U.S. patent application number 10/078027 was filed with the patent office on 2002-09-05 for hull for small watercraft.
Invention is credited to Hattori, Toshiyuki, Nanami, Masayoshi.
Application Number | 20020121231 10/078027 |
Document ID | / |
Family ID | 18901223 |
Filed Date | 2002-09-05 |
United States Patent
Application |
20020121231 |
Kind Code |
A1 |
Hattori, Toshiyuki ; et
al. |
September 5, 2002 |
Hull for small watercraft
Abstract
A hull for a watercraft has a longitudinal axis generally
extending from fore to aft of the watercraft. The hull includes a
seat pedestal forming at least two side walls supporting a seat.
The side walls generally extend longitudinally relative to the
hull. The seat pedestal defines an engine compartment in which an
engine is placed. Each side wall defines a maintenance opening
communicating with the engine compartment. The openings are
elongated along the longitudinal axis. Normally, caps close the
respective openings. Each cap has a bulged out configuration to
form an inner recessed area therein. A portion of an exhaust
conduit extends beyond the opening to occupy one of the recessed
areas. In one arrangement, an air induction system includes a
plenum chamber unit that has a portion disposed close to the
opening. The portion of the plenum chamber unit also defines
another opening thereon.
Inventors: |
Hattori, Toshiyuki;
(Shizuoka, JP) ; Nanami, Masayoshi; (Shizuoka,
JP) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
620 NEWPORT CENTER DRIVE
SIXTEENTH FLOOR
NEWPORT BEACH
CA
92660
US
|
Family ID: |
18901223 |
Appl. No.: |
10/078027 |
Filed: |
February 14, 2002 |
Current U.S.
Class: |
114/55.53 |
Current CPC
Class: |
B63B 34/10 20200201;
B63H 21/32 20130101 |
Class at
Publication: |
114/55.53 |
International
Class: |
B63B 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 15, 2001 |
JP |
2001-038200 |
Claims
What is claimed is:
1. A watercraft comprising a hull having a longitudinal axis
generally extending from fore to aft of the watercraft, the hull
including a seat pedestal having first and second side walls
supporting a seat, the side walls generally extending along the
longitudinal axis, the first side wall defining a first opening
communicating with an internal space defined by the seat pedestal,
the opening being elongated longitudinally.
2. The watercraft as set forth in claim 1 additionally comprising a
closure member to close the first opening, and the closure member
bulging outwardly from the first side wall of the seat
pedestal.
3. The watercraft as set forth in claim 1 additionally comprising
an internal combustion engine placed within the internal space, the
engine including an engine body and at least one engine component
extending along the engine body.
4. The watercraft as set forth in claim 3, wherein at least a
portion of the engine component exists beyond the first
opening.
5. The watercraft as set forth in claim 4 further comprising a
closure member to close the opening, the closure member bulging out
to accommodate the portion of the engine component.
6. The watercraft as set forth in claim 1 additionally comprising a
multi-cylinder engine placed within the internal space, the engine
including an engine body defining at least two cylinders aligned
longitudinally relative to the hull, the first opening having a
length that is approximately the same as a length of the engine
body.
7. The watercraft as set forth in claim 6, wherein the engine
additionally includes at least one engine component connected with
the respective cylinders, the engine component at least in part
extending close to the first opening.
8. The watercraft as set forth in claim 6, wherein the engine
additionally includes at least one engine component connected with
the respective cylinders, the engine component at least in part, is
disposed beyond the first opening.
9. The watercraft as set forth in claim 1 additionally comprising a
second opening in the second side wall, the first and second
openings being elongated with a length generally equal to each
other.
10. The watercraft as set forth in claim 9, wherein the first
opening is positioned more forward than the second opening.
11. The watercraft as set forth in claim 1 additionally comprising
a second opening in the second side wall, a front end of the first
opening being positioned more forward than a front end of the
second opening.
12. The watercraft as set forth in claim 1 additionally comprising
a second opening in the second side wall, a rear end of the first
opening being positioned more rearward than a rear end of the
second opening.
13. The watercraft as set forth in claim 1 additionally comprising
a top wall bridging the side walls, the top wall defining a second
opening, a longitudinal length of the first opening being longer
than half a longitudinal length of the second opening.
14. The watercraft as set forth in claim 1, wherein the hull
additionally includes footwells positioned on either side of the
seat pedestal.
15. A watercraft comprising a hull, a seat pedestal supporting a
seat, an engine compartment defined by the seat pedestal, an
internal combustion engine disposed in the engine compartment, the
engine including an engine body and at least one engine component
extending along the engine body, the seat pedestal including at
least first and second side walls extending longitudinally relative
to the hull, at least the first side wall defining an oblong
opening extending along the engine body.
16. The watercraft as set forth in claim 15 additionally comprising
a closure member configured to close the opening, the closure
member bulging outwardly to accommodate the portion of the engine
component.
17. The watercraft as set forth in claim 16, wherein the engine
component includes an exhaust conduit.
18. The watercraft as set forth in claim 15, wherein the engine
includes an air induction system and an exhaust system, and either
one of the air induction system or the exhaust system at least in
part exists close to the opening.
19. The watercraft as set forth in claim 18 further comprising a
closure member configured to close the opening, the closure member
bulging out to form an inner recessed area, and at least one of a
portion of the air induction system and a portion of the exhaust
system being disposed in the recessed area.
