Jet propulsion watercraft, jet propulsion watercraft control system, and method for maintaining jet propulsion watercraft in docked state

Abstract

A jet propulsion watercraft includes a controller configured or programmed to, when a docked state maintenance operation is performed to maintain a hull in a state docked at a pier, perform a docked state maintenance control to control a water flow generator to maintain generation of a jet of water from the water flow generator while controlling a water flow direction adjuster to maintain a direction of the jet of water generated from the water flow generator in a direction to cause the hull to be pressed against the pier.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to Japanese Patent Application No. 2024-200058 filed on Nov. 15, 2024. The entire contents of this application are hereby incorporated herein by reference.BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to jet propulsion watercrafts, jet propulsion watercraft control systems, and methods for maintaining jet propulsion watercrafts in docked states.2. Description of the Related Art

[0003] A jet propulsion watercraft using a jet of water as a propulsive force for its hull is known in general. Such a jet propulsion watercraft is disclosed in Japanese Patent Laid-Open No. 2018-001945, for example.

[0004] Japanese Patent Laid-Open No. 2018-001945 discloses a jet propulsion watercraft using a jet of water as a propulsive force for its hull. The jet propulsion watercraft described in Japanese Patent Laid-Open No. 2018-001945 performs a docking assistance control to control the magnitude and direction of a jet of water such that the hull is moved to and docked at a pier when a watercraft user located away from the hull performs an operation to dock the hull at the pier. In other words, the jet propulsion watercraft described in Japanese Patent Laid-Open No. 2018-001945 is able to move the hull to and dock it at the pier even when the watercraft user is located away from the hull.

[0005] However, in the jet propulsion watercraft described in Japanese Patent Laid-Open No. 2018-001945, after the hull is docked at the pier, the hull docked at the pier has difficulty staying in place due to the influence of weather and currents. Therefore, it is desired to configure the jet propulsion watercraft such that the hull is maintained in a state docked at the pier after the hull is docked at the pier, even when the watercraft user is located away from the hull.SUMMARY OF THE INVENTION

[0006] Example embodiments of the present invention provide jet propulsion watercrafts, jet propulsion watercraft control systems, and methods for maintaining jet propulsion watercrafts in docked states that each maintain hulls in states docked at piers after the hulls are docked at the piers, even when watercraft users are located away from the hulls.

[0007] A jet propulsion watercraft according to an example embodiment of the present invention includes a hull, a water flow generator to generate a jet of water to provide a propulsive force to the hull, a water flow direction adjuster to adjust a direction of the jet of water from the water flow generator, and a controller configured or programmed to, when a docked state maintenance operation is performed to maintain the hull in a state docked at a pier, perform a docked state maintenance control to control the water flow generator to maintain generation of the jet of water from the water flow generator while controlling the water flow direction adjuster to maintain the direction of the jet of water from the water flow generator in a direction to cause the hull to be pressed against the pier.

[0008] A jet propulsion watercraft according to an example embodiment of the present invention includes the controller configured or programmed to, when the docked state maintenance operation is being performed to maintain the hull in a state docked at the pier, perform the docked state maintenance control to control the water flow generator to maintain generation of the jet of water from the water flow generator while controlling the water flow direction adjuster to maintain the direction of the jet of water from the water flow generator in the direction to cause the hull to be pressed against the pier. Accordingly, the docked state maintenance operation is performed such that the docked state maintenance control is performed to automatically maintain adjustment of the direction of the jet of water in the direction to cause the hull to be pressed against the pier. Consequently, even when a watercraft user is located away from the hull, the hull is maintained in a state docked at the pier after the hull is docked at the pier.

[0009] In a jet propulsion watercraft according to an example embodiment of the present invention, the water flow direction adjuster preferably includes a deflector rotatable in a right-left direction of the hull to change the direction of the jet of water from the water flow generator to a right side or a left side with respect to a centerline of the hull, and the controller is preferably configured or programmed to, during the docked state maintenance control, control an orientation of the deflector such that the direction of the jet of water from the water flow generator is maintained to the right side or the left side with respect to the centerline of the hull in the right-left direction. Accordingly, during the docked state maintenance control, adjustment of the direction of the jet of water to the direction to cause the hull to be pressed against the pier is easily maintained. When the hull is pressed against the pier, frictional resistance occurs between the hull and the pier. Therefore, even when the jet of water, the direction of which has been adjusted, includes a component in the forward-rearward direction of the hull, the hull is maintained in a state pressed against the pier.

[0010] In such a case, the water flow direction adjuster preferably further includes a reverse bucket rotatable in an upward-downward direction of the hull to change a ratio between a rearward component of the jet of water that is directed toward a rear side of the hull to move the hull forward and a forward component of the jet of water that is directed toward a front side of the hull to move the hull rearward, and the controller is preferably configured or programmed to, during the docked state maintenance control, control an orientation of the reverse bucket such that the rearward component and the forward component of the jet of water generated from the water flow generator are maintained in a state in which the rearward component and the forward component cancel each other out. Accordingly, during the docked state maintenance control, a state in which a propulsive force is not generated in the forward-rearward direction of the hull is easily maintained. Thus, movement of the hull in the forward-rearward direction from an initial position at the start of the docked state maintenance control during the docked state maintenance control is reduced or prevented.

[0011] In a jet propulsion watercraft including the controller configured or programmed to, during the docked state maintenance control, control the orientation of the deflector such that the direction of the jet of water from the water flow generator is maintained to the right side or the left side with respect to the centerline of the hull in the right-left direction, the controller is preferably configured or programmed to, when a docked state release operation is performed to release the docked state maintenance control while the docked state maintenance control is being performed, control the orientation of the deflector such that the direction of the jet of water generated from the water flow generator is maintained in a direction along the centerline of the hull in the right-left direction. Accordingly, the docked state release operation is performed such that adjustment of the direction of the jet of water in the direction to cause the hull not to be pressed against the pier is automatically maintained. In other words, the docked state release operation is performed such that the docked state maintenance control is easily released.

[0012] In a jet propulsion watercraft including the controller configured or programmed to, during the docked state maintenance control, control the orientation of the deflector such that the direction of the jet of water from the water flow generator is maintained to the right side or the left side with respect to the centerline of the hull in the right-left direction, the controller is preferably configured or programmed to, during the docked state maintenance control, control the orientation of the deflector such that the direction of the jet of water from the water flow generator is maintained at a rightmost position or a leftmost position within a variable range relative to the centerline of the hull in the right-left direction. Accordingly, during the docked state maintenance control, the component of the jet of water, the direction of which has been adjusted, in the forward-rearward direction of the hull is maintained relatively small. Thus, movement of the hull in the forward-rearward direction from the initial position at the start of the docked state maintenance control during the docked state maintenance control is reduced or prevented.

[0013] In a propulsion watercraft according to an example embodiment of the present invention, the water flow generator preferably includes a power unit as a power source to generate the jet of water, and the controller is preferably configured or programmed to, during the docked state maintenance control, control the power unit such that a rotation speed of the power unit is maintained at a speed lower than a predetermined rotation speed. Accordingly, during the docked state maintenance control, the jet of water generated from the water flow generator is maintained relatively small. Thus, during the docked state maintenance control, the component of the jet of water, the direction of which has been adjusted, in the forward-rearward direction of the hull is maintained relatively small. Consequently, movement of the hull in the forward-rearward direction from the initial position at the start of the docked state maintenance control during the docked state maintenance control is reduced or prevented.

[0014] In such a case, the power unit preferably includes an engine, and the controller is preferably configured or programmed to, during the docked state maintenance control, control the engine such that the engine is maintained in an idling state. Accordingly, a configuration is easily achieved to maintain the jet of water from the water flow generator relatively small during the docked state maintenance control.

[0015] A jet propulsion watercraft according to an example embodiment of the present invention preferably further includes a communicator to communicate with a remote control to remotely control the hull, and a manual operator to operate the hull, and the controller is preferably configured or programmed to perform the docked state maintenance control when a signal indicating that the remote control has received the docked state maintenance operation is received from the remote control via the communicator, or when the docked state maintenance operation is being performed on the manual operator. Accordingly, when the watercraft user is not on the hull, the watercraft user is able to cause the controller to perform the docked state maintenance control by performing the docked state maintenance operation on the remote control. When the watercraft user is on the hull, the watercraft user is able to cause the controller to perform the docked state maintenance control by performing the docked state maintenance operation on the remote control or the manual operator.

