Information
-
Patent Grant
-
6419531
-
Patent Number
6,419,531
-
Date Filed
Monday, June 19, 200024 years ago
-
Date Issued
Tuesday, July 16, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Morano; S. Joseph
- Vasudeva; Ajay
Agents
- Knobbe, Martens, Olson & Bear, LLP
-
CPC
-
US Classifications
Field of Search
US
- 440 1
- 440 2
- 440 38
- 340 689
- 340 984
- 340 985
- 340 986
- 340 987
- 123 198 D
- 123 198 DB
- 123 198 DC
-
International Classifications
-
Abstract
A small watercraft with an emergency shut-off system is provided. The emergency shut-off system is configured to shut off the engine of the small watercraft when the small watercraft is overturned. The emergency shut-off system comprises an electronic control unit that is operatively coupled to an overturn sensor and the engine. The electronic control unit is configured to sense a signal generated by the overturn switch. The electronic control unit is also configured to determine if the signal generated by the overturn switch continues for a period longer than a preset amount of time and to shut off the engine if the signal generated by the overturn switch continues beyond the preset amount of time.
Description
PRIORITY INFORMATION
The present application is based on and claims priority to Japanese Patent Application No. 11-170731, which was filed on Jun. 17, 1999, the entire contents of which are hereby expressly incorporated by reference. The entire contents of Japanese Patent Application No. 11-75968, which was filed on Mar. 19, 1999, is also hereby expressly incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a control system for a personal watercraft. More particularly, the present invention relates to a emergency shut-off system for a personal watercraft.
2. Description of Related Art
As personal watercraft have become popular, they have become increasingly fast. Today, personal watercrafts are capable of speeds greater than 60 mph. To attain such speeds, personal watercrafts are driven by high power output motors.
Typically, two-cycle engines are used in personal watercraft because two-cycle engines have a fairly high power to weight ratio. One disadvantage of two-cycle engines, however, is that they produce relatively high emissions. In particular, large amounts of carbon monoxide and hydrocarbons are produced during operation of the engine. When steps are taken to reduce these emissions, other undesirable consequences typically result, such as an increase in the weight of the engine, the cost of manufacture, and/or the reduction of power.
It has been suggested that four-cycle engines replace two-cycle engines in personal watercraft. Four-cycle engines typically produce less hydrocarbon emissions than two-cycle engines while still producing a relatively high power output. However, adapting four-cycle engines for use in personal watercraft has its own engineering and technical challenges.
For example, as compared to two-cycle engines, four-cycle engines are typically more susceptible to water corrosion. Accordingly, personal watercraft with four-cycle engines typically include an emergency shut-off system that prevents water from entering the engine compartment when the personal watercraft is overturned. An example of such an emergency shut-off system is disclosed in Japanese Patent Laid Open No. 8-49596 (1996). This particular emergency shut-off system includes an overturn switch. The overturn switch includes a weight that sways back and forth as the personal watercraft is rocked from side to side. When the weight sways beyond a specified range, a circuit in the overturn switch is closed and the engine is shut off. Thus, the air pressure inside the engine compartment remains positive and water is less likely to be drawn into the engine compartment if the watercraft is overturned.
There, however, are several problems associated the emergency shut-off system described above. In particular, the circuit in the overturn switch can close when the watercraft is making a sharp or quick turn. That is, the weight can sway beyond the specified range during a sharp or quick turn as well as when the watercraft is overturned.
SUMMARY OF THE INVENTION
Thus, there exists a need for a improve emergency shut-off system that does not suffer significantly from these problems.
Thus, one aspect of the present invention is a method of operating an emergency shut-off system for a small watercraft is disclosed. The small watercraft comprises a hull that defines an engine compartment, an internal combustion engine supported within the engine compartment, an overturn switch, and an electronic control unit that is in electrical communication with the overturn switch. A signal from the overturn switch is sensed by the electronic control unit. The emergency shut-off system determines if the overturn switch is generating a signal for at least a preset amount of time. If the overturn switch has generated a signal for at least the preset amount of time, the engine is shut off.
Another aspect of the present invention is another method of operating an emergency shut-off system for a small watercraft. The small watercraft includes a hull that defines an engine compartment, an internal combustion engine supported within the engine compartment, a water level detection sensor positioned in the engine compartment, a bilge pump, and an electronic control unit that is in electrical communication with the sensor and the pump. The electronic control unit senses a signal from the water level detection sensor. The engine is shut off when the water level detection sensor indicates that water in the engine compartment exceeds a preset level. The bilge pump is activated.
Yet another aspect of the present invention is a small watercraft comprising a hull that defines an engine compartment, an internal combustion engine supported within the engine compartment, and an emergency shut-off system. The emergency shut-off system comprises an overturn switch and an electronic control unit that is in electrical communication with the overturn switch and the engine. The electronic control unit is configured to sense a signal generated by the overturn switch. The electronic control unit is also configured to determine if the signal generated by the overturn switch continues for a period longer than a preset amount of time. The electronic control unit is further configure to shut off the engine if the signal generated by the overturn switch continues beyond the preset amount of time.
Another aspect of the present invention is a small watercraft comprising a hull that defines an engine compartment, an internal combustion engine supported within the engine compartment, a water level detection sensor positioned in the engine compartment, a bilge pump positioned within the hull, and an electronic control unit. The electronic control unit is in electrical communication with the bilge pump and the engine. The sensor is configured to send a signal to the electronic control unit when water in the engine compartment rises above a specified level. The electronic control unit is configured to sense the signal from the water level detection sensor, to shut off the engine and to activate a bilge pump that is positioned within the engine compartment.
Another aspect of the present invention is a small watercraft comprising a hull that defines an engine compartment, an internal combustion engine supported within the engine compartment, a bilge pump positioned within the hull, and an electronic control unit in electrical communication with the bilge pump and the internal combustion engine. The watercraft also includes means for shutting off the engine when the watercraft is overturned.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features of the invention will now be described with reference to the drawings of preferred embodiments of the present invention. The illustrated embodiments of the emergency shut-off system, which are employed in a watercraft, are intended to illustrate, but not to limit, the invention. The drawings contain the following figures:
FIG. 1
is a side elevation view of a small watercraft with the rear portion of the watercraft shown in cross-section and certain internal components of the watercraft being illustrated with hidden lines;
FIG. 2
is a front cross-sectional view of an engine of the watercraft;
FIG. 3
is an enlarged left side view of the engine with a lower portion of the engine shown in cross-section and certain internal components being illustrated with hidden lines;
FIG. 4
is a top plan view of the engine with a cross-sectional view of an intake silencer taken along line
4
—
4
of
FIG. 5
;
FIG. 5
is a cross-sectional view of the intake silencer taken along line
5
—
5
of
FIG. 3
;
FIG. 6
is an enlarged right side view of the engine with a portion of an exhaust system shown in cross-section;
FIG. 7
is a cross-sectional view of a set of intake pipes and a vapor separator taken along line
7
—
7
of
FIG. 2
;
FIG. 8A
is a cross-sectional view of the lower portion of the engine;
FIG. 8B
is a top plan view of a lower cover;
FIG. 9
is a top plan view of a modified arrangement of the lower cover;
FIG. 10
is a partial cross-sectional view of a modified arrangement of the lower portion of the engine;
FIG. 11
is schematic illustration of an overturn switch;
FIG. 12
is schematic illustration of an emergency stop system;
FIG. 13
is a cross-sectional view of a water level detection sensor;
FIG. 14
is a left side view of a modified arrangement of an intake system of the engine;
FIG. 15
is a cross-sectional view of an intake silencer of the modified intake system;
FIG. 16
is a right side view of a modified exhaust system;
FIG. 17
is a schematic illustration of a control system for the modified intake and exhaust cooling systems;
FIG. 18
is a front cross-sectional view of another modified arrangement of the engine;
FIG. 19
is a side view of a modified arrangement of a pump unit and lubrication tank;
FIG. 20
is a side cross-sectional view of the pump unit;
FIG. 21
is a side cross-sectional view of the lubrication tank;
FIG. 22
is a front cross-sectional view of the pump unit;
FIG. 23
is a rear view of the lubrication tank (i.e., viewed from a rear side of the watercraft);
FIG. 24
is a top plan view of the lubrication tank; and,
FIG. 25
is a top cross-sectional view of the lubrication tank taken along line
25
—
25
of FIG.
19
.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
The present invention generally relates to an improved emergency shut-off system having certain features and advantages in accordance with the present invention. The emergency shut-off system is described in conjunction with a personal watercraft because this is an application in which the system has particular utility. Accordingly, an exemplary personal watercraft
10
will first be described in general detail to assist the reader's understanding of the environment of use. Of course, those of ordinary skill in the relevant arts will readily appreciate that the emergency shut-off system described herein can also have utility in a wide variety of other settings, for example, without limitation, small jet boats and the like.
