Jet propulsion system and jet propulsion watercraft

Abstract

A jet propulsion system includes a jet propulsion mechanism including a nozzle, a manual operator, a wireless controller, and a controller configured or programmed to, in a wireless watercraft maneuvering mode, perform a switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to a manual watercraft maneuvering mode based on the manual operator being operated.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to Japanese Patent Application No. 2024-197856 filed on Nov. 13, 2024. The entire contents of this application are hereby incorporated herein by reference.BACKGROUND OF THE INVENTION1. Field of the Invention

[0002] The present invention relates to jet propulsion systems and jet propulsion watercrafts.2. Description of the Related Art

[0003] A jet propulsion watercraft including a jet propulsion mechanism is known in general. Such a jet propulsion watercraft is disclosed in Japanese Patent Laid-Open No. 2019-055671, for example.

[0004] Japanese Patent Laid-Open No. 2019-055671 discloses a jet propulsion watercraft including a jet propulsion mechanism. The jet propulsion watercraft includes a remote control to remotely control the jet propulsion watercraft.

[0005] However, in the jet propulsion watercraft described in Japanese Patent Laid-Open No. 2019-055671, when a watercraft body is remotely controlled by the remote control, the watercraft body may be moved by the remote control in a manner not intended by a watercraft user on board the watercraft body. For example, when the watercraft body is remotely controlled by the remote control, the watercraft body may move closer to an obstacle ahead, or move toward a restricted area. Therefore, when the watercraft user on board the watercraft body notices that the watercraft body is being moved by remote control in a manner not intended by the watercraft user on board the watercraft body, there is a need for the watercraft user on board the watercraft body to be able to immediately resolve such a situation.SUMMARY OF THE INVENTION

[0006] Example embodiments of the present invention provide jet propulsion systems and jet propulsion watercrafts that each enable watercraft users on board watercraft bodies to, when the watercraft bodies are being moved by wireless control in a manner not intended by the watercraft users on board the watercraft bodies, enable the watercraft users on board the watercraft bodies to immediately resolve such a situation.

[0007] A jet propulsion system according to an example embodiment of the present invention includes a jet propulsion mechanism located at a stern of a watercraft body and including a nozzle including a jetting port to eject a jet of water to generate a propulsive force, a manual operator to control movement of the watercraft body by changing at least one of a magnitude of the propulsive force of the jet of water, an orientation of the jet of water in a right-left direction, or an orientation of the jet of water in a forward-rearward direction, a wireless controller configured or programmed to instruct movement of the watercraft body by wireless communication with the watercraft body, and a controller on the watercraft body and configured or programmed to, in a wireless watercraft maneuvering mode in which the movement of the watercraft body is instructed by the wireless controller, perform a switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to a manual watercraft maneuvering mode in which the watercraft body is moved by a watercraft user operating the manual operator based on the manual operator being operated by the watercraft user on board the watercraft body.

[0008] A jet propulsion system according to an example embodiment of the present invention includes the manual operator to control movement of the watercraft body by changing at least one of the magnitude of the propulsive force of the jet of water, the orientation of the jet of water in the right-left direction, or the orientation of the jet of water in the forward-rearward direction, and the controller on the watercraft body and being configured or programmed to, in the wireless watercraft maneuvering mode in which movement of the watercraft body is instructed by the wireless controller, perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode in which the watercraft body is moved by the watercraft user operating the manual operator based on the manual operator being operated by the watercraft user on board the watercraft body. Accordingly, the watercraft user on board the watercraft body operates the manual operator to forcibly switch the wireless watercraft maneuvering mode to the manual watercraft maneuvering mode such that the wireless watercraft maneuvering mode is terminated, and the manual watercraft maneuvering mode in which the watercraft body is moved by an operation based on the intention of the watercraft user is immediately started. Therefore, when the watercraft body is being moved by wireless control in a manner not intended by the watercraft user on board the watercraft body, the watercraft user on board the watercraft body is able to immediately resolve such a situation by himself / herself. In particular, when the watercraft user on board the watercraft body notices a situation in which the wireless watercraft maneuvering mode should be terminated, such as when the watercraft body continues to move toward an obstacle ahead, switching the wireless watercraft maneuvering mode to the manual watercraft maneuvering mode allows the intention of the watercraft user to be prioritized, and allows the watercraft body to be moved immediately, and thus the above configuration is effective.

[0009] A jet propulsion system according to an example embodiment of the present invention preferably further includes a notifier to provide a notification indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed. Accordingly, the watercraft user or a wireless user not on board the watercraft body easily recognizes through the notifier that the wireless watercraft maneuvering mode has been switched to the manual watercraft maneuvering mode.

[0010] In a jet propulsion system according to an example embodiment of the present invention, the jet propulsion mechanism preferably includes an impeller to generate the jet of water, the manual operator preferably includes a propulsive force change operator to increase or decrease a rotation speed of the impeller to increase or decrease the magnitude of the propulsive force obtained by the jet of water, and the controller is preferably configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the propulsive force change operator being operated by the watercraft user in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user operating the propulsive force change operator to accelerate the watercraft body in order to avoid an obstacle, for example.

[0011] In such a case, the propulsive force change operator preferably includes a throttle lever to increase or decrease the rotation speed of the impeller according to an amount of operation of the throttle lever, the throttle lever preferably includes a lever position sensor to detect the amount of operation of the throttle lever, and the controller is preferably configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the lever position sensor detecting an operation on the throttle lever in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user operating the throttle lever to accelerate the watercraft body.

[0012] In a jet propulsion system in which the propulsive force change operator includes the throttle lever including the lever position sensor, the throttle lever preferably includes a forward movement throttle lever to move the watercraft body forward, and a reverse movement throttle lever to move the watercraft body rearward, the lever position sensor preferably includes a forward movement lever position sensor to detect an amount of operation of the forward movement throttle lever, and a reverse movement lever position sensor to detect an amount of operation of the reverse movement throttle lever, and the controller is preferably configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the forward movement lever position sensor detecting an operation on the forward movement throttle lever or the reverse movement lever position sensor detecting an operation on the reverse movement throttle lever in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user operating the forward movement throttle lever or the reverse movement throttle lever to accelerate the watercraft body.

[0013] In a jet propulsion system according to an example embodiment of the present invention, the controller is preferably configured or programmed to limit the magnitude of the propulsive force of the jet of water ejected from the jet propulsion mechanism by setting a temporary upper limit on the magnitude of the propulsive force of the jet of water when the manual operator is operated to perform the switching control. Accordingly, when the watercraft user reflexively operates the manual operator to suddenly increase the magnitude of the propulsive force in order to avoid an obstacle, for example, sudden acceleration of the watercraft body is reduced or prevented.

[0014] In a jet propulsion system including the notifier, the notifier preferably includes a sound emitter to emit a predetermined notification sound indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed. Accordingly, even when visibility is poor or the watercraft user is not able to take his / her eyes off the direction of travel, for example, the watercraft user or the wireless user easily recognizes by the sound emitted from the sound emitter that the wireless watercraft maneuvering mode has been switched to the manual watercraft maneuvering mode.

