Patent Publication Number: US-6210243-B1

Title: Fuel pump arrangement for watercraft

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates in general to an engine, and in particular to a component layout for a marine engine, including an arrangement of the fuel pump. 
     2. Description of Related Art 
     Internal combustion engines are commonly used to power small watercrafts such as personal watercraft. These watercraft include a hull which defines an engine compartment Personal watercraft often employ an inline, multi-cylinder, crankcase compression, two-cycle engine. The engine conventionally lies within the engine compartment with the in-line cylinders aligned along a longitudinal axis of the watercraft hull. The output shaft of the engine is coupled to a water propulsion device of the watercraft, such as a jet propulsion unit. 
     Generally, the engine of the small watercraft also includes an air intake system, an exhaust system, a fuel supply system, and other components to operate the engine. Air is supplied to the engine from the outside of the hull for use in the combustion process. Typically, air flows through one or more ducts in the hull into the engine compartment, and then through the intake system to the cylinders. An exhaust system communicates with the cylinders of the engine and extends to a discharge that is located near the stern of the watercraft. 
     Fuel is also supplied to the engine for use in the combustion process. In order to accurately meter the fuel and improve engine operating efficiency and performance, the fuel may be injected with one or more fuel injectors. Each injector has an electrically operated valve which selectively opens and closes, controlling the flow of fuel through the injectors to the engine. In this arrangement, fuel is supplied to the fuel injectors at a high pressure by a fuel pump. 
     Personal watercraft also commonly include an access opening that is formed in the watercraft deck above the engine. A longitudinally extending, straddle-type seat normally covers the access opening to close the engine compartment. On occasions, a rider may need to open the access opening while the watercraft is floating in a body of water in order to make minor repairs or adjustments. 
     Prior arrangements of the fuel pump within the engine compartment posed the risk that water could enter the engine compartment through the uncovered access opening and contact the fuel pump, which consequently could damage the fuel pump and/or its electrical contacts. In addition, water that enters the engine compartment also tends to splash about within the engine compartment due to the pitching and rocking movement of the watercraft as it moves through the water With either direct contact or subsequent internal splashing, the water can corrode or otherwise damage the pump and/or interrupt the electrical current flow to the pump. In some cases, this may permanently damage the pump as well as affect the operation of the engine. 
     SUMMARY OF THE INVENTION 
     To overcome this problem, the present invention positions the fuel pump directly onto the engine housing in one of multiple locations. In each location, the fuel pump is at least partially shielded from water that enters into the engine compartment either directly through the access opening or indirectly due to splashing of water that has accumulated in the bottom of the engine compartment 
     In accordance with one aspect of the present invention, a watercraft comprises a hull that defines an engine compartment and an engine contained within the engine compartment. The engine compartment has an access opening positioned above the engine for access thereto. The engine includes an air intake system and a fuel pump supplying fuel to the engine. The fuel pump is positioned on the engine so as to be at least partially shielded from water that may pass through said access opening in said engine compartment. 
    
    
     Further aspects, features, and advantages of the present invention will become apparent from the detailed description of the preferred embodiments that follow. 
     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 watercraft. The illustrated embodiments are intended to illustrate, but not to limit the invention. The drawings contain the following figures: 
     FIG. 1 is a side elevational view of an embodiment of the present invention showing a watercraft partially sectioned to illustrate an interior engine compartment that houses an engine configured and arranged in accordance with the present invention. 
     FIG. 2 is a partial top plan view of the embodiment of FIG.  1 . 
     FIG. 3 is a front elevational view of the embodiment of FIG.  1 . 
     FIG. 4 is a block diagram, illustrating the fuel supply system employed in the first embodiment of the present invention. 
     FIG. 5 is a front elevational view of another embodiment of an engine configured and arranged in accordance with the present invention. 
     FIG. 6 is a partial top plan view of an additional embodiment of an engine configured and arranged in accordance with the present invention. 
     FIG. 7 is a front elevational view of the engine of FIG.  6 . 