The small watercraft and a corresponding engine
12
used in the small watercraft will be described with initial reference to
FIGS. 1 and 18
. With reference to
FIG. 18
, it is apparent that the engine
12
of
FIG. 18
is a modified arrangement of the engine
12
of FIG.
1
. Thus, the engine
12
will be described and the modifications to the engine
12
of
FIG. 18
will also be described. Like reference numerals will be used for like elements of the personal watercraft
10
and engine
12
. The watercraft
10
is also described with reference to a coordinate system. The coordinate system includes a longitudinal axis that extends from the bow to the stern of the watercraft. The coordinate system further includes a lateral axis that extends from the port side to starboard side, in a direction generally normal to the longitudinal axis. Relative heights are expressed as elevations referenced to the undersurface of the watercraft. In addition, several of the figures include a label F
R
that is used to indicate the general direction in which the watercraft travels during normal forward operation.
With reference now to
FIG. 1
, the watercraft
10
includes a hull
16
that is defined by a lower portion
18
and a top portion or deck
20
. These portions of the hull
16
are preferably formed from a suitable material, such as, for example, a molded fiberglass reinforced resin. A bond flange
22
preferably connects the lower portion
18
to the deck
20
. Of course, any other suitable means may be used to interconnect the lower portion
18
and the deck
20
. Alternatively, the lower portion
18
and the deck
20
can be integrally formed.
As viewed in the direction from the bow to the stem, the deck
20
includes a bow portion
24
, a control mast
26
, and a rider's area
28
. The bow portion
24
preferably includes a hatch cover (not shown). The hatch cover preferably is pivotally attached to the deck
20
such that it is capable of being selectively locked in a substantially closed watertight position. A storage bin (not shown) preferably is positioned beneath the hatch cover.
The control mast
26
supports a handlebar assembly
32
. The handlebar assembly
32
controls the steering of the watercraft
10
in a conventional manner. The handlebar assembly
32
preferably carries a variety of controls for the watercraft
10
, such as, for example, a throttle control (not shown), a start switch (not shown), and a lanyard switch (not shown). Additionally, a gauge assembly (not shown) is preferably mounted to the upper deck section
20
forward of the control mast
30
. The gauge assembly can include a variety of gauges, such as, for example, a fuel gauge, a speedometer, an oil pressure gauge, a tachometer, and a battery voltage gauge.
The rider area
28
lies rearward of the control mast
26
and includes a seat assembly
36
. The illustrated seat assembly
36
includes at least one seat cushion
38
that is supported by a raised pedestal
40
. The raised pedestal
40
forms a portion of the upper deck
20
, and has an elongated shape that extends longitudinally substantially along the center of the watercraft
10
. The seat cushion
38
desirably is removably attached to a top surface of the raised pedestal
40
by one or more latching mechanisms (not shown) and covers the entire upper end of the pedestal
40
for rider and passenger comfort.
An engine access opening
42
is located in the upper surface of the illustrated pedestal
40
. The access opening
42
opens into an engine compartment
44
formed within the hull
16
. The seat cushion
38
normally covers and substantially seals the access opening
42
to reduce the likelihood that water will enter the engine compartment
44
. When the seat cushion
38
is removed, the engine compartment
44
is accessible through the access opening
42
.
With particular reference to
FIG. 18
, the upper deck portion
20
of the hull
16
advantageously includes a pair of generally planar areas
54
positioned on opposite sides of the seat pedestal
40
, which define foot areas
56
. The foot areas
56
extend generally along and parallel to the sides of the pedestal
40
and are substantially enclosed on the lateral sides by the pedestal
40
and a raised gunnel. In this position, the operator and any passengers sitting on the seat assembly
36
can place their feet on the foot areas
56
during normal operation of the watercraft
10
and the feet generally are protected from water passing along the sides of the moving watercraft. A nonslip (e.g., rubber) mat desirably covers the foot areas
56
to provide increased grip and traction for the operator and passengers.
The interior of the hull
16
includes one or more bulkheads
58
(see
FIG. 1
) that can be used to reinforce the hull
16
internally and that also can serve to define, in part, the engine compartment
44
and a propulsion compartment
60
(see FIG.
1
), which propulsion compartment
60
is arranged generally rearward from the engine compartment
44
. The engine
12
is mounted within the engine compartment
44
in any suitable manner preferably at a central transverse position of the watercraft
10
. Preferably, a set of resilient engine mounts
62
are used to connect the engine
12
to a set of stringers
64
. The illustrated stringers
64
are formed on a liner
66
, which can also include other contours and mounting surfaces. The liner
66
can be made out of any suitable material, such as molded fiberglass-reinforced resin. The liner
66
preferably is bonded to the inner surface of the lower hull portion
18
. In another arrangement, the stringers
64
may be molded into the lower portion
18
of the hull
16
, or may be formed separately and then bonded to the inner surface of the lower portion
18
. In yet another arrangement, which is illustrated in
FIG. 1
, the hull
16
includes one or more dividing boards
68
that extend in a transverse direction along the inner surface of the lower hull portion. The transversely extending dividing boards
68
support a longitudinally extending dividing board
70
that can be used to support the engine mounts
62
.
With reference again to
FIG. 1
, a fuel tank
74
preferably is arranged in front of the engine
12
and is suitably secured to the hull
16
of the watercraft
10
. A fuel filler tube (not shown) preferably extends between the fuel tank
74
and the upper deck
20
, thus allowing the fuel tank
74
to be filled with fuel B via the tube.
A forward air duct
76
extends through the upper deck portion
20
. The forward air duct
76
allows atmospheric air C to enter and exit the engine compartment
44
. Similarly, a rear air duct
78
extends through an upper surface of the seat pedestal
40
, preferably beneath the seat cushion
38
, thus also allowing atmospheric air C to enter and exit the engine compartment
44
. Preferably, the rear air duct
78
terminates below the longitudinally extending dividing board
70
. Air may pass through the air ducts
76
,
78
in both directions (i.e., into and out of the engine compartment
44
). Except for the air ducts
76
,
78
, the engine compartment
44
is substantially sealed so as to enclose the engine
12
of the watercraft
10
from the body of water in which the watercraft
10
is operated.
Both the forward and rear air ducts
76
,
78
preferably include shut-off valves
77
,
79
. The shut-off valves
77
,
79
can be made in a variety of ways but in the illustrated embodiment they are butterfly valves. Preferably, the shut-off valves
77
,
79
are positioned in the forward and rear air ducts,
76
,
78
such that they lie above the engine compartment
44
. The shut-off valves
77
,
79
are connected to actuators, which open and close the shutoff valves
77
,
79
. The purpose and function of the shut-off valves
77
,
79
will be described in detail below.
The lower hull section
18
is designed such that the watercraft
10
planes or rides on a minimum surface area of the aft end of the lower hull section
18
in order to optimize the speed and handling of the watercraft
10
by reducing the wetted surface area, and therefore the drag associated with that surface area. For this purpose, as best seen in
FIG. 18
, the lower hull section
18
has a generally V-shaped configuration formed by a pair of inclined sections that extend outwardly from a keel line
80
to outer chines
86
at a dead rise angle. The inclined sections extend longitudinally from the bow
24
toward the transom
82
(see
FIG. 1
) of the lower hull section
18
and extend outwardly to sidewalls
84
of the lower hull section
18
. The sidewalls
84
are generally flat and straight near the stem of the lower hull section
18
and smoothly blend towards a longitudinal center of the watercraft
10
at the bow. The lines of intersection between the inclined sections and the corresponding sidewalls
84
form the outer chines
86
which affect handling, as known in the art.
With reference again to
FIG. 1
, toward the transom
82
of the watercraft
10
, the inclined sections of the lower hull section
18
extend outwardly from a recessed channel or tunnel
88
that is recessed within the lower hull section in a direction that extends upward toward the upper deck section
20
. The tunnel
88
has a generally parallelepiped shape and opens through the transom
82
of the watercraft
10
.
In the illustrated watercraft, a jet pump unit
90
propels the watercraft
10
. The jet pump unit
90
is mounted within the tunnel
88
formed on the underside of the lower hull section
18
by a plurality of bolts (not shown). An intake duct
92
, defined by the hull tunnel
88
, extends between the jet pump unit
90
and an inlet opening
94
that opens into a gullet
96
. The duct
92
leads to an impeller housing
98
.
A steering nozzle
100
is supported at the downstream end of a discharge nozzle
102
of the impeller housing
98
by a pair of vertically extending pivot pins (not shown). In an exemplary embodiment, the steering nozzle
100
has an integral lever on one side that is coupled to the handlebar assembly
32
through, for example, a bowden-wire actuator, as known in the art. In this manner, the operator of the watercraft
10
can move the steering nozzle
100
to effect directional changes of the watercraft
100
.