[0015] In a jet propulsion system including the notifier, the notifier preferably includes a display to display a predetermined notification indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed. Accordingly, even when the engine noise is loud, for example, the watercraft user easily and visually recognizes through the display that the wireless watercraft maneuvering mode has been switched to the manual watercraft maneuvering mode.

[0016] In a jet propulsion system according to an example embodiment of the present invention, the manual operator preferably includes a shift lever to switch a shift state, and the controller is preferably configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the watercraft user operating the shift lever to switch the watercraft body between forward movement and reverse movement in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user performing a shift switching operation on the shift lever, such as switching forward movement to reverse movement.

[0017] In a jet propulsion system according to an example embodiment of the present invention, the manual operator preferably includes a steering operator operable by the watercraft user, the steering operator preferably includes a steering sensor to detect an amount of operation of the steering operator, and the controller is preferably configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the steering sensor detecting an operation on the steering operator in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user turning the steering operator right and left in order to avoid an obstacle, for example.

[0018] A jet propulsion system according to an example embodiment of the present invention preferably further includes a steering actuator including an electric motor to rotate the nozzle in the right-left direction using a drive force of the electric motor to change the orientation of the jet of water from the jetting port in the right-left direction in the wireless watercraft maneuvering mode, and the controller is preferably configured or programmed to stop a supply of drive power to the electric motor by the switching control to enable the watercraft user to maneuver the watercraft body using the manual operator in the manual watercraft maneuvering mode. Accordingly, when the watercraft user performs a steering operation after the wireless watercraft maneuvering mode is forcibly switched to the manual watercraft maneuvering mode, a load is prevented from being applied to the electric motor.

[0019] In such a case, a jet propulsion system preferably further includes a steering operator operable by the watercraft user, and the steering actuator preferably further includes a transmission gear to transmit drive forces of the electric motor and the steering operator to the nozzle, a nozzle-side steering cable including a first end connected to the transmission gear and a second end connected to the nozzle to push and pull the nozzle, and an operator-side steering cable including a first end connected to the transmission gear and a second end connected to the steering operator to push and pull the nozzle. Accordingly, a drive force is transmitted from the steering operator and the electric motor to the nozzle via the transmission gear and the nozzle-side steering cable, which are provided as components common to the steering operator and the electric motor. Thus, the number of components is reduced, and the system structure is simplified.

[0020] In a jet propulsion system according to an example embodiment of the present invention, the wireless watercraft maneuvering mode preferably includes a remote watercraft maneuvering mode in which the watercraft body is remotely maneuvered using the wireless controller, and an automatic movement mode in which the watercraft body is automatically moved by remotely instructing the watercraft body to move automatically using the wireless controller. Accordingly, in the remote watercraft maneuvering mode or the automatic movement mode, the watercraft user on board the watercraft body operates the manual operator to forcibly switch the remote watercraft maneuvering mode or the automatic movement mode to the manual watercraft maneuvering mode in order to avoid an obstacle, for example.

[0021] A jet propulsion watercraft according to an example embodiment of the present invention includes a watercraft body, a jet propulsion mechanism located at a stern of the watercraft body and including a nozzle including a jetting port to eject a jet of water from the jetting port to generate a propulsive force, a manual operator to control movement of the watercraft body by changing at least one of a magnitude of the propulsive force of the jet of water, an orientation of the jet of water in a right-left direction, or an orientation of the jet of water in a forward-rearward direction, a wireless controller configured or programmed to instruct movement of the watercraft body by wireless communication with the watercraft body, and a controller on the watercraft body and configured or programmed to, in a wireless watercraft maneuvering mode in which the movement of the watercraft body is instructed by the wireless controller, perform a switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to a manual watercraft maneuvering mode in which the watercraft body is moved by a watercraft user operating the manual operator based on the manual operator being operated by the watercraft user on board the watercraft body.

[0022] A jet propulsion watercraft according to an example embodiment of the present invention includes the manual operator to control movement of the watercraft body by changing at least one of the magnitude of the propulsive force of the jet of water ejected from the jet propulsion mechanism, the orientation of the jet of water in the right-left direction, or the orientation of the jet of water in the forward-rearward direction, and the controller on the watercraft body being configured or programmed to, in the wireless watercraft maneuvering mode in which movement of the watercraft body is instructed by the wireless controller, perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode in which the watercraft body is moved by the watercraft user operating the manual operator based on the manual operator being operated by the watercraft user on board the watercraft body. Accordingly, the watercraft user on board the watercraft body operates the manual operator to forcibly switch the wireless watercraft maneuvering mode to the manual watercraft maneuvering mode such that the wireless watercraft maneuvering mode is terminated, and the manual watercraft maneuvering mode in which the watercraft body is moved by an operation based on the intention of the watercraft user is immediately started. Therefore, when the watercraft body is being moved by wireless control in a manner not intended by the watercraft user on board the watercraft body, the watercraft user on board the watercraft body is able to immediately resolve such a situation by himself / herself. In particular, when the watercraft user on board the watercraft body notices a situation in which the wireless watercraft maneuvering mode should be terminated, such as when the watercraft body continues to move toward an obstacle ahead, switching the wireless watercraft maneuvering mode to the manual watercraft maneuvering mode allows the intention of the watercraft user to be prioritized, and allows the watercraft body to be moved immediately, and thus the above configuration is effective.

[0023] A jet propulsion watercraft according to an example embodiment of the present invention preferably further includes a notifier to provide a notification indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed. Accordingly, the watercraft user or a wireless user not on board the watercraft body easily recognizes through the notifier that the wireless watercraft maneuvering mode has been switched to the manual watercraft maneuvering mode.

[0024] In a jet propulsion watercraft according to an example embodiment of the present invention, the jet propulsion mechanism preferably includes an impeller to generate the jet of water, the manual operator preferably includes a propulsive force change operator to increase or decrease a rotation speed of the impeller to increase or decrease the magnitude of the propulsive force obtained by the jet of water, and the controller is preferably configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the propulsive force change operator being operated by the watercraft user in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user operating the propulsive force change operator to accelerate the watercraft body in order to avoid an obstacle, for example.

[0025] In such a case, the propulsive force change operator preferably includes a throttle lever to increase or decrease the rotation speed of the impeller according to an amount of operation of the throttle lever, the throttle lever preferably includes a lever position sensor to detect the amount of operation of the throttle lever, and the controller is preferably configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the lever position sensor detecting an operation on the throttle lever in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user operating the throttle lever to accelerate the watercraft body.

[0026] In a jet propulsion watercraft in which the propulsive force change operator includes the throttle lever including the lever position sensor, the throttle lever preferably includes a forward movement throttle lever to move the watercraft body forward, and a reverse movement throttle lever to move the watercraft body rearward, the lever position sensor preferably includes a forward movement lever position sensor to detect an amount of operation of the forward movement throttle lever, and a reverse movement lever position sensor to detect an amount of operation of the reverse movement throttle lever, and the controller is preferably configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the forward movement lever position sensor detecting an operation on the forward movement throttle lever or the reverse movement lever position sensor detecting an operation on the reverse movement throttle lever in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user operating the forward movement throttle lever or the reverse movement throttle lever to accelerate the watercraft body.

