U.S. patent application number 09/942058 was filed with the patent office on 2002-02-28 for watercraft fuel supply system.
Invention is credited to Katoh, Naoki, Nakase, Ryoichi, Nanami, Masayoshi, Ozawa, Shigeyuki.
Application Number | 20020023627 09/942058 |
Document ID | / |
Family ID | 18365708 |
Filed Date | 2002-02-28 |
United States Patent
Application |
20020023627 |
Kind Code |
A1 |
Nakase, Ryoichi ; et
al. |
February 28, 2002 |
Watercraft fuel supply system
Abstract
An improved fuel delivery and injection system for a small
watercraft engine reduces the heat effects within an enclosed
engine compartment upon a fuel pump of and the fuel within a fuel
injection system. The fuel delivery system includes a vapor
separator and a high-pressure fuel pump. The fuel pump is at least
partially located within the vapor separator. The fuel within the
vapor separator cools the fuel pump. The vapor separator also is
positioned between a pair of air ducts such that an air stream
between the ducts cools the fuel within the vapor separator. This
arrangement consequently improves the consistency of the air/fuel
ratio in the fuel charges delivered to the engine cylinders,
provides a compact structure between the fuel pump, and the vapor
separator and improves the durability of the fuel pump.
Inventors: |
Nakase, Ryoichi; (Iwata,
JP) ; Katoh, Naoki; (Iwata, JP) ; Ozawa,
Shigeyuki; (Iwata, JP) ; Nanami, Masayoshi;
(Iwata, JP) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
620 NEWPORT CENTER DRIVE
SIXTEENTH FLOOR
NEWPORT BEACH
CA
92660
US
|
Family ID: |
18365708 |
Appl. No.: |
09/942058 |
Filed: |
August 28, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09942058 |
Aug 28, 2001 |
|
|
|
08777486 |
Dec 30, 1996 |
|
|
|
Current U.S.
Class: |
123/516 ;
123/509; 440/88J; 440/88R; 440/89C; 440/89F; 440/89H; 440/89J |
Current CPC
Class: |
F02M 31/20 20130101;
Y02T 10/12 20130101; B63B 34/10 20200201; F02M 37/20 20130101; B63H
21/38 20130101; B63H 21/14 20130101 |
Class at
Publication: |
123/516 ;
123/509; 440/88 |
International
Class: |
F02M 037/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 28, 1995 |
JP |
7-343978 |
Claims
What is claimed is:
1. A small watercraft comprising a hull including an engine
compartment, an internal combustion engine positioned within the
engine compartment and powering a propulsion device of the
watercraft, and a fuel supply system including a fuel pump which
draws fuel from a vapor separator and supplies fuel to at least one
charge former of the engine through a fuel supply line.
2. A small watercraft as in claim 1, wherein said fuel pump is at
least partially located within the vapor separator.
3. A small watercraft as in claim 1, wherein said at least one
charge former is a fuel injector, and said fuel supply system
includes a fuel return line which communicates with the at least
one fuel injector and the vapor separator to return excess fuel
supplied to the at least one fuel injector to the vapor
separator.
4. A small watercraft as in claim 1, wherein the fuel supply system
includes a main fuel tank in fluidic connection with the vapor
separator, and the vapor separator is located between a front end
of the engine and the main fuel tank.
5. A small watercraft as in claim 1, wherein the engine includes a
flywheel magneto located at the front end of the engine, and the
vapor separator is at least partially positioned above the flywheel
magneto.
6. A small watercraft as in claim 1, wherein the hull includes at
least two air openings located on opposite sides of the engine, and
the vapor separator is positioned between the air openings.
7. A small watercraft as in claim 1 additionally comprising an
exhaust system which communicates with at least one exhaust port of
the engine to expel exhaust gases outside the engine compartment,
the exhaust system including a water trap positioned on a side of a
longitudinal axis of the watercraft hull opposite of the side on
which the vapor separator is located.
8. A small watercraft as in claim 7, wherein the vapor separator is
mounted to a side wall of the hull.
9. A small watercraft as in claim 8, wherein at least one damper is
positioned between the hull and the vapor separator.
10. A small watercraft as in claim 1, wherein the vapor separator
includes a valve arranged to control fuel flow into an inlet port
of the vapor separator and a float positioned within a tank of the
vapor separator and arranged to operate said valve in order to
maintain a predetermined fuel level within the tank.
11. A small watercraft as in claim 10, wherein said float rotates
about a pivot shaft.
12. A small watercraft as in claim 11, wherein said pivot shaft is
arranged within the vapor separator with an axis of the pivot shaft
arranged generally transverse to a longitudinal axis of the
hull.
13. A small watercraft as in claim 1, wherein said fuel supply
system includes a breather pipe which connects a vapor port of the
vapor separator to an induction system of the engine, and a check
valve communicating with the breather pipe and positioned between
the induction system and the vapor separator.
14. A small watercraft as in claim 1, wherein said fuel supply
system includes a breather pipe which connects a vapor port of the
vapor separator to an induction system of the engine, and an end of
the breather pipe that is connected to the induction system is
lower than the vapor port.
15. A small watercraft comprising a hull including an engine
compartment, a fuel-injected, internal combustion engine positioned
within the engine compartment and powering a propulsion device of
the watercraft, and a fuel supply system including a fuel pump
which supplies fuel to at least one fuel injector of the engine,
the fuel pump being located in front of the engine.