     FIG. 8 is a partial top plan view of another embodiment of an engine configured and arranged in accordance with the present invention. 
     FIG. 9 is a front elevational view of the engine of FIG.  8 . 
     FIG. 10 is a schematic block diagram of the fuel supply system, similar to FIG. 4, but illustrates a forward position of the fuel pump on the engine. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
     The present invention has particular utility for use with a personal watercraft. Before describing the present invention, however, an exemplary personal watercraft will first be described in general details to assist the reader&#39;s understanding of the engine. The exemplary watercraft is suited for movement through a body of water toward a front end or bow of the watercraft. 
     As illustrated in FIG. 1, a watercraft  10  includes a hull  12  formed by a lower hull section  14  and an upper deck section  16 . The hull sections  14 ,  16  are formed from a suitable material such as, for example, a molded fiberglass-reinforced resin. The lower hull section  14  and the upper deck section  16  are fixed to each other around the peripheral edges  18  in any suitable manner. 
     As viewed in the direction from the bow to the stem of the watercraft  10 , the upper deck section  16  includes a bow portion at the front of the watercraft, a control portion extending rearward therefrom, and a seating area extending from the control area toward the back of the watercraft. The bow portion slopes upwardly toward the control portion and includes an opening (not shown) for access to the interior of the watercraft hull  12 . A hatch or lid  20  covers the opening to inhibit an influx of water into the hull  12 , and also slopes upwardly to the control portion. 
     The control portion extends rearward from the bow portion and includes a display panel (not shown) and a handlebar assembly  22 . The handlebar assembly  22  controls the steering of the watercraft  10  in a conventional manner and also carries a variety of watercraft controls, such as, for example, a throttle control, a start switch and a lanyard switch. 
     The seating area is, as shown in FIG. 1, comprises an operator/passenger seat  24  detachably mounted longitudinally along the center of the watercraft  10  that may be straddled by an operator, in the middle of the watercraft, and by at least one or two passengers to the rear during use. The middle position of the operator on the watercraft  10  gives the watercraft  10  fore and aft balance when the operator rides alone. Although not illustrated, the seat  24  can be made as two discrete sections: a front seat section and a rear seat section, both detachably mounted separately to the upper deck section  16  using known latching mechanisms. 
     The lower hull section  14  of the personal watercraft  10  includes within its interior an engine compartment  28  that houses the engine and peripheral components and/or systems below the seat  24 . Such peripheral systems include an air intake system, a fuel delivery system, and an exhaust system. Typically, a fuel tank  26  and a buoyant block (not shown) are located within the lower hull section  14  directly in front of the engine compartment  28 . The fuel tank  26  is mounted to the bottom surface  38  of the lower hull  14  using a plurality of fuel tank mounts (not shown). The buoyant block adds buoyancy to the watercraft  10 . 
     Typically, an air supply system ventilates the engine compartment  28  by supplying fresh air thereto. Such an air supply system desirably includes at least one air duct, and preferably at least two. For example, one air duct  30  may be located toward the front of the engine compartment  28  while another air duct  32  is provided toward the rear of the engine compartment. Both ducts  30 ,  32  preferably include an upper end  34  that extents up into the upper deck section  16  and a lower end outlet  36  that terminates close to and just above a bottom surface  38  of the engine compartment  28 . 
     An internal combustion engine  40 , which powers the watercraft  10 , is housed within the engine compartment  28  and is mounted in approximately a central position in the watercraft  10 . Separating the engine compartment  28  from the seat  24  is an access opening  41  defined in the upper deck section  16 . The seat  24  covers the access opening  41  so that the removal of the seat  24  exposes the engine  40  within the engine compartment  28 . Typically, the engine  40  comprises a plurality of in-line cylinders  42  that operate on a two-cycle principle, although types of engines are suitable, e.g., four cycle, crankcase compression, etc. The engine  40  is preferably positioned such that the row of in-line cylinders  42  lies parallel to a longitudinal axis  44  of the watercraft  10  that runs bow to stern. The engine  40  and its peripheral systems (air intake, fuel delivery, and exhaust systems) interconnect with one another within the engine compartment  28 . To the rear of the engine compartment is a jet propulsion unit  60 , described further below. 
