JP2008175192A - Fuel supply system for outboard motor - Google Patents

Abstract

A fuel supply device for an outboard motor that improves the ease of assembly of a high-pressure fuel pump into a vapor separator, reduces the size of the vapor separator, and improves the maintainability of the vapor separator.
A vapor separator (V) is formed by screwing a cover (2) and a lower main body (1), and a constant liquid level controller (Y) is formed and held in the vapor separator (V) by a constant liquid level control device (C). The The cover 2 is provided with a support arm portion 2d, and a locking hole 2e is formed at the lower end. The pump holder 9 is provided with an engaging arm portion 9d, and an engaging protrusion 9e is provided at the upper end. The bottomed cylinder portion 9c of the pump holder 9 is inserted into the lower end of the high-pressure fuel pump P, and the engagement protrusion 9e of the pump holder 9 is engaged with the locking hole 2e of the cover 2, so that the high-pressure fuel pump P 9 and the cover 2 are clamped and fixed. The filter member 12 a of the fuel filter 12 is disposed in the projection plane of the high-pressure fuel pump P in the longitudinal axis direction XX of the high-pressure fuel pump P.
[Selection] Figure 1

Description

  In the present invention, fuel in a fuel tank is pressurized to a low pressure by a low-pressure fuel pump, and the low-pressure fuel is supplied into a vapor separator formed by screwing with a lower housing and a cover covering the lower casing, and in the vapor separator. The constant liquid level controller forms and holds a constant fuel level, and the fuel in the vapor separator is further pressurized to a high pressure by a high-pressure fuel pump disposed in the vapor separator. The present invention relates to a fuel supply device for an outboard motor that is injected and supplied to an engine via a fuel injection valve attached to a pipe.

A fuel supply device for such an outboard motor is disclosed in Patent Document 1. According to this, the vapor separator is formed as a vapor separator that is substantially sealed by a lower casing and a cover that closes the upper opening of the lower casing, and the high-pressure fuel pump housed in the vapor separator is a high-pressure fuel pump. It is clamped and fixed between the lower housing and the cover via rubber mounts arranged in contact with the upper and lower ends of the pump, respectively. The pump suction passage of the high-pressure fuel pump opens to the side of the high-pressure fuel pump, and a fuel filter including a filter member is mounted and disposed toward the opening.
JP-A-5-248322

  According to such a conventional fuel supply device for an outboard motor, the high pressure fuel pump is assembled into the vapor separator by attaching rubber mounts to the upper end and the lower end of the high pressure fuel pump. Cover the high-pressure fuel pump with the cover toward the upper end, cover the lower casing toward the lower end of the high-pressure fuel pump, and screw the opposing flange between the lower casing and the cover together. And the cover. According to the above, the assembly of the high-pressure fuel pump into the vapor separator is performed in such a state that the lower housing and the cover are arranged to face each other and the periphery of the high-pressure fuel pump is surrounded by the lower housing and the cover. It is difficult to confirm whether the high-pressure fuel pump is correctly placed and assembled at a predetermined position. Assembling the high-pressure fuel pump into the vapor separator requires skill and assembly. Workability is greatly hindered. A lower rubber mount is attached to the lower end of the high-pressure fuel pump, and this rubber mount is disposed in contact with the bottom of the lower housing. (This is because the high-pressure fuel pump is sandwiched between the lower housing and the cover.) According to this, the filter member of the fuel filter cannot be disposed facing the lower end of the high-pressure fuel pump. According to the above, the filtering member is disposed so as to protrude greatly to the side of the high-pressure fuel pump, which hinders the downsizing of the vapor separator. At this time, it is possible to downsize the vapor separator by reducing the filtration area of the filter member, but it is necessary to frequently perform maintenance work of the fuel filter, which is not preferable in practice. Furthermore, in such a fuel supply device for an outboard motor, it is used in a place where water is present as compared with the usage environment of automobiles and motorcycles. According to this, the air vent drilled in the vapor separator is used. Water, seawater, etc. may enter the vapor separator through the holes and stay in the vapor separator. Compared with other applications, the vapor separator is decomposed and the water that accumulates in the vapor separator is removed more frequently. . Here, during such maintenance work, when the lower casing and the cover are unscrewed and the lower casing is removed, the high-pressure fuel pump held between the lower casing and the cover falls off the vapor separator. According to this, the maintenance workability is greatly hindered.