[0027] In a jet propulsion watercraft according to an example embodiment of the present invention, the controller is preferably configured or programmed to limit the magnitude of the propulsive force of the jet of water ejected from the jet propulsion mechanism by setting a temporary upper limit on the magnitude of the propulsive force of the jet of water when the manual operator is operated to perform the switching control. Accordingly, when the watercraft user reflexively operates the manual operator to suddenly increase the magnitude of the propulsive force in order to avoid an obstacle, for example, sudden acceleration of the watercraft body is reduced or prevented.

[0028] In a jet propulsion watercraft including the notifier, the notifier preferably includes a sound emitter to emit a predetermined notification sound indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed. Accordingly, even when visibility is poor or the watercraft user is not able to take his / her eyes off the direction of travel, for example, the watercraft user or the wireless user easily recognizes by the sound emitted from the sound emitter that the wireless watercraft maneuvering mode has been switched to the manual watercraft maneuvering mode.

[0029] 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

[0030] FIG. 1 is a side view showing a jet propulsion watercraft on which a jet propulsion system is mounted according to an example embodiment of the present invention.

[0031] FIG. 2 is an enlarged side view showing a portion of a jet propulsion watercraft on which a jet propulsion system is mounted according to an example embodiment of the present invention.

[0032] FIG. 3 is a block diagram of a jet propulsion system according to an example embodiment of the present invention.

[0033] FIG. 4 is a diagram showing a jet propulsion watercraft and a wireless controller configured or programmed to communicate wirelessly with the jet propulsion watercraft according to an example embodiment of the present invention.

[0034] FIG. 5 is a diagram showing a display screen of a wireless controller of a jet propulsion system according to an example embodiment of the present invention.

[0035] FIG. 6 is a schematic plan view illustrating right and left rotation of a nozzle of a jet propulsion mechanism of a jet propulsion system according to an example embodiment of the present invention.

[0036] FIG. 7 is a schematic side view illustrating upward and downward rotation (trim) of a nozzle of a jet propulsion mechanism according to an example embodiment of the present invention.

[0037] FIG. 8 is a schematic side view illustrating upward and downward rotation of a reverse bucket of a jet propulsion mechanism according to an example embodiment of the present invention.

[0038] FIG. 9 is a partial enlarged view of a portion A in FIG. 2.

[0039] FIG. 10 is a diagram showing an operator according to an example embodiment of the present invention from the rear side.

[0040] FIG. 11 is a schematic plan view illustrating a switching control.

[0041] FIG. 12 is a flowchart of a control process for a switching control according to an example embodiment of the present invention.DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0042] Example embodiments of the present invention are hereinafter described with reference to the drawings.

[0043] A jet propulsion watercraft 100 according to example embodiments of the present invention is now described with reference to FIGS. 1 to 12.

[0044] The jet propulsion watercraft 100 shown in FIGS. 1 and 2 is a personal watercraft, for example, and travels with a relatively small number of people on board. The jet propulsion watercraft 100 is a so-called jet ski or jet bike that glides on the surface of the water. The jet propulsion watercraft 100 includes a watercraft body 110 and a jet propulsion system 120 mounted on the watercraft body 110. The watercraft body 110 includes a hull 111 that defines the bottom of the watercraft, a deck 112 located above the hull 111, and a seat 113 located at the center of the deck 112 in a right-left direction.

[0045] As shown in FIG. 3, the jet propulsion system 120 includes a communicator 1, a wireless controller 2, a jet drive source 3, a jet propulsion mechanism 4 including a nozzle 44 (see FIG. 1) to eject a jet of water, an actuator 5 to change the orientation of the jet of water, an operator 6, a notifier 7, a controller 8, and a GPS receiver 9. The actuator 5 includes a steering actuator 50 and a trim actuator 55 to drive the nozzle 44, and a reverse actuator 56 to drive a reverse bucket 45.

[0046] In the figures, an X direction represents the forward-rearward direction of the jet propulsion watercraft 100. In the X direction, an X1 direction (FRD) represents a forward movement direction, and an X2 direction (BWD) represents a reverse movement direction. In the figures, a Y direction represents the right-left direction of the jet propulsion watercraft 100. In the figures, a Z direction represents the upward-downward direction of the jet propulsion watercraft 100, a Z1 direction represents an upward direction, and a Z2 direction represents a downward direction.

[0047] In a wireless watercraft maneuvering mode in which movement of the watercraft body 110 is instructed by the wireless controller 2, the jet propulsion system 120 (controller 8) according to an example embodiment of the present invention performs a switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to a manual watercraft maneuvering mode in which the watercraft body 110 is moved by a watercraft user U1 (see FIG. 11) operating a manual operator 6a based on the manual operator 6a being operated by the watercraft user U1 on board the watercraft body 110. In other words, in the wireless watercraft maneuvering mode in which the jet propulsion watercraft 100 is moved according to an instruction from the wireless controller 2, the controller 8 immediately terminates the wireless watercraft maneuvering mode when the watercraft user U1 reflexively operates the manual operator 6a such as a throttle lever 61 to avoid an obstacle, for example. Furthermore, the controller 8 immediately starts the manual watercraft maneuvering mode such that an operation performed reflexively becomes effective. The switching control is to give priority to an operation consciously performed by the watercraft user U1 to avoid an obstacle, for example, over movement of the watercraft body 110 in the wireless watercraft maneuvering mode. The switching control is described below in detail.

[0048] The communicator 1 shown in FIG. 3 is provided on the watercraft body 110. The communicator 1 establishes wireless communication with the wireless controller 2. As an example, the communicator 1 establishes wireless communication with the wireless controller 2 via Bluetooth (registered trademark). The communicator is not limited to Bluetooth and may be a wireless communicator using other communication standards, such as Wi-Fi (registered trademark). The watercraft user U1 causes the wireless controller 2 to establish wireless communication with the communicator 1 as preparations to operate the jet propulsion watercraft 100 (see FIG. 4).

[0049] The wireless controller 2 is held by the watercraft user U1 (see FIG. 11) on board the watercraft body 110 of the jet propulsion watercraft 100, or by a wireless user U2 (see FIG. 11) not on board the watercraft body 110. As an example, the wireless controller 2 is a smartphone. The wireless controller is not limited to a smartphone and may be a dedicated communication device to wirelessly communicate with the jet propulsion watercraft or a tablet terminal, for example. A dedicated application is installed in the wireless controller 2 to establish communication with the jet propulsion watercraft 100.

[0050] The wireless controller 2 is configured or programmed instruct movement of the watercraft body 110 by wireless communication with the watercraft body 110. The wireless watercraft maneuvering mode, in which movement of the watercraft body 110 is instructed by the wireless controller 2, includes the following two modes: a remote watercraft maneuvering mode and an automatic movement mode.