     With continuing reference to FIG. 1, extending rearward from a lower portion of the engine  40  is a drive shaft  62  that is connected by a coupling  64  to an impeller shaft  66 . The impeller shaft  66  extends rearward through a bulkhead and a protective sleeve (not shown), to the jet propulsion unit  60 . A bearing assembly (not shown), which is secured to the bulkhead supports the impeller shaft  66  behind the shaft coupling  62 . The engine powers the drive shaft in a rotational manner so as to rotate the impeller  68  positioned at the rearward most end of the impeller shaft  66  to propel the watercraft  10 . 
     The jet propulsion unit  60  is positioned in a tunnel in the rear center of the lower hull section  14 . The jet propulsion unit  60  includes a gullet  70  having an inlet opening formed on the bottom side of the lower hull section  14 . The gullet  70  extends from the inlet opening to a pressurization chamber  72  which, in turn, communicates with a reduced-diameter nozzle section  74  of the propulsion unit  60 . The jet propulsion unit  60  also includes the rotatable impeller  68  supported by the impeller shaft  66 . 
     When rotating at high speeds, the impeller  68  pressurizes the water within the pressurization chamber  72  and forces the pressurized water through the nozzle section  74  of the jet propulsion unit  60 . A steering nozzle  76  directs the exit direction of the water stream exiting the jet propulsion unit  60 . The steering nozzle  76  is pivotally supported at the rear of the jet propulsion unit  60  to change the thrust angle on the watercraft  10  for steering purposes, as is known in the art. The steering nozzle  76  is connected to the steering handlebar  22  so as to be directed thereby. The steering handle  22  may also include a throttle control for controlling the output of the engine  40  and, thus, the speed of the impeller  68 . 
     The impeller  68  is located toward the front end of the pressurization chamber  72 . A central support (not shown) supports the rear end of the impeller shaft  66  behind the impeller  68  and generally at the center of the pressurization chamber  72 . A bearing assembly (not shown) journals the rear end of the impeller shaft  66  within the support. 
     Within the engine compartment, a water removal system is provided that is in fluid communication with the nozzle section  74  of the propulsion unit  60 . Preferably, the water removal system comprises a bilge system that, as illustrated in FIG. 1, employs a conduit  78  that extends from an inlet in the engine compartment to the nozzle section  74 . Due to the high rate of water flow through the nozzle section  74 , a venturi effect is created that creates suction in the conduit  78 . That suction effect draws water out of the engine compartment through a bilge inlet or water pickup  80  adjacent the engine  40  and near the bottom surface  38  of the lower hull section  14 . As illustrated in FIG. 1, the water-pickup  80  is arranged to be slightly elevated from the bottom surface  38  of the hull  12  of the engine compartment  28 . 
     Alternatively, the water removal system may employ a conventional pump (not shown) that directs water from the bilge region of the hull  12  through the conduit  78  to an outlet (not shown) at the stem of the watercraft  10 . For example, the water may be expelled through an outlet located in a wall of the gullet  70 . 
     In the embodiments illustrated in FIGS. 2 and 3, exhaust gases from the engine  40  are discharged to the water through an exhaust system  46 . The exhaust system  46  includes an exhaust manifold  48 , which is connected to the exhaust output of the engine  40 , and an exhaust pipe  50 , which communicates and receives exhaust gases from the exhaust manifold  48  via an expandable joint  52 . In the illustrated embodiment, the exhaust pipe includes an expansion chamber. The outlet of the exhaust pipe  50  communicates with a water trap device  54 , located toward the rear of the watercraft  10 , which inhibits the backflow of cooling water toward the exhaust pipe  50 . An exhaust discharge pipe  56  connects the water trap  54  to a discharge opening  58 . The exhaust discharge pipe  56  extends over the jet propulsion unit  60  to further inhibit the influx of water into the exhaust system  46 . 
