MARINE PROPULSION SYSTEM

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2024-189837 filed on October 29, 2024, the contents of which are incorporated herein by reference.

BACKGROUND

The present invention relates to a marine propulsion system for propelling a boat.

For example, a boat may be provided with two marine propulsion devices, that is, a first marine propulsion device and a second marine propulsion device, and the first marine propulsion device may be used primarily when moving the boat at high speed, such as when sailing, and the second marine propulsion device may be used primarily when moving the boat at low speed, such as when docking, leaving a shore, or trolling. In this way, the two marine propulsion devices may be used interchangeably to navigate the boat. In addition, an electric outboard device, which uses a motor (electric motor) as a power source to rotate a propeller, is suitable as a marine propulsion device for moving a boat at low speed, because the motor can rotate the propeller at low rotation speed and with high torque. Therefore, an electric outboard device is used as the second marine propulsion device.

When a boat equipped with the two marine propulsion devices is sailing, the first marine propulsion device is operated when the boat is moving at high speed. In this case, the motor of the second marine propulsion device, which is an electric outboard device, is stopped and the second marine propulsion device is tilted up. There are two reasons why the second marine propulsion device is tilted up when the boat is moving at high speed.

The first reason is to protect an inverter included in the second marine propulsion device. That is, the second marine propulsion device is an electric outboard device, and the electric outboard device has an inverter that controls driving of the motor. When the boat is moving at high speed with an electric outboard device tilted down and its motor not being driven, the propeller of the electric outboard device may rotate, causing the motor of the electric outboard device to rotate at high rotation speed even though the motor is not being driven. When the rotation speed of the motor of the electric outboard device increases while the motor is not being driven, power generated by the rotation of the motor increases. This power may adversely affect the inverter of the electric outboard device. For example, an excessively high voltage may be applied to a capacitor in the inverter, causing damage to the capacitor. Therefore, when the boat is moving at high speed, in the second marine propulsion device, whose motor is not being driven, the second marine propulsion device is tilted up to protect the inverter by suppressing generation of power caused by the rotation of the motor associated with the rotation of the propeller.

The second reason is to promote high speed movement of the boat by the first marine propulsion device. In other words, when output of the second marine propulsion device is significantly smaller than output of the first marine propulsion device, even when the second marine propulsion device is tilted down and operated when the boat is moving at high speed, an extent to which the second marine propulsion device contributes to generating a propulsive force of the boat will be small. In fact, a lower part of the second marine propulsion device will be submerged below the water surface, which may increase resistance to propulsion of the boat and hinder the propulsion of the boat. Therefore, when the boat is moving at high speed, the second marine propulsion device is tilted up to promote high speed movement of the boat by the first marine propulsion device.

JP2021-138229A (Patent Literature 1) describes a marine propulsion system intended to protect an electric circuit and an electric motor from induced voltage generated by co-rotation of an electric motor.

SUMMARY OF INVENTION

According to one advantageous aspect of the invention, there is provided a marine propulsion system for propelling a boat, including:

a first marine propulsion device provided on the boat;

a second marine propulsion device that is an electric outboard device and is provided on the boat;

a tilt detector configured to detect a tilt state of the second marine propulsion device; and

a notifier configured to notify that the tilt state of the second marine propulsion device is in a tilt-down state when the tilt detector detects that the tilt state of the second marine propulsion device is in the tilt-down state when a power switch of the first marine propulsion device is turned on.

According to another advantageous aspect of the invention, there is provided a marine propulsion system for propelling a boat, including:

a first marine propulsion device provided on the boat;

a second marine propulsion device that is an electric outboard device and is provided on the boat;

a tilt actuator configured to tilt up the second marine propulsion device; and

a tilt controller configured to control the tilt actuator, in which

the tilt controller controls the tilt actuator to set a tilt state of the second marine propulsion device to a tilt-up state when a power switch of the first marine propulsion device is turned on.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a circuit diagram illustrating a marine propulsion system according to a first example of the present invention.

FIG. 2 is a perspective view illustrating a boat provided with the marine propulsion system according to the first example of the present invention.

FIG. 3A is an explanatory diagram illustrating an auxiliary device (electric outboard device) in the marine propulsion system according to the first example of the present invention, and FIG. 3B is an explanatory diagram illustrating the auxiliary device in a tilt-up state.

FIG. 4A is an exploded view of a tilt detection switch in a tilt detector of the marine propulsion system according to the first example of the present invention, and FIG. 4B is an external view illustrating a switch operating member in the tilt detector.

FIG. 5A is an external view illustrating a swivel bracket and the like of the auxiliary device provided with the tilt detector in the marine propulsion system according to the first example of the present invention, as viewed from the upper right front, and FIG. 5B is an external view illustrating the swivel bracket and the like as viewed from above.

FIGS. 6A to 6D are explanatory diagrams illustrating an operation of the tilt detector in the marine propulsion system according to the first example of the present invention.

FIGS. 7A to 7D are explanatory diagrams illustrating an operation of a tilt detector in a marine propulsion system according to a second example of the present invention.

FIGS. 8A to 8D are explanatory diagrams illustrating an operation of a tilt detector in a marine propulsion system according to a third example of the present invention.

FIGS. 9A to 9D are explanatory diagrams illustrating an operation of a tilt detector in a marine propulsion system according to a fourth example of the present invention.

FIG. 10 is a circuit diagram illustrating a marine propulsion system according to a fifth example of the present invention.

DETAILED DESCRIPTION OF EXEMPLIFIED EMBODIMENTS

As described in the background, for example, when a boat is equipped with a first marine propulsion device used when moving the boat at high speed and a second marine propulsion device which is an electric outboard device used when moving the boat at low speed, the first marine propulsion device is operated and the second marine propulsion device is tilted up when the boat is moving at high speed.

However, when moving the boat at high speed, it is conceivable that, for example, a boat operator may forget to tilt up the second marine propulsion device, and end up operating the first marine propulsion device to move the boat at high speed with the second marine propulsion device in a tilt-down state. When the boat is moved at high speed with the second marine propulsion device in a tilt-down state, as described above, there is a risk that an inverter of the second marine propulsion device will be adversely affected, and there is also a risk that the second marine propulsion device will hinder high speed movement of the boat. Therefore, when the first marine propulsion device is operated to move the boat at high speed, even when an incident occurs in which a boat operator forgets to tilt up the second marine propulsion device, it is necessary to be able to prevent the boat from moving at high speed with the second marine propulsion device in a tilt-down state.

