Abstract:
The invention is an operating system for a fuel cell power plant that includes at least one fuel cell for producing electrical energy from a reducing and oxidant fluid and fuel processing components including a reformer and a burner for processing a hydrocarbon fuel into the reducing fluid, and a direct mass and heat transfer device secured in fluid communication with both a process oxidant stream and a plant exhaust passage, so that the device directly transfers mass such as water exiting the plant in a plant exhaust stream back into the plant within the process oxidant stream. The invention also includes a split oxidant passage that directs the process oxidant stream through the fuel cell and a reformer feed portion of the process oxidant stream into fluid communication with the fuel processing components. The system may also include an anode exhaust passage that directs an anode exhaust from the fuel cell into the burner, then directs the oxidized anode exhaust stream from the burner in heat exchange relationship with the reformer feed portion.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a jet propulsion boat which moves ahead or astern by jetting water sucked from an opening in a boat&#39;s bottom in a backward direction. 
     2. Description of Background Art 
     A known jet propulsion boat of a type operated in a manner similar to that for a motorcycle is configured as follows. A driver sitting astride a seat holds the steering handlebar with both hands to operate the boat to go ahead by actuating an accelerator lever at the right end of the steering handlebar. The operator makes the boat go astern or slow down by operating an operating lever at the left end of the steering handle. 
     A jet propulsion boat of this type has been proposed, for example, in Japanese Patent Laid-open No. Hei 6-156379. The technique disclosed in this document will be briefly described with reference to FIG.  8 . 
     FIG. 8 is a view illustrating the above-described prior art jet propulsion boat. Referring to FIG. 8, the jet propulsion boat designated by reference numeral  100  includes an operating lever  104  mounted on a left grip  102  of a steering handlebar  101 ; an accelerator lever  105  mounted on a right grip  103  of the steering handlebar  101 ; a water jetting nozzle  106  mounted at a stem of the jet propulsion boat  100 ; and a going-astern bucket  108  mounted to the nozzle  106 . 
     An operational procedure for making the jet propulsion boat  100  go astern will be described below. 
     First, the operating lever  104  is operated in the direction shown by an arrow “a” to move the bucket  108  in the direction shown by an arrow “b” up to a position facing to the outlet of the nozzle  106 . Then, the accelerator lever  105  is operated in the direction shown by an arrow “c” while operating the lever  104 , to increase the engine speed. 
     As the engine speed is increased, an impeller (not shown) is rotated at a high speed, to jet water backward from the nozzle  106 . At this time, the direction of the water thus jetted is reversed as shown by an arrow “d” by means of the bucket  108 . In this way, since the water is jetted forward of the jet propulsion boat  100 , the jet propulsion boat  100  goes astern. 
     The prior art jet propulsion boat, however, has the following problem: namely, in the going-astern mode, a driver requires two operations, that is, the operation of the left operating lever  104  with the left hand and the operation of the accelerator lever  105  with the right hand. Since the driver must simultaneously perform the two-operations with both hands, he must shoulder a relatively large burden. In this regard, it has been desired to develop a jet propulsion boat excellent in operability. 
     SUMMARY AND OBJECTS OF THE INVENTION 
     An object of the present invention is to provide a technique capable of improving the operability of a jet propulsion boat. 
     To solve the above-described problem, according to the present invention, there is provided a jet propulsion boat which moves ahead, in a forward mode, by jetting backward water sucked from an opening in a boat&#39;s bottom through a nozzle, and which goes astern or slows down, in a going-asten/slowing-down mode, by shifting a water reversing cup to a position facing to the outlet of the nozzle and reversing the water jetting direction by means of the cup, the jet propulsion boat including: a transmission mechanism for transmitting a force to drive the water reversing cup; an operating piece for pushing/withdrawing the transmission mechanism; an operating force measuring means for measuring an operating force applied to the operating piece, the operating force measuring means being provided on the transmission mechanism or the operating piece; and a propulsion force control means for controlling a water jetting force on the basis of the operating force measured by the operating force measuring means. 
     With this configuration, the water jetting force can be controlled on the basis of the operating force by operating the operating piece to shift the water reversing cup to the position facing to the outlet of the nozzle and further increasing the operating force applied to the operating piece. 