16. A small watercraft as in claim 15, wherein the hull includes at
least two air ducts located on opposite sides of the engine, and
the vapor separator is positioned between the air ducts.
17. A small watercraft as in claim 15, wherein the fuel supply
system includes a vapor separator, and the fuel pump is at least
partially positioned within the vapor separator and is arranged to
draw fuel from the vapor separator.
18. A small watercraft as in claim 15, wherein said fuel pump is
powered by an output shaft of said engine.
19. A small watercraft as in claim 18, wherein a power transmission
device is located on the output shaft of the engine and powers the
fuel pump.
20. A small watercraft as in claim 18, wherein the output shaft of
the engine is connected to an input shaft of the pump.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates in general to an engine of a
small watercraft, and in particular to a fuel supply system for a
watercraft engine.
[0003] 2. Description of Related Art
[0004] Personal watercrafts have become popular in recent years.
This type of watercraft is sporting in nature; it turns swiftly, is
easily maneuverable, and accelerates quickly. Personal watercraft
today commonly carrier one rider and one or two passengers.
[0005] A relatively small hull of the personal watercraft defines
an engine compartment below a rider's area. An internal combustion
engine frequently lies within the engine compartment in front of a
tunnel formed on the underside of the watercraft hull. The internal
combustion engine commonly powers a jet propulsion device located
within the tunnel. An impeller shaft commonly extends between the
engine and the propulsion device for this purpose.
[0006] Personal watercrafts often employ an in-line,
multi-cylinder, crankcase compression, two-cycle engine. The engine
conventionally lies within the engine compartment with the in-line
cylinders aligned along a longitudinal axis of the watercraft hull
(in the bow to stern direction).
[0007] A dedicated carburetor usually supplies fuel to each
cylinder of the engine. Because of the sporting nature of the
watercraft and the tendency for frequent, abrupt directional
changes of the watercraft when used, prior personal watercraft
engine employ floatless-type carburetors. A fuel system used with
the floatless-type carburetors continuously supplies fuel from a
fuel tank to the carburetors while returning excess fuel to the
fuel tank.
[0008] Though floatless carburetors improve fuel delivery to the
engine's intake, prior fuel supply systems have not been so immune
to abrupt directional changes. The fuel pick-up port in the fuel
tank often is exposed to air when the watercraft leans in a turn,
especially when the fuel level within the tank is low. Air in the
fuel line produces a number of adverse affects. The fuel/air ratio
of the charge delivered to the engine cylinders is reduced which
results in poor engine performance. Air in the fuel line also can
destroy the fuel pump's prime, as well as cause some fuel pumps to
run hotter and damage the pump either immediately or over time
(i.e., reduce the pump's durability).
[0009] Carburetored engines also tend to produce a fuel charge of a
less than accurate fuel/air ratio. Consequently, engine performance
is not optimized under all running conditions and greater
pollutants can result.
SUMMARY OF THE INVENTION
[0010] The present watercraft includes a fuel injection engine in
order to improve the accuracy of the fuel/air ratio of charge
delivered to the engine cylinders, as well as to reduce pollutants.
The adaptation of a fuel injected engine into the small watercraft
raises some formidable changes, however, such as, for example,
excessive heating of the fuel and the fuel pump of the fuel
injection system within the enclosed engine compartment of a small
watercraft.
[0011] One aspect of the present invention thus involves a small
watercraft having a hull including an engine compartment. An
internal combustion engine is positioned within the engine
compartment and powers a propulsion device of the watercraft. A
fuel supply system includes a fuel pump which draws fuel from a
vapor separator and supplies fuel to at least one charge former of
the engine through a fuel supply line. The vapor separator removes
fuel vapors from the fuel before the pump delivers the fuel to the
charge formers to reduce at least one detrimental effect that
excessive heat in the engine compartment has on the fuel supply
system.
[0012] The fuel pump desirably is at least partially located within
the vapor separator. The fuel within the vapor separator cools the
fuel pump. The durability of the fuel pump improves as a result.
This design also provides a compact arrangement for the fuel
system.
[0013] Another aspect of the present invention involves a small
watercraft having a hull that defines an engine compartment. A
fuel-injected, internal combustion engine is positioned within the
engine compartment and powers a propulsion device of the
watercraft. A fuel supply system of the engine includes a fuel pump
which supplies fuel to at least one fuel injector of the engine.
