U.S. patent application number 09/734954 was filed with the patent office on 2001-06-21 for air induction system for small watercraft.
Invention is credited to Ishino, Tetsuya.
Application Number | 20010004570 09/734954 |
Document ID | / |
Family ID | 18405406 |
Filed Date | 2001-06-21 |
United States Patent
Application |
20010004570 |
Kind Code |
A1 |
Ishino, Tetsuya |
June 21, 2001 |
Air induction system for small watercraft
Abstract
An induction system for a watercraft is configured to guide air
into an engine disposed within the watercraft for combustion
therein. The induction system includes an inlet assembly. The inlet
assembly includes various constructions for enhancing water
preclusive effects.
Inventors: |
Ishino, Tetsuya; (Hamamatsu,
JP) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
620 NEWPORT CENTER DRIVE
SIXTEENTH FLOOR
NEWPORT BEACH
CA
92660
US
|
Family ID: |
18405406 |
Appl. No.: |
09/734954 |
Filed: |
December 11, 2000 |
Current U.S.
Class: |
440/89F ;
440/88A; 440/88F; 440/88M; 440/88N |
Current CPC
Class: |
F02M 35/168 20130101;
B63B 34/10 20200201; B63J 2/06 20130101; F02M 35/167 20130101; B63H
21/24 20130101 |
Class at
Publication: |
440/88 |
International
Class: |
B63H 021/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 9, 1999 |
JP |
11-349683 |
Claims
What is claimed is:
1. A watercraft comprising a hull having a lower portion and upper
deck portion, an engine compartment within the hull, an engine
disposed within the engine compartment, the engine including at
least one combustion chamber therein, a body disposed within the
engine compartment and occupying a substantial volume of space
within the engine compartment, an induction system configured to
guide air into the combustion chamber for combustion therein, the
induction system including an inlet disposed over the body.
2. The watercraft according to claim 1, wherein the inlet is
disposed directly over the body.
3. The watercraft according to claim 1, wherein the body is a fuel
tank.
4. The watercraft according to claim 1, wherein the body is
disposed forward from the engine.
5. The watercraft according to claim 1, wherein the inlet is
disposed remotely from the engine.
6. The watercraft according to claim 1 additionally comprising a
ventilation conduit having a first end communicating with
atmospheric air surrounding an outside of the hull and a second end
disposed within the hull, the inlet and the second end being
disposed on a same side of the engine.
7. The watercraft according to claim 1, wherein the inlet is
supported within the hull independently from the engine.
8. The watercraft according to claim 1, wherein the inlet is
supported by the body.
9. The watercraft according to claim 8 additionally comprising a
plenum chamber defining a portion of the induction system
downstream from the inlet and a flexible conduit connecting the
inlet with the plenum chamber.
10. A watercraft comprising a hull having a lower portion and upper
deck portion, an engine compartment defined within the hull, an
engine disposed within the engine compartment, the engine including
at least one combustion chamber therein, an induction system
configured to guide air into the combustion chamber for combustion
therein, the induction system including an inlet opening into the
engine compartment, and a splash guard positioned adjacent the
inlet and configured to prevent water within the engine compartment
from splashing into the inlet.
11. The watercraft according to claim 10 additionally comprising a
fuel tank, the inlet being disposed above the fuel tank.
12. The watercraft according to claim 11 wherein the splash guard
extends between the engine and the fuel tank.
13. The watercraft according to claim 12, wherein the splash guard
extends from a surface of the engine body toward the fuel tank.
14. The watercraft according to claim 10 additionally comprising a
body occupying a substantial volume of space, the body being
disposed in the engine compartment and spaced from the engine, the
body including at least one surface, wherein the splash guard
comprises a first edge extending outwardly from the inlet, the
first edge and the surface of the body being substantially aligned
along a vertical plane.
15. The watercraft according to claim 10 additionally comprising a
body disposed within the engine compartment, wherein an outer edge
of the splash guard extends over the body.
16. The watercraft according to claim 15, wherein the body occupies
a substantial volume of space within the engine compartment.
17. The watercraft according to claim 16, wherein the body is a
fuel tank.