A ride plate
104
covers a portion of the tunnel
88
behind the inlet opening
94
to enclose the jet pump unit
90
within the tunnel
88
. In this manner, the lower opening of the tunnel
88
is closed to provide a planing surface for the watercraft
10
. A pump chamber
106
thus is at least partially defined within the tunnel section
88
covered by the ride plate
104
.
An impeller shaft
108
supports an impeller (not shown) within the impeller housing
98
. The aft end of the impeller shaft
108
is suitably supported and journaled within a compression chamber of the housing
98
in a known manner. The impeller shaft
108
extends in a forward direction through the bulkhead
58
. A protective casing preferably surrounds a portion of the impeller shaft
108
that lies forward of the intake gullet
96
. The forward end of the impeller shaft is connected to the engine
12
via a toothed coupling
110
.
The engine
12
, which drives the jet pump unit
90
, will now be described with initial reference to
FIGS. 1 and 2
. The illustrated engine
12
is a four-stroke, in-line straight four cylinder engine. However, it should be appreciated that several features and advantages of the present invention can be achieved utilizing an engine with a different cylinder configuration (e.g., v-type, w-type or opposed), a different number of cylinders (e.g., six) and/or a different principle of operation (e.g., two-cycle, rotary, or diesel principles).
The engine
12
comprises an engine body
112
having a cylinder head
114
, a cylinder block
116
and a crankcase
118
. The crankcase
118
defines a crankcase chamber
119
. The cylinder block
116
preferably is formed with four generally vertically extending cylinder bores
120
. The cylinder bores
120
may be formed from thin liners that are either cast or otherwise secured in place within the cylinder block
116
. Alternatively, the cylinder bores
120
may be formed directly in the base material of the cylinder block
116
. If a light alloy casting is employed for the cylinder block
116
, such liners can be used.
As mentioned above, the illustrated engine
12
is a four cylinder engine; thus, the cylinder block
116
includes four cylinder bores
120
. A piston
122
is provided within each cylinder bore
120
and is supported for reciprocal movement therein. Piston pins
124
connect the pistons
122
to respective connecting rods
126
. The connecting rods
126
, are journaled on the throws of a crankshaft
128
. The crankshaft
128
is journaled by a plurality of bearings within the crankcase
118
to rotate about a crankshaft axis that lies generally parallel to the longitudinal axis of the watercraft
10
. As will be explained in more detail below, the crankcase
118
preferably comprises an upper crankcase member
130
and a lower crankcase member
132
, which are attached to each in any suitable manner.
The cylinder head
114
is provided with individual recesses which cooperate with the respective cylinder bores
120
and the heads of the pistons
122
to form combustion chambers
134
. These recesses are surrounded by a lower cylinder head surface that is generally planar and that is held in sealing engagement with the cylinder block
116
, or with cylinder head gaskets (not shown) interposed therebetween, in a known manner. This planar surface of the cylinder head
114
may partially override the cylinder bores
120
to provide a squish area, if desired. The cylinder head
114
may be affixed to the cylinder block
116
in any suitable manner.
Poppet-type intake valves
136
are slidably supported in the cylinder head
114
in a known manner, and have their head portions engageable with valve seats so as to control the flow of the intake charge into the combustion chambers
134
through intake passages
138
formed in the cylinder head
114
. The intake valves
136
are biased toward their closed position by coil compression springs
140
. The valves
136
are operated by an intake camshaft
142
which is suitably journaled in the cylinder head
114
in a known manner. The intake camshaft
142
has lobes that operate the intake valves
136
through thimble tappets.
The intake camshaft
142
is driven by the crankshaft
128
via a camshaft drive mechanism, which is partially shown in FIG.
3
. In particular, the camshaft drive mechanism includes a timing belt
143
that couples the crankshaft
128
to the intake camshaft
142
. The camshaft drive mechanism is well known in the art; thus, a further description of this mechanism is not necessary for one of ordinary skill in the art to practice the present invention.
With particular reference to
FIG. 2
, the cylinder head
114
includes at least one exhaust passage
144
for each combustion chamber
134
. The exhaust passages
144
emanate from one or more valve seats formed in the cylinder head
114
. At least one exhaust valve
146
is supported for reciprocation in the cylinder head
114
for each combustion chamber
134
, in a manner similar to the intake valves
136
. The exhaust valves
146
also are biased toward their closed position by coiled compression springs
140
. An overhead mounted exhaust camshaft
148
opens and closes the exhaust valves
146
. As with the intake camshaft
142
, the exhaust camshaft
148
is suitably journaled for rotation in the cylinder head
114
and includes cam lobes that cooperate with thimble tappets for operating the exhaust valves
170
in a known manner. In the illustrated engine, the rotational axis of the intake camshaft
142
and the exhaust camshaft
148
are parallel to each other. Like the intake camshaft
142
, the crankshaft
128
drives the exhaust camshaft
148
in a known manner.
A valve cover
150
encloses the camshafts
142
,
148
and is sealably engaged with an upper surface of the cylinder head
114
. As such, the valve cover
150
protects the camshafts
142
,
148
from foreign material and entraps any lubricants provided to the camshafts
142
,
148
.
A suitable ignition system is provided for igniting an air and fuel mixture that is provided to each combustion chamber
134
. Spark plugs
152
(
FIG. 4
) preferably are fired by a suitable ignition system, which can include an electronic control unit (ECU)
154
connected to the engine
12
by one or more electrical cables. Preferably, the ECU
154
is mounted to the bulkhead
58
in a recess
173
. A pulsar-coil (not shown), which may be incorporated into the ECU
154
, generates firing signals for the ignition system. In addition, the ignition system may include a battery for use in providing power to an electric starter and the like. The crankshaft
128
is preferably coupled to a flywheel assembly
156
(FIG.
3
), which preferably is located in front of the engine
12
. The flywheel assembly
156
includes a flywheel magneto (not shown) that forms part of the ignition system. A cover
158
is attached to the front end of the cylinder block
116
and cylinder head
114
to enclose the flywheel assembly
156
.
FIGS. 1-5
illustrate an engine air intake system
160
having certain features, aspects and advantages in accordance with the present invention. With initial reference to
FIGS. 2 and 3
, the illustrated engine air intake system
160
includes intake pipes
162
that communicate with the intake passages
138
formed in the cylinder head
114
. The intake pipes
162
extend generally downwardly from the cylinder head
114
and communicate with an intake chamber
164
, which preferably is positioned entirely lower than the cylinder head
114
. The intake chamber
164
is positioned generally below the intake pipes
162
and along a side of the engine
12
. Inlets
166
(illustrated in dashed lines) of the intake pipes
162
preferably lie below a top wall
168
of the intake chamber
164
. A bottom wall
169
of the intake chamber
164
is preferably inclined so as to converge to a bottom wall low point
165
. A one-way valve
167
is preferably located at the low point
165
. In this manner, fluid within the intake chamber
164
is collected at the low point
165
and drained from the chamber
164
through the valve
167
. In the illustrated embodiment, the low point
165
is positioned generally centrally in the intake chamber
164
. Alternatively, the bottom wall
169
can be arranged so that the low point
165
is disposed at any location along the bottom wall
169
. For example, the low point could be positioned at either end of the bottom wall or adjacent a corner of the chamber
164
.
With reference now to
FIGS. 3 and 4
, a butterfly-type throttle valve
170
preferably is located upstream of an inlet
172
to the intake chamber
164
. As is typical with butterfly-type valves, the illustrated throttle valve
170
includes a valve shaft
174
and a valve disc
176
. The throttle valve
170
regulates the amount of air C delivered to the engine
12
in a manner well known to those of ordinary skill in the art. Preferably, the throttle valve
170
is controlled by a throttle valve control system, which includes the ECU
154
, a throttle valve actuator (not shown), and a throttle valve position sensor
178
. The ECU
154
senses the position of the throttle valve
170
through the valve position sensor
178
and controls the opening and closing of the valve
170
through the throttle valve actuator. In an alternative embodiment, a throttle valve
170
could be positioned in each of the intake pipes
162
.
With particular reference to
FIGS. 3-5
, an intake silencer
180
is positioned generally in front of the illustrated engine
12
. The intake silencer
180
preferably is divided into an upstream chamber
182
and a downstream chamber
184
. A casing
186
defines an internal volume of the intake silencer
180
, and a dividing wall
188
divides the internal volume into the upstream and downstream chambers
182
,
184
. The upstream and downstream chambers
182
,
184
communicate with each other through a connection pipe
190
that extends through the dividing wall
188
. As best seen in
FIG. 5
, the connection pipe
190
preferably connects a lower section
192
of the upstream chamber
182
to a lower section
194
of the downstream chamber
184
.