Furthermore, the above-mentioned JP2021-138229A does not describe or suggest means for preventing the boat from moving at high speed with the second marine propulsion device in a tilt-down state when the first marine propulsion device is operated to move the boat at high speed.

In view of the above, an object of the present invention is to provide a marine propulsion system that, when a first marine propulsion device and a second marine propulsion device which is an electric outboard device are installed on a single boat and the boat is sailing, can prevent the boat from moving at high speed with the second marine propulsion device in a tilt-down state.

A marine propulsion system of a first embodiment of the present invention is a marine propulsion system for propelling a boat, the system including a first marine propulsion device provided on the boat, a second marine propulsion device that is an electric outboard device and is provided on the boat, a tilt detector that detects a tilt state of the second marine propulsion device, and a notifier that notifies a user that the tilt state of the second marine propulsion device is in a tilt-down state when the tilt detector detects that the tilt state of the second marine propulsion device is in a tilt-down state when a power switch of the first marine propulsion device is turned on.

For example, when a boat operator is moving the boat at high speed, he or she tilts up the second marine propulsion device and then turns on the power switch of the first marine propulsion device. Thereafter, the boat operator operates the first marine propulsion device to move the boat at high speed.

When moving the boat at high speed, if the boat operator, for example, forgets to tilt up the second marine propulsion device and turns on the power switch of the first marine propulsion device while the second marine propulsion device is in a tilt-down state, the tilt detector will detect that the tilt state of the second marine propulsion device is in a tilt-down state, and the notifier will notify that the tilt state of the second marine propulsion device is in a tilt-down state. This makes the boat operator aware that the second marine propulsion device is not tilted up. Thereafter, the boat operator tilts up the second marine propulsion device, and then operates the first marine propulsion device to move the boat at high speed.

In this manner, the marine propulsion system according to the first embodiment of the present invention can prevent the boat from moving at high speed with the second marine propulsion device in a tilt-down state.

A marine propulsion system of a second embodiment of the present invention is a marine propulsion system for propelling a boat, the system including a first marine propulsion device provided on the boat, a second marine propulsion device that is an electric outboard device and is provided on the boat, a tilt actuator that tilts up the second marine propulsion device, and a tilt controller that controls the tilt actuator, where the tilt controller controls the tilt actuator to set a tilt state of the second marine propulsion device to a tilt-up state when a power switch of the first marine propulsion device is turned on.

For example, when a boat operator moves the boat at high speed, he or she turns on the power switch of the first marine propulsion device. When the power switch of the first marine propulsion device is turned on, the second marine propulsion device is automatically tilted up by the tilt controller and the tilt actuator. Thereafter, the boat operator operates the first marine propulsion device to move the boat at high speed.

In this manner, the marine propulsion system according to the second embodiment of the present invention can prevent the boat from moving at high speed with the second marine propulsion device in a tilt-down state.

In addition, in the marine propulsion system of the second embodiment of the present invention, the second marine propulsion device is automatically tilted up when the power switch of the first marine propulsion device is turned on, so that when moving the boat at high speed, the boat operator does not need to tilt up the second marine propulsion device before turning on the power switch of the first marine propulsion device. Therefore, the boat operator can easily and quickly start high speed movement of the boat.

First Example

A first example of a marine propulsion system according to the present invention will be described with reference to FIGS. 1 to 6. In the following examples, when describing directions of up (Ud), down (Dd), front (Fd), back (Bd), left (Ld), and right (Rd), they will follow arrows in FIGS. 2, 3, and 5 to 9.

Configuration of Marine Propulsion System

FIG. 1 illustrates a configuration of a marine propulsion system 1 according to a first example of the present invention. FIG. 2 illustrates a boat 51 provided with the marine propulsion system 1.

The marine propulsion system 1 is a system for propelling the boat 51 and is provided on the boat 51. As illustrated in FIG. 1, the marine propulsion system 1 includes a main device 2, a main device battery 3, a main device power supply path 4, a main device power switch 5, an auxiliary device 6, a branch path 20, a tilt detector 21, and an alarm buzzer 41.

As illustrated in FIG. 2, the main device 2 is an outboard device, and is attached to a transom 52 of the boat 51. A boat operator of the boat 51 mainly uses the main device 2 when moving the boat at high speed, such as when sailing. The main device 2 has, for example, an engine (internal combustion engine) as a power source for driving a propeller, and is a high-output, large outboard device compared to the auxiliary device 6. Although detailed illustration is omitted, the main device 2 includes a main device body, a clamp bracket for fixing the main device body to the boat 51, a swivel bracket for supporting the main device body pivotably in the left-right direction relative to the boat 51, and a tilt shaft for connecting the clamp bracket and the swivel bracket to each other. The main device body also includes a propeller that generates a propulsive force for the boat 51, an engine that is a power source for driving the propeller, a drive shaft connected to a crankshaft of the engine, a propeller shaft to which the propeller is attached, a gear mechanism that transmits rotation of the drive shaft to the propeller shaft, and electrical components, and the like. The electrical components include, for example, an engine control unit, an engine starter motor, an ignition device, an electronically controlled throttle device, and sensors. The main device 2 is a specific example of a "first marine propulsion device".

As illustrated in FIG. 1, the main device battery 3 is a secondary battery for supplying power to the main device 2, and is provided on the boat 51. Output voltage of the main device battery 3 is, for example, 12 volts. The main device power supply path 4 is a path that supplies power from the main device battery 3 to the main device 2. The main device power switch 5 is a switch that switches whether power is supplied from the main device battery 3 to the main device 2, and is connected between the main device battery 3 and the main device power supply path 4. When the main device power switch 5 is turned on, power is supplied from the main device battery 3 to the main device 2 via the main device power supply path 4. When the main device power switch 5 is turned off, the supply of power from the main device battery 3 to the main device 2 is cut off. The main device power switch 5 is, for example, an ignition switch for the main device 2. The main device power switch 5 is provided in a cockpit 53 of the boat 51, for example, as illustrated in FIG. 2. The main device power switch 5 is a specific example of a "power switch of a first marine propulsion device", and the main device power supply path 4 is a specific example of a "power supply path".

As illustrated in FIG. 2, the auxiliary device 6 is an outboard device, and is mounted on the transom 52 of the boat 51. The boat 51 is equipped with two devices, the main device 2 and the auxiliary device 6. the boat operator of the boat 51 mainly uses the auxiliary device 6 when moving the boat at a low speed, such as when docking, leaving the shore, or trolling. The auxiliary device 6 has a motor as a power source for driving a propeller, and is, for example, an electric outboard device that is low-output and small compared to the main device 2. The auxiliary device 6 is a specific example of a "second marine propulsion device".