18. A watercraft comprising a hull having a lower portion and upper
deck portion, an engine compartment defined within the hull, an
engine disposed within the engine compartment, the engine including
at least one combustion chamber and an intake port, an induction
system configured to guide air into intake port for combustion in
the combustion chamber, the induction system including a vapor
separator disposed within the hull so as not to be directly above
the engine
19. The watercraft according to claim 18 additionally comprising a
plenum chamber communicating with the intake port, and a conduit
connecting the vapor separator with the plenum chamber.
20. The watercraft according to claim 18, wherein the vapor
separator is disposed remotely from the engine.
21. The watercraft according to claim 18 additionally comprising a
forward facing inlet for guiding atmospheric air into the vapor
separator.
22. The watercraft according to claim 18 additionally comprising a
fuel tank, at least a portion of the vapor separator being disposed
forward from the fuel tank.
23. The watercraft according to claim 18, wherein the vapor
separator comprises a water filter.
24. The watercraft according to claim 23 additionally comprising a
drainage chamber disposed beneath the water filter for collecting
water filtered from air in the vapor separator.
25. The watercraft according to claim 24 additionally comprising a
drain disposed in the drainage chamber.
Description
[0001] This application is based on and claims priority to Japanese
Patent Application No. 11-349683, filed Dec. 9, 1999, the entire
contents of which is hereby expressly incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The present invention is directed to a watercraft, and more
particularly to a water preclusion and sound attenuation system
employed in an induction system for a watercraft engine.
[0004] Description of Related Art
[0005] Personal watercraft have become increasingly popular in
recent years. This type of watercraft is sporting in nature; it
turns swiftly, it is easily maneuverable, and accelerates quickly.
A personal watercraft today commonly carries one rider and up to
three passengers. Typically, the rider and passengers sit on a
straddle-type seat that is formed by the hull of the watercraft.
The straddle-type seat is generally aligned with the longitudinal
axis of the hull. The space beneath the straddle-type seat is
usually used as an engine compartment for supporting the engine
within the watercraft. The engine is preferably arranged within the
engine compartment so that the crankshaft of the engine is aligned
with the longitudinal axis of the watercraft. With the engine
arranged as such, the crankshaft of the engine may be directly
connected to an output shaft for driving a propulsion unit.
Additionally, such an arrangement allows the engine to be arranged
within the seat pedestal. Arranged as such, the engine and seat
pedestal form a compact unit. During operation, the engine and any
passengers straddle the seat as well as the engine while they are
seated on the straddle-type seat. With the hull shaped as such, the
engine is in close spacing with the passengers during operation,
thus allowing the overall size of the watercraft to remain quite
small, resulting in a compact and highly maneuverable
watercraft.
[0006] One problem caused by the speed and maneuverability of these
watercraft is that waterspray generated by the contact of the hull
with the body of water in which the watercraft is operating causes
water to spray upwardly onto the upper deck portion of the
watercraft. Such waterspray increases the flow of water into the
ventilation openings usually disposed on the upper deck of these
watercraft. Such a flow of water into the ventilation openings can
cause several problems. For example, a significant flow of water
droplets into the ventilation openings can accumulate and
eventually puddle in the bottom of the engine compartment within
the watercraft. As the watercraft maneuvers, such puddled water
sloshes within the engine compartment and may enter various
components of the engine, such as, but without limitation, the
induction system. Additionally, water which sloshes and comes into
contact with hot engine components, can vaporize and flow into the
induction system and the combustion chambers within the engine.
Thus, it is desirable to construct an induction system which
reduces the amount of water vapors introduced into the combustion
chambers of the engine.
[0007] Another difficulty faced by owners of personal watercraft is
that, at least partially in response to the noise generated by
personal watercraft, certain recreational facilities have banned
the operation of most personal watercraft.
SUMMARY OF THE INVENTION
[0008] According to one aspect of the present invention, a
watercraft comprises a hull having a lower portion and an upper
deck portion, an engine disposed within the hull which includes at
least one combustion chamber and a body occupying a substantial
volume of space within the engine compartment and is spaced from
the engine. The watercraft also includes an induction system
configured to guide air into the combustion chamber of the engine
for combustion therein. The inlet to the induction system opens
into the engine compartment and is disposed over the body.