     An air intake or induction system  82  supplies an air charge to a plurality of crankcase chambers (not shown) formed within a crankcase  84  of the engine  40 . Air is received by the air intake system  82  through an intake air silencer  86 . In the illustrated embodiment, the silencer  86  is located above and to the side of the cylinders  42 . The silencer  86  includes a plenum chamber (not shown). The plenum chamber of the silencer communicates with a plurality of intake pipes  88  (only one shown). The engine  40  preferably includes an intake pipe  88  for each crankcase chamber and associated cylinder  42 . 
     A throttle valve is housed within each intake pipe  88  and comprises a butterfly-type valve disc  92 . Each throttle valve  92  communicates with an intake passage of an intake manifold  100  attached to the crankcase  84  and/or to the cylinder block  101 . 
     A fuel supply system of the engine  40  includes a fuel pump  102 , a fuel rail  104 , fuel injectors  106 , and fuel pipes interconnecting thereof. FIG. 4 schematically illustrates the fuel supply system of preferred embodiments of the present invention. Fuel is transferred from the fuel tank  26  to the fuel pump  102 , and then supplied to the fuel injector  106  (shown in FIGS. 2,  3 ,  5 ,  6 , and  9 ) by the fuel pump  102 . The fuel pump  102  can be either mechanically or electrically driven. The pump could also be a diaphragm pump operated by the changing pressure within one of the crankcase chambers. 
     A feed pump  108  sends fuel from the fuel tank  26  to the fuel pump  102  through a fuel intake pipe  110 . A water separator filter  112  between the fuel tank  26  and the fuel pump  102  separates water and other contaminants from the fuel. A lubricant pump  114  supplies lubricant (e.g., oil) from the lubricant tank  116  to the water separator filter through an oil pipe  118 . As a result, the oil mixes with the fuel before the fuel is injected into the engine  40 . An oil flow control valve  120  is located in the oil pipe  118  between the oil pump  114  and the water separator filter  112 , and meters oil into the water separator filter  112  at a rate corresponding to the operating condition of the engine  40 . The fuel from the water separator filter  112  is transferred to the fuel pump  102 . The fuel pump  102  supplies the fuel to a fuel filter  122  located between the fuel pump  102  and the fuel rail  104  in a fuel supply pipe  124 . The fuel filter  122  separates water and other contaminants from the fuel. The filtered fuel next is delivered to the fuel rail  104  where fuel is distributed to the fuel injectors  106  connected thereto. Residual fuel is directed out of the fuel rail  104  to a return line  126  to the fuel tank  26 . A pressure regulator  128  is located within this return line  126  to maintain the pressure within the return line  126 . 
     With reference now to FIG. 3, the illustrated engine  40  is desirably mounted beneath the access opening  41  within the engine compartment  28 . A seal member  130  is provided around the access opening  41  to prevent water influx into the engine compartment  28 . 
     A plurality of engine mounts  132  secure the engine  40  to the hull  12  and support the engine  40  within the engine compartment  28  of the watercraft  10 . Each engine mount  132  preferably comprises a pad constructed from rubber or a similar vibration dampening and isolating material to reduce vibration transmission between the engine  40  and the hull  12 . 
     As shown in FIG. 2, the engine  40  is positioned such that the row of cylinders lies in the longitudinal direction  44  of the watercraft  10 . As shown in FIG. 3, the engine  40  is arranged so that the each cylinder  42  is desirably inclined such that a longitudinal center plane  133  of the cylinders  42  is skewed in a lateral direction  134  of the watercraft  10 . The illustrated engine  40  also extends substantially longitudinally; notably, the engine  40  can also be arranged with the output shaft  64  oriented generally in the lateral direction  134 . 
     As shown in FIGS. 2 and 3, the crankcase  84  is located beneath the cylinder block  101 . Integral with the cylinder block  101  are the cylinders  42 . A cylinder head assembly  136  is provided to enclose each cylinder  42 . A spark plug  138  is mounted on top of each cylinder head  136  and has its gap extending into the combustion chamber. The spark plugs  138  are fired by an ignition control unit (not shown) that is controlled by an electronic control unit (not shown) of the engine  40 . A fuel injector  106  is provided to each cylinder  42 . Each fuel injector  106  communicates with the fuel rail  104  through which fuel is supplied by the fuel pump  102 , as described above. In the illustrated embodiment, each fuel injector communicates with a combustion chamber of the respective cylinder through a wall of the cylinder; however, the fuel injector can also communicate with the combustion chamber through the cylinder head. 