The fuel pump is located in front of the engine. In a preferred
embodiment, the fuel pump is a mechanical pump driven by the
engine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other features of the invention will now be
described with reference to the drawings of preferred embodiments
which are intended to illustrate and not to limit the invention,
and in which:
[0015] FIG. 1 is a partial side sectional view of a personal
watercraft illustrating an engine with a fuel supply and injection
system configured in accordance with a preferred embodiment of the
present invention;
[0016] FIG. 2 is a schematic layout of the engine and fuel supply
and injection system of FIG. 1 together with an associated control
system;
[0017] FIG. 3 is a sectional top plan view of the watercraft of
FIG. 1 illustrating the arrangement of the watercraft's components
within a hull of the watercraft;
[0018] FIG. 4 is a cross-sectional view of the watercraft taken
along line 4-4 of FIG. 1;
[0019] FIG. 5 is a partial side sectional view of a personal
watercraft illustrating an engine with a fuel supply and injection
system configured in accordance with another preferred embodiment
of the present invention;
[0020] FIG. 6 is a schematic layout of the engine and fuel supply
and injection system of FIG. 5 together with an associated control
system; and
[0021] FIG. 7 is a sectional top plan view of the watercraft of
FIG. 5 illustrating the arrangement of the watercraft's components
within a hull of the watercraft.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0022] FIG. 1 illustrates a personal watercraft 10 which includes a
fuel supply system configured in accordance with a preferred
embodiment of the present invention. Although the present fuel
supply system is illustrated in connection with an engine for a
personal watercraft, the fuel supply system can be used with other
types of watercraft as well, such as, for example, but without
limitation, small jet boats and the like.
[0023] Before describing the fuel supply system, an exemplary
personal watercraft 10 will first be described in general details
to assist the reader's understanding of the environment of use, the
preferred arrangement of the fuel supply system within the
watercraft 10, and the operation of the fuel supply system. The
watercraft 10 includes a hull 12 formed by a lower hull section 14
and an upper deck section 16. The hull sections 14, 16 are formed
from a suitable material such as, for example, a molded fiberglass
reinforced resin. The lower hull section 14 and the upper deck
section 16 are fixed to each other around the peripheral edges in
any suitable manner.
[0024] As viewed in the direction from the bow to the stem of the
watercraft, the upper deck section 16 includes a bow portion 18, a
control mast 20 and a rider's area 22. The bow portion 18 slopes
upwardly toward the control mast 20 and includes at least one air
duct 24 through which air can enter the hull. A cover 26 extends
above an upper end of the air duct 24 to inhibit an influx of water
into the hull.
[0025] The control mast 20 extends upward from the bow portion 18
and supports a handlebar assembly 28. The handlebar 28 controls the
steering of the watercraft 10 in a conventional manner. The
handlebar assembly 28 also carries a variety of controls of the
watercraft 10, such as, for example, a throttle control, a start
switch and a lanyard switch.
[0026] The rider's area 22 lies behind the control mast 20 and
includes a seat assembly 30. In the illustrated embodiment, the
seat assembly 30 has a longitudinally extending straddle-type shape
which may be straddled by an operator and by at least one or two
passengers. The seat assembly 30, at least in principal part, is
formed by a seat cushion 32 supported by a raised pedestal 34. The
raised pedestal 34 has an elongated shape and extends
longitudinally along the center of the watercraft 10. The seat
cushion 32 desirably is removably attached to a top surface 36 of
the pedestal 34 and covers the entire upper end of the pedestal for
rider and passenger comfort.
[0027] An access opening 38 is located on an upper surface 36 of
the pedestal 34. The access opening 38 opens into an engine
compartment formed within the hull. The seat cushion 32 normally
covers and seals closed the access opening 38. When the seat
cushion 32 is removed, the engine compartment is accessible through
the access opening 38.
[0028] The pedestal 34 also includes a rear air duct 40 located
behind the access opening 38. The air duct 40 communicates with the
atmosphere through a space s between the pedestal 34 and the
cushion 32 which is formed behind the access opening 38. Air passes
through the rear duct 40 in both directions, as schematically
illustrated in FIG. 1.
[0029] The upper deck section 16 of the hull 12 advantageously
includes a pair of raised gunnels (not shown) positioned on
opposite sides of the aft end of the upper deck assembly 16. The
raised gunnels define a pair of foot areas that extend generally
longitudinally and parallel to the sides of the pedestal 34. In
this position, the operator and any passengers sitting on the seat
assembly 30 can place their feet in the foot areas with the raised
gunnels shielding the feet and lower legs of the riders. A non-slip
(e.g., rubber) mat desirably covers the foot areas to provide
increased grip and traction for the operator and the
passengers.
[0030] The lower hull portion 14 principally defines the engine
compartment. Except for the air ducts 24, 40, the engine
compartment is normally substantially sealed so as to enclose an
engine and the fuel system of the watercraft 10 from the body of
water in which the watercraft is operated.
[0031] The lower hull 14 is designed such that the watercraft 10
planes or rides on a minimum surface area of the aft end of the
lower hull 14 in order to optimize the speed and handling of the
watercraft 10 when up on plane. For this purpose, the lower hull
section generally has a V-shaped configuration formed by a pair of
inclined section that extend outwardly from the keel line to outer
chines at a dead rise angle. The inclined sections extend
longitudinally from the bow toward the transom of the lower hull 14
and is seen in FIG. 4, extend outwardly to side walls of the lower
hull. The side walls are generally flat and straight near the stem
of the lower hull and smoothly blend towards the longitudinal
center of the watercraft at the bow. The lines of intersection
between the inclined section and the corresponding side wall form
the outer chines of the lower hull section.
[0032] Toward the transom of the watercraft, the incline sections
of the lower hull extend outwardly from a recessed channel or
tunnel 42 that extends upward toward the upper deck portion 16. The
tunnel 42 has a generally parallelepiped shape and opens through
the rear of the transom of the watercraft 10, as seen in FIG.
1.