[0009] By arranging the inlet to the induction system over the
body, the watercraft according to the present invention reduces the
likelihood that water present within the engine compartment can
splash into the inlet of the induction system. Thus, the likelihood
that the engine is damaged from water within the engine compartment
is also reduced.
[0010] According to another aspect of the present invention, a
watercraft includes a hull having a lower portion and an upper deck
portion and an engine compartment defined within the hull. An
engine is disposed within the engine compartment and includes at
least one combustion chamber therein. The watercraft also includes
an induction system configured to guide air into the combustion
chamber for combustion therein. The induction system includes an
inlet opening into the engine compartment. A splash guard is
positioned adjacent the inlet and configured to prevent water
within the engine compartment from splashing into the inlet.
Preferably, the splash guard extends beneath the inlet so as to
reduce the amount of water from the lower surface of the engine
compartment that may splash into the inlet.
[0011] According to yet another aspect of the present invention, a
watercraft includes a hull having a lower portion and an upper deck
portion and an engine compartment defined within the hull. An
engine is disposed within the engine compartment and includes at
least one combustion chamber having an intake port. An induction
system is configured to guide air into the combustion chamber for
combustion therein and includes a vapor separator disposed within
the hull so as to be not directly above the engine.
[0012] Another aspect of the present invention includes the
realization that performance of a vapor separator within the engine
compartment of a watercraft can be improved if the vapor separator
is not positioned directly above the engine. For example, as a
vapor separator operates, to reduce an amount of water vapor within
an air supply, heat added or conducted into the vapor separator
raises the vapor pressure of the water therein, thus reducing the
effectiveness of the vapor separator to remove water from an
airflow passing therethrough. Heat from the engine can be conducted
into the vapor separator by radiation and/or convection. Thus, by
positioning the vapor separator so as not to be directly over the
engine, heat conducted into the vapor separator from the engine is
thereby attenuated, thus improving the performance of the vapor
separator. Thus, more water vapor is separated from air entering
the induction system thereby further protecting the engine and
improving combustion conditions within the combustion chamber.
[0013] Further aspects, features, and advantages of the present
invention will become apparent from the detailed description of the
preferred embodiments which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above-mentioned and other features of the invention will
now be described with reference to the drawings of preferred
embodiments of the present watercraft. The illustrated embodiments
are intended to illustrate, but not to limit the invention. The
drawings contain the following figures:
[0015] FIG. 1 is a side elevational and partial cut-away view of a
watercraft in accordance with a preferred embodiment of the present
invention. The illustrated watercraft includes a lower portion and
an upper deck portion and several internal components of the
watercraft are shown in phantom line;
[0016] FIG. 2 is a top plan view of the watercraft illustrated in
FIG. 1 with the upper deck portion removed;
[0017] FIG. 3 is a side elevational view and partial cut-away view
of a modification of the watercraft illustrated in FIG. 1 and
illustrating an induction system inlet assembly;
[0018] FIG. 4 is a top plan view of the watercraft illustrated in
FIG. 3 with the upper deck portion removed;
[0019] FIG. 5 is an enlarged top plan view of the induction system
inlet assembly illustrated in FIGS. 3 and 4;
[0020] FIG. 6 is a side elevational view of the induction system
inlet assembly illustrated in FIG. 5;
[0021] FIG. 7 is a side elevational and partial cut-away view of a
watercraft constructed in accordance with a modification of the
embodiment illustrated in FIGS. 1-4;
[0022] FIG. 8 is a top plan view of the modification illustrated in
FIG. 7, with the upper deck portion removed;
[0023] FIG. 9 is an enlarged top plan view of a vapor separator
illustrated in FIG. 7;
[0024] FIG. 10 is a side elevational view of the vapor separator
illustrated in FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
INVENTION
[0025] FIGS. 1 and 2 illustrate different views of a small
watercraft incorporating an induction system configured in
accordance with a preferred embodiment of the present invention.