A lower wall
200
of each chamber
182
,
184
is preferably inclined so as to converge to a chamber low point
195
. A one-way valve
198
is preferably located at each low point
195
. A one-way valve
198
is preferably positioned on the lower wall
200
of each chamber
182
,
184
at the low point
195
. In this manner, fluid within the chambers is collected at the low points
195
and drained through the valve
198
. As with the low point
165
of the intake chamber
164
, the low points
195
of the upstream and downstream chambers
182
,
184
can be positioned at any location along the lower wall
200
.
Each chamber
182
,
184
of the intake silencer
180
preferably includes a dividing plate
196
located near the bottom of the chamber and adjacent the lower wall
200
. The dividing plate
196
includes multiple holes. The purpose and function of the one-way valves
198
and the dividing plate
196
will be described below.
With continued reference to
FIGS. 3-5
, the intake silencer
180
includes at least one inlet
202
, which is open to the engine compartment
44
. The inlet
202
allows air C from the engine compartment
44
to flow into the upstream chamber
182
of the air intake silencer
180
. The inlet
202
preferably is located on a side wall
204
(
FIG. 4
) of the intake silencer
180
such that the inlet
202
opens towards the engine
12
. This arrangement reduces the likelihood that water may splash into the inlet
202
. As best seen in
FIG. 5
, the inlet
202
opens to an upper section
206
of the upstream chamber
182
.
An intake duct
208
connects the downstream chamber
184
of the intake silencer
180
to the intake chamber
164
. Preferably, the intake duct
208
extends downwardly and rearwardly from the intake silencer
180
to the intake chamber
164
. As best seen in
FIG. 5
, the intake duct
208
connects to an outlet
210
of the intake silencer
180
. The outlet
210
preferably is located on a vertical end wall
212
of the intake silencer
180
. More preferably, the outlet
210
is positioned on the vertical side wall such that it is distanced from the top wall
213
of the intake silencer
180
. Moreover, the outlet
210
preferably communicates with an upper section
214
of the upstream chamber
182
, which lies generally vertically above the connection pipe
190
.
One of the features and advantages of the intake system
160
described above is that it prevents water from entering the engine
12
. For example, when the watercraft
10
is rocked vigorously, water can get into the engine compartment
44
through the forward and rear air ducts
76
,
78
, or other openings in the hull
16
. Once inside, the water can be drawn into the upstream chamber
182
of the intake silencer
180
. Air C flows through the intake silencer
180
along a flow path from the inlet
202
through the connection pipe
190
and out the outlet
210
. Since the inlet
202
and outlet
210
are preferably positioned in the upper sections
206
,
214
of their respective chambers
182
,
184
and the connection pipe connects the lower sections
192
,
194
of the chambers
182
,
184
, the flowing air C must drastically change directions as it flows through the intake silencer
180
. Thus, water in the air will be deposited onto the inner walls of the intake silencer
180
and separated from the air. The water collects at the bottom of the intake silencer
180
and is discharged to the through the one-way valves
198
. The dividing plate
196
reduces waves in the accumulated water that may form due to vigorous rocking of the watercraft
10
. This also reduces the amount of water mist that is formed from splashing waves.
If the watercraft
10
overturns, the accumulated water in the intake silencer
180
does not enter the intake duct
208
because the outlet
210
of the intake silencer
180
is located on the end wall
212
and is spaced from the top wall
213
. Accordingly, the outlet
210
is positioned above the inner bottom surface of the intake silencer
180
when the watercraft
10
is overturned. Thus, at the time of the overturn, the accumulated water is less likely to flow through the outlet
210
into the intake duct
208
.
The intake chamber
164
and intake pipes
162
also are arranged to prevent water from entering the engine
12
. Specifically, and as mentioned above, the intake pipes
162
extend downwardly from the cylinder head
114
. The intake chamber
164
is connected to the lower ends of the intake pipes
162
. Air C entering the intake chamber
164
through the throttle valve
170
must change from a rearward flow direction to an upward flow direction to enter the intake pipes. Thus, water entrained in air that flows into the intake chamber
164
tends to deposit along the inner walls and settle at the bottom of the intake chamber
164
. Water that may flow from the intake duct
208
into the intake chamber
164
also will collect at the bottom of the intake chamber
164
. The accumulated water is discharge through the one-way valve
167
located at the bottom of the intake chamber
164
.
Additionally, the inlets
166
of the intake pipes
162
preferably lie below and are spaced from the top wall
168
of the intake chamber
164
. If the watercraft
10
is overturned so that the top wall
168
becomes the bottom surface of the intake chamber
164
, water within the intake chamber
164
will not flow into the intake pipes
162
.
Accordingly, the intake system
160
protects the engine
12
from water that may enter the engine compartment
44
. Moreover, the components of the intake system
160
are generally near the bottom of the watercraft
10
. This lowers the center of gravity and increases the turning ability of the watercraft
10
.
The watercraft
10
also includes a fuel supply system that delivers fuel to the engine
12
. The main components of the fuel supply system generally are illustrated in
FIGS. 1
,
2
,
4
, and
7
. The fuel supply system includes the fuel tank
74
, which is shown schematically in
FIG. 4. A
low pressure pump
216
draws fuel from the fuel tank
74
through a fuel line
215
and through a fuel filter
218
. The fuel filter
218
separates water and other contaminants from the fuel. The low pressure pump
216
, which is preferably positioned on the valve cover
150
, supplies fuel to a vapor separator assembly
220
through a low pressure fuel line
217
.
As best seen in
FIGS. 2 and 7
, the vapor separator
220
preferably is positioned under the intake pipes
162
of the intake system
160
. More preferably, the vapor separator
220
is located in the dead space S (i.e., open space not occupied by other components) between the intake chamber
164
, the intake pipes
162
, and the engine
12
. With reference to
FIG. 2
, a generally vertical datum or reference plane R is defined along the axis of the crankshaft
128
. In addition, a plane P that is generally parallel to the reference plane R is defined at an outermost surface of the crankcase
118
, the cylinder head
114
(i.e., the valve cover
150
) or both (as illustrated), and the vapor separator
220
preferably is positioned between these two planes P, R.
With reference to
FIG. 4
, the vapor separator can be formed in two portions that are integrally formed with the cylinder block and the cylinder head. One portion can include one or more support ribs
222
. In this arrangement, the vapor separator
220
is mounted to a side of the engine
12
by one or more of the support ribs
222
.
With reference again to
FIG. 2
, the intake pipes
162
extend upward from the intake box
164
and inward toward the engine
12
. A protective pocket S is defined below the intake pipes
162
, inward of the intake box
164
and outward of the engine
12
. In some arrangements, portions of the engine
12
(e.g., the cylinder head and the cylinder body) can project outward toward the intake box to further protect the vapor separator. Of course, portions of the intake box can be extended inward in combination with, or in lieu of, protuberances formed on the engine. In the illustrated arrangement, a portion of the cylinder head
114
overhangs beyond the cylinder body
116
and a portion of the cylinder body
116
extends outward to form a protuberance.
It is anticipated that a recess can be formed between the air intake box
164
and the cylinder block
116
to house the vapor separator
220
(e.g., the recess can be formed in one member or both members). Thus, the vapor separator
220
can be at least partially integrated (i.e., manufactured in a single piece) into the cylinder block and cylinder head in some arrangements. In such arrangements, however, it is preferred that the vapor separator be spaced from the cylinder body to reduce the amount of heat transferred between the cylinder bore and the vapor separator. This arrangement protects the vapor separator
220
and the lines (e.g., the low pressure fuel line
217
) connected to the vapor separator
220
from splashing water that has entered the engine compartment. This is desired because the vapor separator
220
and lines connected to the vapor separator
220
are preferably made of aluminum, which can be damaged by water.
With particular reference to
FIG. 7
, the vapor separator
220
includes a high-pressure pump
223
, which is positioned within a housing
224
of the vapor separator
220
. The housing
224
defines a fuel bowl
225
of the vapor separator
220
. A sloped bottom surface of the housing
224
funnels the fuel towards an inlet of the high pressure pump
223
.
The vapor separator
220
also includes an inlet port
226
, a return inlet port
228
, a vapor discharge port
230
, and an outlet port
232
. Preferably, these ports are located on an upper wall
233
of the vapor separator
220
. More preferably, these ports are positioned to extend between adjacent intake pipes. In this manner, the vapor separator
220
can be more compactly arranged with the intake pipes
162
. Such a construction further protects the vapor separator
220
from substantial water damage.
The outlet port
232
communicates with an outlet of the high pressure pump
223
. The vapor discharge port
230
is positioned to the side of the inlet port
226
at a position proximate to the upper end of the housing
224
. The vapor discharge port
230
communicates with a conduit
234
that communicates with the intake system
160
thus recirculating the vapors back into the intake air in any suitable manner.
