JP2024002546A - Outboard motor and vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve improvement in flexibility of layout of an outboard motor and reduction of a size and weight of the outboard motor, by reducing a space in which an exhaust passage is formed.

SOLUTION: An outboard motor 100 is provided with an engine 120; a propeller shaft 111; a propeller 112 mounted on the propeller shaft; a transmission mechanism 130 that transmits rotation of the engine to the propeller shaft; an upper storage body 118u that stores a portion of the engine; a lower storage body 118l that stores a portion of the propeller shaft; and a steering mechanism that turns the lower storage body around a steering axis with respect to the upper storage body. The upper storage body includes an upper exhaust passage ECu having an upper exhaust port EPu, which communicates with the engine. The lower storage body includes a lower exhaust passage ECl having a lower exhaust port EPl. The upper exhaust passage and the lower exhaust passage are configured to be switched between a communication state where the passages are in communication with each other and a non-communication state where the passages are not in communication with each other, in accordance with a rudder angle of the steering mechanism.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2024,JPO&INPIT

Description

The technology disclosed herein relates to outboard motors and ships.

A ship includes a hull and an outboard motor attached to the rear of the hull. An outboard motor is a device that generates thrust to propel a boat. An outboard motor includes an engine, a propeller shaft, a propeller attached to the propeller shaft, a transmission mechanism that transmits engine rotation to the propeller shaft, an upper housing housing at least a portion of the engine, and a propeller shaft attached to the propeller shaft. and a lower container housing at least a portion of the container.

The outboard motor also includes a steering mechanism that rotates the outboard motor around a steering shaft. When the direction of the propeller is changed by the steering mechanism, the direction of the thrust generated by the propeller based on the direction of the ship changes, and the direction of travel of the ship changes. Generally, a steering mechanism for an outboard motor is configured to integrally rotate an upper housing member and a lower housing member around a steering axis.

Conventionally, a configuration of an outboard motor including a steering mechanism that rotates a lower housing body relative to an upper housing body around a steering axis (hereinafter referred to as a "lower-only steering configuration") has been proposed (for example, (See Patent Document 1). In the lower-only steering configuration, only the lower housing body rotates and the upper housing body does not rotate during steering. Therefore, the upper housing body does not interfere with other parts of the vessel during steering, and the maximum steering angle can be increased.

US Patent No. 10800502

An outboard motor is formed with an exhaust flow path for discharging exhaust gas from the engine. More specifically, the upper housing is formed with an upper exhaust flow path that has an upper exhaust port and communicates with the engine, and the lower housing has a lower exhaust flow path that has a lower exhaust port. ing. Exhaust gas from the engine passes through the upper exhaust flow path and is discharged into the air from the upper exhaust port, or through the upper exhaust flow path and the lower exhaust flow path and is discharged into the water from the lower exhaust port.

In the above-mentioned conventional lower-only steering configuration, in order to communicate the upper exhaust flow path and the lower exhaust flow path with each other regardless of the steering angle, an annular communication flow is used to communicate the two over the entire circumference around the steering axis. A road is provided. As a result, the outboard motor requires a larger space for forming an exhaust flow path, which reduces the degree of freedom in layout of the outboard motor and increases the size and weight of the outboard motor.

This specification discloses a technique that can solve the above-mentioned problems.

The technology disclosed in this specification can be realized, for example, as the following form.

(1) The outboard motor disclosed in this specification includes an engine, a propeller shaft, a propeller attached to the propeller shaft, a transmission mechanism that transmits rotation of the engine to the propeller shaft, and a transmission mechanism for transmitting rotation of the engine to the propeller shaft. an upper housing body that houses at least a portion of the propeller shaft; a lower housing body that houses at least a portion of the propeller shaft; and a steering mechanism that rotates the lower housing body about a steering axis with respect to the upper housing body. Be prepared. The upper housing body has an upper exhaust port and an upper exhaust flow path that communicates with the engine. A lower exhaust passage having a lower exhaust port is formed in the lower housing. The upper exhaust flow path and the lower exhaust flow path are configured to switch between a communicating state in which they communicate with each other and a non-communicating state in which they do not communicate with each other, depending on the steering angle of the steering mechanism. .

This outboard motor has a configuration in which the lower housing that houses the propeller shaft rotates (steering) relative to the upper housing that houses the engine, so the upper housing and lower housing are integrally connected to the hull. The maximum steering angle can be increased compared to a configuration in which the steering wheel rotates by rotating. Furthermore, in this outboard motor, the upper exhaust flow path and the lower exhaust flow path are configured to switch between a communicating state and a non-communicating state depending on the steering angle. By providing an annular communication channel on one side of the exhaust channel, the space for forming the exhaust channel can be reduced compared to a configuration in which the two are always in communication regardless of the steering angle, and the layout of the outboard motor is improved. It is possible to improve the degree of freedom and reduce the size and weight of the outboard motor.

(2) Another outboard motor disclosed in this specification includes an engine, a propeller shaft, a propeller attached to the propeller shaft, a transmission mechanism that transmits the rotation of the engine to the propeller shaft, and the an upper housing that houses at least a portion of the engine; a lower housing that houses at least a portion of the propeller shaft; and a steering mechanism that rotates the lower housing about a steering axis relative to the upper housing. Equipped with. The upper housing body has an upper exhaust port and an upper exhaust flow path that communicates with the engine. A lower exhaust passage having a lower exhaust port is formed in the lower housing. The upper exhaust flow path and the lower exhaust flow path are in a communicating state in which they communicate with each other and in a non-communicating state in which they do not communicate with each other, depending on at least one of the steering angle of the steering mechanism and the rotation speed of the engine; It is configured to switch between.