20. The watercraft as set forth in claim 18, wherein the air
induction system includes a plenum chamber unit, a portion of the
plenum chamber unit exists close to the opening.
21. The watercraft as set forth in claim 20, wherein the plenum
chamber unit defines a second opening facing to the first
opening.
22. The watercraft as set forth in claim 21, wherein the plenum
chamber unit includes a filter element in proximity to the second
opening.
23. The watercraft as set forth in claim 15, wherein the hull
additionally includes footrests positioned on either side of the
side walls.
24. A watercraft comprising a hull, an engine supported by the
hull, the engine including an engine body, and an induction system
configured to guide air to the engine body, an inlet of the
induction system facing toward the engine body, and a portion of
the engine body extending below the inlet.
25. The watercraft according to claim 24, wherein a portion of the
induction system extends over the inlet.
26. The watercraft according to claim 24, wherein the engine body
includes a cylinder block which is inclined toward a first side of
the engine body, the inlet facing toward the second side of the
engine body.
Description
PRIORITY INFORMATION
[0001] This application is based on Japanese Application No.
2001-038200, filed Feb. 15, 2001, the entire contents of which is
hereby expressly incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a hull for a
small watercraft, and more particularly to an improved hull for a
small watercraft that includes a seat pedestal defining an internal
space in which an engine can be positioned.
[0004] 2. Description of Related Art
[0005] Relatively small watercraft such as, for example, personal
watercraft have become very popular in recent years. This type of
watercraft is quite sporting in nature and carries one or more
riders. An internal combustion engine powers a jet propulsion unit
that propels the watercraft by discharging water rearwardly. The
engine lies within an engine compartment in front of a tunnel which
is formed in the rear and underside of the watercraft. The jet
propulsion unit generally is placed within the tunnel and includes
an impeller driven by the engine to discharge the water.
[0006] A hull of the watercraft typically includes a seat pedestal
having side walls bridged by a seat. Footwells are positioned on
either side of the side walls. The seat pedestal and the footwells
together define a riders' area. The seat pedestal also defines an
internal space, at least a portion of which is available for an
engine compartment in which the engine is placed. The internal area
and particularly the engine, can be accessed by removing a panel
which covers an opening formed in the hull for maintenance of the
engine, engine components or watercraft components enclosed in the
internal space. However, due to the location and/or the size of the
opening, access to some parts of the engine or components is
extremely difficult if the part is located toward the bottom of the
space or is disposed behind another part. For example, an oil
filter unit of a lubricant system usually is positioned at the
bottom of the engine. Replacement of such a filter therefore is one
of the most difficult tasks associated with regular
maintenance.
[0007] U.S. Pat. No. 5,743,206 discloses circular ports formed on
the side walls of a seat pedestal. The ports are closed with a
round cap. The ports and the caps have cooperating threads so that
the caps can be sealed to the ports and thus prevent water
invasion. Additionally, the ports are sized and positioned to allow
a user to remove and replace the spark plugs from the engine, a
task that is typically performed with one hand.
SUMMARY OF THE INVENTION
[0008] One aspect of the present invention includes the realization
that there are other procedures which a mechanic could perform more
easily if ports on the sides of seat pedestals were larger.
Additionally, it has been found that it is more difficult to
manufacture and operate large port holes that are round and
threaded. For example, the larger a port is, the more difficult is
it to align the threads on the corresponding cap. Additionally, to
make a port, for example, approximately the same length as the
engine, the port would be nearly as tall as the seat pedestal. Such
a port could compromise the rigidity of the seat pedestal. Thus, it
is desirable to provide an improved hull for a small watercraft
that can allow a rider, mechanic or repairperson to work on part of
an engine or other components within the hull with both hands
and/or enhanced visibility of the components.
[0009] In accordance with an aspect of the present invention, a
watercraft comprises a hull. The hull has a longitudinal axis
generally extending from fore to aft of the watercraft. The hull
includes a seat pedestal forming at least two side walls supporting
a seat. The side walls generally extend along the longitudinal
axis. At least one of the side walls defines an opening
communicating with an internal space defined by the seat pedestal.
The opening is elongated longitudinally relative to the hull.
[0010] In accordance with another aspect of the present invention,
a watercraft includes a hull, an engine supported by the hull. The
engine includes an engine body and an induction system configured
to guide air to the engine body. An inlet of the induction system
faces toward the engine body and a portion of the engine body
extends below the inlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and other features, aspects and advantages of the
present invention will now be described with reference to the
drawings of preferred embodiments which are intended to illustrate
and not to limit the invention. The drawings comprise seven
figures.
[0012] FIG. 1 is a side elevational and sectional view of a
personal watercraft configured in accordance with a preferred
embodiment of the present invention.
[0013] FIG. 2 is a top plan view of the watercraft of FIG. 1.
Certain internal components of the watercraft are schematically
shown in solid line.
[0014] FIG. 3 is a partial sectional and rear view (taken along the
line 3-3 of FIG. 1) the watercraft and an engine disposed within
the hull, the hull including side walls having maintenance openings
closed with closure members.
[0015] FIG. 4 is a front, top, and port side perspective view of
the hull and the engine shown in FIG. 3. The hull is shown in
phantom and the bow part of the hull is illustrated as being cut
away.
[0016] FIG. 5 is a top plan view of a modification of the
watercraft illustrated in FIG. 1. Similarly to FIG. 2, certain
internal components of the watercraft are schematically shown in
solid line.