The inlet port
226
connects to the lower pressure fuel line
217
that extends from the low pressure pump
216
. A needle valve
236
operates at a lower end of the intake port
226
to regulate the amount of fuel within the fuel bowl
225
. Specifically, a float
240
that is located within the fuel bowl
225
actuates the needle valve
236
in a known manner. When the fuel bowl
225
contains a low level of fuel B, the float
240
lies in a lower position and opens the needle valve
236
. When the fuel bowl
225
contains a pre-selected amount of fuel B, the float
240
is disposed at a level where it causes the needle valve
236
to close.
The high pressure pump
223
draws fuel through a fuel strainer
242
. The fuel strainer
242
lies generally at the bottom of the fuel bowl
225
. Preferably, the high pressure pump
223
is an electric pump. The high pressure pump
223
draws fuel B from the fuel bowl
225
and pushes the fuel B through the outlet port
232
and into a high pressure fuel line
244
, which is connected to a fuel rail or manifold
246
(FIGS.
2
and
4
).
With reference again to
FIG. 2
, the fuel rail
246
delivers fuel to a plurality of fuel injectors
248
. Preferably, the fuel injectors
248
are situated such that there is at least one fuel injector
248
associated with each intake pipe
162
and intake passage
138
. That is, in the illustrated embodiment, the fuel injectors
248
inject fuel B directly into the air stream passing through the intake pipes
162
and the corresponding intake passages
138
. Preferably, the fuel injectors
248
are opened and closed by solenoid valves, which are, in turn, controlled by the ECU
154
. As will be recognized by those of ordinary skill in the art, certain features, aspects and advantages of the present invention can be used with directly injected engines and carburetted engines as well.
As shown in
FIG. 4
, a fuel return line
249
extends between an outlet port of the fuel rail
246
and the return port
228
of the vapor separator
220
. Preferably, a pressure regulator
250
is positioned in the return line
249
. The pressure regulator
250
maintains the desired fuel pressure at the injectors
248
by bypassing (or returning) some of the fuel to the vapor separator.
The watercraft
10
also includes an engine exhaust system
122
that is illustrated in
FIGS. 1
,
2
,
4
, and
6
. The exhaust system
122
guides exhaust gases produced by the engine
12
to the atmosphere. The engine exhaust system
252
includes the exhaust passages
144
, which communicate with each of the combustion chambers
134
and that are formed within the engine
12
, and an exhaust manifold
254
that communicates with each of the exhaust passages
144
. In the illustrated arrangement, the exhaust manifold
254
is formed integrally with the engine block
116
(see FIG.
2
).
As best seen in
FIG. 6
, an exhaust pipe
256
is connected to the exhaust manifold
254
. The exhaust pipe
256
includes an upstream portion
258
that extends rearwardly, downwardly, and then forwardly from the exhaust manifold
254
. The upstream portion
258
is connected to a generally horizontal portion
260
that extends forwardly from the upstream bent portion
258
. A downstream bent portion
262
extends upwardly from the horizontal portion
260
and is connected to an exhaust collection chamber
264
.
The chamber
264
includes as protruding section
266
that opens up into an enlarged chamber
268
, which is configured to attenuate the noise carried by the flow of exhaust gases, in a known manner. The expansion chamber
264
and the exhaust pipe
256
preferably include cooling passages
270
that are connected to a cooling system by a coolant pipe
272
. The cooling system cools the exhaust gases, the exhaust pipe
256
, and the expansion chamber
264
in a known manner.
The expansion chamber
264
communicates with a water lock
276
via a second exhaust pipe
278
, as shown in FIG.
1
. The water lock
276
is a well-known device that allows exhaust gases to pass, but contains a number of baffles (not shown) that prevent water from passing back through the second exhaust pipe
278
and the expansion chamber
264
and into the engine
12
. In the illustrated arrangement, the water lock
278
is located on one side of the hull tunnel
88
.
The water lock
278
transfers exhaust gases to a third exhaust pipe
280
. The third exhaust pipe
280
extends upwardly, rearwardly and then downwardly to a discharge
282
formed on the hull tunnel
88
. The third exhaust pipe
282
discharges the exhaust gases to the pump chamber
106
, such that the passage of water through the exhaust pipe
282
into the water lock
278
is further inhibited.
The watercraft
10
also includes a dry sump-type lubrication system for lubricating various components of the engine
12
. The lubrication system is referred to generally by the reference numeral
180
and is illustrated in
FIGS. 2
,
3
,
8
A, and
8
B.
The lubrication system
180
includes lubricant collecting passages
286
that are formed at the bottom of the crankcase
32
. The lubricant collecting passages
286
are formed by the lower crankcase member
132
and a lower cover
288
that is secured to the lower crankcase member
132
. The lubricant collecting passages
286
include openings
290
a-d
that are provided at the bottom of each of the crankcase chambers
119
a-d
and that extend through the lower crankcase member
132
. The openings
290
a-d
communicate with transverse passages
292
a-d
that extend to a suction port
300
. The transverse passages
292
a-d
are formed from grooves
294
a-d
located on the lower surface
296
of the lower member
132
and the top surface
298
of the lower cover
288
. With this arrangement, the lubricant collecting passages
286
communicate with each cylinder. Accordingly, lubricant can be removed from the four cylinders.
The suction port
300
is connected to a suction pump
302
. As best seen in
FIGS. 3 and 8
, the suction pump
302
is a positive displacement-type pump that is journaled to an end of the crankshaft
128
at the rear side of the hull
16
. The suction pump
302
draws lubricant up from the lubricant collecting passages
286
and delivers the lubricant to a lubricant tank
304
through a lubricant passage
306
, which is located inside the engine body
112
, and a first lubricant pipe
308
, which includes a negative pressure valve
309
. The lubricant tank
304
is located at the rear of the engine
12
.
With particular reference to
FIG. 3
, the first lubricant pipe
308
is connected to the top of the lubricant tank
304
. The lubricant tank
304
includes a vapor separator
310
, which includes a set of baffles
313
. A first vapor pipe
312
is connected to the top of the lubricant tank
304
. Vapors collected inside lubricant tank
304
are discharged through the first vapor pipe
312
to the intake system
160
. Preferably, the first vapor pipe
312
includes a negative pressure valve
314
.
A transfer pump
316
is located below the lubricant tank
304
and draws lubricant from the lubricant tank
304
through a second lubricant pipe
318
. Preferably, the second lubricant pipe
318
also includes a negative pressure valve
309
. The transfer pump
316
is a positive displacement-type pump that is journaled to the crankshaft
128
in an arrangement similar to the suction pump
302
. The transfer pump
316
delivers lubricant to lubricant galleries provided in the engine body
112
for lubricating moving parts in the engine body
112
. For example, lubricant is supplied to lubricant passages formed within the crankcase
118
for lubricating the crankshaft
128
. Additionally, lubricant is supplied to lubricant galleries configured to guide lubricant to the camshafts
142
,
146
, the valves
136
,
146
, and the cylinder bores
120
(see FIG.
2
). An oil filter
320
(see
FIG. 2
) is provided between the lubricant galleries and the transfer pump
316
.
Blow-by vapors are removed from the lubrication system
284
and released into the intake system
160
through various vapor passages. For example, as mentioned above, vapors from the lubricant tank
304
are delivered to the intake system
160
through the first vapor pipe
312
. Additionally, as shown in
FIG. 3
, a second vapor pipe
322
is connected to the valve cover
150
and the intake system
160
. The second vapor pipe
322
preferably includes a negative pressure valve
314
. The blow-by gases from the inside of the valve cover
150
are discharged through the second vapor pipe
322
to the intake system
160
.
As such, the lubrication system
180
operates under the dry-sump lubrication principle, thus circulating lubricant through the engine
12
using a shallow lubricant pan and allowing the engine
12
to be mounted close to an inner surface of the lower hull section
18
, as compared to engines employing wet sump type lubrication systems. This lowers the center of gravity of the watercraft
10
. Of course, certain features, aspects and advantages of the present invention can be used in wet sump operations.
FIGS. 9 and 10
illustrate a modified arrangement of the lubrication system
180
. In this arrangement, a v-shaped lubrication guide
324
directs lubricant towards the sides
326
of the crankcase chamber
119
. The openings
290
are located at the sides
326
and extend through the lower member
132
to lubricant connecting passages
328
. The lubricant connecting passages
328
are connected to a transverse passage
330
that communicates with the suction port
300
. This arrangement ensures that as the watercraft
10
rocks from side to side, lubricant can be continuously drained from the bottom of the crankcase chamber
119
.
The watercraft
10
preferably includes an emergency shut-off system
400
that is illustrated schematically in FIG.
12
. The emergency shut-off system
400
is configured to determine when the watercraft
10
is overturned. When the emergency shut-off system
400
determines that the watercraft
10
has overturned, the emergency shut-off system
400
is also configured to shut off the engine
12
and/or perform other functions that prevent water entering the engine compartment
44
. As shown in
FIG. 12
, the emergency stop system
400
includes an overturn switch
24
(see FIG.