     Accordingly, two-stage operations, that is, the operation to shift the water reversing cup to the position facing to the outlet of the nozzle and the operation to control the water jetting force can be performed by operating only one operating piece. As a result, the going-astern operation or the slowing-down operation of the jet propulsion boat can be performed by one hand or one foot. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
     FIG. 1 is a side view of a jet propulsion boat according to a first embodiment of the present invention; 
     FIG. 2 is a plan view of the jet propulsion boat according to the first embodiment of the present invention; 
     FIG. 3 is a sectional view taken on line  3 — 3  of FIG. 2; 
     FIGS.  4 ( a ) and  4 ( b ) are views illustrating a first function of the jet propulsion boat according to the first embodiment of the present invention; 
     FIG. 5 is a view illustrating a second function of the jet propulsion boat according to the first embodiment of the present invention; 
     FIG. 6 is a plan view of a jet propulsion boat according to a second embodiment of the present invention; 
     FIG. 7 is a sectional view taken on line  7 — 7  of FIG. 6; and 
     FIG. 8 is a view illustrating a prior art jet propulsion boat. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side view of a jet propulsion boat according to a first embodiment of the present invention wherein a jet propulsion boat  10  includes an engine  15  mounted at an approximately central portion of a hull  11 ; a jet propulsion machine  20  driven by the engine  15  for jetting water, which is sucked from an opening  13  formed in the boat&#39;s bottom  12 , backward of the hull  11 ; a steering handlebar  25  for controlling the turning direction of the hull  11 ; and a going-astern/slowing-down means  30  for allowing the hull  11  to go astern or slow down by reversing the water jetting direction. A fuel tank  17  is mounted below a seat  18 . 
     The jet propulsion machine  20  includes a housing  21  extending backwards from the opening  13  of the boat&#39;s bottom  12 ; an impeller  22  rotatably mounted in the housing  21  and connected to a drive shaft  16  of the engine  15 ; and a nozzle  23  mounted at the rear end of the housing  21  in such a manner as to be swingable in the turning direction of the hull  11 . The jet propulsion machine  20  generates a jet propulsion force by rotating the impeller  22  for sucking water from the opening  13  of the boat&#39;s bottom  12  and jetting the sucked water backward of the hull  11  through the nozzle  23 . 
     FIG. 2 is a plan view of the jet propulsion boat according to the first embodiment of the present invention. The steering handlebar  25  is rotatably mounted at an approximately central portion of the boat body  11  (see FIG.  1 ). When the steering handlebar  25  is turned to the right or left by a driver holding the right and left grips  26  and  27 , the jet propulsion boat  10  is turned to the right or left. 
     The going-astern/slowing-down means  30  includes a water reversing cup  32  vertically swingably mounted to the nozzle  23  with bolts  33 ; a link mechanism  35  as a transmission mechanism for shifting the water reversing cup  32  between a position over the nozzle  23  and a position behind the nozzle  23  (that is, a position facing an outlet  23   a  of the nozzle  23 ); a going-astern/slowing-down lever  42  as an operating piece for pushing/withdrawing the link mechanism  35 ; an operating force measuring means  45 , provided on the link mechanism  35 , for measuring an operating force applied to the going-astern/slowing-down lever  42 ; and a propulsion force control means  50  for controlling a water jetting force on the basis of the operating force measured by the operating force measuring means  45 . 
     The link mechanism  35  has a link  36  rotatably mounted to the engine  15  with a bolt  37 , wherein one end  36   a  of the link  36  is connected to the going-astern/slowing-down lever  42  with a wire  38 , and the other end  36   b  of the link  36  is connected to the water reversing cup  32  with a rod  39 . When the going-astern/slowing-down lever  42  is operated as shown by an arrow ( 1 ), the one end  36   a  of the link  36  is withdrawn via the wire  38  in the direction shown by an arrow ( 2 ) to turn the link  36  around the bolt  37 , and thereby the other end  36   b  of the link  36  is turned around the bolt  37  to push the rod  39  in the direction shown by an arrow ( 3 ), thereby shifting the water reversing cup  32  at the position facing to the outlet  23   a  of the nozzle  23 . 
     When the operating force applied to the going-astern/slowing-down lever  42  is released, the water reversing cup  32  is returned to the position over the nozzle  23  by a spring force of two return springs  40 . At the same time, the going-astern/slowing-down lever  42  is returned to the original state by a spring force of a lever returning spring (not shown). 
     The going-astern/slowing-down lever  42  is swingably mounted on the left grip  26  of the steering handlebar  25 , and as described above, the lever  42  is operated in the direction shown by the arrow ( 1 ) to withdraw the one end  36   a  of the link  36  via the wire  38  in the direction shown by the arrow ( 2 ). 
     The operating force sensor means  45  includes a position detecting sensor  46  and an operating force measuring sensor  47 . The position detecting sensor  46  is mounted near the link  36 . When the water reversing cup  32  is shifted to the position facing to the outlet  23   a  of the nozzle  23 , the link  36  is brought into contact with the position detecting sensor  46 . In this way, the position detecting sensor  46  detects the going-astern/slowing-down mode. The operating force measuring sensor  47  is mounted on the way of the rod  39  for measuring an operating force applied to the rod  39  (that is, a force pushing the rod  39 ). 