[0016] A jet propulsion watercraft including the controller configured or programmed to, during the docked state maintenance control, control the orientation of the deflector such that the direction of the jet of water from the water flow generator is maintained to the right side or the left side with respect to the centerline of the hull in the right-left direction preferably further includes a deflector actuator to change the orientation of deflector, and the controller is preferably configured or programmed to, during the docked state maintenance control, control the orientation of the deflector using the deflector actuator such that the direction of the jet of water from the water flow generator is maintained to the right side or the left side with respect to the centerline of the hull in the right-left direction. Accordingly, the deflector actuator enables the orientation of the deflector to be easily and automatically controlled during the docked state maintenance control.

[0017] In such a case, a jet propulsion watercraft preferably further includes a deflector operator to receive an operation to rotate the deflector, and the deflector actuator preferably includes an electric motor, a transmission gear to transmit drive forces of the electric motor and the deflector operator, a deflector-side cable including a first end connected to the transmission gear and a second end connected to the deflector to push and pull the deflector to rotate the deflector, and an operator-side cable including a first end connected to the transmission gear and a second end connected to the deflector operator to push and pull the deflector to rotate the deflector. Accordingly, the orientation of the deflector is automatically controlled via the electric motor, the transmission gear, and the deflector-side cable, and is manually controlled via the deflector operator, the operator-side cable, the transmission gear, and the deflector-side cable. Thus, a configuration that enables both manual and automatic control of the orientation of the deflector is easily achieved by simply adding the electric motor and the transmission gear to a configuration that enables manual control of the orientation of the deflector, which is common in the jet propulsion watercraft.

[0018] In a jet propulsion watercraft according to an example embodiment of the present invention, the controller is preferably configured or programmed to, when a speed of the hull is greater than a predetermined speed, not perform the docked state maintenance control even when the docked state maintenance operation is requested. Accordingly, the possibility that the docked state maintenance control is performed when the jet of water generated from the water flow generator is relatively large is prevented. It is relatively difficult to perform the docked state maintenance control when the jet of water from the water flow generator is relatively large, and thus it is preferable to perform the docked state maintenance control when the jet of water from the water flow generator is relatively small.

[0019] In a jet propulsion watercraft including the controller configured or programmed to, during the docked state maintenance control, control the orientation of the reverse bucket such that the rearward component and the forward component of the jet of water from the water flow generator are maintained in a state in which the rearward component and the forward component cancel each other out, the controller is preferably configured or programmed to, when the hull moves in a forward-rearward direction of the hull from an initial position at a start of the docked state maintenance control during the docked state maintenance control, control the orientation of the reverse bucket to differentiate the rearward component and the forward component of the jet of water from the water flow generator from each other such that the hull returns to the initial position at the start of the docked state maintenance control. Accordingly, even when the hull moves in the forward-rearward direction of the hull from the initial position at the start of the docked state maintenance control during the docked state maintenance control, the hull is returned to the initial position at the start of the docked state maintenance control.

[0020] In such a case, the controller is preferably configured or programmed to release the docked state maintenance control when the hull moves a predetermined distance or more in the forward-rearward direction of the hull from the initial position at the start of the docked state maintenance control during the docked state maintenance control. Accordingly, the possibility that a distance that the hull is returned to the initial position at the start of the docked state maintenance control along the forward-rearward direction of the hull becomes relatively large is reduced or prevented. Thus, the possibility that wear of the hull progresses due to the hull moving while being pressed against the pier when the hull is returned to the initial position at the start of the docked state maintenance control is reduced or prevented.

[0021] A jet propulsion watercraft control system according to an example embodiment of the present invention includes a jet propulsion watercraft and a remote control to remotely control the jet propulsion watercraft. The jet propulsion watercraft includes a hull, a water flow generator to generate a jet of water to provide a propulsive force to the hull, a water flow direction adjuster to adjust a direction of the jet of water from the water flow generator, and a controller configured or programmed to, when a docked state maintenance operation is performed to maintain the hull in a state docked at a pier, perform a docked state maintenance control to control the water flow generator to maintain generation of the jet of water from the water flow generator while controlling the water flow direction adjuster to maintain the direction of the jet of water from the water flow generator in a direction to cause the hull to be pressed against the pier.

[0022] In a jet propulsion watercraft control system according to an example embodiment of the present invention, the jet propulsion watercraft includes the controller configured or programmed to, when the docked state maintenance operation is being performed to maintain the hull in a state docked at the pier, perform the docked state maintenance control to control the water flow generator to maintain generation of the jet of water from the water flow generator while controlling the water flow direction adjuster to maintain the direction of the jet of water from the water flow generator in the direction to cause the hull to be pressed against the pier. Accordingly, similarly to the jet propulsion watercraft according to example embodiments of the present invention described above, the docked state maintenance operation is performed such that the docked state maintenance control is performed to automatically maintain adjustment of the direction of the jet of water in the direction to cause the hull to be pressed against the pier. Consequently, similarly to the jet propulsion watercraft according to example embodiments of the present invention described above, even when a watercraft user is located away from the hull, the hull is maintained in a state docked at the pier after the hull is docked at the pier.

[0023] In a jet propulsion watercraft control system according to an example embodiment of the present invention, the water flow direction adjuster preferably includes a deflector rotatable in a right-left direction of the hull to change the direction of the jet of water from the water flow generator to a right side or a left side with respect to a centerline of the hull, and the controller is preferably configured or programmed to, during the docked state maintenance control, control an orientation of the deflector such that the direction of the jet of water from the water flow generator is maintained to the right side or the left side with respect to the centerline of the hull in the right-left direction. Accordingly, similarly to the jet propulsion watercraft according to example embodiments of the present invention described above, during the docked state maintenance control, adjustment of the direction of the jet of water to the direction to cause the hull to be pressed against the pier is easily maintained.

[0024] In such a case, the water flow direction adjuster preferably further includes a reverse bucket rotatable in an upward-downward direction of the hull to change a ratio between a rearward component of the jet of water that is directed toward a rear side of the hull to move the hull forward and a forward component of the jet of water that is directed toward a front side of the hull to move the hull rearward, and the controller is preferably configured or programmed to, during the docked state maintenance control, control an orientation of the reverse bucket such that a rearward component and the forward component of the jet of water from the water flow generator are maintained in a state in which the rearward component and a forward component cancel each other out. Accordingly, similarly to the jet propulsion watercraft according to example embodiments of the present invention described above, during the docked state maintenance control, a state in which a propulsive force is not generated in the forward-rearward direction of the hull is easily maintained. Thus, similarly to the jet propulsion watercraft according to example embodiments of the present invention described above, movement of the hull in the forward-rearward direction from an initial position at the start of the docked state maintenance control during the docked state maintenance control is reduced or prevented.

[0025] In a jet propulsion watercraft control system according to an example embodiment of the present invention, the jet propulsion watercraft preferably includes a communicator to communicate with the remote control, and a manual operator to operate the hull, and the controller is preferably configured or programmed to perform the docked state maintenance control when a signal indicating that the remote control has received the docked state maintenance operation is received from the remote control via the communicator, or when the docked state maintenance operation is being performed on the manual operator. Accordingly, similarly to the jet propulsion watercraft according to example embodiments of the present invention described above, when the watercraft user is not on the hull, the watercraft user is able to cause the controller to perform the docked state maintenance control by performing the docked state maintenance operation on the remote control. When the watercraft user is on the hull, the watercraft user is able to cause the controller to perform the docked state maintenance control by performing the docked state maintenance operation on the remote control or the manual operator.

[0026] A method for maintaining a jet propulsion watercraft in a docked state according to an example embodiment of the present invention includes performing a docked state maintenance operation to maintain a hull of the jet propulsion watercraft in a state docked at a pier, and performing a docked state maintenance control to perform a control to maintain generation of a jet of water while performing a control to maintain a direction of the jet of water in a direction to cause the hull to be pressed against the pier when the docked state maintenance operation is being performed.

[0027] A method for maintaining a jet propulsion watercraft in a docked state according to an example embodiment of the present invention includes performing the docked state maintenance control to perform a control to maintain generation of the jet of water while performing a control to maintain the direction of the jet of water in the direction to cause the hull to be pressed against the pier when the docked state maintenance operation is being performed. Accordingly, similarly to the jet propulsion watercraft and the jet propulsion watercraft control system according to example embodiments of the present invention described above, the docked state maintenance operation is performed such that the docked state maintenance control is performed to automatically maintain adjustment of the direction of the jet of water in the direction to cause the hull to be pressed against the pier. Consequently, similarly to the jet propulsion watercraft and the jet propulsion watercraft control system according to example embodiments of the present invention described above, even when the watercraft user is located away from the hull, the hull is maintained in a state docked at the pier after the hull is docked at the pier.