11
), the ECU
154
(see also
FIG. 1
) and the forward rear intake shutoff valves
77
,
79
that are located in the upper ends of the forward and rear intake ducts
76
,
78
(see
FIG. 1
) and are controlled by the ECU
154
.
FIG. 11
illustrates an arrangement of the overturn switch
402
. The overturn switch
402
includes a pendulum
404
that is configured to pivot about an axis
405
. When the watercraft
10
is overturned, the pendulum
404
pivots, as indicated by the arrow D, and rests against the right or left stopper
406
a,
406
b.
When the pendulum
404
contacts one of the stoppers
406
a,
406
b,
the overturn switch
402
sends a signal to the ECU
154
.
The emergency shut-off system
400
includes methods and apparatus for determining if the watercraft
10
is overturned from the signal generated by the overturn switch
402
. In particular, the emergency shut-off system includes subroutines that determine when the watercraft
10
is overturned from the signal generated by the overturn switch
402
. It should be noted that the ECU
154
, which performs these subroutines, may be in the form of a hard wired feed back control circuit that performs the subroutines describe below. Alternatively, the ECU
154
can be constructed of a dedicated processor and memory for storing a computer program configured to perform the steps described below. Additionally, the ECU
154
can be a general purpose computer having a general purpose processor and the memory for storing a computer program for performing the steps and functions described below.
In one subroutine, the emergency shut-off system
400
is initialized, preferably when an ignition starting device (e.g., a key activated switch) is activated. Once initialized, the emergency shut-off system
400
determines if the overturn switch
402
is generating a signal. If a signal is not being generated, the emergency shut-off system
400
continues monitoring for a signal from the overturn switch
402
. If a signal is being generated, the emergency shut off system
400
then determines if the signal continues for a predetermined amount of time (e.g., several seconds). If the signal does not continue for the predetermined amount of time, the emergency shut off system
400
determines that the watercraft
10
has not been overturned. In such a situation, the emergency shut-off system
400
continues monitoring for a signal from the overturn switch
402
. If the signal does continue for the predetermined amount of time, the emergency shut-off system
400
determines that the watercraft
10
has overturned. The emergency shut-off system
400
then performs certain functions to prevent water from damaging the engine
12
as will be describe in more detail below.
The emergency shut-off system
400
can be arranged in several different ways to determine if the signal from the overturn switch
402
continues for the predetermined amount of time. For example, the emergency shut-off system
400
can be configured such that the signal from the overturn switch
400
must be continues or substantially continues during the predetermined time period. In a modified arrangement, the emergency shut-off system
400
can be configured to determine if the signal from the overturn switch is merely being generated before and after the predetermined time period.
An advantage of the subroutine described above is that the emergency shut-off system
400
does not determine that the watercraft
10
is overturned if the watercraft
10
is merely turning abruptly or rocking back and forth quickly. In such situations, the pendulum
404
contacts the stoppers
406
a,
406
b
for a short period of time. Accordingly, the signal generated by the overturn switch
402
do not continue for a time period greater than the predetermined time.
When the emergency shut off system
400
determines that the watercraft
10
is overturned, the emergency shut-off system
400
stops the engine
12
. Preferably, this is accomplished by stopping the supply electricity to the spark plugs
154
or by closing the fuel injectors
246
. The emergency stop system
400
also preferably closes the forward rear intake shutoff valves
77
,
79
of the forward and rear intake ducts
76
,
78
. This further prevents water from entering the engine compartment.
As shown in
FIG. 12
, the emergency control system
400
also preferably includes an electric bilge pump
408
(see also
FIG. 1
) that is controlled by the ECU
154
. When the emergency stop system
400
detects that the watercraft
10
is overturned or overturned for a predetermined amount of time and then returned to an upright position, the emergency stop system
400
preferably activates the bilge pump
408
. The bilge pump
408
is configured to remove water from the hull
16
and preferably to deliver it to a low pressure part of the jet propulsion unit
90
. Accordingly, water that accumulates in the hull
16
while the watercraft
10
is overturned can be removed.
With reference now to
FIG. 11
, the emergency shut-off system
400
also preferably includes a water level detection sensor
410
that is connected to the ECU
154
and illustrated in FIG.
13
. The water level sensor
410
is configured to detect when water in the engine compartment
44
exceeds a predetermined level (e.g., when the water level exceeds a height of an impeller shaft of the jet propulsion unit
98
). As shown in
FIG. 13
, the illustrated water level sensor
410
includes a cylindrical body
412
that preferably is mounted to a bulkhead
58
near the lower hull
16
in the engine compartment
44
. The cylindrical body
412
includes openings
414
that allow water that has accumulated in the engine compartment
44
to enter the cylindrical body
412
. A buoy
416
is positioned in the cylindrical body
412
and is freely movable in a vertical direction. A positional detection sensor
418
, such as, for example, a magnetic force sensor or infrared sensor, detects the position of the buoy
416
and is connected to the ECU
154
through a sensor controller
420
.
When water is accumulated in the engine compartment
44
, the buoy
416
begins to rise in the cylindrical body
412
. When the buoy
416
reaches the level of the positional detection sensor
418
, the sensor
418
sends a signal through the controller
420
and to the ECU
154
. When such a signal is received by the ECU
154
, the emergency shut-off system
400
stops the engine
12
. In addition, the emergency start system
400
preferably starts the bilge pump
408
, thereby removing the water from the hull
16
. The emergency shut-off system
400
preferably also prevents the engine
12
from being restarted until the water level inside the engine compartment
44
is lower than a predetermined level. It is anticipated that at least two activation levels can be incorporated such that the bilge pump can be controlled (on/off or speed) before the level that results in stopping the engine is reached.
When the watercraft
10
is overturned and the engine
12
is shut off by the emergency stop system
400
, the pressure in the intake system
160
is no longer negative. Accordingly, the negative pressure valves
314
in the vapor pipes
312
,
322
close when the watercraft
10
is overturned. This arrangement prevents lubricant from the lubricant tank
304
and the valve cover
150
from flowing into the intake system
160
. In a modified arrangement, the negative pressure valves
314
can be electronic valves
314
that are controlled by the ECU
154
. In such an arrangement, the emergency shut-off system
400
can be configured to shut the electronic control valves when the emergency shut-off system
400
determines that the watercraft
10
has overturned. Preferably, the valves are designed to be normally closed such that the valves close when power is removed.
In a similar manner, when the watercraft
10
is overturned and the engine
12
is shut off, the negative pressure valves
309
in the first and second lubricant pipes
308
,
318
are closed. These valves
309
prevent the back flow of lubricant from the transfer pump
316
to the lubricant tank
304
and from the lubricant tank
304
to the suction pump
302
. This arrangement allows the lubricant to be stored in the transfer pump
316
when the engine
12
is shut off. Accordingly, lubricant is quickly and smoothly delivered to the engine
12
when the engine
12
is restarted. In a modified arrangement, the negative pressure valves
309
can be electric valves
309
that are closed by the emergency shut-off system
400
when the watercraft
10
is overturned.
In a modified arrangement of the emergency stop system
400
, the overturn switch
402
comprises an lubrication system pressure sensor. When the watercraft
10
is overturned, only a small amount of lubricant is discharged from the transfer pump
316
. Accordingly, the lubrication pressure inside the lubrication system
284
dramatically drops. The emergency shut-off system
400
can be configured to shut off the engine
12
when such a dramatic drop in the lubrication system
284
is detected. In an additional arrangement, the overturn switch
402
comprises an engine compartment pressure sensor that detects the air pressure inside the engine compartment
44
. When the watercraft
10
is overturned, air cannot enter the engine compartment
44
. However, if the engine
12
is still running, the air in the engine compartment
44
is consumed and the air pressure drops. The emergency shut-off system
400
can be configured to shut off the engine
12
when such a pressure change is detected in the engine compartment.
FIGS. 14-17
illustrate a modified arrangement of the intake system
160
. In this arrangement, the one-way valves
167
,
198
(see
FIG. 3
) in the intake silencer
180
and the intake chamber
164
are replaced by drain hoses
500
,
502
(see FIGS.
14
and
15
). In addition, as shown in
FIG. 16
, a drain hose
504
is connected to the bottom of the exhaust pipe
256
.
As shown in
FIG. 17
, the drain hoses
500
,
502
,
504
are connected to a suction port
506
of the bilge pump
408
. The bilge pump
408
is controlled by the ECU
154
, which is connected to a water detection sensor
508
in addition to the overturn switch
402
and the water level sensor
410
. The water detection sensor
508
detects when water has accumulated inside the intake chamber
164
, intake silencer
180
, and/or the exhaust pipe
256
. In one arrangement, the water detection sensor
508
comprises individual water detection sensors located in each of the drain hoses
500
,
502
,
504
. In a modified arrangement, the water detection sensor
508
comprises individual water detection sensors
508
located at the bottom of the intake silencer
180
, intake chamber
164
, and exhaust pipe
256
. In the preferred embodiment, the water detection sensor comprises a single water detection sensor located in the bilge pump
408
or in a common hose
505
that communicates with each of the drain hoses
500
,
502
,
504
.