[0017] FIG. 6 is a starboard side elevational and partial sectional
view of the engine shown in FIG. 5. A maintenance opening on the
starboard side is illustrated in phantom.
[0018] FIG. 7 is a partial sectional and rear view of the
watercraft shown in FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
INVENTION
[0019] With reference to FIGS. 1-4, an overall construction of a
personal watercraft 30 configured in accordance with the present
invention is described below.
[0020] The personal watercraft 30 includes a hull 34 generally
formed with a lower hull section 36 and an upper hull section or
deck 38. Both the hull sections 36, 38 are made of, for example, a
molded fiberglass reinforced resin or a sheet molding compound. The
lower hull section 36 and the upper hull section 38 are coupled
together to define an internal space 40 therebetween. An
intersection of the hull sections 36, 38 is defined in part along
an outer surface gunwale or bulwark 42. The hull 34 houses an
internal combustion engine 44 that powers the watercraft 30.
[0021] As shown in FIGS. 2 and 3, the hull 34 defines a center
plane CP that extends generally vertically from bow to stern with
the watercraft 30 resting in normal upright position. The center
plane CP includes a longitudinal axis LA of the watercraft 30.
Along the center plane CP, the upper hull section 38 generally
includes a hatch cover 48, a steering mast 50 and a seat 52 one
after another from fore to aft.
[0022] In the illustrated embodiment, a bow portion of the upper
hull section 38 slopes upwardly and an opening 54 is defined
through which a rider R (FIG. 3) can conveniently access a storage
area 56 formed within the internal space 40 with bulkheads 57. The
hatch cover 48 is hinged to open and close the opening 54. The term
"rider" in this description means a rider, user, mechanics or
repairperson in the broad sense of the word unless indicated
otherwise or otherwise readily apparent from the context use.
[0023] The steering mast 50 extends generally upwardly toward the
top of the bow portion to support a handle bar 58. The handle bar
58 is provided primarily to allow the rider R to change a thrust
direction of the watercraft 30. The handle bar 58 also carries
control devices such as, for example, a throttle lever (not shown)
for controlling the engine 44.
[0024] The seat 52 extends fore to aft along the center plane CP at
a location behind the steering mast 50. The seat 52 is configured
generally with a saddle shape so that the rider R can straddle the
seat 52. The upper hull section 38 includes a seat pedestal 60 that
forms a pair of side walls 62 which support at least a portion of
the seat 52. The side walls 62 extend fore to aft along the
longitudinal axis LA of the watercraft 30 and becomes wider toward
the bottom.
[0025] The seat 52 comprises a cushion 64 and a rigid backing 66
and is detachably supported by the seat pedestal 60 with the
backing 66 disposed atop the pedestal 60. In the illustrated
embodiment, the seat 52 is formed of a forward portion and a
rearward portion, each independently connected to the pedestal
60.
[0026] An access opening 68 is defined on the top surface of the
pedestal 60 and under the seat 52. A rider, mechanic or
repairperson can conveniently access the internal space 40 through
the access opening 68. Footwells 70 are defined on either side of
the side walls 62 and on an upper surface of the upper hull section
38. The illustrated footwells 70 are generally flat and slope
upwardly toward the aft of the watercraft 30. The seat 52 and the
footwells 70 together define a riders' area.
[0027] The upper hull section 38 also defines front and rear
storage boxes 74, 76. The front storage box 74 is located between
the steering mast 50 and the seat 52, while the rear storage box 76
is located in the rear of the seat 52. The storage box 74
preferably is closed by a cap 77 that is hingedly coupled with the
box 74. When the cap 77 is detached, the storage box 74 is
available for containing a beverage container, gloves, riding
equipment, and the like.
[0028] The entire internal space 40 of the illustrated arrangement
is available for an engine compartment. Thus, the reference numeral
40 can also indicate the engine compartment in this description.
One or more bulkheads can divide the internal space 40 into
multiple compartments, at least one being the engine compartment.
In the illustrated embodiment, one bulkhead 78 is disposed between
the engine 44 and a rear portion of the hull 30.
[0029] A fuel tank 82 is placed in the engine compartment 40 under
the bow portion of the upper hull section 38. The fuel tank 82 is
coupled with a fuel inlet port (not shown) positioned atop the
upper hull section 38 through a proper duct.
[0030] A pair of air ducts or ventilation ducts (not shown) is
provided on either side of the upper hull section 38 so that the
ambient air can enter and exit the engine compartment 40 through
the ducts. Except for the air ducts, the internal space 40 is
substantially sealed to protect the engine 44, a fuel supply system
including the fuel tank 82 and other systems or components from
water.
[0031] The engine 44 preferably is placed within the engine
compartment 40 generally under the seat 52, although other
locations are also possible (e.g., beneath the steering mast 50 or
in the bow). The rider R can access the engine 44 through the
access opening 68 by detaching the seat cushion 60 from the seat
pedestal 60.
[0032] The engine 44 operates on a four-cycle combustion principle.
The engine 44 comprises a cylinder block 90 that preferably defines
four cylinder bores 92 spaced apart from each other from fore to
aft along the center plane CP. That is, four cylinders Cy. 1, Cy.
2, Cy. 3 and Cy. 4 preferably are aligned as shown in FIG. 2. The
engine 44 thus is a L4 (in-line four cylinder) type. The
illustrated four-cycle engine, however, merely exemplifies one type
of engine. Engines having other number of cylinders including a
single cylinder, and having other cylinder arrangements (V and W
type) and other cylinder orientations (e.g., upright cylinder
banks) are all practicable.