The induction system includes enhanced water preclusion
characteristics. Although the present induction system is
illustrated in connection with a personal watercraft, the
illustrated induction system can be used with any type of
watercraft as well, such as, for example, but without limitation,
small jet boats and the like.
[0026] FIGS. 1 and 2 illustrate a watercraft 10 having a hull 12
which is constructed of a top deck portion 14 and a lower portion
16 defining a bow 15 and a stem 17 of the watercraft 10. A gunnel
18 defines an intersection of the lower portion 16 and the deck 14
of the hull 12. The watercraft 10 is suited for movement through a
body of water in a direction F (towards the front end of the
watercraft).
[0027] A seat 20 is positioned on a seat pedestal (not shown) which
is formed by the deck 14. A steering handle 22 is provided adjacent
the seat 20 for use by a user in directing the watercraft 10.
Preferably, a bulwark (not shown) is defined by the gunnel 18 and
extends upwardly along each side of the watercraft 10. A foot step
area is preferably defined between the seat 20 and the bulwark on
each side of the watercraft 10.
[0028] The upper and lower portions 14, 16 define an interior
volume 24 within the hull 12. In the illustrated embodiment, a
bulkhead 26 divides the inner volume 24 into a forward compartment
28 and a rearward compartment 30. In the illustrated embodiment,
the forward compartment 28 defines an engine compartment.
[0029] An engine 32 is positioned in the engine compartment 28. The
engine 32 is connected to the lower portion 16 with several engine
mounts (not shown) which are shaped to be bolted to the lower
portion 16 of the hull or an insert (not shown) which is attached
to the lower hull portion 16.
[0030] The engine 32 is preferably at least partially accessible
through a maintenance opening (not shown) which itself is
accessible by removing the seat 20. The engine 32 includes a
crankshaft (not shown) which is located at least partially within a
crankcase 34, and which is connected to a flywheel (not shown) in a
known manner. The engine 32 includes a flywheel cover 36 arranged
at a forward end of the crankcase 34 of the engine 32.
[0031] The engine 32 transfers rotational energy from the
rotational crankshaft to a propulsion unit 38 provided in the
rearward compartment 30. The propulsion unit 38 is provided in a
tunnel 40 formed in the lower portion 16 of the hull 12. Arranged
as such, the propulsion unit 38 induces a flow of water into an
inlet of the tunnel 40 and out through a rear outlet of the tunnel
40 to thereby propel the watercraft in a known manner.
[0032] The engine 32 preferably includes a plurality of cylinders
arranged along the longitudinal axis and operates on a four-stroke
principle. Of course, the engine 32 may have any number of
cylinders arranged in different cylinder orientations and may
operate in accordance with other combustion principles (e.g.,
two-cycle, diesel, and rotary principles). The engine 32 includes a
cylinder head mounted to a cylinder block and cooperates therewith
to define a plurality of cylinders. A piston (not shown) is movably
mounted in each cylinder and is connected to the crankshaft via a
connecting rod, in a well known manner. The piston cooperates with
the cylinder head and the cylinder block so as to define a
combustion chamber portion corresponding to each cylinder.
[0033] The engine 32 includes at least one intake port for each
combustion chamber defined therein. In the illustrated embodiment,
the intake ports are defined in the cylinder head, the flow
therethrough being controlled by an intake valve and an intake
valve drive train (not shown).
[0034] In order to process exhaust gases discharged from the engine
32, the watercraft 10 includes an exhaust system 42. As shown in
FIG. 2, the exhaust system 42 includes an exhaust manifold 44 which
is connected to a plurality of exhaust ports defined in the
cylinder head of the engine 32. An outlet of the exhaust manifold
44 communicates with an exhaust pipe 46 extending rearwardly,
through the bulkhead 26, and to an inlet of a watertrap device 48.
A discharge exhaust pipe 50 extends from an outlet of the water
trap device 46 to an exhaust discharge port 52 disposed on a side
of the hull tunnel 40.
[0035] The watercraft 10 also includes a fuel delivery system 54.