  The present invention has been made in view of the above-mentioned problems, and it is possible to improve the ease of assembling the high-pressure fuel pump into the vapor separator and to reduce the size of the vapor separator without reducing the filtration area of the filter member of the fuel filter. An object of the present invention is to provide a fuel supply device for an outboard motor capable of improving the maintenance workability of the vapor separator.

  In order to achieve the above object, the fuel supply device for an outboard motor according to the present invention is provided in a vapor separator in which fuel in a fuel tank is screwed by a lower housing and a cover by a low-pressure fuel pump. In the vapor separator, a constant fuel level is formed and held by the constant liquid level control device, and the fuel in the vapor separator is pressurized by a high-pressure fuel pump disposed in the vapor separator and into the fuel distribution pipe. In a fuel supply device for an outboard motor in which fuel is injected and supplied toward the engine from a fuel injection valve that is supplied and attached to the fuel distribution pipe, a support arm having a locking hole drilled downward from the cover The pump holder has a bottomed cup-like shape, and has an engagement protrusion that protrudes upward from the bottomed cylinder and faces the support arm and engages with the locking hole. The engagement arm portion is erected, and the engagement projection portion protruding from the engagement arm portion of the pump holder is engaged with the engagement hole formed in the support arm portion of the cover, thereby increasing the pressure. A fuel pump is sandwiched and fixed between a cover and a pump holder, and a fuel filter including a filtering member is attached to a pump suction passage that is arranged to protrude from the lower end of the high-pressure fuel pump. It is characterized by being arranged facing the projection surface of the high-pressure fuel pump in the axial direction.

  According to the fuel supply device for an outboard motor according to the present invention, the high pressure fuel pump is attached to the vapor separator as follows. First, the bottomed cylinder part of the pump holder is inserted upward from the lower end of the high-pressure fuel pump, and the bottom part of the bottomed cylinder part is placed in contact with the lower end of the high-pressure fuel pump. Next, the engaging arm portion of the pump holder is arranged facing the support arm portion of the cover, and the engaging protrusion protruding from the engaging arm portion is engaged toward the locking hole formed in the supporting arm portion. In this arrangement, the high-pressure fuel pump is securely held and fixed by the cover and the pump holder. According to the above, since the high pressure fuel pump is assembled by the pump holder in a state where the lower part of the cover is all open, the assembly can be performed with the high pressure fuel pump visually observed. Thus, it is possible to surely confirm whether or not the vehicle has fallen, and the workability of the fuel pump can be greatly improved without requiring skill in the work. In addition, the fuel filter attached to the pump suction path protruding from the lower end of the high-pressure fuel pump can be disposed in the projection surface of the high-pressure fuel pump in the longitudinal axis direction of the high-pressure fuel pump. It is possible to prevent the filtering member from protruding to the side of the high-pressure fuel pump corresponding to the portion disposed in the projection surface of the high-pressure fuel pump. According to the above, the protrusion of the filtration member to the side of the high-pressure fuel pump can be reduced without reducing the filtration area of the filtration member, which is effective in reducing the size of the vapor separator. In addition, when performing maintenance work to remove the water accumulated in the vapor separator, the lower housing is removed from the cover when the lower housing is removed from the cover and the water accumulated in the lower housing is removed. The high pressure fuel pump is still held by the pump holder toward the cover. According to the above, since the high-pressure fuel pump does not fall off even during such maintenance work, the maintenance workability can be greatly improved.