[0033] With reference to FIG. 3, each cylinder bore 92 has a center
axis CA that is slanted from the center plane CP with an angle
.theta. so that the overall height of the engine 44 is shorter. All
the center axes CA of the cylinder bores 92 preferably are inclined
relative to the center plane CP at the same angle.
[0034] Pistons 94 are reciprocally disposed within the cylinder
bores 92. A cylinder head member 96 is affixed to an upper end
portion of the cylinder block 90 to close respective upper ends of
the cylinder bores 92, and thus defines combustion chambers with
the cylinder bores 92 and the pistons 94.
[0035] A crankcase member 100 is affixed to a lower end portion of
the cylinder block 90 to close respective lower ends of the
cylinder bores 92 and to define a crankcase chamber 102 with the
cylinder block 90. A crankshaft 104 is journaled for rotation by
the crankcase member 100. Connecting rods 106 couple the crankshaft
104 with the pistons 94 so that the crankshaft 104 rotates with the
reciprocal movement of the pistons 94.
[0036] The cylinder block 90, the cylinder head member 96 and the
crankcase member 100 together define an engine body 108. The engine
body 108 preferably is made of aluminum based alloy. In the
illustrated arrangement, the engine body 108 is oriented in the
engine compartment 40 to position the crankshaft 104 generally
parallel to the center plane CP and to extend generally along the
longitudinal axis LA. In the illustrated embodiment, a center axis
105 of the crankshaft 104 is offset from the center plane CP a
distance L as shown in FIG. 3. In some arrangements, other
orientations of the engine body 108 also are possible (e.g., with a
transverse or vertical oriented crankshaft).
[0037] Engine mounts 112 extend from either side of the engine body
108. The engine mounts 112 preferably include resilient portions
made of flexible material, for example, a rubber material. The
engine body 108 is mounted on the lower hull section 36,
specifically, a hull liner, by the engine mounts 112 so that
vibrations from the engine 44 are attenuated.
[0038] The engine 44 preferably comprises an air induction system
to guide air to the combustion chambers. The illustrated air
induction system includes four inner intake passages 114 defined in
the cylinder head member 96. The intake passages 114 communicate
with the associated combustion chambers through one or more intake
ports 116. Intake valves 118 are provided at the intake ports 116
to selectively connect and disconnect the intake passages 114 with
the combustion chambers. In other words, the intake valves 118 move
between open and closed positions of the intake ports 116.
[0039] Preferably, the air induction system also includes a plenum
chamber unit or air intake box 122 disposed above the engine body
108 and below the seat 52. The illustrated plenum chamber unit 122
has a generally rectangular shape in a plan view (FIG. 2) and
defines a plenum chamber therein for smoothing intake air and
quieting intake air. Other shapes of the plenum chamber unit 122 of
course are possible, but it is preferable to make the plenum
chamber as large as possible within the space provided between the
engine body 108 and the seat 52.
[0040] With continued reference to FIG. 3, the plenum chamber unit
122 preferably comprises an upper member and a lower member coupled
together. The lower member defines four apertures disposed in line
and generally parallel to the center plane CP.
[0041] Preferably, four throttle bodies 126 extend through the
apertures and are fixed to the lower chamber member. Each throttle
body 126 has an inlet 128 that opens to the interior of the plenum
chamber. The throttle bodies 126 are generally positioned on the
port side of the plenum chamber. Respective bottom ends of the
throttle bodies 126 are coupled with the associated inner intake
passages 114. The throttle bodies 126 preferably extend generally
vertically but slant toward the port side oppositely from the
center axis CA of the engine body 108. Air in the plenum chamber
thus is drawn to the combustion chambers through the throttle
bodies 126.
[0042] A throttle valve 130 is journaled for pivotal movement on
each throttle body 126 with a valve shaft. Preferably, the valve
shaft links all of the throttle valves 130. The pivotal movement of
the valve shaft is controlled by the throttle lever on the handle
bar 58 through a control cable. The rider R thus can control an
opening degree of the throttle valves 130 by operating the throttle
lever to obtain various engine speeds. That is, an amount of air
passing through the throttle bodies 126 is measured or regulated by
this mechanism. Normally, the greater the opening degree, the
higher the rate of airflow and the higher the engine speed.
[0043] One or more air inlet ports 134 are formed on the lower
member to draw air into the plenum chamber. In the illustrated
embodiment, a filter assembly or air cleaner unit 136 is positioned
on the starboard side of the plenum chamber and opposite the
throttle bodies 126. The filter assembly 136 contains at least one
filter element therein.
[0044] The engine 44 preferably comprises an indirect or port
injected fuel supply system. The fuel supply system includes four
fuel injectors 138 with one injector allotted to each throttle body
126. The fuel injectors 138 are affixed to a fuel rail (not shown)
that is mounted on the throttle bodies 126. The fuel injectors 138
have injection nozzles opening downstream of the throttle valves
130. The fuel injectors 138 spray fuel through the nozzles at
certain injection timing and for certain duration under control of
an electronic control unit (ECU) (not shown). The sprayed fuel is
drawn into the combustion chambers together with the air to form an
air/fuel charge therein. A direct fuel injection system that sprays
fuel directly into the combustion chambers can replace the indirect
fuel injection system described above. Moreover, other charge
forming devices such as, for example, carburetors can be used
instead of the fuel injection system.