The fuel delivery system 54 includes a fuel tank 56 and at least
one charge former (not shown). Fuel from the fuel tank 56 is
supplied to the charge formers via at least one fuel delivery line
(not shown). The configuration of the fuel delivery system 54 is
constructed in accordance with the type of fuel chargers provided
in the engine 32. For example, watercraft 10 can include a fuel
delivery system configured for delivering fuel to carburetors which
serve as charge formers for the engine 32 or fuel injectors
configured to perform direct or indirect fuel injection.
[0036] With reference to FIGS. 1 and 2, the watercraft 10 also
includes at least one ventilation air duct 58, which allows air
from the atmosphere surrounding the watercraft 10 to enter the
engine compartment 28. As shown in FIG. 1, the ventilation air duct
50 includes an inlet end 60 which is exposed to ambient air
surrounding the watercraft 10 and a second end 62 which opens into
the engine compartment 28. In the illustrated embodiment, the
outlet 62 of the duct 58 is arranged so as to be positioned below
an upper surface 64 of the fuel tank 56. A hatch assembly 66
extends over the first end 60 of the ventilation duct 58.
[0037] The watercraft 10 also includes an induction system 68 which
is configured to guide air into the combustion chambers defined
within the engine 32. The induction system 68 includes an inlet
assembly 70 and a first plenum chamber 72. In the illustrated
embodiment, the inlet assembly 70 includes a trumpet-shaped inlet
74 disposed over the upper surface 64 of the fuel tank 56.
[0038] As shown in FIG. 2, the inlet assembly 70 is supported on
the upper surface 54 of the fuel tank by a bracket assembly 76. The
inlet assembly 70 is connected to a flexible coupling 78 which, in
turn, is connected to a second intake pipe 80. The intake pipe 80
extends into an interior of the plenum chamber 72.
[0039] The plenum chamber 72 can be constructed in any known
manner. Preferably, the plenum chamber 72 is connected to at least
one throttle body which is configured to control an air flow from
an interior of the plenum chamber 72 into the combustion chambers
within the engine 32. Where carburetors are used as the charge
formers for the engine 32, the throttle valves can be incorporated
into the carburetors.
[0040] By arranging the inlet 74 of the inlet assembly 70 over the
fuel tank 56, the induction system 68 of the present invention
allows the induction system to draw air from a position within the
engine compartment 28 which is distal from the engine 32. Thus, the
air entering the inlet 74 is not likely to have been heated
significantly by the engine 32.
[0041] Additionally, by connecting the first inlet pipe 75 to the
second inlet pipe 80 with a flexible connector 78, installation of
the inlet assembly 70 is made easier. For example, during the
assembly of the watercraft 10, the engine 32 and the fuel tank 56
are installed into the engine compartment 28 separately from each
other. Thus, when the first inlet pipe 75 is connected to the
second inlet pipe, the alignment of the first inlet pipe 75 and the
second inlet pipe 80 can be adjusted by the flexation of the
flexible connector 78 thus allowing compensation for alignment
differences between the bracket 76 and the second inlet pipe
80.
[0042] With reference to FIG. 1, the induction system 68 preferably
also includes a second inlet assembly 82. As shown in FIG. 1, the
second inlet assembly 82 includes a third inlet pipe 84 defining an
inlet 86 at a first end of the third intake pipe 84 and second end
88 opening into the interior of the plenum chamber 72. The inlet 86
opens into the rearward compartment 30.
[0043] In order to guide air into and out of the rearward
compartment 30, a second ventilation duct 90 extends into the
rearward compartment 30. The ventilation duct 90 includes an upper
end 92 communicating with the ambient air surrounding the
watercraft 10. A second end 94 of the ventilation duct 90 opens
into the rearward compartment 30. Thus, air from the outside of the
watercraft can enter the rearward compartment 30 via the
ventilation duct 90. Subsequently, air from the compartment 30 can
enter the inlet 86 and provide additional air to the interior of
the plenum chamber 72.
[0044] With reference to FIGS. 2-6, modification of the inlet
assembly 70 is shown therein. The other components of the
watercraft 10, however, are constructed in accordance with the
description of FIGS. 1 and 2. Thus, similar features are ascribed
the same reference numerals used for corresponding elements from
FIGS. 1 and 2 for ease of description.