     The use of the position detecting sensor  46  has the following advantage; namely, if the water reversing cup  32  is caught by some foreign matter and locked before it reaches the position facing to the outlet  23   a  of the nozzle  23 , no signal is supplied from the position detecting sensor  46  to the propulsion force control means  50  although a signal is supplied from the operating force measuring sensor  47  to the propulsion force control means  50 , with a result that the propulsion force control means  50  does not carry out the control of the water jetting force on the basis of the operating force measured by the operating force measuring sensor  47 . 
     The propulsion force control means  50  includes a control unit  51 . When receiving a going-astern/slowing-down mode signal from the position detecting sensor  46  and an operating force measuring signal from the operating force measuring sensor  47 , the control unit  51  supplies a signal corresponding to the magnitude of the operating force measuring signal (that is, the degree of the operating force) to a drive unit  52 . On the basis of the signal supplied from the control unit  51 , the drive unit  52  is operated such that a rack  55  is moved in the direction shown by an arrow ( 4 ) by rotating a pinion  54  with a motor  53  to withdraw a wire  56  for adjusting the opening degree of a throttle valve  57  thereby controlling the water jetting force. 
     The wire  56  is connected to an accelerator lever  58 , and therefore, the throttle valve  57  can be withdrawn in the opening direction by operating the accelerator lever  58  in the direction shown by an arrow ( 5 ). 
     FIG. 3 is a sectional view taken on line  3 — 3  of FIG. 2, showing a state in which the water reversing cup  32  is returned to the position over the nozzle  23  by the spring force of the return springs  40 . 
     At this time, since the water reversing cup  32  is moved to a position higher than the outlet  23   a  of the nozzle  23 , water jetted from the outlet  23   a  of the nozzle  23  does not collide against the water reversing cup  32 , and accordingly, the water can be jetted backward from the outlet  23   a  of the nozzle  23 . 
     When the water reversing cup  32  is shifted to the position facing to the outlet  23   a  of the nozzle  23  as shown by an imaginary line in FIG. 3, the water jetting direction is reversed by means of the water reversing cup  32 . 
     The function of the jet propulsion boat  10  configured as described above will be described below. 
     FIGS.  4 ( a ) and  4 ( b ) are views illustrating a first function of the jet propulsion boat according to the first embodiment of the present invention. Referring to FIG.  4 ( a ), when the going-astern/slowing-down lever  42  is operated in the direction shown by the arrow ( 1 ), the one end  36   a  of the link  36  is withdrawn via the wire  38  in the direction shown by the arrow ( 2 ) to turn the link  36  around the bolt  37 , so that the other end  36   b  of the link  36  is turned around the bolt  37  to push the rod  39  in the direction shown by the arrow ( 3 ), thereby shifting the water reversing cup  32  to the position facing to the outlet  23   a  of the nozzle  23 . 
     Referring to FIG.  4 ( b ), when the link  36  is brought into contact with the position detecting sensor  46 , the sensor  46  detects the going-astern/slowing-down mode. In such a state, the operating force applied to the going-astern/slowing-down lever  42  is further increased to apply an operating force to the rod  39 . The operating force applied to the rod  39  is measured by the operating force measuring sensor  47 . 
     When receiving a going-astern/slowing-down mode signal detected by the position detecting sensor  46  and an operating force measuring signal detected by the operating force measuring sensor  47 , the control unit  51  supplies a signal corresponding to the magnitude of the operating force measuring signal (that is, the degree of the operating force) to the drive unit  52 . On the basis of the signal supplied from the control unit  51 , the drive unit  52  is operated such that the rack  55  is moved in the direction shown by the arrow ( 4 ) by rotating the pinion  54  with the motor  53  to withdraw the wire  56  for adjusting the opening degree of the throttle valve  57  thereby increasing the engine speed. 
     FIG. 5 is a view illustrating a second function of the jet propulsion boat according to the first embodiment of the present invention. As the engine speed is increased, the impeller  22  of the jet propulsion machine  20  (see FIG. 1) is rotated at a high speed, whereby water is jetted backward from the outlet  23   a  of the nozzle  23 . The jet propulsion boat  10  is thus allowed to go astern by reversing the streams of the jetted water in the directions shown by arrows ( 6 ) by means of the water reversing cup  32 . 
     In this way, the driver can control the water jetting force on the basis of the operating force by operating the going-asten/slowing-down lever  42  with one hand to shift the water reversing cup  32  to the position facing to the outlet  23   a  of the nozzle  23  and further increasing the operating force applied to the going-astern/slowing-down lever  42 . 