[0033] In the illustrated embodiment, a jet pump unit 44 propels
the watercraft. The jet pump unit 44 is mounted within the tunnel
42 formed on the underside of the lower hull section 16 by a
plurality of bolt 46. An intake duct 48 of the jet pump unit 44
defines an inlet opening 50 that opens into a gullet 52. The gullet
52 leads to an impeller housing 54 in which the impeller of the jet
pump 44 operates. An impeller duct assembly 56, which acts as a
pressurization chamber, delivers the water flow from the impeller
housing to a discharge nozzle housing 58.
[0034] A steering nozzle 60 is supported at the downstream end of
the discharge nozzle 58 by a pair of vertically extending pivot
pins. In an exemplary embodiment, the steering nozzle 60 has an
integral lever on one side that is coupled to the handlebar
assembly 28 through, for example, a bowden-wire actuator, as known
in the art. In this manner, the operator of the watercraft can move
the steering nozzle 58 to effect directional changes of the
watercraft 10.
[0035] A ride plate 62 covers a portion of the tunnel 42 behind the
inlet opening 50 to enclose the pump chambers 54, 56 and the nozzle
assembly 58 within the tunnel 42. In this manner, the lower opening
of the tunnel 42 is closed to provide a planing surface for the
watercraft.
[0036] An impeller shaft 64 supports the impeller within the
impeller housing 54. The aft end of the impeller shaft 64 is
suitable supported and journalled within the compression chamber 56
in a known manner. The impeller shaft 64 extends in the forward
direction through a front wall of the tunnel 42. A protective
casing surrounds a portion the impeller shaft 64 that lies forward
of the intake gullet 52. In the illustrated embodiment, the
protective casing has a tubular shape and is integrally formed with
the intake duct 48.
[0037] An internal combustion engine 66 of the watercraft powers
the impeller shaft 64 to drive the impeller of the jet pump unit
44. The engine 66 is positioned within the engine compartment and
is mounted primarily beneath the control mast 20.
Vibration-absorbing engine mounts 68 secure the engine 66 to the
lower hull portion 14 in a known manner. The engine 66 is mounted
in approximately a central position in the watercraft 10.
[0038] In the illustrated embodiment, the engine 66 includes two
in-line cylinders 67 and operates on a two-stroke, crankcase
compression principle. The engine 66 is positioned such that the
row of cylinders lies parallel to a longitudinal axis of the
watercraft 10, running from bow to stern. This engine type,
however, is merely exemplary. Those skilled in the art will readily
appreciate that the present fuel delivery system can be used with
any of a variety of engine types having other number of cylinders,
having other cylinder arrangements and operating on other
combustion principles (e.g., four-stroke principle).
[0039] As best seen in FIG. 2, a cylinder block 70 and a cylinder
head assembly 72 desirably form the cylinders of the engine. A
piston 74 reciprocates within each cylinder of the engine 66 and
together the pistons 74 drive an output shaft 76, such as a
crankshaft, in a known manner. A connecting rod 78 links the
corresponding piston 74 to the crankshaft 76. The corresponding
cylinder bore, piston and cylinder head of each cylinder forms a
variable-volume chamber, which at a minimum volume defines a
combustion chamber.
[0040] The crankshaft 76 desirably is journalled with a crankcase,
which in the illustrated embodiment is formed between a crankcase
member 80 and a lower end of the cylinder block 70. Individual
crankcase chambers 82 of the engine are formed within the crankcase
by dividing walls and sealing disks, and are sealed from one
another with each crankcase chamber communicating with a dedicated
variable-volume chamber. Each crankcase chamber 82 also
communicates with a charge former of an induction system 84 (which
is described below in detail) through a check valve (e.g., a
reed-type valve). Because the internal details of the engine 66
desirably are conventional, a further description of the engine
construction is not believed necessary to understand and practice
the invention.
[0041] The output shaft 76 carries a flywheel assembly 86 on a
front end of the shaft at a position forward of the row of
cylinders. The flywheel assembly 86 includes a flywheel magneto
which forms part of a spark timing circuit, as described below. A
cover 88 is attached to the front end of the cylinder block 70 and
cylinder head 72 to enclose the flywheel assembly 86.
[0042] As seen in FIG. 1, a coupling 90 interconnects the engine
crankshaft 76 to the impeller shaft 64. A bearing assembly 92,
which is secured to the bulkhead, supports the impeller shaft 64
behind the shaft coupling 90.
[0043] As seen in FIG. 1, the output shaft 76 drives a generator 94
(e.g., an alternator) to produce electricity for the watercraft 10.
For this purpose, the output shaft 76 carries a drive pulley 96 at
a position between the coupling 90 and a rear surface of the engine
66. Alternatively, an intermediate shaft can connect the output
shaft to the coupling and carry the drive pulley. The generator 94
is mounted to the cylinder head 72 and includes a pulley coupled to
an input shaft of the generator 94. In the illustrated embodiment,
the axes of the generator input shaft 76 and the engine output
shaft lie in parallel, and the generator pulley lies within the
same transverse plane as the drive pulley 76, and desirably lies
directly above the drive pulley 76. A belt 98 interconnects
together the drive pulley 96 and the generator pulley such that the
drive pulley 96 drives the generator pulley, i.e., the pulleys
rotate together.