[0028] A method for maintaining a jet propulsion watercraft in a docked state according to an example embodiment of the present invention preferably further includes launching the hull from a trailer used to transport the hull at a shore, and operating a remote control to move the hull, which has been launched from the trailer, to the pier and dock the hull at the pier, and the performing of the docked state maintenance operation preferably includes performing the docked state maintenance operation on the remote control such that the docked state maintenance control is performed on the hull that has been launched from the trailer, moved to the pier, and docked at the pier. Accordingly, after the watercraft user launches the hull from the trailer at the shore and operates the remote control to move the hull to the pier and dock the hull at the pier, the hull is maintained in a state docked at the pier while the watercraft user moves from the shore to the hull.

[0029] A method for maintaining a jet propulsion watercraft in a docked state according to an example embodiment of the present invention preferably further includes operating a manual operator of the hull to move the hull from offshore to the pier and dock the hull at the pier, operating a remote control to move the hull from the pier to a shore, and loading the hull onto a trailer used to transport the hull at the shore, and the performing of the docked state maintenance operation preferably includes performing the docked state maintenance operation on the remote control or the manual operator such that the docked state maintenance control is performed on the hull that has been moved from offshore to the pier and docked at the pier. Accordingly, after the watercraft user moves the hull from offshore to the pier and docks the hull at the pier and before the watercraft user operates the remote control to move the hull from the pier to the shore in order to load the hull onto the trailer at the shore, the hull is maintained in a state docked at the pier while the watercraft user moves from the hull to the shore.

[0030] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is a block diagram of a jet propulsion watercraft control system according to an example embodiment of the present invention.

[0032] FIG. 2 is a side view of a jet propulsion watercraft according to an example embodiment of the present invention.

[0033] FIG. 3 is a plan view showing a state in which a deflector of a jet propulsion watercraft according to an example embodiment of the present invention is oriented along the centerline of a hull in a right-left direction.

[0034] FIG. 4 is a plan view showing a state in which the orientation of a deflector of a jet propulsion watercraft according to an example embodiment of the present invention is tilted to the right of a hull from a direction along the centerline of the hull in a right-left direction.

[0035] FIG. 5 is a plan view showing a state in which the orientation of a deflector of a jet propulsion watercraft according to an example embodiment of the present invention is tilted to the left of a hull from a direction along the centerline of the hull in a right-left direction.

[0036] FIG. 6 is a perspective view showing a reverse bucket of a jet propulsion watercraft according to an example embodiment of the present invention.

[0037] FIG. 7 is a side view showing a state in which a reverse bucket of a jet propulsion watercraft according to an example embodiment of the present invention is in a forward movement position.

[0038] FIG. 8 is a side view showing a state in which a reverse bucket of a jet propulsion watercraft according to an example embodiment of the present invention is in a rearward movement position.

[0039] FIG. 9 is a side view showing a state in which a reverse bucket of a jet propulsion watercraft according to an example embodiment of the present invention is in a rearward movement position.

[0040] FIG. 10 is a diagram showing a deflector actuator of a jet propulsion watercraft according to an example embodiment of the present invention.

[0041] FIG. 11 is a side view showing a state in which a reverse bucket of a jet propulsion watercraft according to an example embodiment of the present invention is in a neutral position.

[0042] FIG. 12 is a plan view showing a state in which a reverse bucket of a jet propulsion watercraft according to an example embodiment of the present invention is in a neutral position.

[0043] FIG. 13 is a diagram showing a state in which a hull of a jet propulsion watercraft according to an example embodiment of the present invention is docked at a pier.

[0044] FIG. 14 is a diagram illustrating a method for maintaining a jet propulsion watercraft in a docked state according to an example embodiment of the present invention.

[0045] FIG. 15 is another diagram illustrating a method for maintaining a jet propulsion watercraft in a docked state according to an example embodiment of the present invention.DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0046] Example embodiments of the present invention are hereinafter described with reference to the drawings.

[0047] A jet propulsion watercraft 100 and a jet propulsion watercraft control system 101 according to example embodiments of the present invention are now described with reference to FIGS. 1 to 13.

[0048] As shown in FIG. 1, the jet propulsion watercraft control system 101 includes the jet propulsion watercraft 100 and a remote control 102 to remotely control the jet propulsion watercraft 100.

[0049] As shown in FIG. 2, the jet propulsion watercraft 100 is a personal watercraft, for example. The jet propulsion watercraft 100 includes a hull 10, a water flow generator 20, a water flow direction adjuster 30, a controller 40, a communicator 50, and a manual operator 60. In the figures, arrow FWD represents the front side of the hull 10, and arrow BWD represents the rear side of the hull 10. In the figures, arrow R represents the right side of the hull 10, and arrow L represents the left side of the hull 10. In the figures, arrow Z1 represents the upper side of the hull 10, and arrow Z2 represents the lower side of the hull 10.

[0050] As shown in FIG. 2, the water flow generator 20 generates a jet of water to provide a propulsion force to the hull 10. The water flow generator 20 is driven by a power unit 21, which functions as a power source to generate a jet of water, to draw water into a water passage 25, which includes an opening on the lower surface of a rear portion of the hull 10, and eject the drawn-in water from a nozzle 24 located at the rear end of the hull 10 to generate a jet of water toward the rear of the hull 10. The water flow generator 20 includes the power unit 21, a drive shaft 22, an impeller 23, the nozzle 24, and the water passage 25. In the figures, the jet of water is indicated by a bold arrow.

[0051] The power unit 21 includes an engine including a crankshaft 21a. The engine obtains a drive force to rotate the crankshaft 21a by burning a mixture of air drawn in through an intake passage (not shown) including a throttle valve (not shown) and fuel in a combustion chamber.

[0052] The drive shaft 22 extends in the forward-rearward direction of the hull 10, the front end of the drive shaft 22 is connected to the crankshaft 21a, and the rear end of the drive shaft 22 is located within the water passage 25. The impeller 23 is fixed in the vicinity of the rear end of the drive shaft 22 and located within the water passage 25. The impeller 23 rotates together with the drive shaft 22 to generate a water flow toward the nozzle 24 within the water passage 25. The nozzle 24 is located at the most downstream position of the water passage 25. The nozzle 24 functions as a water outlet (jetting port). Water is ejected from the nozzle 24 to generate a jet of water toward the rear of the hull 10. As shown in FIG. 3, a central portion of the nozzle 24 in the right-left direction of the hull 10 is located on the centerline CL of the hull 10 in the right-left direction.

[0053] As shown in FIG. 2, the water flow direction adjuster 30 adjusts the direction of the jet of water generated from the water flow generator 20. The water flow direction adjuster 30 includes a deflector 31, a reverse bucket 32, and a deflector actuator 33.

[0054] As shown in FIGS. 3 to 5, the deflector 31 is rotatable in the right-left direction of the hull 10 so as to change the direction of the jet of water generated from the water flow generator 20 to the right or left side with respect to the centerline CL of the hull 10. In other words, the deflector 31 is rotatable in the right-left direction of the hull 10 so as to tilt the direction of the jet of water generated from the water flow generator 20 to the right or left of the hull 10 from a direction along the centerline CL of the hull 10 in the right-left direction. Specifically, the deflector 31 has a cylindrical shape so as to surround the rear end of the nozzle 24. The deflector 31 is attached to the rear end of the nozzle 24. The deflector 31 is rotatable in the right-left direction of the hull 10 around an axis extending in the upward-downward direction of the hull 10. The deflector 31 is rotated in the right-left direction of the hull 10 such that the orientation of the deflector 31 is tilted to the right or left of the hull 10 from the direction along the centerline CL of the hull 10 in the right-left direction, such that the direction of the water (jet of water) ejected from the nozzle 24 is tilted to the right or left of the hull 10 from the direction along the centerline CL of the hull 10 in the right-left direction at the rear of the hull 10.

[0055] As shown in FIGS. 6 to 9, the reverse bucket 32 is rotatable in the upward-downward direction of the hull 10 around an axis extending in the right-left direction of the hull 10 so as to change a ratio between a rearward component of the jet of water that is directed toward the rear side of the hull 10 to move the hull 10 forward and a forward component of the jet of water that is directed toward the front side of the hull 10 to move the hull 10 rearward. Specifically, as shown in FIG. 7, the reverse bucket 32 is attached to the rear end of the nozzle 24. As shown in FIG. 6, the reverse bucket 32 includes a pair of curved surfaces 32a that are curved to direct the jet of water toward the reverse bucket 32 to the right and left sides of the hull 10, respectively, and a pair of water flow outlet holes 32b that are connected to the curved surfaces 32a and penetrate right and left portions of the reverse bucket 32, respectively, so as to direct the incoming jet of water diagonally forward of the hull 10. Then, depending on the rotational position of the reverse bucket 32 in the upward-downward direction of the hull 10, a proportion of the jet of water that has passed through the deflector 31, is not changed in direction by the reverse bucket 32, and moves rearward or diagonally rearward of the hull 10, and a proportion of the jet of water that has passed through the deflector 31, is changed in direction by the reverse bucket 32, and moves diagonally forward of the hull 10, change. In other words, depending on the rotational position of the reverse bucket 32 in the upward-downward direction of the hull 10, the ratio between the rearward component and the forward component of the jet of water generated from the water flow generator 20 changes.