This outboard motor has a configuration in which the lower housing body that houses the propeller shaft rotates (steering) relative to the upper housing body that houses the engine, so the upper housing body and the lower housing body are integrally connected to the hull. The maximum steering angle can be increased compared to a configuration in which the steering wheel rotates by rotating. Furthermore, in this outboard motor, the upper exhaust flow path and the lower exhaust flow path are configured to switch between a communicating state and a non-communicating state depending on at least one of the steering angle and the engine speed. , compared to a configuration in which an annular communication flow path is provided in one of the upper exhaust flow path and the lower exhaust flow path so that the two are always communicated regardless of the steering angle or engine rotation speed, It is possible to reduce the space required for the outboard motor, improve the degree of freedom in the layout of the outboard motor, and reduce the size and weight of the outboard motor.

Note that the technology disclosed in this specification can be realized in various forms, for example, in the form of an outboard motor, a ship equipped with an outboard motor and a hull, etc. .

According to the outboard motor disclosed in this specification, the space for forming the exhaust flow path can be reduced, the degree of freedom in layout of the outboard motor can be improved, and the size and weight of the outboard motor can be reduced. reduction can be achieved.

A perspective view schematically showing the configuration of a ship 10 according to the present embodiment A side view schematically showing the configuration of an outboard motor 100 An explanatory diagram schematically showing the state of steering by the steering mechanism 170 Explanatory diagram showing the configuration near the boundary between the outboard motor upper unit UU and the outboard motor lower unit LU Explanatory diagram showing the configuration near the boundary between the outboard motor upper unit UU and the outboard motor lower unit LU Explanatory diagram showing the configuration near the boundary between the outboard motor upper unit UU and the outboard motor lower unit LU Explanatory diagram showing the configuration near the boundary between the outboard motor upper unit UU and the outboard motor lower unit LU Explanatory diagram showing the positional relationship between the lower exhaust communication hole 184 and the upper exhaust communication hole 194 according to the steering angle θ1 Explanatory diagram showing the positional relationship between the lower exhaust communication hole 184 and the upper exhaust communication hole 194 according to the steering angle θ1 An explanatory diagram showing an exhaust mode according to the rotational speed of the engine 120 and the rudder angle θ1 in the outboard motor 100 of the present embodiment Explanatory diagram showing the positional relationship between the lower cooling water communication hole 186 and the upper cooling water communication hole 196 according to the steering angle θ1 Explanatory diagram showing the positional relationship between the lower cooling water communication hole 186 and the upper cooling water communication hole 196 according to the steering angle θ1 An explanatory diagram showing the cooling water passage communication area Sc according to the steering angle θ1 in the outboard motor 100 of the present embodiment Explanatory diagram showing the positional relationship between the lower cooling water communication hole 186 and the upper cooling water communication hole 196 according to the steering angle θ1 in a modified example

A. Embodiment:
(Configuration of ship 10)
FIG. 1 is a perspective view schematically showing the configuration of a ship 10 according to the present embodiment. In FIG. 1 and other drawings to be described later, arrows representing each direction with respect to the position of the ship 10 are shown. More specifically, each figure shows arrows representing FRONT, REAR, LEFT, RIGHT, UPPER, and LOWER. There is. The front-rear direction, the left-right direction, and the up-down direction (vertical direction) are directions that are perpendicular to each other.

The boat 10 includes a hull 200 and an outboard motor 100.

(Configuration of hull 200)
The hull 200 is a part of the ship 10 on which the crew members board. The hull 200 includes a hull main body portion 202 having a living space 204, a cockpit 240 installed in the living space 204, and a control device 250 installed near the cockpit 240. The control device 250 is a device for maneuvering the ship, and includes, for example, a steering wheel 252, a shift/throttle lever 254, a joystick 255, a monitor 256, and an input device 258. Further, the hull 200 includes a partition wall 220 that partitions the rear end of the living space 204, and a transom 210 located at the rear end of the hull 200. A space 206 exists between the transom 210 and the partition wall 220 in the front-rear direction.

(Configuration of outboard motor 100)
FIG. 2 is a side view schematically showing the configuration of the outboard motor 100. In the following, unless otherwise specified, the outboard motor 100 in the standard attitude will be described. The reference posture is a posture in which the rotational axis Ac of the crankshaft 124, which will be described later, extends in the vertical direction, and the rotational axis Ap of the propeller shaft 111 extends in the longitudinal direction. The longitudinal direction, the lateral direction, and the vertical direction are each determined based on the outboard motor 100 in a reference attitude.

The outboard motor 100 is a device that generates thrust to propel the boat 10. The outboard motor 100 is attached to a transom 210 at the rear of the hull 200. Outboard motor 100 includes an outboard motor main body 110, a suspension system 150, and a steering mechanism 170.

(Configuration of outboard motor main body 110)
The outboard motor main body 110 includes an engine 120, a propeller shaft 111, a propeller 112, a transmission mechanism 130, a cowl 114, and a casing 116.

The cowl 114 is a housing disposed above the outboard motor main body 110. The cowl 114 includes a lower cowl 114b that constitutes the lower part of the cowl 114, and an upper cowl 114a that constitutes the upper part of the cowl 114. Upper cowl 114a is removably attached to lower cowl 114b.

The casing 116 is a storage body located below the cowl 114 and disposed at the bottom of the outboard motor main body 110. The casing 116 includes a lower casing 116b that constitutes the lower part of the casing 116, and an upper casing 116a that constitutes the upper part of the casing 116.