When the ECU
154
receives a signal from the water detection sensor
508
indicating that water is present in the intake chamber
164
, intake silencer
180
, and/or the exhaust pipe
256
, the ECU
154
sends a control signal to the bilge pump
408
to drain the accumulated water from the intake chamber
164
, intake silencer
180
, and/or the exhaust pipe
256
. This arrangement further ensures that water does not enter the engine
12
through the intake system
160
and/or the exhaust system
252
. Preferably, the ECU
154
is also configured to drive the bilge pump
408
when the overturn switch
402
detects that the watercraft
10
has overturned or when the water level sensor
410
detects that water has accumulated inside the engine compartment
44
.
As discussed above,
FIG. 18
illustrates a modified arrangement of the engine
12
, the intake system
160
and the fuel system. In this arrangement, a cylinder axis CA of the engine
12
is inclined at an angle F to the left side of the watercraft
10
. The intake system
160
includes carburetors
552
that are connected to the intake passages
138
and cylinder head
114
through corresponding joints
554
. The upstream side of the carburetors
552
are connected to the intake chamber
164
by the intake pipes
162
. The intake pipes
162
are connected to the intake silencer
180
by the intake duct
208
as in the previous arrangements.
Preferably, in this arrangement, the carburetors
552
are inclined upwardly. The intake pipes
162
, therefore, extend laterally to the left from the carburetors
552
and then extend downwardly. To connect to the intake chamber
164
, the intake pipes
162
bend to the right and then extend laterally and downwardly to the intake chamber
164
. The inlets
166
of the intake pipes
162
are spaced from the inner surface of the intake chamber
164
. In this arrangement, water may enter the carburetor
552
will tend to flow downwardly toward the intake chamber
164
due to the downward incline of the carburetor
552
.
The inclined nature of the engine
12
makes more space available for the exhaust system
252
. Accordingly, the expansion chamber
264
can be made larger with a greater angle of curvature. This reduces the exhaust resistance and increases engine
12
output power. Additionally, the inclined engine
12
enables the watercraft
10
to have a lower center of gravity, thus improving stability.
FIGS. 19-25
illustrate a modified arrangement of the lubrication system
284
. As shown in
FIG. 19
, a pump unit
600
is mounted at a rear surface
602
of the crank case
118
. An oil tank
604
that is preferably made of an aluminum alloy is mounted above the pump unit
600
.
As best seen in
FIG. 20
, the pump unit
600
is comprised of a first suction pump
606
, a second suction pump
608
and a lubricant transfer pump
610
. Each of the pumps,
606
,
608
,
610
are generally axially aligned and are journaled to a pump shaft
612
, which is splined to the rear of and is co-axial with the crankshaft
128
. In the illustrated arrangement, the first suction pump
606
is situated furthest from the crankshaft
128
and the lubricant transfer pump
610
is situated closest to the crankshaft
128
. The second suction pump
608
is located between the first suction pump
606
and the transfer pump
610
.
The pumps
606
,
608
,
610
are trochoidal pumps. Accordingly, they include rotors
614
,
616
,
618
that are secured to and rotate with pump shaft
612
. The rotors
614
,
616
,
618
are enclosed by a pump housing
620
.
The pump housing
620
is comprised of an outer housing
622
that is secured to the crankcase
118
. The outer housing
622
forms an outer periphery of the pump unit
600
. The pump housing
620
also includes an inner housing
624
and an inner cover
626
that is secured inside the outer housing
622
. A pump cover
628
is secured to the rear side
630
of the outer housing
622
. The pump shaft
612
is rotatably supported in the pump cover
628
and the inner cover
626
through bearings
632
and
634
.
The pump unit
600
is assembled by securing the outer housing
622
to the crank case
118
with a bolt
636
. The inner housing
624
and inner cover
626
also are secured to the outer housing
622
with a bolt
638
. A seal member
641
lies between the inner cover
626
and the crank case
118
and prevents substantial leakage. A bolt
642
also secures the pump cover
628
to the outer housing
622
.
With continued reference to
FIG. 20
, the pump housing
620
defines lubricant collecting passages
650
. The lubricant collecting passages
650
communicate with the crankcase chamber
119
, preferably in a manner similar to the arrangements illustrated in
FIG. 8
or
FIGS. 9 and 10
.
As shown in
FIG. 22
, one of the lubricant collecting passages
650
is connected to a first inlet passage
652
that is also defined by the pump housing
620
. A second lubricant collecting passage
650
is connected to a second inlet passage
654
, which also is defined by the pump housing
620
.
As indicated by the solid arrow
655
, the first suction pump
606
draws lubricant from the collecting passage
650
and the first inlet passage
652
and delivers the lubricant to a first outlet passage
656
. Similarly, the second suction pump
608
draws lubricant through the second inlet passage
654
and delivers it to a second outlet passage
658
, as indicated by the alternate long and short dashed line
660
. A third inlet passage
662
communicates with the lubricant tank
604
and the transfer pump
610
. As indicated by short dashed lines
664
, the transfer pump
610
delivers lubricant from the third inlet passage
662
to a third outlet passage
668
, which is also defined by the pump housing
622
.
The lubricant tank
604
is secured to the outer housing
622
by mounting bolts
670
. The third inlet passage
662
is connected an outlet opening
672
in the lubricant tank
604
. Sealing members
674
between the outer housing
622
and the lubricant tank
604
generally prevent the lubricant from leaking past the connection between the third inlet passage
662
and the outlet opening
672
.
The third outlet passage
668
, which is connected to the transfer pump
610
and the third inlet passage
662
, communicates with an engine lubrication passage
676
. As shown in
FIG. 20
, a spring biased ball check valve
678
is located between the engine lubrication passage
676
and the transfer pump
610
. This arrangement generally prevents the lubricant inside the lubricant tank
604
from draining towards the engine
12
when the engine
12
is shut off.
As shown in
FIGS. 20-25
, the lubricant tank
604
is comprised of a body
700
that is secured in the pump unit
600
by the mounting bolts
670
and a lid
702
that is secured by bolts
704
to the top of the tank body
700
. The lubricant tank
604
also includes a vapor separator
706
that is located inside the tank body
700
and connection pipes
708
and
710
that extend through the tank body
700
. The connection pipes
708
,
710
are connected to the first and second outlet passages
656
,
658
, as best seen in FIG.
22
. The connection is sealed by sealing ring
712
.
As shown in
FIG. 21
, the tank body
700
has a coolant passage
714
in its upper side. The coolant passage
714
encircles the upper side of the tank body
700
(see also FIG.
25
). Coolant is supplied from the cooling system through a coolant hose coupling member
716
located on the rear wall
718
of the tank body
700
. The coolant is discharged from another coolant hose coupling member
719
that is also located on the rear wall
718
.
As shown in
FIGS. 23 and 24
, the tank body
700
includes brackets
720
that are mounted in the cylinder body
120
and cylinder head
114
through mounting bolts
722
with rubber cushions
724
. Preferably, the tank body
700
is mounted with two mounting bolts
722
on each side of the tank body
700
.
With continued reference to
FIG. 23
, the lid
702
closes an upper opening of the tank body
700
. The lid
702
includes a ventilation hose coupling member
730
and lubricant cap
734
with an integral lubricant level gauge. The lubricant cap
734
closes the lubricant filling port
736
. The ventilation hose coupling member
730
is coupled to a hose (not shown) for delivering vapors inside the lubricant tank
604
to the intake system
160
.
As best seen in
FIG. 21
, the coupling member
730
is connected to the lubricant tank
604
by a communication passage
738
formed in the lid
702
. In the illustrated arrangement, a ball-type check valve
740
is positioned in the communication passage
738
for preventing the passage of lubricant into the intake system
160
from the lubricant tank
604
. The connection between the coupling member
730
and the communication passage
738
is sealed by a sealing member
674
.
The lid
702
of the lubrication tank
604
includes a damping member
742
. The damping member
742
includes an arm
744
that projects from the lid
702
and a flat plate
746
that extends vertically from the tip of the arm
744
. The flat plate
746
faces a stopper surface (not shown) formed in the cylinder head cover
150
(see also FIG.
19
). Accordingly, the damping member
742
restricts rocking movement of the lubricant tank
604
in the longitudinal and transverse directions relative to the engine
12
. However, the damping member
742
does not restrict the movement of the lubricant tank
604
in the vertical direction.
With reference to
FIG. 21
, the vapor separator
706
is configured to remove vapors contained in the lubricant delivered from the first and second suction pumps
606
,
608
through the connection pipes
708
,
710
. The vapor separator
706
is comprised of an upper lid
750
that is secured by bolts
752
to the upper side of the lid
702
(see also FIG.