[0051] In the remote watercraft maneuvering mode, the watercraft body 110 is remotely operated using the wireless controller 2. When “remote watercraft maneuvering” of mode switching buttons 21 at the upper left of a display screen 20 (see FIG. 5) of the dedicated application of the wireless controller 2 is selected, the mode switches to the remote watercraft maneuvering mode. When “manual watercraft maneuvering” of the mode switching buttons 21 is selected, the mode switches to the manual watercraft maneuvering mode in which the watercraft user U1 operates a steering operator 60 to maneuver the jet propulsion watercraft 100. In the remote watercraft maneuvering mode, the jet propulsion watercraft 100 is freely remotely controlled to move using watercraft body operation buttons 22 (such as a forward (F) button, a reverse (R) button, and right and left turn buttons at the center of the screen) on the display screen 20. The jet propulsion system 120 (controller 8) according to an example embodiment of the present invention switches from the wireless watercraft maneuvering mode to the manual watercraft maneuvering mode by the switching control even when “manual watercraft maneuvering” of the mode switching buttons 21 is not selected.

[0052] In the automatic movement mode, the watercraft body 110 is automatically moved by remotely instructing the watercraft body 110 to move automatically using the wireless controller 2. The automatic movement mode includes modes such as automatic return, fixed point holding, and launching support.

[0053] As shown in FIG. 1, the jet drive source 3 includes an engine 30, a crankshaft 31, and a coupling 32. The engine 30 is, for example, a multi-cylinder internal combustion engine. The crankshaft 31 is an output shaft to output a torque generated by the engine 30. The crankshaft 31 extends rearward from the engine 30. The coupling 32 is provided at the rear end of the crankshaft 31 and connects and fixes the crankshaft 31 to an impeller shaft 41 of the jet propulsion mechanism 4.

[0054] The jet propulsion mechanism 4 generates a propulsive force by ejecting a jet of water from a jetting port 44a of the nozzle 44. The jet propulsion mechanism 4 includes a water passage 40, the impeller shaft 41, an impeller 42 to generate a jet of water, a nozzle 43 fixed to the rear end of the water passage 40, the nozzle 44 drivably installed on the nozzle 43, and the reverse bucket (reverse gate) 45.

[0055] The water passage 40 extends from a lower portion of the watercraft body 110 toward a stern 114. Water is taken into the water passage 40 through a water intake 40a in the lower portion of the watercraft body 110. The impeller shaft 41 extending rearward is provided in the water passage 40. The impeller 42 is fixed to the impeller shaft 41. The impeller 42 rotates integrally with the impeller shaft 41 to generate a rearward flow. The impeller shaft 41 is connected to the crankshaft 31 via the coupling 32. Therefore, the rotation speed of the impeller 42 increases or decreases as the rotation speed of the engine 30 increases or decreases.

[0056] The nozzle 43 shown in FIG. 6 performs a function to jet water flowing through the water passage 40 toward the rear nozzle 44. The nozzle 44 is attached to the nozzle 43 from the rear. The nozzle 44 is located at the stern 114 of the watercraft body 110. The nozzle 44 includes the jetting port 44a for jetting water. The nozzle 44 functions as a deflector to change the orientation of the jet of water ejected from the jetting port 44a. Specifically, the nozzle 44 is attached to the nozzle 43 so as to be rotatable in the right-left direction around a central axis C1 of an upward-downward central shaft 46 extending in the upward-downward direction (the steering position is adjustable around the upward-downward central shaft 46). The central axis C1 is located at the center of the nozzle 44 in the right-left direction. The nozzle 44 is rotated in the right-left direction by the steering actuator 50.

[0057] The nozzle 44 shown in FIG. 7 is attached to the nozzle 43 so as to be rotatable in the upward-downward direction around a central axis C2 of a right-left central shaft 47 extending in the right-left direction (the trim position is adjustable around the right-left central shaft 47). The central axis C2 is located at the center of the nozzle 44 in the upward-downward direction. The nozzle 44 is rotated in the upward-downward direction by the trim actuator 55. Thus, the nozzle 44 is rotated in the upward-downward direction and the right-left direction such that the orientation of the jet of water ejected from the jetting port 44a changes.

[0058] The reverse bucket 45 shown in FIG. 8 changes the orientation of the jet of water in the forward-rearward direction. The reverse bucket 45 rotationally moves between a position above the nozzle 44 and a position behind the nozzle 44. When moving to the position behind the nozzle 44, the reverse bucket 45 covers the jetting port 44a from behind such that the jet of water is directed forward, and the orientation of the jet of water is changed forward. The reverse bucket 45 is rotatable in the upward-downward direction around a central axis C3 of a right-left central shaft 48 extending in the right-left direction. The reverse bucket 45 is rotated in the upward-downward direction by the reverse actuator 56. Depending on the position of the reverse bucket 45, the jet propulsion watercraft 100 switches between a forward movement state, a reverse movement state, and a neutral state in which a forward thrust and a reverse thrust are substantially equal to each other. The jet propulsion watercraft 100 is in the reverse movement or neutral state when the reverse bucket 45 covers the jetting port 44a from behind, and is in the forward movement state when the reverse bucket 45 does not cover the jetting port 44a from behind. The reverse bucket 45 includes, on both the right and left sides thereof, jetting openings 45a each having a substantially cylindrical shape with a central axis directed diagonally forward to the right of the watercraft body 110.

[0059] Referring to FIGS. 2 and 9, the steering actuator 50 includes an electric motor 51 as a drive source, a transmission gear 52 to transmit the drive forces of the electric motor 51 and the steering operator 60 to the nozzle 44, a nozzle-side steering cable 53, and an operator-side steering cable 54. In the wireless watercraft maneuvering mode, the steering actuator 50 uses the drive force of the electric motor 51 to rotate the nozzle 44 in the right-left direction to change the orientation of the jet of water from the jetting port 44a in the right-left direction. The steering actuator 50 is able to rotate the nozzle 44 in the right-left direction even when the jet of water is not being ejected.

[0060] The electric motor 51 includes a motor shaft 51a, a transmission shaft 51b, and a clutch 51c to switch a connection state between the motor shaft 51a and the transmission shaft 51b. The jet propulsion watercraft may not include a clutch. A bevel gear 51d is provided on the side of the transmission shaft 51b opposite to the clutch 51c.

[0061] The transmission gear 52 includes a first gear 52a including a bevel gear 521 to mesh with the bevel gear 51d and a pinion 522, and a second gear 52b including a rack to mesh with the pinion 522. The nozzle-side steering cable 53 includes a first end connected to the transmission gear 52 and a second end connected to the nozzle 44, and pushes and pulls the nozzle 44. The operator-side steering cable 54 includes a first end connected to the transmission gear 52 and a second end connected to the steering operator 60, and pushes and pulls the nozzle 44 via the second gear 52b and the nozzle-side steering cable 53. The nozzle-side steering cable 53 and the operator-side steering cable 54 are push-pull cables. The operator-side steering cable 54 also pushes and pulls the steering operator 60 when the electric motor 51 is driven. That is, when the electric motor 51 is driven, the steering operator 60 operates even when the watercraft user U1 (see FIG. 11) does not operate the steering operator 60. The nozzle-side steering cable 53 is connected to a steering cable connector 44b of the nozzle 44. The nozzle 44 is rotated in the right-left direction by being pushed and pulled by the nozzle-side steering cable 53.