  Hereinafter, an embodiment of a fuel supply device for an outboard motor of the present invention will be described with reference to FIG. Reference numeral 1 denotes a lower housing having a bottomed cup shape having a bottom portion 1a on the lower side and an opening on the upper side and a flange portion 1b extending to the side at the opening end. Reference numeral 2 denotes a cover for closing the opening of the lower housing, and the cover 2 has the following configuration. Reference numeral 2a denotes a high-pressure fuel discharge hole that opens to the upper bottom portion 2b of the cover 2. Specifically, the high-pressure fuel discharge hole 2a has a discharge passage insertion hole 2c that opens to the upper bottom portion 2b. Further, a plurality (three or four) of support arm portions 2d are provided so as to protrude outward from the upper bottom portion 2b on the outer side of the discharge passage insertion hole 2c. A locking hole 2e is formed in the vicinity of the lower end. The support arm portions are preferably arranged at equal intervals on the circumference. Further, the low pressure fuel inflow hole 2f is opened in the upper bottom portion 2b. Specifically, the low pressure fuel inflow hole 2f is opened in the upper bottom portion 2b through a valve seat press-fitting hole 2g. Further, the following constant liquid level control device C is attached to the cover 2. A valve seat 3 is press-fitted and arranged in the valve seat press-fitting hole 2g, and a valve seat 3b facing downward is formed in a flow passage 3a penetrating the inside. Reference numeral 4 denotes a valve body that is movably disposed in the flow path 3a of the valve seat 3 and has a valve portion 4a that faces the valve seat 3b and opens and closes the valve seat 3b. The lower end of the valve body 4 is the valve seat. 3 is arranged to project downward from the lower end of 3. Reference numeral 5 denotes a float arm disposed facing the lower end of the valve body 4, the left end of which is rotatably supported by a float arm pin 6 supported by the cover 2, and the float 7 is attached to the right end. That is, when the float 7 moves downward, the float arm 5 rotates clockwise in the figure with respect to the float arm pin 6 so that the valve portion 4a of the valve body 4 opens the valve seat 3b of the valve seat 3, while the float 7 When 7 moves upward, the float arm 5 rotates counterclockwise with respect to the float arm pin 6, and the valve portion 4 a of the valve body 4 closes the valve seat 3 b of the valve seat 3. Note that a flange 2 h that abuts against the flange 1 b of the lower housing 1 is formed at the opening end below the cover 2. Next, the pump holder 9 will be described. The pump holder 9 has a bottomed cylinder part 9c formed by a bottom part 9a below and a cylindrical part 9b projecting upward from the bottom part 9a, and an upper end of the bottomed cylinder part 9c (in other words, an upper end of the cylindrical part 9b). ) And an engaging arm portion 9d protruding further upward. The engaging arm portion 9d is formed facing the support arm portion 2d so as to overlap and contact the inner side surface of the support arm portion 2d of the cover 2, and the engaging arm portion 9d is the number of the support arm portions 2d. Further, an engaging protrusion 9e that is engaged and disposed in the locking hole 2e of the support arm 2d is formed in the vicinity of the upper end of the engaging arm 9d so as to protrude laterally. The pump holder 9 is formed of a synthetic resin material, and this swings the engaging arm portion 9d by utilizing its elasticity when the engaging protrusion 9e is engaged in the engaging hole 2e. This is to make it happen. A through hole 9f is formed in the bottom 9a.

  Next, assembly of the vapor separator V will be described. A constant liquid level control device C including a valve seat 3, a valve body 4, a float arm 5, a float arm pin 6, and a float 7 is assembled in the cover 2 in advance. Further, the lower part of the high pressure fuel pump P is inserted and arranged in the bottomed cylindrical part 9c of the pump holder 9. At this time, the lower outer periphery of the high pressure fuel pump P is inserted and arranged in the cylindrical part 9b with a small gap. The lower end Pa of the fuel pump P is disposed facing the bottom portion 9a via the cushion ring 10. A pump suction path Pb is formed at the lower end Pa of the high-pressure fuel pump P so as to protrude downward, and this pump suction path Pb passes through a through hole 9f that penetrates the bottom 9a of the pump holder 9. And projecting downward from the bottom 9a. An annular collar member 11 is disposed on the upper end Pc of the high-pressure fuel pump P. The annular collar member 11 is preferably formed of an elastic material, but the collar member 11 can be eliminated. A fuel filter 12 including a filtering member 12a is attached to the pump suction path Pb. According to the above, the bottomed cylindrical portion 9c of the pump holder P is inserted and arranged near the lower end Pa of the high-pressure fuel pump P, the collar member 11 is inserted and arranged near the upper end Pc of the high-pressure fuel pump P, and the pump suction path Pb. The fuel filter 12 provided with the filtering member 12a was attached.