[0045] The engine 44 preferably comprises a firing or ignition
system. The ignition system includes four spark plugs (not shown),
one spark plug allotted to each combustion chamber. The spark plugs
are affixed to the cylinder head member 96 so that electrodes,
which are defined at ends of the plugs, are exposed to the
respective combustion chambers. The spark plugs fire the air/fuel
charges in the combustion chambers at an ignition timing under
control of the ECU. The air/fuel charge thus is burned within the
combustion chambers to move the pistons 92 generally
downwardly.
[0046] The engine 44 also includes an exhaust system configured to
guide burnt charges, i.e., exhaust gases, from the combustion
chambers. In the illustrated embodiment, the exhaust system
includes four inner exhaust passages 142 defined within the
cylinder head member 96. The exhaust passages 142 communicate with
the associated combustion chambers through one or more exhaust
ports 144. Exhaust valves 146 are provided at the exhaust ports 144
to selectively connect and disconnect the exhaust passages 142 from
the combustion chambers. In other words, the exhaust valves 146
move between open and closed positions of the exhaust ports
144.
[0047] In the illustrated embodiment, an exhaust manifold 150
depends from the cylinder head member 96 at a starboard side
surface thereof as shown in FIG. 3. The exhaust manifold 150 is
connected with the inner exhaust passages 142 to collect exhaust
gases from the respective inner exhaust passages 142. An exhaust
conduit 152 is connected with the exhaust manifold 150 downstream
thereof and extends forwardly on the starboard side, turns toward
the port side and then further extends rearwardly on the port side.
The exhaust conduit 152 is one of engine component which extends
along the engine body 108. The exhaust conduit 152 can comprise two
or more conduit sections. An end portion of the exhaust conduit 152
in the illustrated arrangement passes through the bulkhead 78 to
the rear portion of the hull 34. The reference numeral 152S
generally indicates part of the exhaust conduit 152 extending on
the starboard side, while the reference numeral 152P generally
indicates other part of the exhaust conduit 152 extending on the
port side. The illustrated exhaust manifold 150 and the exhaust
conduit 152 at least in part include a water jacket 154 coaxially
surrounding exhaust passages 155 as shown in FIG. 3.
[0048] The end portion of the exhaust conduit 152, which is the
furthest downstream portion of the conduit part 152P, is connected
to a water-lock or first exhaust silencer 156 disposed in the rear
portion of the hull 34 on the port side. The water-lock 156 is
connected to a second exhaust silencer 158 through a connecting
pipe 160. The second exhaust silencer 158 is disposed on the center
plane CP and is positioned higher than the water-lock 156. A
discharge pipe 162 extends generally rearwardly from the second
exhaust silencer 158 and is connected to a portion of a tunnel 164
on the starboard side.
[0049] The tunnel 164 is a recessed portion formed on the underside
of the lower hull section 36. The discharge pipe 162 opens to the
exterior of the watercraft 30 in a submerged position. Thus, the
exhaust gases are discharged to a body of water surrounding the
watercraft 30 through the discharge pipe 162. The respective
exhaust silencers 156, 158 define one or more expansion chambers
therein to reduce exhaust noise. In addition, because of the
particular arrangement of the last part of the exhaust system, the
water that can enter the opening part of the discharge pipe 162 is
inhibited from going further to the exhaust conduit 152 not only
when the watercraft 30 is in the normal position but also in any
capsized positions as is well known.
[0050] The engine 44 includes a valvetrain drive for actuating the
intake and exhaust valves 118, 146. In the illustrated embodiment,
the valvetrain drive comprises a double overhead camshaft drive
including an intake camshaft 168 and an exhaust camshaft 170. The
intake and exhaust camshafts 168, 170 actuate the intake and
exhaust valves 118, 146, respectively. The intake camshaft 168
extends generally horizontally over the intake valves 118 from fore
to aft in parallel to the center plane CP, while the exhaust
camshaft 146 extends generally horizontally over the exhaust valves
146 from fore to aft also in parallel to the center plane CP. Both
the intake and exhaust camshafts 168, 170 are journaled for
rotation by the cylinder head member 96 with a plurality of
camshaft caps. The camshaft caps holding the camshafts 168, 170 are
affixed to the cylinder head member 96. A cylinder head cover
member 172 extends over the camshafts 168, 170 and the camshaft
caps, and is affixed to the cylinder head member 96 to define a
camshaft chamber.
[0051] The intake and exhaust camshafts 168, 170 each have cam
lobes. Each cam lobe is associated with each one of the intake
valves 118 and the exhaust valves 146, respectively. The intake and
exhaust valves 118, 146 are biased to a closed position via, for
example, springs. When the intake and exhaust camshafts 168, 170
rotate, the respective cam lobes push the associated valves 118,
146 to open the respective ports against the biasing force of the
springs. The air thus can enter the combustion chambers when the
intake valves 118 are opened and the exhaust gases can move out
from the combustion chambers when the exhaust valves 146 are
open.
[0052] The crankshaft 104 preferably drives the intake and exhaust
camshafts 168, 170. Preferably, the respective camshafts 168, 170
have driven sprockets affixed to ends thereof. The crankshaft 104
also has a drive sprocket. Each driven sprocket has a diameter
which is twice as large as a diameter of the drive sprocket. A
flexible transmitter such as, for example, a timing chain or belt
is wound around the drive and driven sprockets. When the crankshaft
104 rotates, the drive sprocket drives the driven sprockets via the
timing chain, and then the intake and exhaust camshafts 168, 170
rotate also. The rotational speed of the camshafts 168, 170 are
reduced to half of the rotational speed of the crankshaft 104
because of the differences in diameters of the drive and driven
sprockets. A tensioner of the flexible transmitter is provided to
give proper tension to the flexible transmitter. A tension adjuster
178 (FIG. 3) is provided to adjust the tension of the tensioner.