[0044] With reference to FIGS. 1-3, an exhaust system is provided
to discharge exhaust byproducts from the engine 66 to the
atmosphere and/or to the body of water in which the watercraft 10
is operated. The exhaust system includes an exhaust manifold 100
that is affixed to the side of the cylinder block 70 and which
receives exhaust gases from the variable-volume chambers through
exhaust ports in a well-known manner.
[0045] An outlet end of the exhaust manifold 100 communicates with
a C-shaped pipe section. This C-pipe includes an inner tube that
communicates directly with the discharge end of the exhaust
manifold 100. An outer tube surrounds the inner tube to form a
coolant jacket between the inner and outer tubes. Although not
illustrated, the C-pipe includes an inlet port positioned near its
inlet end. The inlet port communicates with a water jacket of the
engine 66.
[0046] The outlet end of the C-pipe communicates with an expansion
chamber 102. In the illustrated embodiment, the expansion chamber
102 has a tubular shape in which an expansion volume 104 is defined
within an annular, thick wall. Coolant jacket passages extend
through the expansion chamber wall and communicate with the coolant
jacket of the C-pipe.
[0047] A flexible coupling connects the outlet end of the C-pipe to
the inlet end of the expansion chamber 102. The flexible coupling
also can includes an outlet port which communicates with an
internal coolant passage within the flexible coupling. The coolant
passage places the coolant jacket and the coolant passages in
communication.
[0048] The outlet end of the expansion chamber 102 is fixed to
reducer pipe which tapers in diameter toward its outlet. The pipe
has a dual shell construction formed by an inner shell which
defines an exhaust flow passage. The expansion volume 104
communicates with this passage.
[0049] An outer shell is connected to the inner shell and defines a
cooling jacket about the inner shell. The coolant jacket passages
of the expansion chamber communicate with the coolant jacket of the
pipe to discharge a portion of the coolant with the exhaust
gases.
[0050] A catalyzer 106 can be disposed within the space defined at
the mating ends of the expansion chamber and the reducer pipe. For
instance, the catalyzer 106 can include an annular shell supporting
a honeycomb-type catalyst bed. The catalyst bed is formed of a
suitable catalytic material such as that designed to treat and
render harmless hydrocarbons, carbon monoxide, and oxides of
nitrogen. An annular flange supports the annular shell generally at
the center of the flow path through the expansion chamber volume.
In this manner, all exhaust gas flow through the expansion chamber
102 passes through the catalyst bed. The annular flange can be held
between outlet end of the expansion chamber and the inlet end of
the reducer pipe.
[0051] The lower section of the reducer pipe includes a downwardly
turned portion that terminates at the discharge end. The inner
shell stops short of the outer shell such that the water flow
through the water jacket merges with the exhaust gas flow through
the exhaust passage at the discharge end.
[0052] A flexible pipe 108 is connected to the discharge end of the
reducer pipe and extends rearward along one side of the watercraft
hull tunnel 42. The flexible conduit 108 connects to an inlet
section of a water trap device 110. The water trap device 110 also
lies within the watercraft hull 12 on the same side of the tunnel
42.
[0053] The water trap device 110 has a sufficient volume to retain
water and to preclude the back flow of water to the expansion
chamber 102 and the engine 66. Internal baffles within the water
trap device 110 help control water flow through the exhaust
system.
[0054] An exhaust pipe 112 extends from an outlet section of the
water trap device 110 and wraps over the top of the tunnel 42 to a
discharge end 114. The discharge end 114 desirably opens into the
tunnel 42 at an area that is close to or actually below the water
level with the watercraft 10 floating at rest on the body of
water.
[0055] As seen in FIG. 2, the induction system 84 is located on a
side of the engine 66 opposite of the exhaust system and supplies a
fuel/air charge the variable-volume chambers. In the illustrated
embodiment, the induction system 84 includes an air intake silencer
116. The silencer 116 is located above the engine 66 and includes a
plenum chamber.
[0056] The plenum chamber of the silencer 116 communicates with a
plurality of throttle devices 118. The engine 66 desirably includes
a number of throttle devices 118 equal in number to the number of
cylinders. In the illustrated embodiment, the throttle devices 118
are throttle valves. A throttle shaft supports a butterfly-type
valve plate 120 within a throat 122 of the throttle valve 118.
[0057] Each throttle valve 118 communicates with an intake passage
124 of an intake manifold 126. The manifold 126 is attached to the
crankcase member 80 and/or cylinder block 70 to place each intake
passage 124 in communication with one of the crankcase chambers 82.
In the illustrated embodiment, the intake passage 124 desirably has
an arcuate shape with a portion of the passage 124 extending
generally transverse to a rotational axis of the crankshaft 76 and
to a longitudinal axis of the watercraft 10. As a result, the
throttle valve 118 and intake silencer 116 are distanced from the
cylinder block and cylinder head assemblies 70, 72.
[0058] A check valve (e.g., a reed valve) is disposed within each
intake passage 124 at the junction between the intake manifold 126
and the crankcase member 80. In the illustrated embodiment, a reed
valve assembly 128 includes a pair of reed valves 130 which open
upon upward movement to the piston 74 to permit an influx of a
fuel/air charge into the corresponding crankcase camber 82 and
close upon downward movement of the piston 74 to inhibit reverse
air flow from the chamber 82 into the intake manifold 126.