[0056] As shown in FIG. 7, when the reverse bucket 32 is rotated such that all or most of the jet of water that has passed through the deflector 31 does not hit the reverse bucket 32 (the reverse bucket 32 is in the forward movement position), the direction of the jet of water that has passed through the deflector 31 is not changed by the reverse bucket 32. Therefore, when the deflector 31 is oriented along the centerline CL of the hull 10 in the right-left direction as shown in FIG. 3, and the reverse bucket 32 is in the forward movement position as shown in FIG. 7, all or most of the jet of water that has passed through the deflector 31 continues to flow rearward. In such a case, the jet of water that has passed through the water flow direction adjuster 30 includes almost only a rearward component, and thus the hull 10 moves forward. When the orientation of the deflector 31 is tilted to the right or left of the hull 10 from the direction along the centerline CL of the hull 10 in the right-left direction as shown in FIGS. 4 and 5, and the reverse bucket 32 is in the forward movement position as shown in FIG. 7, all or most of the jet of water that has passed through the deflector 31 continues to flow obliquely rearward. In such a case, the jet of water that has passed through the water flow direction adjuster 30 includes a forward component and a component in the right-left direction of the hull, and thus the hull 10 moves obliquely forward.

[0057] When the reverse bucket 32 is rotated such that all or most of the jet of water that has passed through the deflector 31 hits the reverse bucket 32 (the reverse bucket 32 is in the rearward movement position) as shown in FIG. 8, the direction of the jet of water that has passed through the deflector 31 is changed by the reverse bucket 32. Therefore, when the deflector 31 is oriented along the centerline CL of the hull 10 as shown in FIG. 9, and the reverse bucket 32 is in the rearward movement position as shown in FIG. 8, all or most of the jet of water that has passed through the deflector 31 hits the pair of curved surfaces 32a of the reverse bucket 32 and is discharged obliquely forward symmetrically from the pair of water flow outlet holes 32b of the reverse bucket 32, as shown in FIG. 9. In such a case, the resultant force of the jet of water that has passed through the water flow direction adjuster 30 includes almost only the forward component, and thus the hull 10 moves rearward.

[0058] As shown in FIG. 10, the deflector actuator 33 changes the orientation of the deflector 31. Specifically, the deflector actuator 33 includes an electric motor 33a, a transmission gear 33b, a deflector-side cable 33c, an operator-side cable 33d, and a clutch 33e. The transmission gear 33b transmits the drive forces of the electric motor 33a and a deflector operator 61. The transmission gear 33b includes a rack and a pinion, for example. The deflector-side cable 33c includes a first end connected to the transmission gear 33b and a second end connected to the deflector 31 to push and pull the deflector 31 to rotate the deflector 31. The operator-side cable 33d includes a first end connected to the transmission gear 33b and a second end connected to the deflector operator 61 (described below) to push and pull the deflector 31 to rotate the deflector 31. The clutch 33e is provided between the electric motor 33a and the transmission gear 33b, and switches between a state in which the drive force of the electric motor 33a is transmitted to the transmission gear 33b and a state in which the drive force of the electric motor 33a is not transmitted to the transmission gear 33b.

[0059] As shown in FIG. 1, the controller 40 includes an arithmetic unit such as a central processing unit (CPU), and storages such as a read-only memory (ROM) and a random access memory (RAM). The controller 40 controls driving of the power unit 21, the orientation of the deflector 31, the orientation of the reverse bucket 32, etc.

[0060] The communicator 50 communicates with the remote control 102. The communicator 50 communicates wirelessly with the remote control 102 via Bluetooth (registered trademark) or Wi-Fi (registered trademark), for example.

[0061] The manual operator 60 operates the hull 10. The manual operator 60 includes the deflector operator 61 to receive operations to rotate the deflector 31.

[0062] As shown in FIG. 14, the remote control 102 is a smartphone. The remote control 102 operates the hull 10, similarly to the manual operator 60. Specifically, application software is installed on the remote control 102 to operate the jet propulsion watercraft 100.

[0063] As shown in FIGS. 11 to 13, when a docked state maintenance operation is performed to maintain the hull 10 in a state docked at a pier 201, the controller 40 performs a docked state maintenance control to control the water flow generator 20 to maintain the jet of water generated from the water flow generator 20 while controlling the water flow direction adjuster 30 to maintain the direction of the jet of water generated from the water flow generator 20 in a direction that causes the hull 10 to be pressed against the pier 201. FIG. 12 shows an example in which the left side of the hull 10 is pressed against the pier 201.

[0064] Specifically, as shown in FIG. 12, during the docked state maintenance control, the controller 40 controls the orientation of the deflector 31 using the deflector actuator 33 such that the direction of the jet of water generated from the water flow generator 20 is maintained to the right or left side with respect to the centerline CL of the hull 10 in the right-left direction. In other words, during the docked state maintenance control, the controller 40 controls the orientation of the deflector 31 using the deflector actuator 33 such that the direction of the jet of water generated from the water flow generator 20 is maintained in a state tilted to the right or left of the hull 10 from the direction along the centerline CL of the hull 10 in the right-left direction. Thus, the jet of water that hits one (the right curved surface 32a in the example shown in FIG. 12) of the pair of curved surfaces 32a of the reverse bucket 32 is discharged diagonally forward (diagonally forward right in the example shown in FIG. 12) from one (the right water flow outlet hole 32b in the example shown in FIG. 12) of the pair of water flow outlet holes 32b of the reverse bucket 32. Furthermore, during the docked state maintenance control, the controller 40 controls the orientation of the deflector 31 such that the direction of the jet of water generated from the water flow generator 20 is maintained at the rightmost or leftmost position (the rightmost position in the example shown in FIG. 12) within a variable range relative to the centerline CL of the hull 10 in the right-left direction. In other words, during the docked state maintenance control, the controller 40 controls the orientation of the deflector 31 such that the direction of the jet of water generated from the water flow generator 20 is maintained in a state tilted to the rightmost or leftmost side within a range in which the direction of the jet of water is tiltable to the right or left of the hull 10 from the direction along the centerline CL of the hull 10 in the right-left direction. When a docked state release operation is performed to release the docked state maintenance control while the docked state maintenance control is being performed, the controller 40 controls the orientation of the deflector 31 such that the direction of the jet of water generated from the water flow generator 20 is maintained in the direction along the centerline CL of the hull 10 in the right-left direction. That is, when the docked state release operation is performed to release the docked state maintenance control while the docked state maintenance control is being performed, the controller 40 controls the orientation of the deflector 31 such that the direction of the jet of water is maintained in a direction that causes the hull 10 not to be pressed against the pier 201.

[0065] As shown in FIG. 11, during the docked state maintenance control, the controller 40 controls the orientation of the reverse bucket 32 such that the rearward component and the forward component of the jet of water generated from the water flow generator 20 are maintained in a state in which they cancel each other out. In other words, the controller 40 rotates the reverse bucket 32 to a position between the forward movement position and the rearward movement position at which a portion (about a half to two-thirds, for example) of the jet of water that has passed through the deflector 31 hits the reverse bucket 32 (the reverse bucket 32 is in a neutral position). When the orientation of the deflector 31 is tilted to the right or left of the hull 10 (the right in the example shown in FIG. 12) from the direction along the centerline CL of the hull 10 in the right-left direction, and the reverse bucket 32 is in the neutral position as shown in FIG. 11, a portion of the jet of water that has passed through the deflector 31 hits one (the right curved surface 32a in the example shown in FIG. 12) of the pair of curved surfaces 32a of the reverse bucket 32 and is discharged diagonally forward (diagonally forward right in the example shown in FIG. 12) from one (the right water flow outlet hole 32b in the example shown in FIG. 12) of the pair of water flow outlet holes 32b. The remaining jet of water that has passed through the deflector 31 continues to flow diagonally rearward (diagonally rearward right in the example shown in FIG. 12). In such a case, the jet of water discharged diagonally forward from one (the right water flow outlet hole 32b in the example shown in FIG. 12) of the pair of water flow outlet holes 32b includes a forward component and a rightward component, and the jet of water flowing diagonally rearward (diagonally rearward right in the example shown in FIG. 12) includes a rearward component. Therefore, when the orientation of the reverse bucket 32 is controlled such that the forward component and the rearward component of the resultant force of the jet of water that has passed through the water flow direction adjuster 30 cancel each other out, the resultant force of the jet of water that has passed through the water flow direction adjuster 30 includes almost only one of the rightward and leftward components (the rightward component in the example shown in FIG. 12). Thus, as shown in FIG. 13, the direction of the jet of water that has passed through the water flow direction adjuster 30 is in the direction that causes the hull 10 to be pressed against the pier 201. When the hull 10 is pressed against the pier 201, frictional resistance occurs between the hull 10 and the pier 201, and thus even when the jet of water that has passed through the water flow direction adjuster 30 includes a component in the forward-rearward direction, the hull 10 is maintained in a state pressed against the pier 201.