The tension adjuster 178 exposes itself at a side surface of the
cylinder head member 96 on the starboard side.
[0053] Ambient air enters the engine compartment 40 through the air
ducts. The air is introduced into the plenum chamber defined by the
plenum chamber unit 122 through the air inlet ports 134 and then
drawn into the throttle bodies 126. The filter assembly 136 removes
foreign particles from the air. The air in the plenum chamber is
supplied to the combustion chambers.
[0054] The throttle valves 130 in the throttle bodies 126 regulate
an amount of the air flowing toward the combustion chambers. The
air flows into the combustion chambers when the intake valves 118
are opened. At the same time, the fuel injectors 138 spray fuel
into the intake ports 116 under the control of the ECU. Air/fuel
charges are thus formed and are delivered to the combustion
chambers.
[0055] The air/fuel charges are fired by the spark plugs also under
the control of the ECU. The burnt charges, i.e., exhaust gases, are
discharged to the body of water surrounding the watercraft 30
through the exhaust system. The combustion of the air/fuel charges
causes the pistons 94 reciprocate within the cylinder bores 92 and
thereby causes the crankshaft 104 to rotate.
[0056] The engine 44 preferably includes a lubrication system that
delivers a lubricant, such as oil, to engine portions for
inhibiting frictional wear of such portions. In the illustrated
embodiment, a closed-loop type, dry-sump lubrication system is
employed. Lubricant oil for the lubrication system preferably is
stored in a lubricant reservoir or tank 182 disposed at the rear of
the engine body 108 and is affixed thereto.
[0057] An oil filter unit 184 is detachably mounted on the
crankcase member 100 on the port side of the engine body 108. The
oil filter unit 184 contains at least one filter element to remove
foreign substances from the lubricant oil circulating in the
lubrication system. The oil filter unit 184 also can separate water
component from the lubricant oil. The lubrication system includes
one or more oil pumps that are preferably driven by the crankshaft
104 in the circulation loop to deliver the lubricant oil from the
lubricant reservoir 182 to the engine portions that need
lubrication and then return it to the reservoir 182.
[0058] The watercraft 30 preferably employs a water cooling system
for cooling the engine body 108 and the exhaust system. Preferably,
the cooling system is an open-loop type that introduces cooling
water from the body of water in which the watercraft is operating.
The cooling system can include a water pump and a plurality of
water jackets and/or conduits. The foregoing water jacket 154 (FIG.
3) is part of the water jackets.
[0059] The engine 44 and the particular external portions of the
exhaust system is disclosed in, for example, a co-pending U.S.
application filed Jan. 31, 2001, titled INTERNAL COMBUSTION ENGINE,
which is Ser. No. 09/918,980, the entire contents of which is
hereby expressly incorporated by reference.
[0060] In the illustrated embodiment, a jet pump assembly 188
propels the watercraft 30. The jet pump assembly 188 is mounted in
the tunnel 164. The tunnel 164 has a downward facing inlet port 190
opening toward the body of water. A pump housing 192 of the pump
assembly 188 is disposed within a portion of the tunnel 164 and
communicates with the inlet port 190. An impeller 194 is journaled
for rotation within the pump housing 192.
[0061] An impeller shaft 196 extends forwardly from the impeller
194 and is coupled with an output shaft 198 via a coupling unit
200. The output shaft 198 is connected with the crankshaft 104 of
the engine 32 to output the engine power. An axis 202 (FIG. 3) of
the output shaft 198 (FIG. 3) extends on the center plane CP.
Because the axis 105 of the crankshaft 104 is offset from the
center plane CP in the illustrated arrangement as shown in FIG. 3,
a connecting mechanism couples the crankshaft 104 with the output
shaft 198. In the illustrated arrangement, a gear connection (not
shown) is employed for the mechanism. The crankshaft 104 drives the
impeller shaft 196 through the gear connection, the output shaft
198 and the coupling unit 200 accordingly.
[0062] A rear end of the pump housing 192 defines a discharge
nozzle 206. A deflector or steering nozzle 208 is affixed to the
discharge nozzle 206 for pivotal movement about a steering axis
which extends approximately vertically. A cable connects the
deflector 208 with the steering mast 50 so that the rider R can
steer the deflector 208, and thereby change the direction of travel
of the watercraft 30. Additionally, a reverse bucket 210 is
pivotally mounted on the deflector 208 about an axis which extends
generally horizontally. The rider R thus can move the watercraft 30
backwardly by lowering the reverse bucket 210 over the nozzles 206,
208. The reverse bucket 210 is configured such that when it is in a
lowered position (not shown), water discharged through the steering
nozzle 208 is directed forwardly, thus causing rearward movement of
the watercraft 30.
[0063] When the crankshaft 104 of the engine 32 drives the impeller
shaft 196 through the output shaft 198, the impeller 194 rotates.