[0059] The engine 66 also desirably includes the same number of
charger formers as the number of cylinders. In the illustrated
embodiment, the charger formers are fuel injectors 132 which spray
fuel into the corresponding intake passage 124; however, the
present fuel delivery system can be used with other types of charge
formers and arrangements of the charge formers within the engine
(e.g., direct injection) as well.
[0060] The fuel delivery system supplies fuel to the fuel injectors
132. The fuel delivery system includes a main fuel tank 134 located
within the hull 12. In the illustrated embodiment, a plurality of
vibration-damping mounts 136 support the fuel tank 134 at a
position in front of the engine 66. Any of a variety of known
means, such as, for example, straps, can be used to secure the fuel
tank 134 to the lower hull portion 14 in this position.
[0061] A fuel filler hose 138 extends between a filler cap assembly
140 and the fuel tank 134. In the illustrated embodiment, the
filler cap assembly 140 is secured to the bow portion 18 of the
hull upper deck 16 to the side and in front of the control mast 20.
In this manner, the fuel tank 134 can be filled from outside the
hull 12 with the fuel passing through the fuel filler hose 138 into
the fuel tank 134.
[0062] As seen in FIGS. 1 and 2, a fuel supply line 142 links the
fuel tank 134 and a vapor separator assembly 144. A low pressure
fuel pump 146 is located within the fuel supply line 142 to produce
a flow of fuel into the vapor separator assembly 144. The low
pressure fuel pump 146 draws fuel through a stand pipe in the fuel
tank 134, through a portion of the fuel supply line 134 and through
a fuel filter 148 before the fuel is delivered to a fuel bowl 150
of the vapor separator assembly 144.
[0063] The low pressure fuel pump 146 can either be mechanically or
electrically driven. For instance, in the illustrated embodiment,
the low pressure fuel pump 146 is driven by an electric motor. The
pump, however, can be a diaphragm pump operated by the changing
pressure within one of the crankcase chambers.
[0064] The vapor separator assembly 144 includes a vapor separator
as well as a high-pressure pump 152 which is positioned within the
housing of the vapor separator assembly 144. The housing defines an
inner cavity 150 which forms the fuel bowl of the vapor separator.
The housing can have a sloped bottom surface to funnel the fuel
towards an influent port of the pump 152 which is generally
positioned at the bottom of the fuel bowl.
[0065] The housing defines an inlet port 154, a return port 156,
and a vapor discharge port 158. The vapor discharge port 158 is
positioned to the side of the inlet port 154 at a position
proximate to the upper end of the housing. A breather conduit 160
connects the vapor discharge port 158 to one or more of the intake
passages 124 of the induction system 84 as illustrated in FIG. 2.
In the illustrated embodiment, the breather passage 160 terminates
at a port 161 located near the reed valve assembly 128. The port
161 desirably lies at a level below the vapor discharge port 158-in
order to inhibit an ingress of water into the fuel system through
the breather passage 160.
[0066] A check-type valve 162 desirably is placed within the
breather conduit 160 to permit fuel flow through the line 160 only
in the direct from the vapor separator 144 to the intake passage
124. In this manner, the valve 162 prevents any water which might
enter the induction system 84--for instance when the watercraft 10
is capsized--from entering the fuel supply system through the
breather conduit 160.
[0067] The inlet port 154 connects to the fuel supply line 142 that
extends from the low pressure pump 146. A needle valve 164 operates
at a lower end of the intake port 154 to regulate the amount of
fuel within the fuel bowl 150. A float 166 within the fuel bowl
actuates the needle valve 164. The float 166 includes a buoyant
body 168 supported by a pivot arm 170. The pivot arm 170 is
pivotally attached to an inner flange within the housing by a pivot
shaft 172 and at a point proximate to the lower end of the housing
inlet port 154. The pivot arm also supports the needle valve 164 in
a position lying directly beneath a valve seat formed on the lower
end of the inlet port 154. Movement of the pivot arm 170 causes the
needle valve 164 to open and close the inlet port 154 by either
seating against or moving away from the valve seat, depending upon
the rotational direction of the pivot arm 170.
[0068] In the illustrated embodiment, the pivot shaft 172 extends
in a direction which is generally transverse to the longitudinal
axis as well as the direction of travel of the watercraft 10. This
orientation of the pivot shaft 172 generally isolates the function
of the float 166 from turning movements of the watercraft 10. That
is, the movement of the watercraft 10 when turning does not cause
the float 166 to rotate about the pivot shaft 172. The pivot shaft
172, in the alternative as illustrated in FIG. 4, can extend in a
direction generally parallel to the direction of travel in order to
isolate the float 166 from moments produced when the watercraft 10
accelerates or decelerates.
[0069] When the fuel bowl 150 contains a low level of fuel, the
float 166 lies in a lower position (as represented in FIG. 2). The
needle valve 164 is opened with the float 166 in this lowered
position and fuel flows from the low pressure pump 146, through the
delivery conduit 142 and into the fuel bowl 150 through the inlet
port 154. When the fuel bowl 150 contains a preselected amount of
fuel, the float 166 rises to a level where it causes the needle
valve 164 to seat against valve seat at the lower end of the inlet
port 154. The preselected amount of fuel desirably lies below the
inlet port 154, the return port 156 and the vapor discharge port
158.
