper part of the fuel tank 10 and an upper part of the case 100 are connected via an overflow pipe 116.
[0074] With the above described structure, the embodiment of Fig. 9 can obtain the same effects as the embodiment of Fig. 7.
Eighth Embodiment
[0075] Fig. 7 shows the fuel level inside the case 100 being kept at a constant height. Fig. 10 shows the whole of the case 100 being always filled with fuel. The main difference between the embodiment of Fig. 10 and Fig. 7 is that means for keeping the height of the fuel level constant (for example, the fuel solenoid 110, liquid level sensor 112 and controller 114) are not required.
[0076] A high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34, being the principal high-pressure fuel components, are housed inside the case 100. Fuel is always supplied from the fuel supply pipe to the case 100 by actuation of the low-pressure fuel pump 18, and the case 100 is always filled with fuel. Fuel that has overflowed in the case 100 is returned to the fuel tank 10 by way of the overflow pipe 116.
[0077] Fuel returned to the fuel pressure regulator 34 is returned directly to the inside of the case 100. The air chamber 70 of the fuel pressure regulator 34 is connected to an engine intake pipe through a pressure introduction tube 72. The overflow pipe 108 is connected above the fuel level of the fuel tank 10 via an overflow pipe 116.
[0078] The air chamber 70 of the fuel pressure regulator 34 can be connected higher up than the fuel level inside the case 100, instead of to the engine intake pipe. Fuel returned to the fuel pressure regulator 34 can also be returned to the fuel tank 10 instead of to the inside of the case 100.
[0079] With the present invention constructed as described above, since high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34) inside the case 100 are surrounded by fuel, there is no problem even if there is fuel leakage to the high-pressure fuel components. Also, even in the event that the temperature inside the case 100 becomes high and vapor is generated from that fuel, that vapor is returned to the fuel tank 10 by way of the overflow pipe 116.
[0080] Thus, with the present invention, high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34), are housed inside the case 100 shielded from the outside. With this structure, even if fuel leakage occurs with the high-pressure fuel components, leaked fuel becomes mixed with fuel inside the case 100 which means that it is possible to prevent a boat getting soiled by leaked fuel, and to prevent causes of fuel catching fire.
[0081] Also, by housing the high-pressure fuel components inside the case 100, water and salt water do not come into direct contact with the high-pressure fuel components making it possible to prevent corrosion and rust of the high-pressure fuel components. As well as this, since it is possible to prevent corrosion and rust, it is possible to put high-pressure fuel components for an automobile engine to use as high-pressure fuel components for a marine engine without modification.
[0082] Thus, with the present invention, the three high-pressure fuel components (high-pressure fuel pump 24, high-pressure fuel filter 26 and fuel pressure regulator 34), are housed inside the case 100. Also, of these high-pressure fuel components, it is possible to house at least the high-pressure fuel pump 24 inside the case 100, and to take at least one of the high-pressure fuel filter 26 and the fuel pressure regulator out of the case 100. It is also possible to house these high-pressure fuel components in separate cases (refer to Fig. 5 and Fig. 6).
[0083] A fuel injector for a marine engine of the present invention described above has the following effects.
1 - High-pressure fuel components of a fuel injector applied to a marine engine are shielded inside a case. In this way, even if fuel leakage occurs with the high-pressure fuel components, leaked fuel can be accumulated inside the case which means that it is possible to prevent a boat getting soiled by leaked fuel, and to prevent causes of fuel catching fire.
2 - High-pressure fuel components of a fuel injector applied to a marine engine are shielded inside a case. As a result, it is possible to prevent saltwater damage and corrosion in the ocean, and to improve the durability of the fuel injector.
3 - High-pressure fuel components are gathered together inside a case. Accordingly, it is sufficient to carry out corrosion treatment only for this case, and there is no need for special fuel components for a marine engine that use corrosion resistant material in order to prevent salt water damage and corrosion, or to carry out special surface treatments. In addition, it becomes possible to use existing high-pressure fuel components in a fuel injector for a marine engine, without incurring any additional cost.
4 - High-pressure fuel components are housed all together inside a case. This makes it possible to handle all the high-pressure fuel components as if they were a single component, which increases the degree of freedom of attachment devices, and increases the ease of piping work and maintenance. Also, it is possible to prevent deformation or damage to the high-pressure fuel components due to external forces during distribution or use.
5 - If the inside of the case is filled with grease and the internal component surfaces coated with a rust preventing agent or rust preventing oil, in order to obtain even better corrosion inhibiting effects, the rust preventing agent or rust preventing oil is not washed away which means that the corrosion inhibiting effects are maintained over a long period of time.
1. A fuel injector for a marine engine provided with a fuel tank and high-pressure fuel
components, wherein the high-pressure fuel components are housed inside a case shielded
from the atmosphere, the atmosphere and a space higher up than a fuel level of the
fuel tank are connected by an atmosphere connecting pipe, an air check valve, for
leading only air from the atmosphere to a fuel tank side, is provided mid-way along
the atmosphere connecting pipe, and an intermediate position, in the atmosphere connecting
pipe, between the fuel tank and the air check valve is connected to the inside of
the case by a ventilation pipe.