[0066] During the docked state maintenance control, the controller 40 controls the power unit 21 such that the rotation speed of the power unit 21 is maintained at a speed lower than a predetermined rotation speed. Specifically, during the docked state maintenance control, the controller 40 controls the engine such that the engine is maintained in an idling state.

[0067] The controller 40 performs the docked state maintenance control when a signal indicating that the remote control 102 has received the docked state maintenance operation is received from the remote control 102 via the communicator 50, or when the docked state maintenance operation is being performed on the manual operator 60. In other words, regardless of whether a watercraft user 202 is on the hull 10 or not on the hull 10 (when the watercraft user 202 is located away from the hull 10), the watercraft user 202 is able to perform the docked state maintenance operation such that docked state maintenance control is performed.

[0068] When the speed of the hull 10 is greater than a predetermined speed, the controller 40 does not perform the docked state maintenance control even when the docked state maintenance operation is requested. The predetermined speed is set according to the size, shape, etc. of the jet propulsion watercraft 100.

[0069] As shown in FIG. 13, during the docked state maintenance control, the controller 40 controls the orientation of the reverse bucket 32 to differentiate the rearward component and the forward component of the jet of water generated from the water flow generator 20 from each other such that the hull 10 returns to the initial position P0 at the start of the docked state maintenance control when the hull 10 moves in the forward-rearward direction of the hull 10 from an initial position P0 at the start of the docked state maintenance control. The initial position P0 at the start of the docked state maintenance control refers to the position of the hull 10 at the time at which the docked state maintenance control is started by performing the docked state maintenance operation after the hull 10 is docked at the pier 201. In other words, the controller 40 controls the orientation of the reverse bucket 32 such that the resultant force of the jet of water includes a rightward component or a leftward component (a leftward component in the example shown in FIG. 13), and the component in the forward-rearward direction is increased such that the hull 10 is movable in the forward-rearward direction. During the docked state maintenance control, the controller 40 releases the docked state maintenance control when the hull 10 moves a predetermined distance or more in the forward-rearward direction of the hull 10 from the initial position P0 at the start of the docked state maintenance control. The predetermined distance is set according to the size, shape, etc. of the jet propulsion watercraft 100.

[0070] A method for maintaining the jet propulsion watercraft 100 in a docked state according to example embodiments of the present invention is now described with reference to FIGS. 14 and 15.

[0071] As shown in FIG. 14, in step S11, at a shore 203, the watercraft user 202 operates the remote control 102 to launch the hull 10 from a trailer 204 used to transport the hull 10.

[0072] In step S12, at the shore 203, the watercraft user 202 operates the remote control 102 to move the hull 10, which has been launched from the trailer 204, from the shore 203 to the pier 201 and dock the hull 10 at the pier 201.

[0073] In step S13, at the shore 203, the watercraft user 202 performs the docked state maintenance operation on the remote control 102 to maintain the hull 10 in a state docked at the pier 201. That is, at the shore 203, the watercraft user 202 performs the docked state maintenance operation on the remote control 102 such that the docked state maintenance control is performed on the hull 10 that has been launched from the trailer 204, moved to the pier 201, and docked at the pier 201.

[0074] In step S14, the controller 40 performs the docked state maintenance control to control the water flow generator 20 to maintain generation of the jet of water while controlling the water flow direction adjuster 30 to maintain the direction of the jet of water in the direction that causes the hull 10 to be pressed against the pier 201. That is, the controller 40 performs the docked state maintenance control when the docked state maintenance operation is being performed. The controller 40 continuously performs the docked state maintenance control until the docked state release operation is performed to release the docked state maintenance control when the docked state maintenance control is being performed.

[0075] In step S15, the watercraft user 202 moves from the shore to the hull 10.

[0076] In step S16, the watercraft user 202 performs the docked state release operation on the remote control 102 or the manual operator 60 to release the docked state maintenance control.

[0077] In step S17, the controller 40 releases the docked state maintenance control. That is, the controller 40 releases the docked state maintenance control when the docked state release operation is performed.

[0078] As shown in FIG. 15, in step S21, offshore, the watercraft user 202 on board the hull 10 operates the manual operator 60 of the hull 10 to move the hull 10 from offshore to the pier 201 and dock the hull 10.

[0079] In step S22, on the hull 10, the watercraft user 202 performs the docked state maintenance operation on the remote control 102 or the manual operator 60 to maintain the hull 10 in a state docked at the pier 201. That is, on the hull 10, the watercraft user 202 performs the docked state maintenance operation on the remote control 102 or the manual operator 60 such that the docked state maintenance control is performed on the hull 10 that has been moved from offshore to the pier 201 and docked at the pier 201.

[0080] In step S23, the controller 40 performs the docked state maintenance control to control the water flow generator 20 to maintain generation of the jet of water while controlling the water flow direction adjuster 30 to maintain the direction of the jet of water in the direction that causes the hull 10 to be pressed against the pier 201. That is, the controller 40 performs the docked state maintenance control when the docked state maintenance operation is being performed. The controller 40 continuously performs the docked state maintenance control until the docked state release operation is performed to release the docked state maintenance control when the docked state maintenance control is being performed.

[0081] In step S24, the watercraft user 202 moves from the hull 10 to the shore 203.

[0082] In step S25, the watercraft user 202 performs the docked state release operation on the remote control 102 or the manual operator 60 to release the docked state maintenance control.

[0083] In step S26, the controller 40 releases the docked state maintenance control. That is, the controller 40 releases the docked state maintenance control when the docked state release operation is being performed.

[0084] In step S27, at the shore 203, the watercraft user 202 operates the remote control 102 to move the hull 10 from the pier 201 to the shore 203.

[0085] In step S28, at the shore 203, the watercraft user 202 operates the remote control 102 to load the hull 10 onto the trailer 204 used to transport the hull 10.

[0086] According to the various example embodiments of the present invention described above, the following advantageous effects are achieved.

[0087] According to an example embodiment of the present invention, the jet propulsion watercraft 100 includes the controller 40 configured or programmed to, when the docked state maintenance operation is being performed to maintain the hull 10 in a state docked at the pier 201, perform the docked state maintenance control to control the water flow generator 20 to maintain generation of a jet of water from the water flow generator 20 while controlling the water flow direction adjuster 30 to maintain the direction of the jet of water generated from the water flow generator 20 in the direction that causes the hull 10 to be pressed against the pier 201. Accordingly, the docked state maintenance operation is performed such that the docked state maintenance control is performed to automatically maintain adjustment of the direction of the jet of water in the direction that causes the hull 10 to be pressed against the pier 201. Consequently, even when the watercraft user 202 is located away from the hull 10, the hull 10 is maintained in a state docked at the pier 201 after the hull 10 is docked at the pier 201.

[0088] According to an example embodiment of the present invention, the water flow direction adjuster 30 includes the deflector 31 rotatable in the right-left direction of the hull 10 to change the direction of the jet of water generated from the water flow generator 20 to the right or left side with respect to the centerline CL of the hull 10. Furthermore, the controller 40 is configured or programmed to, during the docked state maintenance control, control the orientation of the deflector 31 such that the direction of the jet of water generated from the water flow generator 20 is maintained to the right or left side with respect to the centerline CL of the hull 10 in the right-left direction. Accordingly, during the docked state maintenance control, adjustment of the direction of the jet of water to the direction that causes the hull 10 to be pressed against the pier 201 is easily maintained. When the hull 10 is pressed against the pier 201, frictional resistance occurs between the hull 10 and the pier 201. Therefore, even when the jet of water, the direction of which has been adjusted, includes the component in the forward-rearward direction of the hull 10, the hull 10 is maintained in a state pressed against the pier 201.