[0070] In the illustrated embodiment, the high pressure pump 152 is
integrated into the vapor separator housing assembly 144. The high
pressure pump 152 draws fuel into its influent port through a fuel
strainer 174. The fuel strainer 174 lies generally at the bottom of
the fuel bowl 150.
[0071] The pump 152 includes an electric motor which drives an
impeller shaft of the pump 152. The impeller shaft supports an
impeller that rotates in a pump cavity. In an exemplary embodiment,
the pump is a centrifugal pump; however, other types of pumps, such
as a rotary vane pump, can be used as well.
[0072] The vapor separator assembly 144 can include a lid which is
removably attached to a base portion of the housing by a plurality
of conventional fasteners. A seal extends around the periphery of
the housing at the joint between the lid and the housing base.
[0073] With reference to FIG. 2, the high pressure side of the fuel
delivery system supplies fuel to the fuel injectors 132 of the
induction system 84. The high pressure pump 152 draws fuel from the
fuel bowl 150 of the vapor separator 144 and pushes the fuel
through a conduit 176 which is connected to a fuel rail or manifold
178. The pump 152 delivers fuel under high pressure through the
conduit 176 to the fuel rail 178. A check valve (not shown) is
disposed within the conduit 176 to prevent a back-flow of fuel from
the fuel rod 178.
[0074] The fuel rail 178 has an elongated shape. An inlet port of
the fuel rod 178 communicates with the conduit 176 which carries
fuel from the high pressure pump 152. The inlet port opens into a
manifold chamber which extends along the length of the fuel rod
178.
[0075] The fuel rail 178 delivers fuel to each fuel injector 132.
For this purpose, the manifold chamber of the fuel rod 178
communicates with the plurality of supply ports defined along the
length of the fuel rail 178. Each supply port receives an inlet end
of the corresponding fuel injector 132 and communicates with an
inlet port of the fuel injector 132 to supply the fuel injector 132
with fuel.
[0076] In the illustrated embodiment, the fuel rail 178 lies
generally parallel to the direction of travel of the watercraft 10,
and also to the longitudinal axis of the watercraft 10 and the
rotational axis of the crankshaft 76. Fuel desirably flows through
the fuel rail 178 in a direction from bow to stem in order to
utilize the momentum of the fuel toward the watercraft's stem to
increase the pressure within the fuel rail 178. As a result, a
smaller size high pressure pump 152 can be used. The fuel can flow
in the opposite direction, i.e., stem to bow, but this would
require a larger size pump.
[0077] A fuel return line 180 extends between an outlet port of the
fuel rail 178 and the fuel bowl 152 of the vapor separator 144. The
return line 180 completes the flow loop defined by the high
pressure side of the fuel supply system to generally maintain a
constant flow of fluid through the fuel rail 178. The constant fuel
flow through the high pressure side of the fuel delivery system
inhibits heat transfer to the fuel and thus reduces fuel
vaporization in the fuel rail 178.
[0078] A pressure regulator 182 is positioned within the return
line 180. The pressure regulator 182 generally maintains a desired
fuel pressure at the injectors (e.g., 50-100 atm). The regulator
182 regulates pressure by dumping excess fuel back to the vapor
separator 144, as known in the art.
[0079] A control system manages the operation of the engine 66. The
control system includes an electronic control unit (ECU) 184 that
receives signals from various sensors regarding a variety of engine
functions. As schematically illustrated in FIG. 2, a crankcase
position sensor 186 senses the angular position of the crankshaft
76 and also the speed of its rotation. The sensor 186 produces a
signal(s) which is indicative of angular orientation and speed.
Another sensor 188 determines the throttle orientation to determine
the opening degree of the throttle valves 118. The sensor 188
produces a signal indicative of the throttle valve position.
[0080] The ECU 184 receives these signals from the sensors 186, 188
to control injection timing and duration, as well as spark timing.
For this purpose, the ECU 184 communicates with each fuel injector
132, and specifically the solenoid 190 used with each fuel injector
132. The ECU 184 controls the operation of the solenoid 190 in
order to manage fuel injection timing and duration, the latter
affecting the fuel/air ratio of the produced charge. The desired
stoichiometric fuel/air ratio will depend upon the amount of air
flow into the engine 66, which is a function of the opening degree
of the throttle valve 120. This information is stored within a
memory device with which the ECU 184 communicates. The ECU 184 thus
processes the information signal received from the throttle valve
sensor 188 and determines the amount of fuel to be injected for the
sensed operating condition of the engine. The ECU 184 also uses the
information from the crankshaft sensor 186 to determine the point
during the engine's revolution to initiate fuel injection.
[0081] In addition to controlling fuel injection, the ECU 184 also
control ignition timing. For this purpose the ECU controls a
capacitor discharge ignition unit 192, and the firing of the spark
plugs 194. The generator 94 powers one or more charging coil
(schematically illustrated as part of the capacitor discharge
ignition unit) which increases the voltage of the charge eventually
delivered to the spark plugs 194. The generator 94 also charges one
or more batteries 196, as known in the art.
[0082] The capacitor discharge unit 192 desirably controls the
discharge of one ignition coil for each spark plug 196. The
capacitor discharge ignition unit 192 receives a signal from the
ECU 184 which manages the discharge timing.