     In other words, two-stage operations, that is, the operation to shift the water reversing cup  32  to the position facing to the outlet  23   a  of the nozzle  23  and the operation to control the water jetting force can be performed only by operating the going-asten/slowing-down lever  42 . 
     A second embodiment will be described with reference to FIGS. 6 and 7. In this embodiment, the same members as those in the first embodiment are designated by the same characters, and the overlapped description thereof is omitted. FIG. 6 is a plan view of a jet propulsion boat according to a second embodiment of the present invention. 
     Referring to FIG. 6, a jet propulsion boat  60  is configured such that the going-astern/slowing-down lever  42  of the going-astern/slowing means  30  adopted in the first embodiment is replaced with a going-astern/slowing-down pedal  66  (operating piece) of a going-astern/slowing-down means  65 , which is mounted on a left floor portion  72  of a hull  71 . 
     The going-astern/slowing-down means  65  includes a link mechanism, an operating force measuring means and a propulsion force control means having the same configurations as those of the link mechanism  35 , operating force measuring means  45  and propulsion force control means  50  in the first embodiment, respectively. 
     FIG. 7 is a sectional view taken on line  7 — 7  of FIG.  6 . The going-astern/slowing-down pedal  66  has an approximately L-shaped arm  67  rotatably mounted on a recessed upper surface  73  of the left floor portion  72  with a pin  68 . A tip  67   a  of the arm  67  is connected to one end  36   a  of a link  36  by means of a wire  38 . 
     Accordingly, when the going-astern/slowing-down pedal  66  is depressed in the direction shown by an arrow ( 7 ), the one end  36   a  of the link  36  is withdrawn via the wire  38  in the direction shown by an arrow ( 8 ) to turn the link  37  around a bolt  37 , and thereby the other end  36   b  of the link  36  is turned around the bolt  37  to push a rod  39  in the direction shown by an arrow ( 9 ), thereby shifting a water reversing cup to a position facing to the outlet of a nozzle like the first embodiment. 
     After that, like the first embodiment, by increasing the depressed force (operating force) of the going-asten/slowing-down pedal  66  to adjust the opening degree of a throttle valve, the engine speed is increased to rotate an impeller of a jet propulsion machine at a high speed, thereby controlling the jetting force of water jetted backward by the jet propulsion machine. On the other hand, the jet propulsion boat is allowed to go astern by reversing the water jetting direction by means of the water reversing cup. 
     In this way, the driver can control the water jetting force on the basis of the operating force by operating the going-astern/slowing-down pedal  66  with one foot to shift the water reversing cup to the position facing to the outlet of the nozzle and further increasing the operating force applied to the going-astern/slowing-down pedal  66 . 
     In other words, two-stage operations, that is, the operation to shift the water reversing cup to the position facing to the outlet of the nozzle and the operation to control the water jetting force can be performed only by operating the going-astern/slowing-down pedal  66 . 
     In the embodiments, description has been made by way of the example in which the going-astern/slowing-down means  30  (or  65 ) is used in the going-astern mode; however, the going-astern/slowing-down means  30  (or  65 ) can be driven during the going-ahead operation of the jet propulsion boat  10  (or  60 ). By driving the going-astern/slowing-down means  30  (or  65 ) during the going-ahead operation of the jet propulsion boat  10  (or  60 ), it is possible to efficiently slow down the jet propulsion boat  10  (or  60 ). 
     While the position detecting sensor  46  and the operating force measuring sensor  47  are mounted in the embodiments, only the operating force measuring sensor  47  may be mounted. 
     In the embodiments, the operating force measuring sensor  47  is mounted on the rod of the link mechanism  35 ; however, it may be mounted on the going-astern/slowing-down lever  42  or the going-astern/slowing-down pedal  66  with the same effect. 
     Although the going-astern/slowing-down pedal  66  is mounted on the left floor portion  72  of the hull  71  in the second embodiment, it may be mounted on a right floor portion of the hull  71 . 
     The present invention configured as described above exhibits the following effects: 
     The present invention is configured such that an operating force is measured by the operating force measuring means and the water jetting force is controlled on the basis of the operating force thus measured. Accordingly, it is possible to control the water jetting force on the basis of the operating force by operating the operating piece to shift the water reversing cup to the position facing to the outlet of the nozzle and further increasing the operating force applied to the operating piece. 
     As a result, two-stage operations, that is, the operation to shift the water reversing cup to the position facing to the outlet of the nozzle and the operation to control the water jetting force can be performed by operating only one operating piece. 
     Accordingly, since the going-astern operation or the slowing-down operation of the jet propulsion boat can be performed by one hand or one foot, it is possible to simplify the operation of the jet propulsion boat, that is, improve the operability of the jet propulsion boat. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.