[0089] According to an example embodiment of the present invention, the water flow direction adjuster 30 includes the reverse bucket 32 rotatable in the upward-downward direction of the hull 10 to change the ratio between the rearward component of the jet of water that is directed toward the rear side of the hull 10 to move the hull 10 forward and the forward component of the jet of water that is directed toward the front side of the hull 10 to move the hull 10 rearward. Furthermore, the controller 40 is configured or programmed to, during the docked state maintenance control, control the orientation of the reverse bucket 32 such that the rearward component and the forward component of the jet of water generated from the water flow generator 20 are maintained in a state in which the rearward component and the forward component cancel each other out. Accordingly, during the docked state maintenance control, a state in which a propulsive force is not generated in the forward-rearward direction of the hull 10 is easily maintained. Thus, movement of the hull 10 in the forward-rearward direction from the initial position P0 at the start of the docked state maintenance control during the docked state maintenance control is reduced or prevented.

[0090] According to an example embodiment of the present invention, the controller 40 is configured or programmed to, when the docked state release operation is performed to release the docked state maintenance control while the docked state maintenance control is being performed, control the orientation of the deflector 31 such that the direction of the jet of water generated from the water flow generator 20 is maintained in the direction along the centerline CL of the hull 10 in the right-left direction. Accordingly, the docked state release operation is performed such that adjustment of the direction of the jet of water in the direction that causes the hull 10 not to be pressed against the pier 201 is automatically maintained. In other words, the docked state release operation is performed such that the docked state maintenance control is easily released.

[0091] According to an example embodiment of the present invention, the controller 40 is configured or programmed to, during the docked state maintenance control, control the orientation of the deflector 31 such that the direction of the jet of water generated from the water flow generator 20 is maintained at the rightmost or leftmost position within the variable range relative to the centerline CL of the hull 10 in the right-left direction. Accordingly, during the docked state maintenance control, the component of the jet of water, the direction of which has been adjusted, in the forward-rearward direction of the hull 10 is maintained relatively small. Thus, movement of the hull 10 in the forward-rearward direction from the initial position P0 at the start of the docked state maintenance control during the docked state maintenance control is reduced or prevented.

[0092] According to an example embodiment of the present invention, the water flow generator 20 includes the power unit 21 as a power source to generate a jet of water. Furthermore, the controller 40 is configured or programmed to, during the docked state maintenance control, control the power unit 21 such that the rotation speed of the power unit 21 is maintained at a speed lower than the predetermined rotation speed. Accordingly, during the docked state maintenance control, the jet of water generated from the water flow generator 20 is maintained relatively small. Thus, during the docked state maintenance control, the component of the jet of water, the direction of which has been adjusted, in the forward-rearward direction of the hull 10 is maintained relatively small. Consequently, movement of the hull 10 in the forward-rearward direction from the initial position P0 at the start of the docked state maintenance control during the docked state maintenance control is reduced or prevented.

[0093] According to an example embodiment of the present invention, the power unit 21 includes an engine. Furthermore, the controller 40 is configured or programmed to, during the docked state maintenance control, control the engine such that the engine is maintained in an idling state. Accordingly, a configuration is easily achieved to maintain the jet of water generated from the water flow generator 20 relatively small during the docked state maintenance control.

[0094] According to an example embodiment of the present invention, the jet propulsion watercraft 100 includes the communicator 50 to communicate with the remote control 102 to remotely control the hull 10, and the manual operator 60 to operate the hull 10. Furthermore, the controller 40 is configured or programmed to perform the docked state maintenance control when the signal indicating that the remote control 102 has received the docked state maintenance operation is received from the remote control 102 via the communicator 50, or when the docked state maintenance operation is being performed on the manual operator 60. Accordingly, when the watercraft user 202 is not on the hull 10, the watercraft user 202 is able to cause the controller 40 to perform the docked state maintenance control by performing the docked state maintenance operation on the remote control 102. When the watercraft user 202 is on the hull 10, the watercraft user 202 is able to cause the controller 40 to perform the docked state maintenance control by performing the docked state maintenance operation on the remote control 102 or the manual operator 60.

[0095] According to an example embodiment of the present invention, the jet propulsion watercraft 100 includes the deflector actuator 33 to change the orientation of deflector 31. Furthermore, the controller 40 is configured or programmed to, during the docked state maintenance control, control the orientation of the deflector 31 using the deflector actuator 33 such that the direction of the jet of water generated from the water flow generator 20 is maintained to the right or left side with respect to the centerline CL of the hull 10 in the right-left direction. Accordingly, the deflector actuator 33 enables the orientation of the deflector 31 to be easily and automatically controlled during the docked state maintenance control.

[0096] According to an example embodiment of the present invention, the jet propulsion watercraft 100 includes the deflector operator 61 to receive an operation to rotate the deflector 31. Furthermore, the deflector actuator 33 includes the electric motor 33a, the transmission gear 33b to transmit the drive forces of the electric motor 33a and the deflector operator 61, the deflector-side cable 33c including the first end connected to the transmission gear 33b and the second end connected to the deflector 31 to push and pull the deflector 31 to rotate the deflector 31, and the operator-side cable 33d including the first end connected to the transmission gear 33b and the second end connected to the deflector operator 61 to push and pull the deflector 31 to rotate the deflector 31. Accordingly, the orientation of the deflector 31 is automatically controlled via the electric motor 33a, the transmission gear 33b, and the deflector-side cable 33c, and is manually controlled via the deflector operator 61, the operator-side cable 33d, the transmission gear 33b, and the deflector-side cable 33c. Thus, a configuration that enables both manual and automatic control of the orientation of the deflector 31 is easily achieved by simply adding the electric motor 33a and the transmission gear 33b to a configuration that enables manual control of the orientation of the deflector 31, which is common in the jet propulsion watercraft 100.

[0097] According to an example embodiment of the present invention, the controller 40 is configured or programmed to, when the speed of the hull 10 is greater than the predetermined speed, not perform the docked state maintenance control even when the docked state maintenance operation is requested. Accordingly, the possibility that the docked state maintenance control is performed when the jet of water generated from the water flow generator 20 is relatively large is prevented. It is relatively difficult to perform the docked state maintenance control when the jet of water generated from the water flow generator 20 is relatively large, and thus it is preferable to perform the docked state maintenance control when the jet of water generated from the water flow generator 20 is relatively small.

[0098] According to an example embodiment of the present invention, the controller 40 is configured or programmed to, when the hull 10 moves in the forward-rearward direction of the hull 10 from the initial position P0 at the start of the docked state maintenance control during the docked state maintenance control, control the orientation of the reverse bucket 32 to differentiate the rearward component and the forward component of the jet of water generated from the water flow generator 20 from each other such that the hull 10 returns to the initial position P0 at the start of the docked state maintenance control. Accordingly, even when the hull 10 moves in the forward-rearward direction of the hull 10 from the initial position P0 at the start of the docked state maintenance control during the docked state maintenance control, the hull 10 is returned to the initial position P0 at the start of the docked state maintenance control.

[0099] According to an example embodiment of the present invention, the controller 40 is configured or programmed to release the docked state maintenance control when the hull 10 moves the predetermined distance or more in the forward-rearward direction of the hull 10 from the initial position P0 at the start of the docked state maintenance control during the docked state maintenance control. Accordingly, the possibility that a distance that the hull 10 is returned to the initial position P0 at the start of the docked state maintenance control along the forward-rearward direction of the hull 10 becomes relatively large is reduced or prevented. Thus, the possibility that wear of the hull 10 progresses due to the hull 10 moving while being pressed against the pier 201 when the hull 10 is returned to the initial position P0 at the start of the docked state maintenance control is reduced or prevented.

[0100] According to an example embodiment of the present invention, the method for maintaining the jet propulsion watercraft 100 in a docked state includes a step (S14, S23) of performing the docked state maintenance control to perform a control to maintain generation of the jet of water while performing a control to maintain the direction of the jet of water in the direction that causes the hull 10 to be pressed against the pier 201 when the docked state maintenance operation is being performed. Accordingly, similarly to the advantageous effects of the jet propulsion watercraft and the jet propulsion watercraft control system described above, the docked state maintenance operation is performed such that the docked state maintenance control is performed to automatically maintain adjustment of the direction of the jet of water in the direction that causes the hull 10 to be pressed against the pier 201. Consequently, similarly to the advantageous effects of the jet propulsion watercraft and the jet propulsion watercraft control system described above, even when the watercraft user 202 is located away from the hull 10, the hull 10 is maintained in a state docked at the pier 201 after the hull 10 is docked at the pier 201.