     The exhaust manifold  48  is affixed to the cylinder block  101  on one side of the inclined cylinder center plane  133  to receive exhaust gases from the combustion chambers. As shown in FIG. 2, the exhaust manifold  48  receives exhaust gases from each cylinder  42  and communicates with the exhaust pipe  50  via the elastic joint  52 . The exhaust pipe  50  loops around a front end of the cylinder block  101  and extends along the other side of the inclined cylinder center plane  133 . The exhaust pipe  50  desirably includes an inner tube that communicates directly with the discharge end of the exhaust manifold  48 . An outer tube surrounds the inner tube to form a coolant jacket  144  between the inner and outer tubes. In the illustrated embodiment, the inner tube terminates within the outer tube at a point behind the engine so as to merge at least a portion of the cooling water with the exhaust flow through the exhaust pipe. 
     With reference to FIGS. 2 and 3, on the a side of the crankcase  84  opposite to the side of the cylinder  42  from which the exhaust manifold  48  passes, the air intake system  82  is provided to supply an air charge to a plurality of crankcase chamber formed within the crankcase  84 . The air intake manifold  100  is affixed to the crankcase  84 , and the air intake system  82 , including the air intake pipe  88  and the intake silencer  86 , extends upwardly from the intake manifold  100 . The air intake silencer  86  is located above and to the side of the cylinder block  101 . 
     As described above, fuel is supplied to the fuel injectors  106  through the fuel supply system, which includes the fuel pump  102  and the fuel rail  104 . In the first embodiment, the fuel pump  102  is mounted on the crankcase  84  below the air intake manifold  100 . A bracket  146  connects the fuel pump  102  to the side of the crankcase  84 . Advantageously, the bracket  146  includes an elastic material, such as rubber, to avoid transferring the vibration of the engine  40 . The fuel pump  102  is arranged on the engine  40  such that the air intake pipe  88  and the air intake silencer  86  extend above at least a portion of the fuel pump  102 , as shown in FIG.  2 . Advantageously, at least either the air intake silencer  86  or the intake pipe  88  shields the fuel pump  102  above it. Thus, although water may enter inadvertently the engine compartment  28  through the uncovered access opening  41 , the fuel pump  102  may be protected against water contact. 
     With reference to FIG. 1, the fuel pump  102  is advantageously positioned above the level of the water pickup  80  of the bilge system such that water that enters the engine compartment  28  may not fill to the level of the fuel pump  102  within the watercraft hull  12 . Further, the fuel pump  102  advantageously is in a position higher than the outlet  36  of the air ducts  30 ,  32  so as to inhibit water that may enter the engine compartment  28  through the air ducts  30 ,  32  from contacting the fuel pump  102 . The fuel pump  102  also desirably lies between the front end of the engine and the shaft coupling  62 . In the illustrated embodiment, the fuel pump  102  thus lies between the locations of a flywheel-magneto assembly  63  and the coupling  62  so as not to be affected by the vibration thereof. 
     In the illustrated embodiment, a flywheel cover  65  encloses the flywheel-magneto assembly  63  on the front end of the engine  40 ; however, in accordance with other variations the flywheel-magneto assembly  63  can be located at the rear of the engine  40 . As understood from FIG. 2, the flywheel of the assembly  63  is coupled to a front end of the crankshaft  64 . For this purpose, the flywheel desirably is mounted to a shaft (not shown) that is connected to the crankshaft  64 . A pulsar coil is used with the flywheel-magneto assembly  63  to produce a signal indicative of a particular crankshaft angle. The signal pulse desirably is received and processed by an ECU to determine the specific crankshaft angle at a given time for ignition and fuel injection timing, as known in the art. The flywheel-magneto assembly  63  also desirably includes a charging coil to charge a conventional capacitor discharge ignition circuit (CDI). 
