Control system for small watercraft

Information

  • Patent Grant
  • 6419531
  • Patent Number
    6,419,531
  • Date Filed
    Monday, June 19, 2000
    24 years ago
  • Date Issued
    Tuesday, July 16, 2002
    22 years ago
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)
Number Name Date Kind
2773953 Lawick Dec 1956 A
3999178 Hamilton Dec 1976 A
4011848 Coddington Mar 1977 A
4050396 Ridgeway Sep 1977 A
4276454 Zathan Jun 1981 A
4341178 Price Jul 1982 A
4766329 Santiago Aug 1988 A
4871996 Tsunamoto et al. Oct 1989 A
5033428 Sasaki Jul 1991 A
5846102 Nitta et al. Dec 1998 A
6024068 Nakase et al. Feb 2000 A
Foreign Referenced Citations (1)
Number Date Country
8-49596 Feb 1996 JP