[0101] According to an example embodiment of the present invention, the method for maintaining the jet propulsion watercraft 100 in a docked state includes a step (S11) of launching the hull 10 from the trailer 204 used to transport the hull 10 at the shore 203, and a step (S12) of operating the remote control 102 to move the hull 10, which has been launched from the trailer 204, to the pier 201 and dock the hull 10 at the pier 201. Furthermore, a step (S13, S22) of performing the docked state maintenance operation includes a step (S13) of performing the docked state maintenance operation on the remote control 102 such that the docked state maintenance control is performed on the hull 10 that has been launched from the trailer 204, moved to the pier 201, and docked at the pier 201. Accordingly, after the watercraft user 202 launches the hull 10 from the trailer 204 at the shore 203 and operates the remote control 102 to move the hull 10 to the pier 201 and dock the hull 10 at the pier 201, the hull 10 is maintained in a state docked at the pier 201 while the watercraft user 202 moves from the shore 203 to the hull 10.

[0102] According to an example embodiment of the present invention, the method for maintaining the jet propulsion watercraft 100 in a docked state includes a step (S21) of operating the manual operator 60 of the hull 10 to move the hull 10 from offshore to the pier 201 and dock the hull 10 at the pier 201, a step (S27) of operating the remote control 102 to move the hull 10 from the pier 201 to the shore 203, and a step (S28) of loading the hull 10 onto the trailer 204 used to transport the hull 10 at the shore 203. Furthermore, the step (S13, S22) of performing the docked state maintenance operation includes a step (S22) of performing the docked state maintenance operation on the remote control 102 or the manual operator 60 such that the docked state maintenance control is performed on the hull 10 that has been moved from offshore to the pier 201 and docked at the pier 201. Accordingly, after the watercraft user 202 moves the hull 10 from offshore to the pier 201 and docks the hull 10 at the pier 201 and before the watercraft user 202 operates the remote control 102 to move the hull 10 from the pier 201 to the shore 203 in order to load the hull 10 onto the trailer 204 at the shore 203, the hull 10 is maintained in a state docked at the pier 201 while the watercraft user 202 moves from the hull 10 to the shore 203.

[0103] The example embodiments of the present invention described above are illustrative in all points and not restrictive. The extent of the present invention is not defined by the above description of the example embodiments but by the scope of the claims, and all modifications within the meaning and range equivalent to the scope of the claims are further included.

[0104] For example, while in the docked state maintenance control, the controller 40 preferably controls the orientation of the reverse bucket 32 such that the rearward component and the forward component of the jet of water generated from the water flow generator 20 are maintained in a state in which they cancel each other out in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, during the docked state maintenance control, the controller may not control the orientation of the reverse bucket such that the rearward component and the forward component of the jet of water generated from the water flow generator are maintained in a state in which they cancel each other out. In such a case, during the docked state maintenance control, the reverse bucket is maintained in a state in which the direction of the jet of water generated from the water flow generator is not changed (the reverse bucket is in the rearward movement position), and the direction of the jet of water is maintained in the direction that causes the hull to be pressed against the pier by controlling only the orientation of the deflector.

[0105] While the controller 40 preferably controls the orientation of the deflector 31 such that the direction of the jet of water generated from the water flow generator 20 is maintained in the direction along the centerline CL of the hull 10 in the right-left direction when the docked state release operation is performed to release the docked state maintenance control while the docked state maintenance control is being performed in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the controller may not control the orientation of the deflector such that the direction of the jet of water generated from the water flow generator is maintained in the direction along the centerline of the hull in the right-left direction when the docked state release operation is performed to release the docked state maintenance control while the docked state maintenance control is being performed. In such a case, the controller may control the water flow generator to stop generating the jet of water when the docked state release operation is performed to release the docked state maintenance control while the docked state maintenance control is being performed.

[0106] While in the docked state maintenance control, the controller 40 preferably controls the orientation of the deflector 31 such that the direction of the jet of water generated from the water flow generator 20 is maintained at the rightmost or leftmost position within the variable range relative to the centerline CL of the hull 10 in the right-left direction in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, during the docked state maintenance control, the controller may alternatively control the orientation of the deflector such that the direction of the jet of water generated from the water flow generator is maintained at a position other than the rightmost or leftmost position within the variable range relative to the centerline of the hull in the right-left direction.

[0107] While in the docked state maintenance control, the controller 40 preferably controls the power unit 21 such that the rotation speed of the power unit 21 is maintained at a speed lower than the predetermined rotation speed in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, during the docked state maintenance control, the controller may alternatively control the power unit of the water flow generator such that the rotation speed of the power unit of the water flow generator is maintained at a speed equal to or higher than the predetermined rotation speed.

[0108] While the power unit 21 preferably includes an engine, and the controller 40 preferably controls the engine such that the engine is maintained in an idling state during the docked state maintenance control in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the power unit may alternatively include an electric motor. In such a case, the controller may control the electric motor such that the rotation speed of the electric motor is maintained at a speed that enables a drive force, which is the same in magnitude as a drive force generated when the engine is idling, to be generated during the docked state maintenance control.

[0109] While the jet propulsion watercraft 100 preferably includes the communicator 50 to communicate with the remote control 102 to remotely control the hull 10, and the manual operator 60 to operate the hull 10, and the controller 40 preferably performs the docked state maintenance control when the signal indicating that the remote control 102 has received the docked state maintenance operation is received from the remote control 102 via the communicator 50, or when the docked state maintenance operation is being performed on the manual operator 60 in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the controller may alternatively perform the docked state maintenance control only when the signal indicating that the remote control has received the docked state maintenance operation is received from the remote control via the communicator, or when the docked state maintenance operation is being performed on the manual operator.

[0110] While the jet propulsion watercraft 100 preferably includes the deflector operator 61 to receive an operation to rotate the deflector 31, and the deflector actuator 33 preferably includes the electric motor 33a, the transmission gear 33b to transmit the drive forces of the electric motor 33a and the deflector operator 61, the deflector-side cable 33c including the first end connected to the transmission gear 33b and the second end connected to the deflector 31 to push and pull the deflector 31 to rotate the deflector 31, and the operator-side cable 33d including the first end connected to the transmission gear 33b and the second end connected to the deflector operator 61 to push and pull the deflector 31 to rotate the deflector 31 in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the deflector actuator may alternatively include the electric motor, a transmission gear to transmit the drive force of the electric motor and not transmit the drive forces of the deflector operator, and the deflector-side cable including the first end connected to the transmission gear and the second end connected to the deflector to push and pull the deflector to rotate the deflector, but not the operator-side cable including the first end connected to the transmission gear and the second end connected to the deflector operator to push and pull the deflector to rotate the deflector. That is, the deflector actuator (a configuration to automatically control the orientation of the deflector) and a configuration to manually control the orientation of the deflector may be provided independently of each other.

[0111] While when the speed of the hull 10 is greater than the predetermined speed, the controller 40 preferably does not perform the docked state maintenance control even when the docked state maintenance operation is requested in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the controller may alternatively perform the docked state maintenance control regardless of the speed of the hull when the docked state maintenance operation is being performed.

[0112] While the controller 40 preferably controls the orientation of the reverse bucket 32 to differentiate the rearward component and the forward component of the jet of water generated from the water flow generator 20 from each other such that the hull 10 returns to the initial position P0 at the start of the docked state maintenance control when the hull 10 moves in the forward-rearward direction of the hull 10 from the initial position P0 at the start of the docked state maintenance control during the docked state maintenance control in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, even when the hull moves in the forward-rearward direction of the hull from the initial position at the start of the docked state maintenance control the during docked state maintenance control, the controller may not control the orientation of the reverse bucket such that the hull returns to the initial position at the start of the docked state maintenance control.

[0113] While the controller 40 preferably releases the docked state maintenance control when the hull 10 moves the predetermined distance or more in the forward-rearward direction of the hull 10 from the initial position P0 at the start of the docked state maintenance control during the docked state maintenance control in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the controller may alternatively control the orientation of the reverse bucket such that the hull returns to the initial position without releasing the docked state maintenance control regardless of a distance that the hull has moved in the forward-rearward direction of the hull from the initial position at the start of the docked state maintenance control during the docked state maintenance control.

[0114] While the step (S13, S22) of performing the docked state maintenance operation preferably includes the step (S13) of performing the docked state maintenance operation on the remote control 102 such that the docked state maintenance control is performed on the hull 10 that has been launched from the trailer 204, moved to the pier 201, and docked at the pier 201 in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the step of performing the docked state maintenance operation may not include the step of performing the docked state maintenance operation on the remote control such that the docked state maintenance control is performed on the hull that has been launched from the trailer, moved to the pier, and docked at the pier. That is, the method for maintaining the jet propulsion watercraft in a docked state may not be used when the watercraft user moves from the shore to the hull docked at the pier.