Water is drawn from the surrounding body of water through the inlet
port 190. The pressure generated in the pump housing 174 by the
impeller 194 produces jet stream of the water that is discharged
through the discharge nozzle 206 and the deflector 208. The water
jet produces thrust to propel the watercraft 30. The rider R can
steer the deflector 208 with the handle bar 58 of the steering mast
50 to turn the watercraft 30 in either right or left direction. In
the illustrated arrangement, the jet pump assembly 188 also
functions as the water pump of the cooling system with a portion of
the water pressurized by the impeller 194 being drawn off for the
cooling system, as known in the art.
[0064] The access opening 68 provided under the seat 52
conveniently is used for maintenance of the engine 44, engine
related components and/or watercraft related components. However,
certain components are not easily accessed from the opening 68
because they are positioned distally from the opening 68. Some
components are located behind other components and thus,
maintenance or repair procedures can be difficult.
[0065] For example, the oil filter unit 184 is deep within the
engine compartment and beneath a portion of the exhaust system. The
tension adjuster 178 is placed behind the plenum chamber unit
122.
[0066] In accordance with another aspect of the present invention,
the watercraft 30 thus has additional maintenance openings. With
reference to FIGS. 2-4, the additional maintenance openings and
arrangements around the openings are described in detail below.
[0067] In the illustrated arrangement, the side wall 62 of the seat
pedestal 60 on the starboard side defines a maintenance opening
220S communicating with the engine compartment 40, while the side
wall 62 of the seat pedestal 60 on the port side defines another
maintenance opening 220P also communicating with the engine
compartment 40. The respective openings 220S, 220P are oblong and
elongated fore to aft generally parallel to the longitudinal axis
LA.
[0068] The openings 220S, 220P preferably are positioned in
proximity to engine portions, engine related components and/or
watercraft related components. The oil filter unit 184, the tension
adjuster 178, the spark plugs and the engine mounts 112 are
exemplary engine portions. The engine related components include,
for example but without limitation, the external portions of the
exhaust system and the fuel tank 82. The watercraft related
components in turn include, for example but without limitation, the
air ducts and a bilge pump, if any, to bail out water at the bottom
of the internal space 44. Preferably, the openings 220S, 220P are
positioned at vertical locations with appropriate distances from
top and bottom ends of the walls 62.
[0069] The openings 220S, 220P can have a length that is
approximately the same length as the engine body 108. This provides
an additional advantage by allowing a rider or mechanic to access
various components with relative ease. For example, certain
components, such as the exhaust manifold 150, are mounted with
numerous mounting bolts disposed along the length of the engine
body. Thus, by sizing the openings 220S, 220P with a length that is
approximately as long as the engine body 108, a rider or mechanic
can see and access such an arrangement of bolts more easily than
through those access openings of the prior art.
[0070] Both the horizontal and vertical positions of the openings
220S, 220P can be determined at locations that are mostly close to
major and/or primary maintenance portions and/or components. Also,
the horizontal and vertical lengths of the openings 220S, 220P can
be determined such that preferably both hands H are accessible to
the maintenance portions.
[0071] For example, in the illustrated arrangement, the opening
220S on the starboard side is located forwardly than the opening
220P on the port side, and the vertical length of the opening 220P
is longer than the vertical length of the opening 220S. Each
horizontal length of the openings 220S, 220P is generally equal to
each other, and the length is at least longer than a half of the
access opening 68, preferably approximately as long as the engine
body 108, as noted above.
[0072] The oil filter unit 184 can be located either in front of
the engine body 108 or in the rear of the engine body 108. The
openings 220S, 220P thus can be elongated sufficiently enough for
at least one hand H of the rider R can reach the oil filter unit
wherever it is located. The wider the openings 220S, 220P, the
easier the hand or hands H reach target portions. The elongated
openings 220S, 220P also are helpful for a rider or mechanic in
seeing certain small components that could be inadvertently missed.
That is, the elongated openings 220S, 220P also enhance visibility
of the target portions.
[0073] Although any oblong configurations can be selected for the
openings 220S, 220P, an oval shape, particularly, a streamline
shape being enlarged at the forward end is one presently preferred
shape. The openings 220S, 220P could be rectangular shape.
[0074] Caps or closure members 224S, 224P close the openings 220S,
220P, respectively. The respective caps 224S, 224P define a flange
226 on each peripheral edge thereof and are affixed to the side
walls 62 by fasteners 228 such as, for example, bolts and nuts. A
seal member 230 that has a shape corresponding to the shape of the
flange 226 preferably is disposed between the flanges 226 and the
peripheral edge of the openings 220S, 220P.
[0075] The caps 224S, 224P preferably has the same shape as of the
openings 220S, 220P. Each illustrated cap 224S, 224P is bulged out
to form an inner recessed area 232. The bulged configuration
preferably is part of a stream line shape or tear drop shape so
that possible noise made by wind is effectively reduced. Each
recessed area 232 of the cap 224S, 224P preferably has a depth D
between a top end and a bottom end as shown in FIG. 3. The depth D
and the configuration of each cap 224S, 224P can be determined not
to interfere with the legs LG and the ankles AK of the rider R.
[0076] The recessed areas 232 advantageously expand the internal
space 40. Because of this expansion of the space 40, for example, a
portion of the exhaust conduit 152P can extend beyond the opening
220P outwardly to occupy the increased space of the recessed area
232 of the cap 224P as shown in FIG. 3 and also shown in phantom
line 228 of FIG. 2. The portion of the exhaust conduit 152P thus
can be larger than that of a conventional construction without
making the seat pedestal 60 itself wider. Thus, the output of the
engine 44 can be improved without changing the basic shape of the
pedestal 60 and seat 52.