     As shown in FIGS. 1 and 2, a starter motor  148  is advantageously arranged on the engine  40  in line with the fuel pump  102  in the longitudinal direction  44  such that the air intake pipe  88  and the air intake silencer  86  also extend above at least a portion of the starter motor  148 . In the embodiment illustrated in FIGS. 1-4, the starter motor  148  is positioned in front of the fuel pump  102  so as to lie near the flywheel assembly  63 . A pinion of the starter motor  148  drives a ring gear of the flywheel assembly  63  as known in the art. The starter motor  148  can also lie at other locations on the engine relative to the fuel pump  102 . For instance, as understood from FIG. 10, the fuel pump  102  can lie near the front end of the engine  40  on one side and the starter motor  148  can lie on the other side. The positions of the fuel pump  102  and the starter motor  148  can also be reversed from that depicted in FIG. 1 when the flywheel assembly  63  is located at a rear end of the engine  40 . 
     With the fuel pump  102  positioned below the intake system, either the air intake silencer  86  or the air intake pipe  88  advantageously shields the starter motor  148  above it. Further, the starter motor  148  is advantageously arranged on the engine  40  at the same level as the fuel pump  102 . The starter motor  148  thus also enjoys the advantages of the arrangement of the fuel pump  102  with respect to water that accumulates in the bottom of the engine compartment  28 . 
     FIG. 5 illustrates another embodiment of the engine arrangement of the present invention. In connection with the following embodiments, like elements between the embodiments are referred by like numerals, and the foregoing description of like components between the embodiments should be understood to apply equally to all embodiments, unless indicated otherwise. 
     As illustrated, the fuel pump  102  is mounted on a lower surface of one of the air intake pipes  88  via a bracket  146 , by which the air intake pipe  88  shields the fuel pump  102  from water contact. Since the fuel pump  102  is still located under the air intake silencer  86 , the fuel pump  102  can be protected by the intake silencer  86  as well. Further, advantageously, relatively low temperature air, which passes through the air intake pipe  88 , can cool the fuel pump  102 . 
     An additional embodiment of the fuel pump arrangement according to the present invention is illustrated in FIGS. 6 and 7. The fuel pump  102  of this embodiment is mounted on the side of the crankcase  84  where the exhaust manifold  48  is affixed. Although not illustrated, a bracket connects the fuel pump  102  to the crankcase side as described in connection with FIGS. 3 and 5. As illustrated, the fuel pump  102  is placed under the inclined cylinder block  101  and the exhaust manifold  48 . Thus, the exhaust manifold  48  and the cylinder block  101  shield at least a part of the fuel pump  102  from the water that may enter the engine compartment  28 . Also, the fuel pump  102  is located between a pair of engine mounts  132  on the exhaust manifold side of the crankcase  84 . The engine mounts  132  located at both sides of fuel pump  102  may block the water that may splash about within the engine compartment  28  due to the pitching of the watercraft  10  as it moves through the water. 
     FIGS. 8 and 9 illustrate another embodiment of the fuel pump arrangement according to the present invention. In this embodiment, the exhaust manifold  48  extends from the cylinder block  101  at a side opposite to the embodiment shown in FIGS. 6 and 7. Like the embodiment of FIGS. 6 and 7, the fiel pump  102  is mounted below the cylinder block  101 . The inclined cylinder block  101  and the exhaust pipe  50  protect at least a part of the fuel pump  102  from the water that may enter the engine compartment  28 . 
     The present engine is particularly useful with personal watercraft. This environment of use, however, is merely exemplary. The present engine is also suitable for other types of watercraft as well, for example small jet boats and the like, as well as for use in other applications. It also is understood that various aspects of each of the above-described embodiments can be combined together in order to suit a specific application. Other embodiments apparent to those of ordinary skill in the art are also within the scope of this invention. Accordingly, the scope of the invention is intended to be defined only by the claims that follow.