In the following description, the cowl 114 and the upper casing 116a are also referred to as the "upper container 118u", and the lower casing 116b is also referred to as the "lower container 118l". In addition, the upper housing 118u and each component housed or integrated in the upper housing 118u of the outboard motor main body 110 are collectively referred to as an "outboard motor upper unit UU". Of these, the lower housing 118l and each component housed or integrated in the lower housing 118l are collectively referred to as an "outboard motor lower unit LU."

Engine 120 is a prime mover that generates power. Engine 120 is configured by, for example, an internal combustion engine. The engine 120 is disposed at a relatively upper position in the outboard motor main body 110, and at least a portion of the engine 120 is housed within the cowl 114. The engine 120 has a crankshaft 124 that converts reciprocating motion of a piston (not shown) into rotational motion. The crankshaft 124 is arranged with its rotational axis Ac extending in the vertical direction.

The propeller shaft 111 is a rod-shaped member. The propeller shaft 111 is disposed at a relatively lower position in the outboard motor main body 110 so as to extend in the front-rear direction. At least a portion of propeller shaft 111 is housed within lower casing 116b. More specifically, the front end of the propeller shaft 111 is housed in the lower casing 116b, and the rear end of the propeller shaft 111 projects rearward from the lower casing 116b.

The propeller 112 is a rotating body having multiple blades. The propeller 112 is attached to the rear end of the propeller shaft 111. As the propeller shaft 111 rotates around the rotation axis Ap, the propeller 112 also rotates. The propeller 112 generates thrust by rotating.

The transmission mechanism 130 is a mechanism that transmits the rotation of the engine 120 to the propeller shaft 111. At least a portion of transmission mechanism 130 is housed within casing 116. Transmission mechanism 130 has a drive shaft 132 and a shift mechanism 134.

The drive shaft 132 is a rod-shaped member. The drive shaft 132 is arranged below the crankshaft 124 of the engine 120 so as to extend in the vertical direction. The upper end of the drive shaft 132 is connected to the crankshaft 124. Drive shaft 132 rotates with rotation of engine 120 (rotation of crankshaft 124).

The shift mechanism 134 is connected to the lower end of the drive shaft 132 and to the front end of the propeller shaft 111. Shift mechanism 134 includes, for example, a plurality of gears and a clutch that switches meshing of the gears, and transmits rotation of drive shaft 132 accompanying rotation of engine 120 to propeller shaft 111 in a switchable direction. When the shift mechanism 134 transmits the rotation of the drive shaft 132 as rotation in the forward direction to the propeller shaft 111, the propeller 112 rotating in the forward direction together with the propeller shaft 111 generates thrust in the forward direction. Conversely, when the shift mechanism 134 transmits the rotation of the drive shaft 132 to the propeller shaft 111 as rotation in the reverse direction, the propeller 112 rotating in the reverse direction together with the propeller shaft 111 generates thrust in the reverse direction.

(Configuration of suspension device 150)
The suspension device 150 is a device that suspends the outboard motor main body 110 on the hull 200. The suspension device 150 includes a pair of left and right clamp brackets 152, a tilt shaft 160, and a connection bracket 156.

The pair of left and right clamp brackets 152 are arranged at the rear of the hull 200 so as to be spaced apart from each other in the left-right direction, and are fixed to the transom 210 of the hull 200 with bolts, for example. Each clamp bracket 152 has a cylindrical support portion 152a in which a through hole extending in the left-right direction is formed.

The tilt shaft 160 is a rod-shaped member. The tilt shaft 160 is rotatably supported within the through hole of the support portion 152a of the clamp bracket 152. The tilt axis At, which is the center line of the tilt axis 160, constitutes an axis in the horizontal direction (left-right direction) in the tilt operation of the outboard motor 100.

The connection bracket 156 is arranged so as to be sandwiched between the pair of clamp brackets 152, and is supported by the support portion 152a of the clamp bracket 152 via the tilt axis 160 so as to be rotatable around the tilt axis At. The connection bracket 156 is fixed to the outboard motor main body 110. The connection bracket 156 is rotated about the tilt axis At with respect to the clamp bracket 152 by a tilt device (not shown) including an actuator such as a hydraulic cylinder.

When the connection bracket 156 rotates around the tilt axis At with respect to the clamp bracket 152, the outboard motor main body 110 fixed to the connection bracket 156 also rotates around the tilt axis At. As a result, a tilt operation is realized in which the outboard motor main body 110 is vertically rotated with respect to the hull 200. The tilting operation of the outboard motor 100 causes the boat to move in a range from a tilt-down state in which the propeller 112 is located underwater (a state in which the outboard motor 100 is in the reference attitude) to a tilt-up state in which the propeller 112 is located above the water surface. The angle of the outer machine main body 110 around the tilt axis At can be changed. It is also possible to perform a trim operation in which the angle of the outboard motor main body 110 around the tilt axis At is adjusted to adjust the attitude of the boat 10 when it is running.

(Configuration of steering mechanism 170)
The steering mechanism 170 is a mechanism for realizing steering in the outboard motor 100. FIG. 3 is an explanatory diagram schematically showing the state of steering by the steering mechanism 170. As shown in FIG. 3, the steering mechanism 170 is configured to achieve steering by rotating the outboard motor lower unit LU of the outboard motor main body 110 around the steering axis As. In other words, the steering mechanism 170 is a mechanism that rotates the lower housing 118l (lower casing 116b) around the steering axis As with respect to the upper housing 118u (cowl 114 and upper casing 116a) shown in FIG. be. In this embodiment, the steering axis As is the central axis of the drive shaft 132.

Column A in FIG. 3 shows a state in which the outboard motor lower unit LU is not rotated about the steering axis As with respect to the outboard motor upper unit UU (that is, the rudder angle θ1 is 0°). There is. In this state, the direction of the thrust generated by the propeller 112 provided in the outboard motor lower unit LU is forward, so that the bow moves forward.