[0045] With reference to FIGS. 3 and 4, the inlet assembly 70'
includes a first intake pipe 100 extending from an interior of the
plenum chamber 72. In the illustrated embodiment, the intake pipe
100 includes a trumpet-shaped inlet 102 facing forwardly and
opening into the interior of the engine compartment 28. The inlet
assembly 70' also includes a splash guard 104. The splash guard 104
extends from a surface 106 of the plenum chamber 72 adjacent to the
inlet 102. Preferably, the splash guard 104 is bowl-shaped.
[0046] As shown in FIG. 3, during the operation of the watercraft
10, a significant amount of water 108 can enter the hull 12 in a
number of ways. For example, during operation of the watercraft 10
in a body water, water can be sprayed into the air by the impact of
the hull 12 with the surface of the body of water in which the
watercraft 10 is operating. Such sprayed water can enter the intake
duct 58 through the inlet 60 and collect in the engine compartment
28. Additionally, the watercraft 10 may be capsized during
operation and water may flow directly through the ventilation duct
58 into the engine compartment 28. After capsizing or as a result
of water spray entering the engine compartment 28 through the
ventilation duct 50, water 108 collected in the engine compartment
28 can be violently splashed within the engine compartment 28 thus
causing large droplets 110 to splash upwardly toward the inlet 102.
Thus, the splash guard 104 is configured to prevent water from the
engine compartment from splashing into the inlet 102.
[0047] In the illustrated embodiment, engine 32 and the fuel tank
56 are spaced from each other. The splash guard 104 extends from
the surface 106 of the plenum chamber 72 to a position adjacent a
surface 112 of the fuel tank 56. In the illustrated embodiment, the
surface 106 of the plenum chamber 72 from which the intake pipe 100
extends is a forward surface of the plenum chamber and the surface
112 with the fuel tank 56 is a rear surface of the fuel tank. Thus,
the flash guard 104 can be sized or arranged to cooperate with the
surface 112 of the fuel tank 56 to provide a further shielding from
splashes of water 110 within the engine compartment 120. In the
illustrated embodiment, a forward edge 114 of the splash guard 104
and the rear surface 112 above the fuel tank 56 is substantially
aligned along the vertical plane. As such, the splash guard 104 and
the fuel tank 56, which occupies a substantial volume of space
within the engine compartment 28, cooperate to prevent splashing
water 110 from reaching the inlet 102. With reference to FIG. 3,
forward edge 114 can be arranged so as to at least partially
overlap the upper surface 64 of the fuel tank 56. As such, the
splash guard 104 will provide a further shielding of the inlet 102
from splashing water 110 within the engine compartment 28.
[0048] With reference to FIG. 5, the inlet assembly 70' preferably
includes at least one drain 116 formed in the splash guard 104. In
the illustrated embodiment, the splash guard 104 includes two
drains, one on each side of the longitudinal axis A of the intake
pipe 100. By including at least one drain 116 in the splash guard
104, water that does reach the upper side of the splash guard 104
is returned to the engine compartment 28, thereby reducing the
amount of water that may splash into the inlet 102.
[0049] With reference to FIG. 6, the splash guard 104 is preferably
fixed to the front surface 106 of the plenum chamber 72.
Additionally, the plenum chamber 72 is preferably formed with a
body member 118 and a removable cover 120. The removable cover 120
is locked to the body 118 with a slide lock mechanism 122.
[0050] With respect to FIGS. 7 and 8, a further modification to the
inlet assemblies 70, 70', identified as reference numeral 70", is
illustrated therein. The remaining features of the watercraft 10
illustrated in FIGS. 7 and 8 and constructed in accordance with the
above descriptions of FIGS. 1-6. Similar features thus are ascribed
the same reference numerals used for the corresponding elements
from FIGS. 1-6 for ease of description.
[0051] The inlet 70" includes a first intake pipe 124 which has a
forward facing inlet 126 and an outlet 128 disposed within the
engine compartment 128. The outlet communicates with a vapor
separator 130, a further detailed description of which is set forth
below with reference to FIGS. 9 and 10. The vapor separator 130 is
disposed such that it is not directly above the engine 32.