[0115] While the step (S13, S22) of performing the docked state maintenance operation preferably includes the step (S22) of performing the docked state maintenance operation on the remote control 102 or the manual operator 60 such that the docked state maintenance control is performed on the hull 10 that has been moved from offshore to the pier 201 and docked at the pier 201 in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the step of performing the docked state maintenance operation may not include the step of performing the docked state maintenance operation on the remote control or the manual operator such that the docked state maintenance control is performed on the hull that has been moved from offshore to the pier and docked at the pier. That is, the method for maintaining the jet propulsion watercraft in a docked state may not be used when the watercraft user moves from the hull docked at the pier to the shore.

[0116] While the jet propulsion watercraft 100 is preferably a personal watercraft in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the jet propulsion watercraft may alternatively be a sports boat.

[0117] While the remote control 102 is preferably a smartphone in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the remote control may alternatively be a tablet terminal or a dedicated remote control to remotely control the jet propulsion watercraft.

[0118] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.

Claims

1. A jet propulsion watercraft comprising:a hull;a water flow generator to generate a jet of water to provide a propulsive force to the hull;a water flow direction adjuster to adjust a direction of the jet of water from the water flow generator; anda controller configured or programmed to, when a docked state maintenance operation is performed to maintain the hull in a state docked at a pier, perform a docked state maintenance control to control the water flow generator to maintain generation of the jet of water from the water flow generator while controlling the water flow direction adjuster to maintain the direction of the jet of water from the water flow generator in a direction to cause the hull to be pressed against the pier.

2. The jet propulsion watercraft according to claim 1, whereinthe water flow direction adjuster includes a deflector rotatable in a right-left direction of the hull to change the direction of the jet of water from the water flow generator to a right side or a left side with respect to a centerline of the hull; andthe controller is configured or programmed to, during the docked state maintenance control, control an orientation of the deflector such that the direction of the jet of water from the water flow generator is maintained to the right side or the left side with respect to the centerline of the hull in the right-left direction.

3. The jet propulsion watercraft according to claim 2, whereinthe water flow direction adjuster further includes a reverse bucket rotatable in an upward-downward direction of the hull to change a ratio between a rearward component of the jet of water that is directed toward a rear side of the hull to move the hull forward and a forward component of the jet of water that is directed toward a front side of the hull to move the hull rearward; andthe controller is configured or programmed to, during the docked state maintenance control, control an orientation of the reverse bucket such that the rearward component and the forward component of the jet of water from the water flow generator are maintained in a state in which the rearward component and the forward component cancel each other out.

4. The jet propulsion watercraft according to claim 2, wherein the controller is configured or programmed to, when a docked state release operation is performed to release the docked state maintenance control while the docked state maintenance control is being performed, control the orientation of the deflector such that the direction of the jet of water from the water flow generator is maintained in a direction along the centerline of the hull in the right-left direction.

5. The jet propulsion watercraft according to claim 2, wherein the controller is configured or programmed to, during the docked state maintenance control, control the orientation of the deflector such that the direction of the jet of water from the water flow generator is maintained at a rightmost position or a leftmost position within a variable range relative to the centerline of the hull in the right-left direction.

6. The jet propulsion watercraft according to claim 1, whereinthe water flow generator includes a power unit as a power source to generate the jet of water; andthe controller is configured or programmed to, during the docked state maintenance control, control the power unit such that a rotation speed of the power unit is maintained at a speed lower than a predetermined rotation speed.

7. The jet propulsion watercraft according to claim 6, whereinthe power unit includes an engine; andthe controller is configured or programmed to, during the docked state maintenance control, control the engine such that the engine is maintained in an idling state.

8. The jet propulsion watercraft according to claim 1, further comprising:a communicator to communicate with a remote control to remotely control the hull; anda manual operator to operate the hull; whereinthe controller is configured or programmed to perform the docked state maintenance control when a signal indicating that the remote control has received the docked state maintenance operation is received from the remote control via the communicator, or when the docked state maintenance operation is being performed on the manual operator.

9. The jet propulsion watercraft according to claim 2, further comprising:a deflector actuator to change the orientation of deflector; whereinthe controller is configured or programmed to, during the docked state maintenance control, control the orientation of the deflector with the deflector actuator such that the direction of the jet of water from the water flow generator is maintained to the right side or the left side with respect to the centerline of the hull in the right-left direction.

10. The jet propulsion watercraft according to claim 9, further comprising:a deflector operator to receive an operation to rotate the deflector; whereinthe deflector actuator includes:an electric motor;a transmission gear to transmit drive forces of the electric motor and the deflector operator;a deflector-side cable including a first end connected to the transmission gear and a second end connected to the deflector to push and pull the deflector to rotate the deflector; andan operator-side cable including a first end connected to the transmission gear and a second end connected to the deflector operator to push and pull the deflector to rotate the deflector.

11. The jet propulsion watercraft according to claim 1, wherein the controller is configured or programmed to, when a speed of the hull is greater than a predetermined speed, not perform the docked state maintenance control even when the docked state maintenance operation is requested.

12. The jet propulsion watercraft according to claim 3, wherein the controller is configured or programmed to, when the hull moves in a forward-rearward direction of the hull from an initial position at a start of the docked state maintenance control during the docked state maintenance control, control the orientation of the reverse bucket to differentiate the rearward component and the forward component of the jet of water from the water flow generator from each other such that the hull returns to the initial position at the start of the docked state maintenance control.

13. The jet propulsion watercraft according to claim 12, wherein the controller is configured or programmed to release the docked state maintenance control when the hull moves a predetermined distance or more in the forward-rearward direction of the hull from the initial position at the start of the docked state maintenance control during the docked state maintenance control.

14. A jet propulsion watercraft control system comprising:a jet propulsion watercraft; anda remote control to remotely control the jet propulsion watercraft; whereinthe jet propulsion watercraft includes:a hull;a water flow generator to generate a jet of water to provide a propulsive force to the hull;a water flow direction adjuster to adjust a direction of the jet of water from the water flow generator; anda controller configured or programmed to, when a docked state maintenance operation is performed to maintain the hull in a state docked at a pier, perform a docked state maintenance control to control the water flow generator to maintain generation of the jet of water from the water flow generator while controlling the water flow direction adjuster to maintain the direction of the jet of water from the water flow generator in a direction to cause the hull to be pressed against the pier.

15. The jet propulsion watercraft control system according to claim 14, whereinthe water flow direction adjuster includes a deflector rotatable in a right-left direction of the hull to change the direction of the jet of water generated from the water flow generator to a right side or a left side with respect to a centerline of the hull; andthe controller is configured or programmed to, during the docked state maintenance control, control an orientation of the deflector such that the direction of the jet of water from the water flow generator is maintained to the right side or the left side with respect to the centerline of the hull in the right-left direction.

16. The jet propulsion watercraft control system according to claim 15, whereinthe water flow direction adjuster further includes a reverse bucket rotatable in an upward-downward direction of the hull to change a ratio between a rearward component of the jet of water that is directed toward a rear side of the hull to move the hull forward and a forward component of the jet of water that is directed toward a front side of the hull to move the hull rearward; andthe controller is configured or programmed to, during the docked state maintenance control, control an orientation of the reverse bucket such that the rearward component and the forward component of the jet of water from the water flow generator are maintained in a state in which the rearward component and the forward component cancel each other out.

17. The jet propulsion watercraft control system according to claim 14, whereinthe jet propulsion watercraft includes:a communicator to communicate with the remote control; anda manual operator to operate the hull; whereinthe controller is configured or programmed to perform the docked state maintenance control when a signal indicating that the remote control has received the docked state maintenance operation is received from the remote control via the communicator, or when the docked state maintenance operation is being performed on the manual operator.

18. A method for maintaining a jet propulsion watercraft in a docked state, the method comprising:performing a docked state maintenance operation to maintain a hull of the jet propulsion watercraft in a state docked at a pier; andperforming a docked state maintenance control to perform a control to maintain generation of a jet of water while performing a control to maintain a direction of the jet of water in a direction to cause the hull to be pressed against the pier when the docked state maintenance operation is being performed.

19. The method according to claim 18, further comprising:launching the hull from a trailer used to transport the hull at a shore; andoperating a remote control to move the hull, which has been launched from the trailer, to the pier and dock the hull at the pier; whereinthe performing of the docked state maintenance operation includes performing the docked state maintenance operation on the remote control such that the docked state maintenance control is performed on the hull that has been launched from the trailer, moved to the pier, and docked at the pier.

20. The method according to claim 18, further comprising:operating a manual operator of the hull to move the hull from offshore to the pier and dock the hull at the pier;operating a remote control to move the hull from the pier to a shore; andloading the hull onto a trailer used to transport the hull at the shore; whereinthe performing of the docked state maintenance operation includes performing the docked state maintenance operation on the remote control or the manual operator such that the docked state maintenance control is performed on the hull that has been moved from offshore to the pier and docked at the pier.

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