Column B in FIG. 3 shows a right steering state in which the outboard motor lower unit LU is rotated counterclockwise around the steering axis As by a rudder angle θ1 with respect to the outboard motor upper unit UU. In this state, the direction of the thrust generated by the propeller 112 is diagonally forward to the left, so the stern of the boat is pushed to the left and the bow of the boat curves to the right.

Column C in FIG. 3 shows a left steering state in which the outboard motor lower unit LU is rotated clockwise around the steering axis As by a rudder angle θ1 with respect to the outboard motor upper unit UU. In this state, the direction of the thrust generated by the propeller 112 is diagonally forward to the right, so the stern of the boat is pushed to the right and the bow of the boat moves to the left.

As described above, by rotating the outboard motor lower unit LU around the steering axis As by the steering mechanism 170, the direction of the thrust generated by the propeller 112 with respect to the direction of the hull 200 is changed, and the direction of the thrust generated by the propeller 112 is changed, and the Steering is achieved. In this embodiment, during steering by the steering mechanism 170, only the outboard motor lower unit LU rotates around the steering axis As, and the outboard motor upper unit UU does not rotate. Therefore, the outboard motor upper unit UU does not interfere with other parts of the vessel 10 during steering, and the maximum steering angle can be increased.

4 to 7 are explanatory diagrams showing the configuration near the boundary between the outboard motor upper unit UU and the outboard motor lower unit LU. FIG. 4 shows a cross-sectional configuration near the boundary, and FIG. 5 shows an external configuration of a lower component member 180 that is a part of the lower housing 118l that constitutes the outboard motor lower unit LU. , FIG. 6 shows an external appearance of an upper component 190 that is part of the upper housing 118u that constitutes the outboard motor upper unit UU, and FIG. 7 shows the lower component 180 and the upper component 190. It shows the connection relationship with.

As shown in FIGS. 4, 5, and 7, the lower component member 180 is a member that constitutes the top portion of the lower container 118l of the outboard motor lower unit LU. The lower component member 180 has a flat plate part 181 and a substantially cylindrical cylindrical part 182 that projects upward from the flat plate part 181. The upper surface of the cylindrical portion 182 is covered, and a through hole 183 is formed in the upper surface. The drive shaft 132 is inserted into the through hole 183. The lower component member 180 is rotatable about the steering axis As with respect to the drive shaft 132.

As shown in FIGS. 4, 6, and 7, the upper component member 190 is a member that constitutes the lowest part of the upper container 118u of the outboard motor upper unit UU. The upper component member 190 includes a flat plate part 191, a substantially cylindrical cylindrical part 192 projecting upward from the flat plate part 191, and a box located on the opposite side (front) of the flat plate part 191 with respect to the cylindrical part 192. It has a shaped part 193.

A substantially cylindrical rotating member 108 in which a through hole 109 extending in the vertical direction is formed is accommodated in the hollow portion of the cylindrical portion 192 of the upper component member 190. A drive shaft 132 is inserted through the through hole 109 of the rotating member 108 . The rotating member 108 is rotatable about the steering axis As with respect to the upper component member 190 and the drive shaft 132. Further, the tip of the cylindrical portion 182 of the lower component member 180 is inserted below the rotating member 108 in the hollow portion of the cylindrical portion 192, and the cylindrical portion 182 is joined to the rotating member 108 by a plurality of bolts. has been done. Therefore, the lower component 180 is rotatable around the steering axis As with respect to the upper component 190 and the drive shaft 132, together with the rotating member 108. Further, the steering mechanism 170 includes an actuator such as a hydraulic cylinder, and rotates the outboard motor lower unit LU including the lower component member 180 with respect to the outboard motor upper unit UU including the upper component member 190. . With this configuration, the function of the steering mechanism 170 that rotates the outboard motor lower unit LU around the steering axis As is realized.

(Configuration of exhaust flow path EC)
As shown in FIGS. 2 and 4, the outboard motor main body 110 is formed with an exhaust flow path EC for discharging exhaust gas from the engine 120. More specifically, an upper exhaust passage ECu communicating with the engine 120 is formed in the upper housing 118u that constitutes the outboard motor upper unit UU. The upper exhaust flow path ECu has an upper exhaust port EPu. The upper exhaust port EPu is formed at a position above the waterline when the ship 10 is on the water. Further, a lower exhaust flow path ECl is formed in the lower housing body 118l that constitutes the outboard motor lower unit LU. The lower exhaust flow path ECl has a lower exhaust port EPl. The lower exhaust port EPl is formed at a position below the waterline when the ship 10 is on the water, and in this embodiment is provided near the center of the propeller 112. As described later, the upper exhaust flow path ECu and the lower exhaust flow path ECl communicate with each other under certain conditions.

When the rotation speed of the engine 120 is relatively low, the pressure of the exhaust from the engine 120 is relatively low, so the exhaust passes through the upper exhaust passage ECu and is discharged into the air from the upper exhaust port EPu. On the other hand, when the rotation speed of the engine 120 is relatively high, the pressure of the exhaust from the engine 120 is relatively high, so the exhaust passes through the upper exhaust passage ECu and is discharged into the air from the upper exhaust port EPu. When the upper exhaust flow path ECu and the lower exhaust flow path ECl are in communication with each other, the air flows from the upper exhaust flow path ECu to the lower exhaust flow path ECl, and is discharged into the water from the lower exhaust port EPl. In this specification, the upper exhaust port EPu is also referred to as an idle exhaust port, exhaust from the upper exhaust port EPu is also referred to as idle exhaust, and the lower exhaust port EPl is also referred to as a boss exhaust port, and exhaust from the lower exhaust port EPl is also referred to as an idle exhaust. Also called boss exhaust.