Preferably, the vapor separator 130 is disposed partially forward
from the fuel tank 56.
[0052] The inlet assembly 70" also includes a second intake pipe
132 having an inlet 134 communicating with the vapor separator 130
and an outlet 136 communicating with an interior of the vapor
separator 72. Preferably, at least a portion of the second intake
pipe 132 is inclined such that the inlet 134 is lower than the
outlet 136. In the illustrated embodiment, the second intake pipe
132 includes an inclined portion 135.
[0053] With reference to FIGS. 9 and 10, the vapor separator 130
includes an outer housing 138. The housing 138 includes an inlet
140 which cooperates with the outlet 128 of the first intake pipe
124. The housing 138 also includes an air outlet 142 which
cooperates with the inlet 134 of the second intake pipe 132. A
cylindrical water filter device 144 is disposed within the housing
138. The filter 144 is configured to allow air to pass therethrough
and to substantially prevent water and water vapor from passing
therethrough. Thus, the filter 144 cooperates with the housing to
define an air chamber 146 and a water collection chamber 148.
[0054] The water collection chamber 148 includes at least one drain
150 and preferably a plurality of drains 150, configured to allow
water collected therein to flow into the engine compartment 28
which can then be removed by any known bilge system.
[0055] During operation, air from the atmosphere surrounding
watercraft 10 enters the inlet 126 of the first intake pipe 124.
Such air, which is often times mixed with water and water vapor due
to the movement of the watercraft 10 along the surface of a body of
water, flows through the first intake pipe 124 and into the vapor
separator 130. The filter 144 allows air to pass radially
therethrough and thus into the air chamber 146. Additionally, the
filter 144 prevents at least some of the water and water vapor
contained in the air flow from passing therethrough and thus causes
the water and water vapor to pass downwardly into the water
collection chamber 148. Thus, the water content of the air entering
the air chamber 146 is reduced relative to the water content of the
air entering the inlet 126.
[0056] Air from the air chamber 146 then passes into the inlet 144
of the second intake pipe 132 and eventually into the plenum
chamber 172. Water that is collected in the water collection
chamber 148 is drained by at least one drain 150 and allowed to
pass into the engine compartment 28 which then can be drained from
the engine compartment 28 with a known bilge system.
[0057] With reference to FIGS. 7 and 8, the vapor separator 130 is
arranged within the hull 112 so as not to be directly over the
engine 132. Thus, the heat transferred from the engine 32 to the
vapor separator 130 is reduced. By reducing the heat transfer to
the vapor separator, the performance of the vapor separator can be
enhanced. For example, raising the temperature of air which has
some water content, also raises the vapor pressure of water within
such air. Thus, by reducing the transfer of heat into the vapor
separator 130, the effect of heat from the engine 32 on the
performance of the vapor separator 130 is attenuated.
[0058] Referring to FIG. 7, the second intake pipe 132 preferably
includes a subresonator chamber 152. The subresonator chamber 152
is branched from the second intake pipe 132 and communicates with
the second intake pipe 132 through a throat 154. The subresonator
chamber 152 is configured to attenuate noise generated in the
reduction system 68 of the watercraft 10. Preferably, the
subresonator chamber 152 is in the form of a Helmholtz resonator
which is turned to attenuate noise generated in the induction
system 68. As such, the subresonator chamber 152 provides
attenuation of noise generated by the induction system 68 thereby
quieting emitted from the watercraft 10 during operation.
[0059] As noted above, the inlet 134 is lower than the outlet 136.
Thus, if water passes through the filter 144 and into the inlet
134, it is less likely that such water can migrate upward through
the second intake pipe 132 and into the plenum chamber 72. Thus, by
arranging the inlet 134 is lower than the outlet 136, the water
preclusive character of the inlet assembly 70" is further
enhanced.
[0060] Accordingly, 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. Of course, the watercraft need not include all
these features to appreciate some of the aforementioned advantages
associated with the present watercraft. Accordingly, the scope of
the invention is intended to be defined only by the claims that
follow.
* * * * *