2. The fuel injector for a marine engine of claim 1, wherein the high-pressure fuel components
housed inside the case are at least one from among a high-pressure fuel pump, a fuel
pressure regulator and a high-pressure fuel filter.
3. The fuel injector for a marine engine of claim 2, wherein the high-pressure fuel components
housed inside a case are housed in individual cases, and internal parts of the individual
cases are connected by the ventilation pipe.
4. The fuel injector for a marine engine of any one of claims 1 to 3, provided with a
fuel check valve, for preventing outflow of fuel from the fuel tank, provided further
towards the fuel tank side than a connection position of the atmosphere connection
pipe to the ventilation pipe.
5. The fuel injector for a marine engine of any one of claims 1 to 4, wherein the case
is made of a rust preventative material.
6. The fuel injector for a marine engine of any one of claims 1 to 4, wherein the case
is coated with a rust preventative oil.
7. The fuel injector for a marine engine of any one of claims 1 to 4, wherein the inside
of the case is filled with grease.
8. A fuel injector for a marine engine provided with a fuel tank and high-pressure fuel
components, wherein the high-pressure fuel components are housed inside a case shielded
from the atmosphere, the atmosphere and a space higher up than a fuel level of the
fuel tank are connected by an atmosphere connecting pipe, an air check valve, for
leading only the atmosphere from the atmosphere to a fuel tank side, is provided mid-way
along the atmosphere connecting pipe, the case and the fuel tank are connected by
a ventilation pipe, and a fuel check valve for allowing passage of fuel only from
the case side to the tank side is provided mid-way along the ventilation pipe.
9. The fuel injector for a marine engine of claim 8, wherein the high-pressure fuel components
housed inside the case are at least one from among a high-pressure fuel pump, a fuel
pressure regulator and a high-pressure fuel filter.
10. The fuel injector for a marine engine of claim 9, wherein the high-pressure fuel components
housed inside a case are housed in individual cases, and internal parts of the individual
cases are connected by the ventilation pipe.
11. The fuel injector for a marine engine of any one of claims 8 to 10, wherein the case
is made of a rust preventative material.
12. The fuel injector for a marine engine of any one of claims 8 to 10, wherein the case
is coated with a rust preventative oil.
13. The fuel injector for a marine engine of any one of claims 8 to 10, wherein the inside
of the case is filled with grease.
14. A fuel injector for a marine engine provided with a vapor separator and high-pressure
fuel components, wherein the high-pressure fuel components are housed inside a case
shielded from the atmosphere, the inside of the case and a space above a fuel level
of the vapor separator are connected by a ventilation pipe, and the space of the vapor
separator and the atmosphere are connected by an atmosphere connecting pipe.
15. The fuel injector for a marine engine of claim 14, wherein the high-pressure fuel
components housed inside the case are at least one from among a high-pressure fuel
pump, a fuel pressure regulator and a high-pressure fuel filter.
16. The fuel injector for a marine engine of claim 14, wherein the high-pressure fuel
components housed inside a case are housed in individual cases, and internal parts
of the individual cases are connected by the ventilation pipe.
17. The fuel injector for a marine engine of any one of claims 14 to 16, wherein the case
is made of a rust preventative material.
18. The fuel injector for a marine engine of any one of claims 14 to 16, wherein the case
is coated with a rust preventative oil.
19. The fuel injector for a marine engine of any one of claims 14 to 16, wherein the case
is filled with grease.
20. A fuel injector for a marine engine provided with a fuel tank and high-pressure fuel
components, wherein a case is provided connected to the fuel tank via a fuel supply
pipe, wherein fuel from the fuel tank is introduced into the case through the fuel
supply pipe, the high-pressure fuel components are housed inside the case, and a position
above the fuel tank and a position above internal parts of the case are connected
by an overflow pipe.
21. The fuel injector for a marine engine of claim 20, provided with means for maintaining
a fuel level of the fuel stored inside the case at a specified height, wherein, when
excess fuel has been supplied to the inside of the case, surplus fuel inside the case
is returned to the fuel tank through the overflow pipe.
22. The fuel injector for a marine engine of claim 20, provided with a low-pressure fuel
point mid-way along the fuel supply pipe, wherein the inside of the case is filled
with fuel, and surplus fuel supplied to the inside of the case is returned to the
fuel tank through the overflow pipe.
23. The fuel injector for a marine engine of claim 10, wherein of the high-pressure fuel
components, at least a high-pressure fuel pump is housed the inside the case.
24. The fuel injector for a marine engine of any one of claims 20 to 23, wherein the case
is made of a rust preventative material.
25. The fuel injector for a marine engine of any one of claims 20 to 23, wherein the case
is coated with a rust preventative oil.