A switching valve 102 that opens and closes the flow path is provided on the upper exhaust flow path ECu. When the switching valve 102 is in the open state, exhaust gas from the engine 120 can pass through the position of the switching valve 102 in the upper exhaust flow path ECu and proceed to the lower exhaust flow path ECl side. On the other hand, when the switching valve 102 is in the closed state, the exhaust from the engine 120 is stopped at the position of the switching valve 102 in the upper exhaust flow path ECu, and the flow of exhaust gas toward the lower exhaust flow path ECl is restricted.

Next, with reference to FIGS. 4 to 7, the configuration of the communication portion between the upper exhaust flow path ECu and the lower exhaust flow path ECl in the exhaust flow path EC will be described.

As shown in FIGS. 4, 5, and 7, a lower exhaust communication hole 184 that penetrates in the vertical direction is formed in the flat plate portion 181 of the lower component member 180 that constitutes the uppermost part of the lower container 118l. The lower exhaust communication hole 184 is an opening on the upper end side of the lower exhaust flow path ECl formed in the lower housing 118l. In this embodiment, the general shape of the lower exhaust communication hole 184 when viewed in the vertical direction is a substantially rectangular shape extending by a predetermined width along a part of the circumferential direction around the steering axis As. The lower exhaust communication hole 184 is an example of a second communication port in the claims.

As shown in FIGS. 4, 6, and 7, an upper exhaust communication hole 194 that penetrates in the vertical direction is formed in the flat plate portion 191 of the upper structural member 190 that constitutes the lowest part of the upper container 118u. The upper exhaust communication hole 194 is an opening on the lower end side of the upper exhaust flow path ECu formed in the upper housing 118u. In this embodiment, the general shape of the upper exhaust communication hole 194 when viewed in the vertical direction is a substantially rectangular shape whose width along the circumferential direction is narrower than that of the lower exhaust communication hole 184. The area of the lower exhaust communication hole 184 is larger than the area of the upper exhaust communication hole 194. The upper exhaust communication hole 194 is an example of a first communication port in the claims.

8 and 9 are explanatory diagrams showing the positional relationship between the lower exhaust communication hole 184 and the upper exhaust communication hole 194 according to the steering angle θ1. Column A in FIG. 8 shows the positional relationship (hereinafter simply referred to as "positional relationship") between the lower exhaust communication hole 184 and the upper exhaust communication hole 194 when the steering angle θ1 is 0°. Column B in FIG. 9 shows the positional relationship when the steering angle θ1 is 20°, column C in FIG. 9 shows the positional relationship when the steering angle θ1 is 30°, and column D in FIG. The column shows the positional relationship when the steering angle θ1 is 120°. Note that the steering angle θ1 here means the steering angle when turning to the right. However, the exhaust mode described below is the same when the vehicle is steered to the left.

As shown in FIGS. 8 and 9, when the lower structural member 180 rotates around the steering axis As with respect to the upper structural member 190 due to steering, the positional relationship between the lower exhaust communication hole 184 and the upper exhaust communication hole 194 changes. Change. More specifically, the lower exhaust communication hole 184 rotates relatively around the steering axis As. Thereby, the communication area between the lower exhaust communication hole 184 and the upper exhaust communication hole 194, that is, the communication area between the lower exhaust flow path ECl and the upper exhaust flow path ECu (hereinafter referred to as "exhaust flow path communication area Se"). changes.

FIG. 10 is an explanatory diagram showing the exhaust mode according to the rotational speed of the engine 120 and the steering angle θ1 in the outboard motor 100 of this embodiment. As shown in FIG. 10, when the steering angle θ1 is 0° or more and 20° or less (see columns A and B in FIG. 8), the upper exhaust communication hole 194 formed in the upper component member 190 is The entirety thereof overlaps (is included in) the lower exhaust communication hole 184 formed in the lower component member 180. In this state, the upper exhaust passage ECu formed in the upper housing 118u and the lower exhaust passage ECl formed in the lower housing 118l are in a communication state where they communicate with each other, and the lower exhaust passage ECl and the lower exhaust Exhaust into the water (boss exhaust) via the port EPl becomes possible. Further, the exhaust flow passage communication area Se becomes the maximum value E0.

When the steering angle θ1 is greater than 20 degrees and less than about 57 degrees (see column C in FIG. 9), a portion of the upper exhaust communication hole 194 formed in the upper component member 190 is The remaining part of the upper exhaust communication hole 194 overlaps with the lower exhaust communication hole 184 formed in the lower component member 180 and does not overlap with the lower exhaust communication hole 184 . In addition, when the steering angle θ1 is larger than about 57° (see column D in FIG. 9), the entire upper exhaust communication hole 194 formed in the upper component member 190 is formed in the lower component member 180 when viewed in the vertical direction. It does not overlap with the lower exhaust communication hole 184. In this state, at least a portion of the upper exhaust communication hole 194 of the upper exhaust flow path ECu formed in the upper container 118u and at least one portion of the lower exhaust communication hole 184 of the lower exhaust flow path ECl formed in the lower container 118l. The parts are in a non-communicating state where they do not communicate with each other, and exhaust into the water (boss exhaust) via the lower exhaust flow path ECl and the lower exhaust port EPl becomes impossible. At this time, the switching valve 102 is closed in order to restrict the flow of exhaust gas from the upper exhaust flow path ECu to the lower exhaust flow path ECl side.