FIG. 3A illustrates the auxiliary device 6. As illustrated in FIG. 3A, the auxiliary device 6 includes an auxiliary device body 7, a clamp bracket 14 for fixing the auxiliary device body 7 to the boat 51, a swivel bracket 15 for supporting the auxiliary device body 7 pivotably in the left-right direction relative to the boat 51, and a tilt shaft 16 for connecting the clamp bracket 14 and the swivel bracket 15 to each other. The auxiliary device body 7 also includes a propeller 8 that generates a propulsive force for the boat 51, a motor 9 that is a power source for driving the propeller, an inverter 10 that controls the motor 9, a drive shaft 11 connected to an output shaft of the motor 9, a propeller shaft 12 to which the propeller 8 is attached, and a gear mechanism 13 that transmits rotation of the drive shaft 11 to the propeller shaft 12. In addition, the auxiliary device 6 is provided with a tilt cylinder 17 which is an actuator for tilting the auxiliary device body 7 up and down. FIG. 3A illustrates the auxiliary device 6 in a tilt-down state, and FIG. 3B illustrates the auxiliary device 6 in a tilt-up state.

Although not illustrated, the boat 51 is also provided with an auxiliary device battery, which is a secondary battery that supplies power to the motor 9 (inverter 10) and the like provided in the auxiliary device 6. In addition, an auxiliary device power supply path for supplying power from the auxiliary device battery to the auxiliary device 6 is provided between the auxiliary device battery and the auxiliary device. As illustrated in FIG. 2, the cockpit 53 of the boat 51 is provided with an auxiliary device power switch 18 for switching whether power is supplied from the auxiliary device battery to the auxiliary device 6. The auxiliary device power switch 18 is connected between the auxiliary device battery and the auxiliary device power supply path.

As illustrated in FIG. 1, the branch path 20 is a path that supplies power from the main device battery 3 to the alarm buzzer 41, and is connected in parallel to the main device power supply path 4. A tilt detection switch 22 of the tilt detector 21 and the alarm buzzer 41 are connected in series to the branch path 20.

The tilt detector 21 is a device that detects a tilt state of the auxiliary device 6. The tilt detector 21 is provided in the auxiliary device 6. The tilt detector 21 has the tilt detection switch 22. The tilt detection switch 22 is turned on when the tilt state of the auxiliary device 6 is in a tilt-down state as illustrated in FIG. 3A, and is turned off when the tilt state of the auxiliary device 6 is in a tilt-up state as illustrated in FIG. 3B. Specific configuration and operation of the tilt detector 21 will be described below.

The alarm buzzer 41 is a buzzer that alerts a user that the tilt state of the auxiliary device 6 is in a tilt-down state when the tilt detector 21 detects that the tilt state of the auxiliary device 6 is in a tilt-down state when the main device power switch 5 is turned on. The alarm buzzer 41 is configured to emit a buzzer sound when power is supplied to the alarm buzzer 41 from the main device battery 3 via the branch path 20, and to stop the buzzer sound when the supply of power to the alarm buzzer 41 is cut off. The alarm buzzer 41 is provided in, for example, the cockpit 53 of the boat 51 as illustrated in FIG. 2. The alarm buzzer 41 is a specific example of a "notifier".

Function and Operation of Marine Propulsion System

The marine propulsion system 1 has the function of detecting the tilt state of the auxiliary device 6 using the tilt detector 21 when the main device power switch 5 is turned on, and if the tilt state of the auxiliary device 6 is in a tilt-down state, generating a buzzer sound from the alarm buzzer 41 to inform the boat operator that the tilt state of the auxiliary device 6 is in a tilt-down state.

An operation of the marine propulsion system 1 regarding this function will be described with reference to FIG. 1. When the boat operator turns on the main device power switch 5, power is supplied from the main device battery 3 to the main device 2 via the main device power supply path 4. In addition, when the boat operator turns on the main device power switch 5, if the tilt state of the auxiliary device 6 is in a tilt-down state and therefore the tilt detection switch 22 is turned on, power is supplied from the main device battery 3 to the alarm buzzer 41 via the branch path 20. This causes the alarm buzzer 41 to emit a buzzer sound.

While the main device power switch 5 is turned on and the tilt detection switch 22 is turned on, the buzzer sound from the alarm buzzer 41 continues. In addition, when the alarm buzzer 41 is generating a buzzer sound, if the boat operator tilts up the auxiliary device 6 and sets the tilt state of the auxiliary device 6 to a tilt-up state, the tilt detection switch 22 is turned off. As a result, power is no longer supplied from the main device battery 3 to the alarm buzzer 41, and the buzzer sound from the alarm buzzer 41 stops. In addition, when the boat operator turns off the main device power switch 5 while the alarm buzzer 41 is generating a buzzer sound, the buzzer sound from the alarm buzzer 41 will stop even when the auxiliary device 6 is not tilted up.

On the other hand, when the boat operator turns on the main device power switch 5, if the tilt state of the auxiliary device 6 is in the tilt-up state and therefore the tilt detection switch 22 is turned off, no power is supplied from the main device battery 3 to the alarm buzzer 41, so no buzzer sound is generated from the alarm buzzer 41.

Tilt Detector

Configuration of the tilt detector 21 will be specifically described. FIG. 4A illustrates the tilt detection switch 22 in the tilt detector 21 in an exploded state. FIG. 4B illustrates a switch operating member 34 in the tilt detector 21. FIG. 5A illustrates the swivel bracket 15 and the like of the auxiliary device 6 on which the tilt detector 21 is provided, as viewed from the front upper right. FIG. 5B illustrates the swivel bracket 15 and the like of the auxiliary device 6 on which the tilt detector 21 is provided, as viewed from above.

As illustrated in FIGS. 4A and 4B, the tilt detector 21 has the tilt detection switch 22 and the switch operating member 34.

The tilt detection switch 22 is a switch that causes power to be supplied from the main device battery 3 to the alarm buzzer 41 via the branch path 20 when the tilt state of the auxiliary device 6 is in the tilt-down state, and causes power not to be supplied from the main device battery 3 to the alarm buzzer 41 via the branch path 20 when the tilt state of the auxiliary device 6 is in the tilt-up state. In this example, as described above, the tilt detection switch 22 is a switch that is turned on when the tilt state of the auxiliary device 6 is in the tilt-down state and is turned off when the tilt state of the auxiliary device 6 is in the tilt-up state.