[0077] Additionally, the illustrated portion of the exhaust conduit
152P is spaced apart from an inner surface of the cap 224P with a
distance T. Thus, vibration of the conduit portion 152P caused by
the engine operation, if any, is unlikely to be transferred to the
seat pedestal 60. Alternatively, a portion of the plenum chamber of
the air induction system can be positioned in the increased space
of the recessed areas 232.
[0078] The recessed area 232 also can define a relatively large
water pool where water can accumulate in the event that the
watercraft 30 turns over. The larger water pool can reduce a chance
that the water enter engine portions, the external portions of the
exhaust system and/or the air induction system because a water
level within the engine compartment 40 is inevitably lowered by the
recessed areas 232.
[0079] In addition, because the illustrated recessed areas 232 are
formed with the caps 224S, 224P that are separated from the seat
pedestal 60 the upper hull section 38 including the seat pedestal
60 itself can be easily produced because no split dies are
necessary in the molding process of the upper hull section 38.
[0080] It should be noted that the caps can take any shapes other
than the illustrated bulged-shape. For example, a flat shape is
applicable. Moreover, a shape dented toward inside of the internal
space is also practicable.
[0081] With reference to FIGS. 5-7, a modification of the
watercraft 30 is described below and is referred to generally with
the reference numeral 30'. The same members, components, mechanisms
and systems as those that have been already described will be
assigned with the same reference numerals and will not be described
repeatedly.
[0082] As shown in FIGS. 5-7, the watercraft 30' has an exhaust
system arranged differently from the exhaust system of the
watercraft 30 described above with reference to FIGS. 1-4. In the
watercraft 30', an exhaust conduit 240 of the exhaust system is
connected with the exhaust manifold 150 disposed on the starboard
side and extends rearward straightly without turning around the
engine body 108. The exhaust conduit 240 is coupled with the
water-lock 156 which disposed on the starboard side. The water-lock
156, the second exhaust silencer 156, the connecting pipe 160 and
the discharge pipe 162 in this arrangement are disposed in reversed
positions relative to those in the watercraft 30'.
[0083] The discharge pipe 162 is connected to the tunnel 164 at a
location on the port side accordingly. As shown in FIG. 6, the
exhaust conduit 240 forms separate exhaust passages 242 therein to
a location existing in the conduit 240 with the distance P from the
exhaust manifold 150 and then forms a single exhaust passage 244
that unifies the separate passages 242. A water jacket 246
surrounds the exhaust passages 242, 244. The exhaust conduit 152 in
the first arrangement generally has the same internal
construction.
[0084] With reference to FIG. 7, a portion of the exhaust conduit
240 extends beyond the maintenance opening 220S outwardly and
extends through the recessed area 232 of the cap 224S. This portion
of the exhaust conduit 240 is spaced apart from an inner surface of
the cap 224S with a distance T2. The oil filter unit 184 in this
arrangement is disposed generally under the exhaust conduit 240 on
the starboard side.
[0085] As shown in FIG. 7, the watercraft 30' has an air induction
system including a plenum chamber unit 250. The plenum chamber unit
250 is shaped generally as the letter L to extend downwardly on the
port side of the engine 44.
[0086] The filter assembly 136 is positioned in the lower portion
of the unit 250. The air inlet port 134 also is positioned at the
lower portion and is surrounded by the filter assembly 136. The
inlet port 134 opens towards the side surface of the cylinder block
90 of the engine 44.
[0087] The plenum chamber unit 250 defines an opening 252 in
proximity to the maintenance opening 220P on the port side. The
opening 252 can be elongated similarly to the opening 220P. The
opening 252 preferably is closed by a flat cover member 254. The
cover member 254 can be affixed to the plenum chamber unit 250 by
fasteners 256 such as, for example, bolts and nuts.
[0088] Constructed as such, a rider can access the internal space
40 by detaching the cap 224P. Furthermore, with the cover member
254 removed, the rider can reach the filter assembly 136 in the
plenum chamber unit 250 without dissembling the plenum chamber unit
250. The cap 224P preferably is spaced apart from the cover member
254 with a distance T3 so that any vibration of the plenum chamber
unit 250 caused by the engine operation, if any, is not likely to
be transferred to the seat pedestal 60.
[0089] As shown in FIG. 7, the relatively large crankcase member
100 extends under the inlet port 134. This is advantageous because
the inlet port 134 is protected from bilge water that splashes in
the engine compartment 40 during operation of the watercraft 30'.
In addition, this arrangement of the inlet port 134 is particularly
beneficial when the watercraft 30 capsizes because the crankcase
member 100 will then extend over the inlet port 134, thereby
protecting it from water falling toward the access opening 68.
Further, because the inlet port 134 opens toward the center plane
CP, the port 134 is not facing upward when the watercraft is
upright or capsized which aids in preventing water from entering
the inlet port 134.
[0090] Of course, the foregoing description is that of preferred
constructions having certain features, aspects and advantages in
accordance with the present invention. For instance, one of the
side walls can have no maintenance opening. In other words, the
watercraft can have only one opening on either one of the side
walls. To the contrary, two or more openings can be provided on one
side wall. One or more look-in windows, which are elongated and
usually closed, can be provided separately from the maintenance
openings. Accordingly, various changes and modifications may be
made to the above-described arrangements without departing from the
spirit and scope of the invention, as defined by the appended
claims.
* * * * *