As shown in FIG. 10, in the ship 10 of this embodiment, the maximum value of the rotation speed R1 of the engine 120 is, for example, 6000 rpm. However, during actual ship maneuvering, the larger the rudder angle θ1 is, the lower the cruising speed tends to be, and accordingly the rotational speed R1 of the engine 120 also tends to be lower. Therefore, in actual ship maneuvering, the hatched areas (first area A1 and second area A2) in FIG. 10 are used.

In this embodiment, when the rotation speed R1 of the engine 120 is below a predetermined value (for example, 2000 rpm) or when the steering angle θ1 is above a predetermined value (for example, 25°) (i.e., when the rotation speed R1 and the steering angle θ1 are is located within the first region A1 in FIG. 10), idle exhaust is performed in which exhaust from the engine 120 is discharged into the air from the upper exhaust port EPu. At this time, the switching valve 102 is closed in order to restrict the flow of exhaust gas from the upper exhaust flow path ECu to the lower exhaust flow path ECl side.

On the other hand, when the rotation speed R1 of the engine 120 is larger than a predetermined value (for example, 2000 rpm) and the steering angle θ1 is smaller than a predetermined value (for example, 25 degrees) (that is, when the rotation speed R1 and the steering angle θ1 are ), there is an idle exhaust that discharges the exhaust from the engine 120 into the air from the upper exhaust port EPu, and a boss exhaust that discharges the exhaust from the engine 120 into the water from the lower exhaust port EPl. It will be done. At this time, the switching valve 102 is opened in order to flow the exhaust gas from the upper exhaust flow path ECu to the lower exhaust flow path ECl side.

Note that the required exhaust area changes depending on the steering angle θ1 (that is, depending on the rotation speed R1 of the engine 120). Therefore, the area of each part of the exhaust flow path EC is set so that whatever the value of the steering angle θ1 and the rotation speed R1 of the engine 120 is, the required exhaust area in that state is secured. . For example, the maximum value E0 of the exhaust flow passage communication area Se is set to a value sufficient to discharge exhaust gas from the engine 120 driven at the highest rotation speed (for example, 6000 rpm).

(Configuration of cooling water flow path CC)
As shown in FIGS. 2 and 4, the outboard motor main body 110 is formed with a cooling water passage CC through which cooling water for cooling the engine 120 flows. More specifically, an upper cooling water passage CCu communicating with the engine 120 is formed in the upper housing body 118u constituting the outboard motor upper unit UU. Further, a lower cooling water passage CCl is formed in the lower housing 118l that constitutes the outboard motor lower unit LU. The lower cooling water flow path CCl has a water intake WI. The water intake WI is formed at a position below the waterline when the ship 10 is on the water, and in this embodiment is formed in the lower casing 116b. The upper cooling water flow path CCu and the lower cooling water flow path CCl are in communication with each other.

Cooling water for cooling the engine 120 is pumped up from the water intake port WI by a cooling water pump (not shown) that is driven as the drive shaft 132 rotates. The pumped cooling water flows upward in the lower cooling water flow path CCl and the upper cooling water flow path CCu, and is supplied to the engine 120. After being used to cool the engine 120, the cooling water is discharged to the outside through a discharge cooling water flow path (not shown). Note that the cooling water used for cooling the engine 120 may be mixed with the exhaust gas from the engine 120 and discharged to the outside.

Next, with reference to FIGS. 4 to 7, the configuration of the communication portion between the upper cooling water flow path CCu and the lower cooling water flow path CCl in the cooling water flow path CC will be described.

As shown in FIGS. 4, 5, and 7, the cylindrical portion 182 of the lower structural member 180 constituting the uppermost part of the lower container 118l has a plurality of lower cooling water communication holes extending in the radial direction of the cylindrical portion 182. 186 is formed. Each lower cooling water communication hole 186 is an opening on the upper end side of the lower cooling water passage CCl formed in the lower container 118l.

As shown in FIGS. 4, 6, and 7, an upper cooling water communication hole 196 extending in the horizontal direction is formed in the box-shaped portion 193 of the upper component member 190 that constitutes the lowest part of the upper container 118u. The upper cooling water communication hole 196 is an opening on the lower end side of the upper cooling water flow path CCu formed in the upper container 118u.

The lower cooling water passage CCl and the upper cooling water passage CCu communicate with each other via the lower cooling water communication hole 186 and the upper cooling water communication hole 196. When the lower component 180 rotates around the steering axis As with respect to the upper component 190 due to steering, the positional relationship between the lower cooling water communication hole 186 and the upper cooling water communication hole 196 changes. As a result, the communication area between the lower cooling water passage hole 186 and the upper cooling water passage hole 196, that is, the communication area between the lower cooling water passage CCl and the upper cooling water passage CCu (hereinafter referred to as "cooling water passage communication area Sc"). ) changes, and as a result, the amount of cooling water supplied to the engine 120 via the cooling water flow path CC changes.

11 and 12 are explanatory diagrams showing the positional relationship between the lower cooling water communication hole 186 and the upper cooling water communication hole 196 according to the steering angle θ1. Column A in FIG. 11 shows the positional relationship (hereinafter simply referred to as "positional relationship") between the lower cooling water communication hole 186 and the upper cooling water communication hole 196 when the steering angle θ1 is 0°, Column B in FIG. 11 shows the positional relationship when the steering angle θ1 is 15°, and column C in FIG. 11 shows the positional relationship when the steering angle θ1 is 30°. Column D in FIG. 12 shows the positional relationship when the steering angle θ1 is 45°, column E in FIG. 12 shows the positional relationship when the steering angle θ1 is 90°, and column F in FIG. The column shows the positional relationship when the rudder angle θ1 is 120°, the G column in FIG. 12 shows the positional relationship when the rudder angle θ1 is 180°, and the H column in FIG. shows the positional relationship when the steering angle θ1 is 210.5°. Note that the steering angle θ1 here means the steering angle when turning to the right. Further, as shown in FIGS. 11 and 12, in the present embodiment, the plurality of lower cooling water communication holes 186 formed in the lower component member 180 include at least two lower cooling water communication holes 186 having different opening areas. include. Further, the plurality of lower cooling water communication holes 186 are arranged unevenly along the circumferential direction around the steering axis As. Further, the opening area of the upper cooling water communication hole 196 formed in the upper component member 190 is larger than the opening area of the lower cooling water communication hole 186.