As illustrated in FIG. 4A, the tilt detection switch 22 has a switch body 23, a leaf spring 29, and a mounting plate 33.

The switch body 23 is a normally open push button switch. The switch body 23 has a casing 24 that accommodates a movable contact and a fixed contact therein, and a push-button type operator 26 that is provided so as to be capable of appearing and disappearing in directions of arrows A and B relative to the casing 24. The movable contact is configured to be displaced integrally with the operator 26. Further, a biasing member is provided within the casing 24 for biasing the operator 26 in a direction (in the direction of the arrow B) in which the operator 26 protrudes from the casing 24. When a force is applied to the operator 26 in the direction of the arrow A, the operator 26 is displaced in the direction of the arrow A against a biasing force of the biasing member and sinks into the casing 24. As the operator 26 is displaced in the direction of the arrow A, the movable contact is displaced and comes into contact with the fixed contact, turning the switch body 23 on (closed). On the other hand, when the force in the direction of the arrow A is no longer applied to the operator 26, the operator 26 is displaced in the direction of the arrow B by the biasing force of the biasing member and protrudes from the casing 24. As the operator 26 is displaced in the direction of the arrow B, the movable contact is displaced and separated from the fixed contact, turning the switch body 23 off (open). In addition, two cables 27 and 28 are attached to the casing 24. One end of one cable 27 is connected to the fixed contact, and one end of the other cable 28 is connected to the movable contact. Also, for example, as illustrated in FIG. 1, the other end of the cable 27 is connected to the main device power switch 5 via the branch path 20 and the main device power supply path 4, and the other end of the cable 28 is connected to the alarm buzzer 41. As illustrated in FIG. 4A, the casing 24 is formed with a fixing portion 25 for fixing the switch body 23 to the mounting plate 33.

The leaf spring 29 is a member that presses the operator 26 of the switch body 23 in response to movement of the switch operating member 34. The leaf spring 29 is formed, for example, by cutting and bending a metal plate. A fixing portion 30 for fixing the leaf spring 29 to the mounting plate 33 is formed at a base end of the leaf spring 29. A displacement portion 31 that is displaceable in the directions of the arrows A and B in FIG. 4A is formed at a tip of the leaf spring 29. A spring portion 32 is formed between the fixing portion 30 and the displacement portion 31 of the leaf spring 29. The spring portion 32 displaces the displacement portion 31 in the directions of the arrows A and B relative to the fixing portion 30 by elastic deformation.

The mounting plate 33 is a member for mounting the switch body 23 and the leaf spring 29 to the swivel bracket 15 of the auxiliary device 6. The mounting plate 33 is formed into a plate shape from, for example, resin or metal. The mounting plate 33 also has the function of covering and protecting the switch body 23 and the leaf spring 29. The fixing portion 25 of the switch body 23 and the fixing portion 30 of the leaf spring 29 are attached and fixed to the mounting plate 33 using fixing members such as bolts.

The tilt detection switch 22 is provided on the swivel bracket 15 of the auxiliary device 6, as illustrated in FIGS. 5A and 5B. More specifically, the auxiliary device 6 is provided with a pair of clamp brackets 14 on the left and right sides, and the swivel bracket 15 is provided between these clamp brackets 14. A connecting portion 14A is provided at an upper front end of each clamp bracket 14, and a pair of left and right connecting portions 15A are provided at upper front ends of the swivel bracket 15. A hole for inserting the tilt shaft 16 is formed in each of the connecting portions 14A and 15A, and the tilt shaft 16 is inserted into the hole. As a result, each clamp bracket 14 and the swivel bracket 15 are connected to each other via the tilt shaft 16. The tilt shaft 16 is fixed to the connecting portion 14A of each clamp bracket 14 so as not to be pivotable. On the other hand, the swivel bracket 15 is pivotable relative to the tilt shaft 16. As the swivel bracket 15 pivots relative to the tilt shaft 16, the tilt state of the auxiliary device 6 changes from the tilt-down state to the tilt-up state, or from the tilt-up state to the tilt-down state. The tilt detection switch 22 is disposed at a front end of an upper portion of the swivel bracket 15, between the pair of left and right connecting portions 15A. The mounting plate 33 of the tilt detection switch 22 is attached and fixed to a portion between the pair of left and right connecting portions 15A of the swivel bracket 15 using fixing members such as bolts. As a result, the switch body 23 and the leaf spring 29 of the tilt detection switch 22 are fixed between the connecting portions 15A of the swivel bracket 15 via the mounting plate 33. The tilt detection switch 22 pivots integrally with the swivel bracket 15 relative to the tilt shaft 16.

The switch operating member 34 is a member that switches the tilt detection switch 22 on and off by moving the operator 26 of the tilt detection switch 22 in response to the pivoting of the swivel bracket 15 relative to the tilt shaft 16. As illustrated in FIG. 4B, the switch operating member 34 has a cylindrical portion 35, a flange portion 36, and a protrusion portion 37. The switch operating member 34 is made of, for example, metal or resin. The cylindrical portion 35 is formed in a cylindrical shape having an inner diameter that is approximately equal to (strictly speaking, slightly larger than) an outer diameter of the tilt shaft 16. The flange portion 36 is disposed at one axial end portion of the cylindrical portion 35, and is formed in an annular shape, expanding radially outward from the cylindrical portion 35. The protrusion portion 37 is disposed on a surface of the flange portion 36 facing one axial direction side, and protrudes from that surface to one axial direction side.

As illustrated in FIGS. 5A and 5B, the switch operating member 34 is provided on the tilt shaft 16 and disposed between the pair of connecting portions 15A of the swivel bracket 15. Specifically, the tilt shaft 16 is inserted into the cylindrical portion 35 of the switch operating member 34. Moreover, the cylindrical portion 35 is fixed to the tilt shaft 16 using a fixing member such as a bolt. As a result, the switch operating member 34 is unable to pivot relative to the tilt shaft 16.