[0083] The arrangement of the components of the engine 66, engine
control system, fuel supply system and exhaust system are
illustrated in FIGS. 1, 3 and 4. The vapor separator 144 desirably
lies between the front end of the engine 66 and the main fuel tank
134, in a space above the flywheel magneto 86. The vapor separator
144 thus lies in an air flow stream between the air ducts 24, 40,
and near the air flow into the induction system 84. The air flow
over the vapor separator 144 cools the fuel.
[0084] The fuel pump 152 also lies in a similar position within the
engine compartment, and thus is cooled by these air flow streams.
The fuel within the fuel bowl 152 of the vapor separator 144 also
dissipates heat from the high pressure fuel pump 152. As a result,
the fuel pump 152 runs cooler and the durability and life-span of
the pump 152 tends to increase.
[0085] In the illustrated embodiment, the air ducts 24, 40 are
positioned to lie on a longitudinal center line L of the watercraft
hull 10. The output shaft 76 of the engine 66, as well as the row
of cylinders also lie on the longitudinal center line L for
watercraft balance.
[0086] As seen in FIG. 3, the position of the front air duct 24 can
lie either forward or reward of the main fuel tank 134. For
ventilation purposes, however, the air duct 24 desirably lies in
front of the fuel tank 134.
[0087] FIG. 3 also schematically illustrates that the vapor
separator 144 can be positioned at alternative locations within the
engine compartment. The vapor separator 144 can be mounted to the
side wall of the watercraft hull 12. In the two alternative
exemplary locations illustrated in FIG. 3, the vapor separator 144
lies either forward of the front end of the engine 66 or behind the
rear end of the engine 66. In either of these locations, dampers
desirably lie between the hull wall and the vapor separator
assembly 144. The vapor separator 144 in either of these positions
also lies on a side of the longitudinal center line opposite of the
water trap device 110.
[0088] As seen in FIGS. 1 and 3, the battery 196 and the ECU 184
desirably lie beneath the access opening 38 for easy access by a
technician. In this location, the battery 196 also lies within the
air stream between the air ducts 24, 40 for ventilation
purposes.
[0089] FIGS. 5 through 7 illustrate another embodiment of the fuel
delivery system which is similar to the embodiment described above,
except for the elimination of the vapor separator. For this reason,
like reference numerals with an "a" suffix have been used to
indicate like parts between the two embodiments.
[0090] The fuel delivery system includes a high pressure pump 152a.
An input shaft of the pump desirably is driven by the output shaft
76a of the engine 66a. In the illustrated embodiment, the input
shaft of the fuel pump 152a is connected to a front end of the
crankshaft 76a which protrudes forward of the flywheel magneto 86a.
The speed of the pump 152a thus corresponds to engine speed. A gear
train also can be used between the output shaft 76a and the pump
input shaft to produce a speed differential between the pump 152a
and the output shaft 76a.
[0091] The high pressure pump 152a draws fuel through a fuel supply
line 142a directly from the fuel tank 134a. The fuel flows through
a fuel filter 148a before entering the high pressure pump 152a.
From the pump 152a, the fuel flows through a fuel rail 178a
connected to the fuel injectors 132a. A pressure regulator 182a
establishes the pressure within the fuel rail 178a. In the
illustrated embodiment, the pressure regulator 182a lies at the end
of the fuel rail 178a, behind the rear end of the engine 66a. A
return line 180a connects the pressure regulator 182a to the fuel
tank 134a. The pressure regulator 182a thus dumps excess fuel into
the fuel tank 134a through the return line 180a to maintain a
desired fuel pressure. The pressure produced by the pump 152a,
however, advantageously is higher than the desired fuel pressure at
the injectors 132a so as to produce a flow of fuel through the fuel
rail 178a to minimize the degree of heat exposure experienced by
the fuel within the rail 178a.
[0092] The input shaft of the pump 152a also drives an oil pump 200
connected to an oil tank (not shown) by an oil supply line. The oil
pump 200 delivers oil through an oil delivery line 202 to the
induction system 84a for entrainment with the air flow
therethrough. In the illustrated embodiment, the oil delivery line
202 communicates with a port 204 that communicates with the throat
passage 122a of the throttle device 118a. The port 204 desirably
lies upstream of the throttle valve 120a so as to lubricate the
valve 120a.
[0093] FIGS. 5 and 7 illustrate the arrangement of the fuel
delivery system within the watercraft hull 12a. The high pressure
fuel pump 152a is located forward of the front end of the engine
66a, and desirably between the engine 66a and the fuel tank 134a.
Both the fuel tank 134a and the pump 152a lie within an air stream
between a pair of air ducts 24a, 40a that communicate with the
engine compartment formed within the hull 12a. The air ducts 24a,
40a, as well as the fuel and oil pumps 152a, 200 and the fuel tank
134a desirably lie near a longitudinal center line of the hull 12a.
The position of these components within the air flow stream between
the ducts 24a, 40a cools the fuel and the pumps within the confined
engine compartment. As a result, the consistency of the air/fuel
ratio of the produced fuel charge increases and the durability of
the pumps is improved.
[0094] Although this invention has been described in terms of
certain preferred embodiments, other embodiments apparent to those
of ordinary skill in the art are also within the scope of this
invention. Accordingly, the scope of the invention is intended to
be defined only by the claims that follow.
* * * * *