  The high-pressure fuel pump P is assembled to the cover 2 by the following. The pump holder 9 including the high-pressure fuel pump P is moved upward from the lower opening of the cover 2, and according to this, the pump discharge passage Pd protruding upward from the upper end Pc of the high-pressure fuel pump P is covered with the cover 2. And the upper end of the collar member 11 moves toward the upper bottom portion 2b of the cover 2, and the engagement protrusion 9e of the engagement arm portion 9d of the pump holder 9 moves into the inner portion of the discharge passage insertion hole 2c. Moving toward the locking hole 2e while swinging in the direction (high pressure fuel pump P side). Then, in a state where the engagement protrusion 9e of the engagement arm 9d of the pump holder 9 is engaged in the engagement hole 2e of the support arm 2d of the cover 2, the engagement arm 9d swings back to the original position, The upward movement of the pump holder 9 is stopped and the pump holder 9 is engaged with the cover 2, whereby the high-pressure fuel pump P is connected to the upper bottom 2 b of the cover 2 via the cushion ring 10 and the collar member 11. The pump discharge path Pd is inserted and supported in an airtight manner in the discharge path insertion hole 2c by being sandwiched and fixed by the bottom portion 9a of the pump holder 9. As described above, the cover 2 is assembled with the high pressure fuel pump P including the fuel filter 12 and the constant liquid level control device C, and the flange portion 1b of the lower housing 1 is in contact with the flange portion 2h of the cover 2. At the same time, the attachment of the vapor separator V is completed by screwing the flanges 2b and 1b with screws (not shown).

  The low pressure fuel inflow hole 2f of the vapor separator V is connected to the low pressure fuel pump 21 and the fuel tank T through the low pressure fuel pipe 20, and the high pressure fuel discharge hole 2a is connected to the fuel injection valve J through the high pressure fuel pipe 22. A flow path is connected to the fuel distribution pipe D provided.

  According to the above-described fuel supply device for an outboard motor, the fuel in the fuel tank T is pressurized as low pressure fuel by the low pressure fuel pump 21, and this low pressure fuel passes through the low pressure fuel pipe 20, the low pressure fuel inflow hole 2f, and the valve seat 2g. Through the vapor separator V. On the other hand, in the vapor separator V, the low-pressure fuel supplied into the vapor separator V from the valve seat 2g is a constant liquid surface comprising the valve seat 3, the valve body 4, the float arm 5, the float arm pin 6, and the float 7. A constant fuel liquid level YY is formed and held by the control device C. When the high pressure fuel pump P is driven, the foreign matter in the fuel stored in the vapor separator V is filtered by the filter member 12a of the fuel filter 12, and the clean fuel is sent to the high pressure fuel from the pump suction passage Pb. High-pressure fuel sucked into the pump P and pressurized to a high pressure by the pump unit is supplied to the fuel distribution pipe D via the pump discharge passage Pd, the high-pressure fuel discharge hole 2a, and the high-pressure fuel pipe 22, and this high-pressure fuel is injected into the fuel. It is supplied to an engine (not shown) via a valve J.

  Here, according to the fuel supply device for an outboard motor according to the present invention, the assembling property of the high-pressure fuel pump P can be greatly improved. That is, the bottomed cylindrical portion 9c of the pump holder 9 is inserted and arranged on the outer periphery in the vicinity of the lower end Pa of the high pressure fuel pump P, and the high pressure fuel pump P including the pump holder 9 is opened from below the cover 2 in the open state. The high pressure fuel pump P is sandwiched between the pump holder 9 and the cover 2 in a state where the pump holder 9 is moved upward toward the upper bottom portion 2b and the engaging protrusion 9e of the pump holder 9 is engaged with the engaging hole 2e of the cover 2. Fixed. According to the above, the high-pressure fuel pump P is moved downward toward the upper bottom 2b of the cover 2 in the open state, and the engagement protrusion 9e of the pump holder 9 is directed toward the locking hole 2e in the open state. Since it only has to be engaged, it is possible to visually check any of the above mounting states, the high-pressure fuel pump P can be accurately assembled at a predetermined position, and no skill is required for the assembly. The assembly work of the high-pressure fuel pump can be facilitated and reliably performed. Since the pump holder 9 can be assembled in advance to the high-pressure fuel pump P, the assembly is extremely easy.