The operation of the tilt detector 21 will be described in detail below. FIGS. 6A to 6D illustrate the operation of the tilt detector 21. In detail, FIG. 6A illustrates the auxiliary device 6 in a tilt-down state. FIG. 6B illustrates the tilt detector 21 as viewed from a direction of an arrow E in FIG. 6A. FIG. 6C illustrates the auxiliary device 6 in a tilt-up state. FIG. 6D illustrates the tilt detector 21 as viewed in a direction of an arrow F in FIG. 6C. In FIGS. 6B and 6D, only outer diameters of the mounting plate 33 of the tilt detection switch 22 and the fixing members (bolts) that fix the mounting plate 33 to the swivel bracket 15 are illustrated by two-dot chain lines.

As illustrated in FIGS. 6B or 6D, the tilt detection switch 22 of this example is fixed to the swivel bracket 15 so that parts (front portions) of the switch body 23 and the leaf spring 29 are located above the tilt shaft 16. The tilt detection switch 22 is fixed to the swivel bracket 15 so that the leaf spring 29 is located to the right (in the direction of the arrow Rd) of the switch body 23. In addition, the switch operating member 34 is disposed to the right of the leaf spring 29. Moreover, the switch operating member 34 is attached to the tilt shaft 16 so that a protruding end of the protrusion portion 37 faces the tilt detection switch 22, that is, so that a protruding direction of the protrusion portion 37 faces leftward. In addition, the switch operating member 34 is fixed to the tilt shaft 16 so that the protrusion portion 37 is located at an upper portion of the tilt shaft 16.

As illustrated in FIG. 6A, when the swivel bracket 15 pivots relative to the tilt shaft 16 and the tilt state of the auxiliary device 6 changes from the tilt-up state to the tilt-down state, the protrusion portion 37 of the switch operating member 34 comes into contact with the displacement portion 31 of the leaf spring 29, as illustrated in FIG. 6B. As a result, the displacement portion 31 is pushed leftward, and the spring portion 32 of the leaf spring 29 is elastically deformed, displacing the displacement portion 31 leftward, and the displacement portion 31 pushes the operator 26 of the switch body 23 leftward. As a result, the operator 26 sinks into the casing 24 of the switch body 23, and the movable contact of the switch body 23 provided inside the casing 24 comes into contact with the fixed contact. This causes the switch body 23 to turn on, that is, the tilt detection switch 22 to turn on.

On the other hand, as illustrated in FIG. 6C, when the swivel bracket 15 pivots relative to the tilt shaft 16 and the tilt state of the auxiliary device 6 changes from the tilt-down state to the tilt-up state, as illustrated in FIG. 6D, the protrusion portion 37 of the switch operating member 34 moves away from the displacement portion 31 of the leaf spring 29. As a result, the elastic force of the spring portion 32 of the leaf spring 29 causes the displacement portion 31 to be displaced to the right. As a result, the operator 26 of the switch body 23 is displaced rightward so as to protrude from the casing 24 of the switch body 23, and the movable contact of the switch body 23 separates from the fixed contact. This causes the switch body 23 to be turned off, that is, the tilt detection switch 22 to be turned off.

As described above, the marine propulsion system 1 of the first example of the present invention is equipped with the tilt detector 21 that detects the tilt state of the auxiliary device 6, and the alarm buzzer 41 that alerts the user that the tilt state of the auxiliary device 6 is in a tilt-down state when the main device power switch 5 is turned on and the tilt detector 21 detects that the tilt state of the auxiliary device 6 is in a tilt-down state. This configuration makes it possible to prevent the boat 51 from moving at high speed with the auxiliary device 6 in a tilt-down state. That is, when the boat 51 is to move at high speed, the boat operator usually tilts up the auxiliary device 6, then turns on the main device power switch 5 and starts the main device 2. However, when the boat 51 moves at high speed, it is possible that the boat operator will forget to tilt up the auxiliary device 6 and turn on the main device power switch 5 with the auxiliary device 6 in a tilt-down state. In this case, the tilt detector 21 detects that the tilt state of the auxiliary device 6 is in the tilt-down state, and a buzzer sound is emitted from the alarm buzzer 41 to notify the boat operator that the tilt state of the auxiliary device 6 is in the tilt-down state. This makes the boat operator realize that the auxiliary device 6 is not tilted up. Thereafter, the boat operator tilts up the auxiliary device 6 and then operates the main device 2 to move the boat 51 at high speed. In this way, the marine propulsion system of this example can prevent the boat 51 from moving at high speed with the auxiliary device 6 in a tilt-down state.

In addition, the marine propulsion system 1 of this example is configured to realize the function of notifying the boat operator that the tilt state of the auxiliary device 6 is a tilt-down state when the main device power switch 5 is turned on, by including the main device power supply path 4 that supplies power from the main device battery 3 to the main device 2, the branch path 20 connected to the main device power supply path 4, the alarm buzzer 41 connected to the branch path 20 and emits a buzzer sound when power is supplied from the main device battery 3 via the branch path 20, and the tilt detector 21 that detects the tilt state of the auxiliary device 6. The tilt detector 21 has the tilt detection switch 22 that sets a state in which power from the main device battery 3 is supplied to the alarm buzzer 41 via the branch path 20 when the tilt state of the auxiliary device 6 is in the tilt-down state, and sets a state in which power from the main device battery 3 is not supplied to the alarm buzzer 41 via the branch path 20 when the tilt state of the auxiliary device 6 is in the tilt-up state. Therefore, according to the marine propulsion system 1 of this example, the notification function can be realized at low cost. In other words, as another method of realizing the above-mentioned notification function, when the main device power switch 5 is turned on, in conjunction with this, the auxiliary device battery starts supplying power to the auxiliary device 6, and then the auxiliary device 6 detects the tilt state of the auxiliary device 6, and then, based on the detection result, if the tilt state of the auxiliary device 6 is in a tilt-down state, a control signal is sent from the auxiliary device 6 to the alarm buzzer 41, which causes the alarm buzzer 41 to emit a buzzer sound. However, in this method, in order to realize the above-mentioned notification function, a configuration that links the start of power supply from the auxiliary device battery to the auxiliary device 6 with the turning on of the main device power switch 5 or a configuration that controls the alarm buzzer 41 by the auxiliary device 6 must be added to the auxiliary device 6. Therefore, the cost required to realize the above-mentioned notification function is high. In contrast, in the marine propulsion system 1 of this example, in order to realize the above-mentioned notification function, the branch path 20 is connected in parallel to the main device power supply path 4, the tilt detection switch 22 and the alarm buzzer 41 are connected to the branch path 20, and the tilt detection switch 22 is externally attached to the auxiliary device 6. In other words, in the marine propulsion system 1 of this example, in order to realize the above-mentioned notification function, there is no need for a configuration that links the start of power supply from the auxiliary device battery to the auxiliary device 6 with the turning on of the main device power switch 5, nor for a configuration that allows the auxiliary device 6 to control the alarm buzzer 41. Therefore, according to the marine propulsion system 1 of this example, the notification function can be realized at low cost.