[0062] The trim actuator 55 shown in FIG. 7 includes an electric motor (not shown) as a drive source and a trim cable 55a to transmit the drive force of the electric motor to the nozzle 44. The trim actuator 55 uses the drive force of the electric motor to rotate the nozzle 44 in the upward-downward direction to change the orientation of the jet of water in the upward-downward direction. The trim actuator 55 is able to rotate the nozzle 44 in the upward-downward direction even when the jet of water is not being ejected. The trim cable 55a is connected to a trim cable connector 44c of the nozzle 44. The trim cable 55a is a push-pull cable. The trim actuator 55 is driven based on an operation on a trim operator 62.

[0063] The reverse actuator 56 shown in FIG. 8 includes an electric motor (not shown) as a drive source and a reverse cable 56a to transmit the drive force of the electric motor to the reverse bucket 45. The reverse actuator 56 uses the drive force of the electric motor to rotate the reverse bucket 45 in the upward-downward direction to change the orientation of the jet of water in the forward-rearward direction. The reverse cable 56a is connected to a reverse cable connector 45b of the reverse bucket 45. The reverse cable 56a is a push-pull cable.

[0064] As shown in FIG. 10, the operator 6 is provided on the watercraft body 110. The operator 6 includes the manual operator 6a and the trim operator 62. The manual operator 6a controls movement of the watercraft body 110 by changing at least one of the magnitude of the propulsive force of the jet of water ejected from the jet propulsion mechanism 4, the orientation of the jet of water in the right-left direction, or the orientation of the jet of water in the forward-rearward direction.

[0065] The manual operator 6a includes a propulsive force change operator 6b to increase or decrease the rotation speed of the impeller 42 to increase or decrease the magnitude of the propulsive force obtained by the jet of water, and the steering operator 60 that is operable by the watercraft user U1. The propulsive force change operator 6b includes a throttle lever 61 to increase or decrease the rotation speed of the impeller 42 depending on the amount of operation.

[0066] The steering operator 60 includes a pair of bar-shaped grips provided on the right and left sides of the watercraft body 110. The drive force input from the watercraft user U1 to the steering operator 60 is transmitted to the nozzle 44 via the operator-side steering cable 54 shown in FIG. 2, the transmission gear 52, and the nozzle-side steering cable 53. Consequently, the nozzle 44 rotates in the right-left direction.

[0067] The steering operator 60 includes a steering sensor 60a to detect the amount of operation of the steering operator 60. As an example, the steering sensor 60a detects a load associated with rotation of the steering operator 60 when the steering operator 60 is rotated. The steering sensor 60a detects a larger load as the steering operator 60 is operated faster. The steering sensor 60a detects the load by converting distortion of a detector associated with rotation of the steering operator 60 into a load (force). When the detection value of the steering sensor 60a is equal to or greater than a predetermined threshold, the controller 8 determines that the steering operator 60 has been operated by the watercraft user U1. The reason to take the predetermined threshold into consideration when the determination is made is to prevent the switching control from being performed when the steering operator 60 is unintentionally operated slightly (when an erroneous operation is performed such that the detection value of the steering sensor 60a is less than the predetermined threshold).

[0068] The throttle lever61 shown in FIG. 10 increases or decreases the rotation speed of the impeller 42 (opening of a throttle valve of the engine 30) depending on the amount of operation. As the throttle lever 61 is gripped tighter, the amount of operation becomes larger, and thus the force of the jet of water increases. The throttle lever 61 includes a lever position sensor 63 to detect the amount of operation of the throttle lever 61.

[0069] Specifically, the throttle lever 61 includes a forward movement throttle lever 61a to move the watercraft body 110 forward, and a reverse movement throttle lever 61b to move the watercraft body 110 rearward. The forward movement throttle lever 61a is provided along the right steering operator 60. The reverse movement throttle lever 61b is provided along the left steering operator 60. The lever position sensor 63 includes a forward movement lever position sensor 63a to detect the amount of operation of the forward movement throttle lever 61a, and a reverse movement lever position sensor 63b to detect the amount of operation of the reverse movement throttle lever 61b.

[0070] The trim operator 62 includes a trim-up button and a trim-down button. When the trim-up button is pressed, the nozzle 44 is rotated upward by the trim actuator 55. When the trim-down button is pressed, the nozzle 44 is rotated downward by the trim actuator 55.

[0071] The notifier 7 provides a notification indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed. The notifier 7 includes a sound emitter 70 and a display 71.

[0072] When the switching control is performed, the sound emitter 70 emits a predetermined notification sound indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode. For example, the predetermined notification sound is a buzzer sound. Alternatively, the predetermined notification sound may be a voice announcing “the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode”, for example. As an example, the sound emitter 70 includes a speaker that is also able to play music.

[0073] When the switching control is performed, the display 71 displays a predetermined notification indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode. For example, the predetermined notification states “the mode wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode”. Furthermore, as an example, the display 71 includes a display that is also able to display speed, etc.

[0074] The controller 8 is provided on the watercraft body 110. As an example, the controller 8 shown in FIG. 1 includes an engine control unit (ECU), a shift control unit (SCU) to control shifting, a remote control unit (RCU) to control maneuvering in the wireless watercraft maneuvering mode, a steering actuator controller to perform a control to drive the steering actuator 50, etc. Alternatively, the controller may include an integrated control unit. The controller 8 includes a computer that includes a CPU, a ROM, a RAM, etc.

[0075] As described above, in the wireless watercraft maneuvering mode in which movement of the watercraft body 110 is instructed by the wireless controller 2, the controller 8 shown in FIG. 1 performs the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode in which the watercraft body 110 is moved by the watercraft user U1 (FIG. 11) operating the manual operator 6a based on the manual operator 6a being operated by the watercraft user U1.

[0076] In the wireless watercraft maneuvering mode, the controller 8 performs the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the propulsive force change operator 6b (throttle lever 61) of the manual operator 6a being operated by the watercraft user U1. Specifically, in the wireless watercraft maneuvering mode, the controller 8 performs the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the lever position sensor 63 (see FIG. 10) detecting an operation on the throttle lever 61.

[0077] More specifically, in the wireless watercraft maneuvering mode, the controller 8 performs the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the forward movement lever position sensor 63a (see FIG. 10) detecting an operation on the forward movement throttle lever 61a (see FIG. 10) or the reverse movement lever position sensor 63b detecting an operation on the reverse movement throttle lever 61b.

[0078] The controller 8 stops a supply of drive power to the electric motor 51 of the steering actuator 50 by the switching control to enable the watercraft user U1 to maneuver the watercraft body 110 using the manual operator 6a in the manual watercraft maneuvering mode. The controller 8 limits the magnitude of the propulsive force of the jet of water ejected from the jet propulsion mechanism 4 by setting a temporary (instantaneous) upper limit on the magnitude of the propulsive force of the jet of water when the propulsive force change operator 6b is operated to perform the switching control. Specifically, when the upper limit of the rotation speed of the impeller 42 (engine 30) is a first rotation speed before the switching control is performed, the upper limit of the rotation speed of the impeller 42 (engine 30) is limited to a second rotation speed that is lower than the first rotation speed immediately after the switching control. This limit prevents the jet propulsion watercraft 100 from suddenly accelerating even when the watercraft user U1 reflexively grips the throttle lever 61 tight to avoid an obstacle, for example.