As shown in FIGS. 11 and 12, four lower cooling water communication holes 186 are formed in the lower component 180. The four lower cooling water communication holes 186 are arranged along the circumferential direction around the steering axis As. When the steering angle θ1 is 0° (see column A in FIG. 11), one of the four lower cooling water communication holes 186 (hereinafter referred to as "first lower cooling water communication hole 186a") is directed forward. The other one (hereinafter referred to as "second lower cooling water communication hole 186b") opens to the right, and the other one (hereinafter referred to as "third lower cooling water communication hole 186c") opens to the right. is opened rearward, and the other one (hereinafter referred to as "fourth lower cooling water communication hole 186d") is opened diagonally rearward to the left. Thus, in this embodiment, the second lower cooling water communication hole 186b and the fourth lower cooling water communication hole 186d are arranged asymmetrically in the circumferential direction with respect to the position of the first lower cooling water communication hole 186a. ing. Further, the flow path area (area of the cross section perpendicular to the stretching direction) of the first lower cooling water communication hole 186a is larger than the flow path area of the remaining three lower cooling water communication holes 186.

Further, in this embodiment, a groove-like flow path 187 is formed on the outer peripheral surface of the cylindrical portion 182 of the lower component member 180 so as to communicate the four lower cooling water communication holes 186 with each other. However, the groove-like flow path 187 is not provided between the third lower cooling water communication hole 186c and the fourth lower cooling water communication hole 186d. The lower cooling water flow path CCl communicates with the upper cooling water flow path CCu via the lower cooling water communication hole 186, and also communicates with the upper cooling water flow path CCu via the groove-shaped flow path 187.

FIG. 13 is an explanatory diagram showing the cooling water passage communication area Sc according to the steering angle θ1 in the outboard motor 100 of the present embodiment. As shown in FIG. 13, when the steering angle θ1 is 0° (see column A in FIG. 11), the entire first lower cooling water communication hole 186a communicates with the upper cooling water communication hole 196, and the cooling water flow path is connected. The area Sc becomes the maximum value C0. Note that the maximum value C0 of the cooling water passage communication area Sc is the cooling water passage communication area necessary to supply a sufficient amount of cooling water to cool the engine 120 driven at the maximum rotation speed (for example, 6000 rpm). It is set to a value larger than the first value C1 which is Sc.

When steering to the right, when the steering angle θ1 is greater than 0° and less than about 42° (see columns B and C in FIG. 11), the first lower cooling water communication hole 186a communicates with the upper cooling water communication hole 196. However, the communication area gradually decreases as the steering angle θ1 increases. In this embodiment, when the steering angle θ1 becomes larger than about 15°, the cooling water passage communication area Sc falls below the first value C1 described above. Furthermore, when the steering angle θ1 becomes approximately 42°, the cooling water passage communication area Sc supplies a sufficient amount of cooling water to cool the engine 120 driven at a medium rotation speed (for example, 3000 rpm). It becomes equal to the second value C2, which is the cooling water flow passage communication area Sc required for this.

When steering to the right, when the steering angle θ1 is greater than about 42° and less than about 55° (see column D in FIG. 11), none of the lower cooling water communication holes 186 communicates with the upper cooling water communication holes 196. . Therefore, in this state, the lower cooling water flow path CCl communicates with the upper cooling water flow path CCu only via the grooved flow path 187, and the cooling water flow path communication area Sc becomes equal to the communication area via the grooved flow path 187. .

When steering to the right, when the steering angle θ1 is greater than about 55° and less than about 110° (see column E in FIG. 12), the second lower cooling water communication hole 186b communicates with the upper cooling water communication hole 196. . More specifically, the communication area between the second lower cooling water communication hole 186b and the upper cooling water communication hole 196 is such that the steering angle θ1 increases when the steering angle θ1 is larger than about 55° and less than about 72°. In the range where the rudder angle θ1 is larger than about 72° and less than about 107°, it is constant regardless of the rudder angle θ1, and when the rudder angle θ1 is larger than about 107° and less than about 110°. In the range of , it gradually decreases as the steering angle θ1 increases.

When steering to the right, when the steering angle θ1 is greater than about 110° and less than about 160° (see column F in FIG. 12), none of the lower cooling water communication holes 186 communicates with the upper cooling water communication holes 196. . Therefore, in this state, the lower cooling water flow path CCl communicates with the upper cooling water flow path CCu only via the grooved flow path 187, and the cooling water flow path communication area Sc becomes equal to the communication area via the grooved flow path 187. .