In addition, in the marine propulsion system 1 of this example, the tilt detector 21 has the tilt detection switch 22 provided on the swivel bracket 15 of the auxiliary device 6 and the switch operating member 34 provided on the tilt shaft 16 of the auxiliary device 6, and the switch operating member 34 switches the tilt detection switch 22 by moving the operator 26 of the tilt detection switch 22 in response to the pivoting of the swivel bracket 15 relative to the tilt shaft 16 of the auxiliary device 6. According to this configuration, by externally attaching the tilt detection switch 22 to the swivel bracket 15 of the auxiliary device 6 and mounting the switch operating member 34 to the tilt shaft 16 of the auxiliary device 6, means for detecting the tilt state of the auxiliary device 6 can be easily added to the auxiliary device 6.

Second Example

A second example of the marine propulsion system according to the present invention will be described with reference to FIGS. 7A to 7D. In the marine propulsion system of the second example of the present invention, a relationship between movement of the operator of the switch body of the tilt detection switch relative to the casing and generation and stopping of the buzzer sound of the alarm buzzer is reversed from that in the marine propulsion system 1 of the first example of the present invention.

FIG. 7A illustrates the auxiliary device 6 in a tilt-down state, and FIG. 7B illustrates a tilt detector 61 as viewed from a direction of an arrow E in FIG. 7A. FIG. 7C illustrates the auxiliary device 6 in a tilt-up state, and FIG. 7D illustrates the tilt detector 61 as viewed from a direction of an arrow F in FIG. 7C.

As illustrated in FIGS. 7A to 7D, the tilt detector 61 in the second example has a tilt detection switch 62 and a switch operating member 69, similar to the tilt detector 21 in the first example, and the tilt detection switch 62 is attached to the swivel bracket 15 of the auxiliary device 6, and the switch operating member 69 is attached to the tilt shaft 16 of the auxiliary device 6. Similarly to the tilt detection switch 22 in the first example, the tilt detection switch 62 in the second example has a switch body 63, a leaf spring 66, and a mounting plate 68. However, while the switch body 23 in the tilt detector 21 in the first example is a normally open push button switch, the switch body 63 in the tilt detector 61 in the second example is a normally closed push button switch. In other words, when the operator 65 protrudes from the casing 64, a movable contact inside the casing 64 comes into contact with a fixed contact and the switch body 63 turns on (closed), and when the operator 65 is retracted into the casing 64, the movable contact separates from the fixed contact and the switch body 63 turns off (open). In the second example, a shape of a displacement portion 67 of the leaf spring 66 is different from the shape of the displacement portion 31 of the leaf spring 29 in the first example. Furthermore, a shape of a protrusion portion 70 of the switch operating member 69 is different from the shape of the protrusion portion 37 of the switch operating member 34 in the first example. Moreover, as illustrated in FIG. 7B, the switch operating member 69 is fixed to the tilt shaft 16 so that the protrusion portion 70 is located slightly above a front portion of the tilt shaft 16.

As illustrated in FIGS. 7A and 7B, when the tilt state of the auxiliary device 6 becomes the tilt-down state, the protrusion portion 70 of the switch operating member 69 moves away from the displacement portion 67 of the leaf spring 66 of the tilt detection switch 62, causing the operator 65 of the switch body 63 of the tilt detection switch 62 to protrude from the casing 64 of the switch body 63 and turning the switch body 63 on (closed), that is, the tilt detection switch 62 is turned on. When the tilt detection switch 62 is turned on and the main device power switch 5 is turned on, power is supplied from the main device battery 3 to the alarm buzzer 41, and the alarm buzzer 41 emits a buzzer sound. Also, as illustrated in FIGS. 7C and 7D, when the tilt state of the auxiliary device 6 becomes the tilt-up state, the protrusion portion 70 of the switch operating member 69 presses the displacement portion 67 of the leaf spring 66 of the tilt detection switch 62, whereby the operator 65 of the switch body 63 of the tilt detection switch 62 sinks into the casing 64 of the switch body 63 and the switch body 63 is turned off (open), that is, the tilt detection switch 62 is turned off. When the switch body 63 is turned off, the supply of power from the main device battery 3 to the alarm buzzer 41 is cut off, and the alarm buzzer 41 stops making a buzzer sound.

With the marine propulsion system of the second example of the present invention, similarly to the marine propulsion system 1 of the first example of the present invention, when the main device power switch 5 is turned on and the tilt state of the auxiliary device 6 is in a tilt-down state, a buzzer sound is generated from the alarm buzzer 41 to inform the boat operator that the tilt state of the auxiliary device 6 is in a tilt-down state.

In the second example, a normally open push button switch may be used as the switch body 63, and a switching circuit using a transistor may be added to the branch path 20, so that when the switch body 63 is turned off, the switching circuit is turned on, and when the switch body 63 is turned on, the switching circuit is turned off. When the switching circuit is turned on and the main device power switch 5 is turned on, power is supplied from the main device battery 3 to the alarm buzzer 41, and when the switching circuit is turned off, the supply of power from the main device battery 3 to the alarm buzzer 41 is cut off. Even with this configuration, when the main device power switch 5 is turned on and the tilt state of the auxiliary device 6 is in a tilt-down state, a buzzer sound is generated from the alarm buzzer 41, so as to inform the boat operator that the tilt state of the auxiliary device 6 is in a tilt-down state.

Third Example

A third example of the marine propulsion system according to the present invention will be described with reference to FIGS. 8A to 8D. In a marine propulsion system according to the third example of the present invention, a protrusion portion of a switch operating member is brought into contact with an operator of a switch body of a tilt detection switch, and the operator is directly moved by the switch operating member.

FIG. 8A illustrates the auxiliary device 6 in a tilt-down state, and FIG. 8B illustrates a tilt detector 81 as viewed from a direction of an arrow E in FIG. 8A. FIG. 8C illustrates the auxiliary device 6 in a tilt-up state, and FIG. 8D illustrates the tilt detector 81 as viewed from a direction of an arrow F in FIG. 8C.