[0079] In the wireless watercraft maneuvering mode, the controller 8 performs the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the steering sensor 60a detecting an operation on the steering operator 60.

[0080] A specific example of the switching control is now described with reference to FIG. 11. In the example shown in FIG. 11, the watercraft user U1 (passenger) is on board the jet propulsion watercraft 100, and the watercraft body 110 remotely and wirelessly operable by the wireless user U2 using the wireless controller 2 is shown by a two-dot chain line. In the state indicated by the two-dot chain line, the jet propulsion watercraft 100 is in the wireless watercraft maneuvering mode.

[0081] In the state indicated by the two-dot chain line, the watercraft user U1 finds an obstacle O ahead, but the wireless user U2 is unaware of the obstacle O. Therefore, the watercraft user U1 operates the forward movement throttle lever 61a to avoid the obstacle O. Consequently, the controller 8 performs the switching control to forcibly switch from the wireless watercraft maneuvering mode to the manual watercraft maneuvering mode to enable an operation on the forward movement throttle lever 61a. Thus, the obstacle O is avoided by the watercraft user U1 operating the forward movement throttle lever 61a.

[0082] A control process flow for the switching control shown in FIG. 12 is now described. The switching control is performed by the controller 8. The following description of each step begins with the wireless watercraft maneuvering mode in which movement of the watercraft body 110 is instructed by the wireless controller 2.

[0083] In step S1, it is determined whether or not the manual operator 6a has been operated. Specifically, it is determined whether or not the forward movement throttle lever 61a, the reverse movement throttle lever 61b, or the steering operator 60 has been operated. Whether or not the forward movement throttle lever 61a has been operated is determined using the forward movement lever position sensor 63a. Whether or not the reverse movement throttle lever 61b has been operated is determined using the reverse movement lever position sensor 63b. Whether or not the steering operator 60 has been operated is determined using the steering sensor 60a. Specifically, when the detection value of the steering sensor 60a is equal to or greater than the predetermined threshold, the controller 8 determines that the steering operator 60 has been operated by the watercraft user U1. When it is determined that the manual operator 6a has been operated, the process advances to step S2. When it is determined that the manual operator 6a has not been operated, the process operation in step S1 is repeated.

[0084] In step S2, the wireless watercraft maneuvering mode is switched to the manual watercraft maneuvering mode. That is, the switching control is performed. Thus, movement of the watercraft body 110 is no longer able to be controlled by the wireless controller 2. Then, the process advances to step S3.

[0085] In step S3, a temporary (instantaneous) upper limit is set on the magnitude of the propulsive force of the jet of water ejected from the jet propulsion mechanism 4. Then, the process advances to step S4.

[0086] In step S4, a supply of drive power to the electric motor 51 of the steering actuator 50 is stopped. Then, the process advances to END.

[0087] According to the various example embodiments of the present invention described above, the following advantageous effects are achieved.

[0088] According to an example embodiment of the present invention, the jet propulsion system 120 includes the manual operator 6a to control movement of the watercraft body 110 by changing at least one of the magnitude of the propulsive force of the jet of water ejected from the jet propulsion mechanism 4, the orientation of the jet of water in the right-left direction, or the orientation of the jet of water in the forward-rearward direction, and the controller 8 on the watercraft body 110 being configured or programmed to, in the wireless watercraft maneuvering mode in which movement of the watercraft body 110 is instructed by the wireless controller 2, perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode in which the watercraft body 110 is moved by the watercraft user U1 operating the manual operator 6a based on the manual operator 6a being operated by the watercraft user U1 on board the watercraft body 110. Accordingly, the watercraft user U1 on board the watercraft body 110 operates the manual operator 6a to forcibly switch the wireless watercraft maneuvering mode to the manual watercraft maneuvering mode such that the wireless watercraft maneuvering mode is terminated, and the manual watercraft maneuvering mode in which the watercraft body 110 is moved by an operation based on the intention of the watercraft user U1 is immediately started. Therefore, when the watercraft body 110 is being moved by wireless control in a manner not intended by the watercraft user U1 on board the watercraft body 110, the watercraft user U1 on board the watercraft body 110 is able to immediately resolve such a situation by himself / herself. In particular, when the watercraft user U1 on board the watercraft body 110 notices a situation in which the wireless watercraft maneuvering mode should be terminated, such as when the watercraft body 110 continues to move toward an obstacle ahead, switching the wireless watercraft maneuvering mode to the manual watercraft maneuvering mode allows the intention of the watercraft user U1 to be prioritized, and allows the watercraft body 110 to be moved immediately, and thus the above configuration is effective.

[0089] According to an example embodiment of the present invention, the jet propulsion system 120 further includes the notifier 7 to provide a notification indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed. Accordingly, the watercraft user U1 or the wireless user U2 easily recognizes through the notifier 7 that the wireless watercraft maneuvering mode has been switched to the manual watercraft maneuvering mode.

[0090] According to an example embodiment of the present invention, the jet propulsion mechanism 4 includes the impeller 42 to generate a jet of water, and the manual operator 6a includes the propulsive force change operator 6b to increase or decrease the rotation speed of the impeller 42 to increase or decrease the magnitude of the propulsive force obtained by the jet of water. The controller 8 is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the propulsive force change operator 6b being operated by the watercraft user U1 in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user U1 operating the propulsive force change operator 6b to accelerate the watercraft body 110 in order to avoid an obstacle, for example.

[0091] According to an example embodiment of the present invention, the propulsive force change operator 6b includes the throttle lever 61 to increase or decrease the rotation speed of the impeller 42 according to the amount of operation, and the throttle lever 61 includes the lever position sensor 63 to detect the amount of operation of the throttle lever 61. The controller 8 is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the lever position sensor 63 detecting an operation on the throttle lever 61 in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user U1 operating the throttle lever 61 to accelerate the watercraft body 110.

[0092] According to an example embodiment of the present invention, the throttle lever 61 includes the forward movement throttle lever 61a to move the watercraft body 110 forward, and the reverse movement throttle lever 61b to move the watercraft body 110 rearward, and the lever position sensor 63 includes the forward movement lever position sensor 63a to detect the amount of operation of the forward movement throttle lever 61a, and the reverse movement lever position sensor 63b to detect the amount of operation of the reverse movement throttle lever 61b. The controller 8 is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the forward movement lever position sensor 63a detecting an operation on the forward movement throttle lever 61a or the reverse movement lever position sensor 63b detecting an operation on the reverse movement throttle lever 61b in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user U1 operating the forward movement throttle lever 61a or the reverse movement throttle lever 61b to accelerate the watercraft body 110.

[0093] According to an example embodiment of the present invention, the controller 8 is configured or programmed to limit the magnitude of the propulsive force of the jet of water ejected from the jet propulsion mechanism 4 by setting the temporary upper limit on the magnitude of the propulsive force of the jet of water when the propulsive force change operator 6b is operated to perform the switching control. Accordingly, when the watercraft user U1 reflexively operates the propulsive force change operator 6b to suddenly increase the magnitude of the propulsive force in order to avoid an obstacle, for example, sudden acceleration of the watercraft body 110 is reduced or prevented.