24
). As best seen in
FIG. 25
, the vapor separator
706
also includes three vertical plates
754
,
756
,
758
that extend downwardly from the upper lid
750
. The vapor separator
706
further includes panels
760
that form a lubrication passage between the vertical plates
754
-
758
(FIG.
25
). A pipe
762
penetrates the panels
760
and the middle vertical wall
756
. The pipe
762
surrounds the connection pipes
708
,
710
.
The upper lid
750
supports the upper ends of the connection pipes
708
,
710
and a press member
764
that is clamped between the lid
702
. The connection pipes
708
,
710
are inserted through holes
766
that are formed in the middle of the upper lid
750
. Lubricant ports
768
are provided at the sides of the upper lid
750
. The lubricant ports
768
guide lubricant from the connection pipes
708
,
710
towards the vapor separator
706
.
A dividing plate
770
is provided in the lower portion of the lubricant tank
604
for reducing waves while the watercraft
10
is running. As shown in
FIG. 25
, the dividing plate
770
has a generally square shape in the top plan view and is secured in the tank body
700
.
The lubrication system as described with reference to
FIGS. 19-25
has several advantages. For example, the pump unit
600
is located in a dead space (see
FIG. 19
) formed between the coupling
110
and the crank case
118
. Accordingly, the pump unit
600
can utilize a plurality of lubricant pumps with minimal or no effect on the size of the engine
12
.
Another advantage is that the lubricant tank
604
is directly mounted to the upper side of the pump unit
600
. The space above the pump unit
600
can therefore be used to increase the size of the lubricant tank
604
.
Still yet another advantage is that the connection pipes
708
and
710
are located inside the lubricant tank
604
. This arrangement is simpler and takes up less space than an arrangement where the pipes are located outside the lubricant tank
604
.
Of course, the foregoing description is that of certain features, aspects and advantages of the present invention to which various changes and modifications may be made without departing from the spirit and scope of the present invention. Moreover, a watercraft may not feature all objects and advantages discussed above to use certain features, aspects and advantages of the present invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. The present invention, therefore, should only be defined by the appended claims.
Claims
- 1. A method of operating an emergency shut-off system for a small watercraft that includes a hull defining an engine compartment, an internal combustion engine supported within the engine compartment, an overturn switch, and an electronic control unit that is in electrical communication with the overturn switch, the method comprising:responding to a signal from the over switch, determining if the overturn switch is generating the signal for at least a preset amount of time, and shutting off the engine if the overturn switch has generated the signal for at least the preset amount of time.
- 2. A method as in claim 1, further comprising closing one or more shutoff valves that are operatively connected to the electronic control unit and that are positioned within one or more intake passages defined between the hull and the engine compartment when the overturn switch has generated the signal for at least the preset amount of time.
- 3. A method as in claim 1, further comprising activating a bilge pump that is operatively connected to the electronic control unit and that is positioned within the engine compartment when the overturn switch has generated the signal for at least the preset amount of time.
- 4. A method as in claim 1, further comprising closing one or more valves that are operatively connected to the electronic control unit and are positioned within a fuel system of the engine when the overturn switch has generated the signal for at least the preset amount of time.
- 5. A method as in claim 1, further comprising closing one or more valves that are operatively connected to the electronic control unit and are positioned within a lubrication system of the engine when the overturned switch has generated the signal for at least the preset amount of time.
- 6. A method of operating an emergency shut-off system for a small watercraft that includes a hull defining an engine compartment, an internal combustion engine supported within the engine compartment, a water level detection sensor positioned in the engine compartment, a bilge pump, and an electronic control unit that is in electrical communication with the sensor and the pump, the method comprising:responding to a signal from the water level detection sensor, shutting off the engine when the water level detection sensor indicates that water in the engine compartment exceeds a preset level, and activating the bilge pump.
- 7. A method as in claim 6, further comprising preventing the engine from restarting until the water in the engine compartment is less than a second preset level.
- 8. A method as in claim 6, further comprising closing one or more shutoff valves that are operatively connected to the electronic control unit and that are positioned within one or more intake passages defined between the hull and the engine compartment when the water level detection sensor indicates that water in the engine compartment exceeds the preset level.
- 9. A method as in claim 6, further comprising activating the bilge pump that is operatively connected to the electronic control unit and that is positioned within the engine compartment when the water level detection sensor indicates that water in the engine compartment exceeds the preset level.
- 10. A method as in claim 6, further comprising closing one or more valves that are operatively connected to the electronic control unit and that are positioned within a fuel system of the engine when the water level detection sensor indicates that water in the engine compartment exceeds the preset level.
- 11. A method as in claim 6, further comprising closing one or more valves that are operatively connected to the electronic control unit and that are positioned within a lubrication system of the engine when the water level detection sensor indicates that water in the engine compartment exceeds the preset level.
- 12. A small watercraft comprising a hull defining an engine compartment, an internal combustion engine supported within the engine compartment, and an emergency shut-off system comprising an overturn switch, an electronic control unit that is in electrical communication with the overturn switch and with the engine, the electronic control unit configured to receive a signal generated by the overturn switch to determine if the signal generated by the overturn switch continues for a period longer than a preset amount of time, and to shut off the engine if the signal generated by the overturn switch continues beyond the preset amount of time.
- 13. The small watercraft as set forth in claim 12, further comprising one or more intake ducts that guide air into the engine compartment, and one or more intake shutoff valves positioned within the one or more intake ducts, the intake shutoff valves operatively connected to the electronic control unit, and the electronic control unit being further configured to close at least one of the one or more shutoff valves when the signal generated by the overturn switch continues beyond the preset amount.
- 14. The small watercraft as set forth in claim 12, further comprising a bilge pump located within the engine compartment and operatively connected to the electronic control unit, and the electronic control unit is filer configured to activate the bilge pump when the signal generated by the overturn switch continues beyond the preset amount of time.
- 15. The small watercraft as set forth in claim 12, wherein said engine includes a fuel system with one or more valves operatively connected to the electronic control unit, and the electronic control unit is fiber configured to close at least one of the one or more valves in the fuel system when the signal generated by the overturn switch continues beyond the preset amount of time.
- 16. The small watercraft as set forth in claim 12, wherein said engine includes a lubrication system with one or more valves operatively connected to the electronic control unit which is further configured to close at least one of the one or more valves in the lubrication system when the signal generated by the overturn switch continues beyond the preset amount of time.
- 17. A small watercraft comprising a hull defining an engine compartment, an internal combustion engine supported within the engine compartment, a water level detection sensor positioned in the engine compartment, a bilge pump positioned within the engine compartment, and an electronic control unit in electrical communication with the bilge pump and with the engine, the sensor configured to send a signal to the electronic control unit when water in the engine compartment rises above a specified level, the electronic control unit configured to sense the signal from the water level detection sensor and to shut off the engine and to activate the bilge pump.
- 18. The small watercraft as set forth in claim 17, further comprising one or more intake ducts that guide air outside the hull into the engine compartment, and one or more intake shutoff valves positioned within the one or more intake ducts, the intake shutoff valves operatively connected to the electronic control unit, and the electronic control unit fiber configured to close at least one of the one or more shutoff valves when the water level detection sensor indicates that the water in the engine compartment rises above the specified level.
- 19. The small watercraft as set forth in claim 17, wherein said engine includes a fuel system with one or more valves operatively connected to the electronic control unit, and the electronic control unit is further configured to close at least one of the one or more valves in the fuel system when the water level detection sensor indicates that the water in the engine compartment rises above the specified level.
- 20. The small watercraft as set forth in claim 17, wherein said engine includes a lubrication system with one or more valves operatively connected to the electronic control unit, and the electronic control unit is further configured to close at least one of the one or more valves in the lubrication system when the water level detection sensor indicates that the water in the engine compartment rises above the specified level.
- 21. A small watercraft comprising a hull defining an engine compartment, an internal combustion engine supported within the engine compartment a bilge pump positioned within the hull, an electronic control unit in electrical communication with the bilge pump and the internal combustion engine, and means for shutting off the engine when the watercraft is overturned.
- 22. The small watercraft as set forth in claim 21, wherein said means for shutting off the engine comprises an overturn switch that is in electrical communication with the electronic control unit, the electronic control unit configured to sense a signal generated by the overturn switch and to determine if the signal generated by the overt switch continues for a period longer than a preset amount of time.
- 23. The small watercraft as set forth in claim 21, wherein said means for shutting off the engine comprises a water level detection sensor configured to send a signal to the electronic control unit when water in the engine compartment rises above a specified level.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-170731 |
Jun 1999 |
JP |
|
US Referenced Citations (11)
Foreign Referenced Citations (1)
Number |
Date |
Country |
8-49596 |
Feb 1996 |
JP |