As illustrated in FIGS. 8A to 8D, the tilt detector 81 in the third example has a tilt detection switch 82 and a switch operating member 87, similar to the tilt detector 21 in the first example, and the tilt detection switch 82 is attached to the swivel bracket 15 of the auxiliary device 6, and the switch operating member 87 is attached to the tilt shaft 16 of the auxiliary device 6. In the third example, the tilt detection switch 82 has a switch body 83 and a mounting plate 86 for mounting the switch body 83 to the swivel bracket 15. The switch body 83 also has a casing 84 that accommodates a movable contact and a fixed contact therein, and a lever-type operator 85. The switch operating member 87 has a first protrusion portion 88 and a second protrusion portion 89.

As illustrated in FIGS. 8A and 8B, when the tilt state of the auxiliary device 6 becomes the tilt-down state, the first protrusion portion 88 of the switch operating member 87 comes into contact with the operator 85 of the switch body 83 of the tilt detection switch 82, tilting the operator 85 forward. When the operator 85 is tilted forward, the movable contact comes into contact with the fixed contact inside the casing 84 of the switch body 83, turning on the switch body 83, that is, turning on the tilt detection switch 82. When the tilt detection switch 82 is turned on and the main device power switch 5 is turned on, power is supplied from the main device battery 3 to the alarm buzzer 41, and the alarm buzzer 41 emits a buzzer sound. Also, as illustrated in FIGS. 8C and 8D, when the tilt state of the auxiliary device 6 becomes the tilt-up state, the second protrusion portion 89 of the switch operating member 87 comes into contact with the operator 85 of the switch body 83 of the tilt detection switch 82, tilting the operator 85 rearward. When the operator 85 is tilted rearward, the movable contact within the casing 84 of the switch body 83 separates from the fixed contact, turning off the switch body 83, that is, turning off the tilt detection switch 82. When the tilt detection switch 82 is turned off, the supply of power from the main device battery 3 to the alarm buzzer 41 is cut off, and the alarm buzzer 41 stops making a buzzer sound.

With the marine propulsion system of the third example of the present invention, similarly to the marine propulsion system 1 of the first example of the present invention, when the main device power switch 5 is turned on and the tilt state of the auxiliary device 6 is in a tilt-down state, a buzzer sound is generated from the alarm buzzer 41 to inform the boat operator that the tilt state of the auxiliary device 6 is in a tilt-down state.

Fourth Example

A fourth example of the marine propulsion system according to the present invention will be described with reference to FIGS. 9A to 9D. In the marine propulsion system according to the fourth example of the present invention, a protrusion portion of a switch operating member is brought into contact with a movable contact of a switch body of a tilt detection switch, and the movable contact is directly moved by the switch operating member.

FIG. 9A illustrates the auxiliary device 6 in a tilt-down state, and FIG. 9B illustrates a tilt detector 91 as viewed from a direction of an arrow E in FIG. 9A. FIG. 9C illustrates the auxiliary device 6 in a tilt-up state, and FIG. 9D illustrates the tilt detector 91 as viewed from a direction of an arrow F in FIG. 9C.

As illustrated in FIGS. 9A to 9D, the tilt detector 91 in the fourth example has a tilt detection switch 92 and a switch operating member 96, similar to the tilt detector 21 in the first example, and the tilt detection switch 92 is attached to the swivel bracket 15 of the auxiliary device 6, and the switch operating member 96 is attached to the tilt shaft 16 of the auxiliary device 6. In the fourth example, the tilt detection switch 92 has a movable contact 93, a fixed contact 94, and a mounting plate 95. The movable contact 93 and the fixed contact 94 are each formed of a conductive material such as a metal. The mounting plate 95 is made of an insulating material such as resin. Base ends of the movable contact 93 and the fixed contact 94 are fixed to the mounting plate 95. Moreover, the movable contact 93 can be elastically deformed so that its tip end is displaced in a left-right direction in FIGS. 9B or 9D relative to its base end. The switch operating member 96 is made of an insulating material such as resin. The shape of the switch operating member 96 is similar to that of the switch operating member 34 in the first example of the present invention.

As illustrated in FIGS. 9A and 9B, when the tilt state of the auxiliary device 6 is in the tilt-down state, a protrusion portion 97 of the switch operating member 96 comes into contact with the tip end of the movable contact 93 of the tilt detection switch 92. As a result, the tip end of the movable contact 93 is pushed leftward, causing the movable contact 93 to elastically deform, and the tip end of the movable contact 93 comes into contact with a tip end of the fixed contact 94, turning on the tilt detection switch 92. When the tilt detection switch 92 is turned on and the main device power switch 5 is turned on, power is supplied from the main device battery 3 to the alarm buzzer 41, and the alarm buzzer 41 emits a buzzer sound. Also, as illustrated in FIGS. 9C and 9D, when the tilt state of the auxiliary device 6 becomes the tilt-up state, the protrusion portion 97 of the switch operating member 96 moves away from the tip end of the movable contact 93 of the tilt detection switch 92. As a result, the tip end of the movable contact 93 moves to the right due to an elastic force of the movable contact 93, and the tip end of the movable contact 93 separates from the fixed contact 94, turning off the tilt detection switch 92. When the tilt detection switch 92 is turned off, the supply of power from the main device battery 3 to the alarm buzzer 41 is cut off, and the alarm buzzer 41 stops making a buzzer sound.

With the marine propulsion system of the fourth example of the present invention, similarly to the marine propulsion system 1 of the first example of the present invention, when the main device power switch 5 is turned on and the tilt state of the auxiliary device 6 is in a tilt-down state, a buzzer sound is generated from the alarm buzzer 41 to inform the boat operator that the tilt state of the auxiliary device 6 is in a tilt-down state.

Fifth Example

A fifth example of the marine propulsion system according to the present invention will be described with reference to FIG. 10. The marine propulsion system according to the fifth example of the present invention has a function of automatically tilting up the auxiliary device when the main device power switch is turned on.

FIG. 10 illustrates configuration of a marine propulsion system 101 according to the fifth example of the present invention. As illustrated in FIG. 10, the marine propulsion system 101 of the fifth example of the present invention includes the main device 2, the main device battery 3, the main device power supply path 4, the main device power switch 5, the auxiliary device 6, and the branch path 20, similarly to the marine propulsion system 1 of the first example of the present invention. Furthermore, unlike the marine propulsion system 1 of the first example of the present invention, the marine propulsion system 101 of the fifth example of the present invention does not include a tilt detector and an alarm buzzer, but instead includes a remote tilt controller 102.