[0094] According to an example embodiment of the present invention, the notifier 7 includes the sound emitter 70 to emit the predetermined notification sound indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed. Accordingly, even when visibility is poor or the watercraft user U1 is not able to take his / her eyes off the direction of travel, for example, the watercraft user U1 or the wireless user U2 easily recognizes by the sound emitted from the sound emitter 70 that the wireless watercraft maneuvering mode has been switched to the manual watercraft maneuvering mode.

[0095] According to an example embodiment of the present invention, the notifier 7 includes the display 71 to display the predetermined notification indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed. Accordingly, even when the engine noise is loud, for example, the watercraft user U1 easily and visually recognizes through the display 71 that the wireless watercraft maneuvering mode has been switched to the manual watercraft maneuvering mode.

[0096] According to an example embodiment of the present invention, the manual operator 6a includes the shift lever to switch a shift state. The controller 8 is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the watercraft user U1 operating the shift lever to switch the watercraft body 110 between forward movement and reverse movement in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user U1 performing a shift switching operation on the shift lever, such as switching forward movement to reverse movement.

[0097] According to an example embodiment of the present invention, the manual operator 6a includes the steering operator 60 operable by the watercraft user U1, and the steering operator 60 includes the steering sensor 60a to detect the amount of operation of the steering operator 60. The controller 8 is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the steering sensor 60a detecting an operation on the steering operator 60 in the wireless watercraft maneuvering mode. Accordingly, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user U1 turning the steering operator 60 right and left in order to avoid an obstacle, for example.

[0098] According to an example embodiment of the present invention, the jet propulsion system 120 further includes the steering actuator 50 including the electric motor 51 to rotate the nozzle 44 in the right-left direction using the drive force of the electric motor 51 to change the orientation of the jet of water from the jetting port 44a in the right-left direction in the wireless watercraft maneuvering mode, and the controller 8 is configured or programmed to stop a supply of drive power to the electric motor 51 by the switching control to enable the watercraft user U1 to maneuver the watercraft body 110 using the manual operator 6a in the manual watercraft maneuvering mode. Accordingly, when the watercraft user U1 performs a steering operation after the wireless watercraft maneuvering mode is forcibly switched to the manual watercraft maneuvering mode, a load is prevented from being applied to the electric motor 51.

[0099] According to an example embodiment of the present invention, the jet propulsion system 120 further includes the steering operator 60 operable by the watercraft user U1, and the steering actuator 50 includes the transmission gear 52 to transmit the drive forces of the electric motor 51 and the steering operator 60 to the nozzle 44, the nozzle-side steering cable 53 including the first end connected to the transmission gear 52 and the second end connected to the nozzle 44 to push and pull the nozzle 44, and the operator-side steering cable 54 including the first end connected to the transmission gear 52 and the second end connected to the steering operator 60 to push and pull the nozzle 44. Accordingly, a drive force is transmitted from the steering operator 60 and the electric motor 51 to the nozzle 44 via the transmission gear 52 and the nozzle-side steering cable 53, which are provided as components common to the steering operator 60 and the electric motor 51. Thus, the number of components is reduced, and the system structure is simplified.

[0100] According to an example embodiment of the present invention, the wireless watercraft maneuvering mode includes the remote watercraft maneuvering mode in which the watercraft body 110 is remotely maneuvered using the wireless controller 2, and the automatic movement mode in which the watercraft body 110 is automatically moved by remotely instructing the watercraft body 110 to move automatically using the wireless controller 2. Accordingly, in the remote watercraft maneuvering mode or the automatic movement mode, the watercraft user U1 on board the watercraft body 110 operates the manual operator 6a to forcibly switch the remote watercraft maneuvering mode or the automatic movement mode to the manual watercraft maneuvering mode in order to avoid an obstacle, for example.

[0101] 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.

[0102] For example, while the jet propulsion watercraft is preferably a so-called jet ski or jet bike 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 so-called jet-propelled sports boat.

[0103] While the jet drive source preferably includes an engine as a drive source to rotate the impeller in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the jet drive source may alternatively include an electric motor as a drive source to rotate the impeller.

[0104] While the steering sensor preferably detects a load associated with rotation of the steering operator when the steering operator is rotated in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the steering sensor may alternatively be an acceleration sensor to detect acceleration when the steering operator is rotated.

[0105] While the manual operator preferably includes the forward movement throttle lever and the reverse movement throttle lever in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the manual operator may alternatively include a throttle lever to increase or decrease the rotation speed of the impeller (engine) without distinguishing between forward movement and reverse movement, and a shift lever to move the reverse bucket to switch a shift state. In such a case, in the wireless watercraft maneuvering mode, the controller performs the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the watercraft user operating the shift lever to switch the watercraft body between forward movement and reverse movement. Furthermore, similarly to the example embodiments described above, in the wireless watercraft maneuvering mode, the controller performs the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the watercraft user operating the throttle lever. With the structure described above, forcing the wireless watercraft maneuvering mode to switch to the manual watercraft maneuvering mode is triggered by the watercraft user performing a shift switching operation, such as operating the shift lever to switch forward movement to reverse movement.

[0106] While the wireless controller is preferably operable by the wireless user located remotely from the watercraft body in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the wireless controller may alternatively be located on the watercraft body, and the watercraft user on board the watercraft body may alternatively be the wireless user of the wireless controller.

[0107] While there are preferably two operations that trigger the switching control: an operation on the throttle lever and an operation on the steering operator in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, there may alternatively be only one operation that triggers the switching control: an operation on the throttle lever or an operation on the steering operator.

[0108] While the steering actuator is preferably driven by the electric motor in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the steering actuator may alternatively be driven by a cylinder or a solenoid, for example.

[0109] While the wireless watercraft maneuvering mode preferably includes the remote watercraft maneuvering mode and the automatic movement mode in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the wireless watercraft maneuvering mode may alternatively include only one of the remote watercraft maneuvering mode and the automatic movement mode.

[0110] While the notifier preferably includes the sound emitter and the display to provide a notification indicating that the switching control has been performed in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the notifier may alternatively include a notification lamp that switches from an off state to an on (flashing) state when the switching control is performed to provide a notification indicating that the switching control has been performed. Alternatively, the notifier may include only one of the sound emitter and the display.

[0111] While the process operations performed by the controller are described using a flowchart in a flow-driven manner in which processes are performed in order along a process flow for the convenience of illustration in example embodiments described above, the present invention is not restricted to this. In an example embodiment of the present invention, the process operations performed by the controller may alternatively be performed in an event-driven manner in which the processes are performed on an event basis. In this case, the process operations performed by the controller may be performed in a complete event-driven manner or in a combination of an event-driven manner and a flow-driven manner.