  Further, according to the present invention, maintenance work for water, foreign matter, etc. accumulated in the vapor separator V can be performed very easily. That is, in the maintenance work of the vapor separator V, the screw connection between the cover 2 and the lower housing 1 is released, the lower housing 1 is removed from the cover 2, and the stagnation in the lower housing 1. However, even when the lower housing 1 is removed from the cover 2 as described above, the high-pressure fuel pump P is still held between the cover 2 and the pump holder 9. And fixedly held. According to the above, since the high-pressure fuel pump P does not fall off even when the lower casing 1 is removed from the cover 2, maintenance work and workability when the lower casing 1 is assembled to the cover 2 again. Can be greatly improved.

  Furthermore, according to the present invention, the vapor separator V can be reduced in size without reducing the filtration area of the filtration member 12a of the fuel filter 12. That is, the high-pressure fuel pump P is sandwiched and fixed by the pump holder 9 and the cover 2, so that a space K can be formed between the bottom 9 a of the pump holder 9 and the bottom 1 a of the lower housing 1. The filter member 12a of the fuel filter 12 can be disposed in the projection plane of the high-pressure fuel pump P in the longitudinal axis direction XX of the high-pressure fuel pump P. As shown in FIG. 2, the filtration member 12a can be disposed in the projection surface of the high-pressure fuel pump P indicated by the alternate long and short dash line. According to this, the filtration member has an area corresponding to the projection surface. It can suppress that 12a protrudes to the side of the high-pressure fuel pump P. According to the fact that the protrusion of the filter member 12a to the side of the high-pressure fuel pump P can be reduced as described above, the lower housing 1 can be reduced in size, thereby reducing the vapor separator V in size. It was made. Note that the arrangement of the filtration member 12a facing the projection surface of the high-pressure fuel pump P does not mean that the entire filtration member 12a faces the projection surface.

1 is an overall system diagram including a vertical sectional view of a vapor separator showing an embodiment of a fuel supply device for an outboard motor according to the present invention. The principal part cross-sectional view in the BB line of FIG.

Explanation of symbols

2 Cover 2d Support arm part 2e Locking hole 9 Pump holder 9c Bottomed cylinder part 9d Engagement arm part 9e Engagement protrusion 12 Fuel filter 12a Filter member P High-pressure fuel pump Pb Pump suction path XX Longitudinal of high-pressure fuel pump Axial direction

Claims (1)

  The fuel in the fuel tank is supplied by a low-pressure fuel pump into a vapor separator formed by screwing the lower housing and cover, and a constant fuel level is formed and held in the vapor separator by a constant liquid level control device. The fuel in the vapor separator is boosted by a high-pressure fuel pump disposed in the vapor separator and supplied into the fuel distribution pipe, and the fuel is injected and supplied from the fuel injection valve attached to the fuel distribution pipe to the engine. In the fuel supply device for an outboard motor, a support arm portion 2d with a locking hole 2e drilled downward from the cover 2 is provided upright, and a pump holder 9 having a bottomed cup shape is provided on the pump holder 9. An engaging arm portion 9d that protrudes upward from the bottomed tube portion 9c and faces the support arm portion 2d and that is engaged with and disposed in the locking hole 2e is provided upright. By engaging and disposing the engaging protrusion 9e protruding from the engaging arm portion 9d of the holder in the locking hole 2e formed in the support arm portion 2d of the cover 2, the high-pressure fuel pump P is connected to the cover 2. A fuel filter 12 including a filter member 12a is mounted on a pump suction path Pb that is sandwiched and fixed by a pump holder 9 and protruded from a lower end Pa of the high-pressure fuel pump P, and the filter member is attached to the high-pressure fuel pump P. A fuel supply device for an outboard motor, wherein the fuel supply device is disposed facing the projection surface of the high-pressure fuel pump P in the longitudinal axis direction X-X.

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