The auxiliary device 6 has the tilt cylinder 17 as an actuator for tilting the auxiliary device 6 up and down, and a cylinder control device 103 for controlling the tilt cylinder 17. The remote tilt controller 102 is a device that controls the tilt cylinder 17 via the cylinder control device 103 that the auxiliary device 6 has, and tilts the auxiliary device 6 up and down. The remote tilt controller 102 is provided in the boat 51, the main device 2, or the auxiliary device 6. Incidentally, the tilt cylinder 17 is a specific example of a "tilt actuator", and the remote tilt controller 102 is a specific example of a "tilt controller".

The remote tilt controller 102 is connected to the branch path 20 as illustrated in FIG. 10. When the main device power switch 5 is turned on, power is supplied from the main device battery 3 to the remote tilt controller 102. When power is applied to the remote tilt controller 102, the remote tilt controller 102 starts up automatically. Next, the remote tilt controller 102 controls the auxiliary device power switch 18 to turn on the auxiliary device power switch 18, and puts at least the tilt cylinder 17 and the cylinder control device 103 of the auxiliary device 6 into an operable state. Next, the remote tilt controller 102 outputs a remote control signal to the cylinder control device 103 to tilt up the auxiliary device 6. Based on the remote control signal, the cylinder control device 103 controls the tilt cylinder 17 to tilt up the auxiliary device 6. The tilt cylinder 17 is provided with a position sensor that detects a position of a rod of the tilt cylinder 17, and the cylinder control device 103 can recognize the tilt state of the auxiliary device 6 based on the detection signal output from the position sensor. When the tilt state of the auxiliary device 6 becomes the tilt-up state, the cylinder control device 103 outputs a remote control stop request signal to the remote tilt controller 102. The remote tilt controller 102 stops outputting the remote control signal based on the remote control stop request signal. Next, the remote tilt controller 102 controls the auxiliary device power switch 18 to turn off the auxiliary device power switch 18.

In addition, when the main device power switch 5 is turned on and the tilt state of the auxiliary device 6 is in the tilt-up state, the remote tilt controller 102 automatically starts up, and then the auxiliary device power switch 18 is turned on by the remote tilt controller 102, so that at least the tilt cylinder 17 and the cylinder control device 103 of the auxiliary device 6 are placed in an operable state, and then a remote control signal for tilting up the auxiliary device 6 is output from the remote tilt controller 102 to the cylinder control device 103, and immediately thereafter, a remote control stop request signal is output from the cylinder control device 103 to the remote tilt controller 102. Based on the remote control stop request signal, the remote tilt controller 102 immediately stops outputting the remote control signal, and then turns off the auxiliary device power switch 18.

According to the marine propulsion system 101 of the fifth example of the present invention, it is possible to prevent the boat 51 from moving at high speed with the auxiliary device 6 in a tilt-down state. In addition, in the marine propulsion system 101 of the fifth example of the present invention, the auxiliary device 6 is automatically tilted up when the main device power switch 5 is turned on, so that when the boat operator is moving the boat 51 at high speed, he or she does not need to tilt up the auxiliary device 6 before turning on the main device power switch 5. Therefore, the boat operator can easily and quickly start moving the boat 51 at high speed.

In the first example described above, the leaf spring 29 is disposed to the right of the switch body 23, and the switch operating member 34 is disposed to the right of the leaf spring 29. However, the configurations of the switch body 23, the leaf spring 29, and the switch operating member 34 may be reversed left-to-right, and the leaf spring 29 may be disposed to the left of the switch body 23, and the switch operating member 34 may be disposed to the left of the leaf spring 29. The same applies to the second example. Similarly, in the third and fourth examples, the arrangement of the tilt detection switch 82 (92) and the switch operating member 87 (96) may be reversed left-to-right.

In addition, in each of the above examples, the alarm buzzer 41 is used as an example of a notifier that notifies the boat operator that the tilt state of the auxiliary device 6 is in a tilt-down state when the boat operator turns on the main device power switch 5, but the present invention is not limited to this. The notifier may, for example, be a sound generating device other than a buzzer, or a lamp that emits light when the tilt state of the auxiliary device 6 is in a tilt-down state when the main device power switch 5 is turned on, or a wireless communication device that wirelessly transmits a notification to, for example, a portable terminal carried by the boat operator when the tilt state of the auxiliary device 6 is in a tilt-down state when the main device power switch 5 is turned on. In addition, a gauge with a display may be used as the notifier, and when the tilt state of the auxiliary device 6 is in a tilt-down state when the main device power switch 5 is turned on, this fact may be displayed on the display of the gauge.

In the first to fourth examples, the auxiliary device 6 does not need to be provided with the tilt cylinder 17.

In addition, in each of the above examples, the power source of the main device 2 may be a motor instead of an engine. In such a case, when docking, leaving the dock, trolling, or the like, when the motor of the main device is stopped and the main device is tilted down, and the auxiliary device is operated to move the boat at a low speed, it is possible that the main device propeller may rotate unintentionally. However, when the boat's speed is low, even when the propeller of the main device rotates, the rotation speed of the propeller of the main device does not increase, and therefore the power generated by the rotation of the motor of the main device does not become large enough to adversely affect the inverter of the main device.

In addition, in each of the above examples, the marine propulsion system 1 is equipped with one main device 2 and one auxiliary device 6, but the marine propulsion system may be provided with two or more main devices, or the marine propulsion system may be provided with two or more auxiliary devices. For example, two main devices may be mounted on left and right sides of the transom of the boat, and one auxiliary device may be mounted in the center of the transom of the boat. Alternatively, two auxiliary devices may be mounted on left and right sides of the transom of the boat, and one main device may be mounted in the center of the transom of the boat. In addition, in each of the above examples, the main device 2 is a high-output, large outboard device and the auxiliary device 6 is a low-output, small electric outboard device, but the auxiliary device may be an electric outboard device having the same output and size as the main device.

In each of the above examples, the main device or the auxiliary device may be a hybrid outboard device equipped with a motor and an engine. Furthermore, the main device may be a type of marine propulsion device other than an outboard device, such as an inboard/outboard device.

Furthermore, the present invention can be modified as appropriate within the scope that does not deviate from the gist or concept of the invention that can be read from the claims and the entire specification, and marine propulsion systems involving such modifications are also included in the technical concept of the present invention.

According to the above embodiments, when the first marine propulsion device and the second marine propulsion device which is an electric outboard device are installed on a single boat and the boat is sailing, it is possible to prevent the boat from moving at high speed with the second marine propulsion device in a tilt-down state.