[0112] 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 system comprising:a jet propulsion mechanism located at a stern of a watercraft body and including a nozzle including a jetting port to eject a jet of water to generate a propulsive force;a manual operator to control movement of the watercraft body by changing at least one of a magnitude of the propulsive force of the jet of water, an orientation of the jet of water in a right-left direction, or an orientation of the jet of water in a forward-rearward direction;a wireless controller configured or programmed to instruct movement of the watercraft body by wireless communication with the watercraft body; anda controller on the watercraft body and configured or programmed to, in a wireless watercraft maneuvering mode in which the movement of the watercraft body is instructed by the wireless controller, perform a switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to a manual watercraft maneuvering mode in which the watercraft body is moved by a watercraft user operating the manual operator based on the manual operator being operated by the watercraft user.

2. The jet propulsion system according to claim 1, further comprising:a notifier to provide a notification indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed.

3. The jet propulsion system according to claim 1, whereinthe jet propulsion mechanism includes an impeller to generate the jet of water;the manual operator includes a propulsive force change operator to increase or decrease a rotation speed of the impeller to increase or decrease the magnitude of the propulsive force obtained by the jet of water; andthe controller is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the propulsive force change operator being operated by the watercraft user in the wireless watercraft maneuvering mode.

4. The jet propulsion system according to claim 3, whereinthe propulsive force change operator includes a throttle lever to increase or decrease the rotation speed of the impeller according to an amount of operation of the throttle lever;the throttle lever includes a lever position sensor to detect the amount of operation of the throttle lever; andthe controller is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the lever position sensor detecting an operation on the throttle lever in the wireless watercraft maneuvering mode.

5. The jet propulsion system according to claim 4, whereinthe throttle lever includes a forward movement throttle lever to move the watercraft body forward, and a reverse movement throttle lever to move the watercraft body rearward;the lever position sensor includes a forward movement lever position sensor to detect an amount of operation of the forward movement throttle lever, and a reverse movement lever position sensor to detect an amount of operation of the reverse movement throttle lever; andthe controller is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the forward movement lever position sensor detecting an operation on the forward movement throttle lever or the reverse movement lever position sensor detecting an operation on the reverse movement throttle lever in the wireless watercraft maneuvering mode.

6. The jet propulsion system according to claim 1, wherein the controller is configured or programmed to limit the magnitude of the propulsive force of the jet of water by setting a temporary upper limit on the magnitude of the propulsive force of the jet of water when the switching control is performed.

7. The jet propulsion system according to claim 2, wherein the notifier includes a sound emitter to emit a predetermined notification sound indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed.

8. The jet propulsion system according to claim 2, wherein the notifier includes a display to display a predetermined notification indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed.

9. The jet propulsion system according to claim 1, whereinthe manual operator includes a shift lever to switch a shift state; andthe controller is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the watercraft user operating the shift lever to switch the watercraft body between forward movement and reverse movement in the wireless watercraft maneuvering mode.

10. The jet propulsion system according to claim 1, whereinthe manual operator includes a steering operator operable by the watercraft user;the steering operator includes a steering sensor to detect an amount of operation of the steering operator; andthe controller is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the steering sensor detecting an operation on the steering operator in the wireless watercraft maneuvering mode.

11. The jet propulsion system according to claim 1, further comprising:a steering actuator including an electric motor to rotate the nozzle in the right-left direction using a drive force of the electric motor to change the orientation of the jet of water from the jetting port in the right-left direction in the wireless watercraft maneuvering mode; whereinthe controller is configured or programmed to stop a supply of drive power to the electric motor by the switching control to enable the watercraft user to maneuver the watercraft body using the manual operator in the manual watercraft maneuvering mode.

12. The jet propulsion system according to claim 11, further comprising:a steering operator operable by the watercraft user;wherein the steering actuator further includes:a transmission gear to transmit drive forces of the electric motor and the steering operator to the nozzle;a nozzle-side steering cable including a first end connected to the transmission gear and a second end connected to the nozzle to push and pull the nozzle; andan operator-side steering cable including a first end connected to the transmission gear and a second end connected to the steering operator to push and pull the nozzle.

13. The jet propulsion system according to claim 1, wherein the wireless watercraft maneuvering mode includes:a remote watercraft maneuvering mode in which the watercraft body is remotely maneuvered using the wireless controller; andan automatic movement mode in which the watercraft body is automatically moved by remotely instructing the watercraft body to move automatically using the wireless controller.

14. A jet propulsion watercraft comprising:a watercraft body;a jet propulsion mechanism located at a stern of the watercraft body and including a nozzle including a jetting port to eject a jet of water from the jetting port to generate a propulsive force;a manual operator to control movement of the watercraft body by changing at least one of a magnitude of the propulsive force of the jet of water ejected from the jet propulsion mechanism, an orientation of the jet of water in a right-left direction, or an orientation of the jet of water in a forward-rearward direction;a wireless controller configured or programmed to instruct movement of the watercraft body by wireless communication with the watercraft body; anda controller on the watercraft body and configured or programmed to, in a wireless watercraft maneuvering mode in which the movement of the watercraft body is instructed by the wireless controller, perform a switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to a manual watercraft maneuvering mode in which the watercraft body is moved by a watercraft user operating the manual operator based on the manual operator being operated by the watercraft user.

15. The jet propulsion watercraft according to claim 14, further comprising:a notifier to provide a notification indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed.

16. The jet propulsion watercraft according to claim 14, whereinthe jet propulsion mechanism includes an impeller to generate the jet of water;the manual operator includes a propulsive force change operator to increase or decrease a rotation speed of the impeller to increase or decrease the magnitude of the propulsive force obtained by the jet of water; andthe controller is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the propulsive force change operator being operated by the watercraft user in the wireless watercraft maneuvering mode.

17. The jet propulsion watercraft according to claim 16, whereinthe propulsive force change operator includes a throttle lever to increase or decrease the rotation speed of the impeller according to an amount of operation of the throttle lever;the throttle lever includes a lever position sensor to detect the amount of operation of the throttle lever; andthe controller is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the lever position sensor detecting an operation on the throttle lever in the wireless watercraft maneuvering mode.

18. The jet propulsion watercraft according to claim 17, whereinthe throttle lever includes a forward movement throttle lever to move the watercraft body forward, and a reverse movement throttle lever to move the watercraft body rearward;the lever position sensor includes a forward movement lever position sensor to detect an amount of operation of the forward movement throttle lever, and a reverse movement lever position sensor to detect an amount of operation of the reverse movement throttle lever; andthe controller is configured or programmed to perform the switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to the manual watercraft maneuvering mode based on the forward movement lever position sensor detecting an operation on the forward movement throttle lever or the reverse movement lever position sensor detecting an operation on the reverse movement throttle lever in the wireless watercraft maneuvering mode.

19. The jet propulsion watercraft according to claim 14, wherein the controller is configured or programmed to limit the magnitude of the propulsive force of the jet of water by setting a temporary upper limit on the magnitude of the propulsive force of the jet of water when the switching control is performed.

20. The jet propulsion watercraft according to claim 15, wherein the notifier includes a sound emitter to emit a predetermined notification sound indicating that the wireless watercraft maneuvering mode has been forcibly switched to the manual watercraft maneuvering mode when the switching control is performed.

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