When steering to the right, when the steering angle θ1 is greater than about 160° and less than 210.5° (see column G in FIG. 12), the third lower cooling water communication hole 186c communicates with the upper cooling water communication hole 196. do. More specifically, the communication area between the third lower cooling water communication hole 186c and the upper cooling water communication hole 196 is such that the steering angle θ1 increases when the steering angle θ1 is larger than about 160° and less than about 163°. The amount increases gradually. Therefore, in this steering angle range, as the steering angle θ1 increases, the cooling water passage communication area Sc gradually increases. Further, in a range where the steering angle θ1 is greater than about 163° and less than about 197°, the communication area between the third lower cooling water communication hole 186c and the upper cooling water communication hole 196 is constant regardless of the steering angle θ1. It is. However, when the steering angle θ1 exceeds approximately 163° in right steering, the portion of the lower component 180 where the groove-like flow path 187 is not formed (the third lower cooling water communication hole 186c and the fourth lower cooling water communication hole 186d) comes to face the upper cooling water communication hole 196. Therefore, in a range where the steering angle θ1 is greater than about 163° and less than about 197°, the cooling water passage communication area Sc gradually decreases as the steering angle θ1 increases. Further, in a range where the steering angle θ1 is larger than about 197° and less than 210.5°, the communication area between the third lower cooling water communication hole 186c and the upper cooling water communication hole 196 increases as the steering angle θ1 increases. It gradually decreases. Therefore, in this steering angle range, as the steering angle θ1 increases, the cooling water flow passage communication area Sc becomes steeper (larger slope than when the steering angle θ1 is greater than about 163° and less than about 197°). Decrease gradually. In this embodiment, when the steering angle θ1 becomes larger than about 177°, the cooling water passage communication area Sc falls below the second value C2 described above.

When the steering angle θ1 becomes 210.5° in right steering (see column H in FIG. 12), none of the lower cooling water communication holes 186 communicates with the upper cooling water communication holes 196. Further, the groove-like flow path 187 also does not communicate with the upper cooling water communication hole 196. Therefore, in this state, the cooling water passage communication area Sc becomes zero.

In this way, the cooling water passage CC of the outboard motor 100 of the present embodiment is generally configured such that the larger the steering angle θ1 is, the smaller the cooling water passage communication area Sc is. In other words, in the upper cooling water passage CCu and the lower cooling water passage CCl, when the steering angle θ1 is the first steering angle value, the cooling water passage communication area Sc becomes the first area value, and when the steering angle θ1 is the above-mentioned value, the cooling water passage communication area Sc becomes the first area value. The cooling water passage communication area Sc is configured to take a second area value smaller than the first area value when the second steering angle value is larger than the first steering angle value.

As shown in FIG. 13, in the case of steering to the left, the cooling water passage communication area Sc changes in accordance with the change in the steering angle θ1, as in the case of steering to the right. However, as described above, the second lower cooling water communication hole 186b and the fourth lower cooling water communication hole 186d are arranged asymmetrically in the circumferential direction with respect to the position of the first lower cooling water communication hole 186a. Therefore, the manner in which the cooling water passage communication area Sc changes in response to a change in the steering angle θ1 when steering to the left is the same as the manner in which the cooling water passage communication area Sc changes in response to a change in the steering angle θ1 in turning to the right. isn't it.

As described above, in the outboard motor 100 of the present embodiment, the upper housing 118u has an upper exhaust port EPu and an upper exhaust passage ECu communicating with the engine 120 is formed, and the lower housing 118l A lower exhaust flow path ECl having a lower exhaust port EPl is formed in the lower exhaust flow path ECl, and the upper exhaust flow path ECu and the lower exhaust flow path ECl are in a communication state in which they communicate with each other according to the steering angle θ1 of the steering mechanism 170. and a non-communicating state in which they do not communicate with each other. Therefore, according to the outboard motor 100 of the present embodiment, by providing an annular communication passage in one of the upper exhaust passage ECu and the lower exhaust passage ECl, the two are always communicated regardless of the steering angle θ1. The space required for forming the exhaust flow path EC can be reduced compared to the above, and the degree of freedom in layout of the outboard motor 100 can be improved, and the size and weight of the outboard motor 100 can be reduced. Can be done.

B. Variant:
The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified into various forms without departing from the gist thereof. For example, the following modifications are also possible.

The configuration of the ship 10 of the above embodiment is just an example, and can be modified in various ways. For example, in the above embodiment, by making the lower exhaust communication hole 184 a hole (elongated hole) extending along a part of the circumferential direction around the steering axis As, the lower exhaust communication hole 184 The communication area between the upper exhaust communication hole 194 and the exhaust flow passage communication area Se is configured to change, but on the other hand, by making the upper exhaust communication hole 194 a long hole, the lower exhaust gas is changed according to the steering angle θ1. A configuration may be adopted in which the communication area between the communication hole 184 and the upper exhaust communication hole 194, and furthermore, the communication area Se of the exhaust flow path changes.

The exhaust mode (FIG. 10) according to the rotation speed of the engine 120 and the steering angle θ1 in the above embodiment is merely an example, and can be modified in various ways. For example, in the above embodiment, idle exhaust is performed when the rotation speed R1 of the engine 120 is less than or equal to a predetermined value (for example, 2000 rpm) or when the steering angle θ1 is greater than or equal to a predetermined value (for example, 25°), and the engine 120 When the rotation speed R1 is larger than the predetermined value and the steering angle θ1 is smaller than the predetermined value, idle exhaust and boss exhaust are performed. On the other hand, when the rotation speed R1 of the engine 120 is determined based on the rotation speed R1 of the engine 120, and the idle exhaust is performed when the rotation speed R1 of the engine 120 is below the predetermined value, and when the rotation speed R1 of the engine 120 is larger than the predetermined value, An idle exhaust and a boss exhaust may be performed. Alternatively, it may be determined based on the steering angle θ1, and idle exhaust is performed when the steering angle θ1 is greater than or equal to a predetermined value, and idle exhaust and boss exhaust are performed when the steering angle θ1 is smaller than the predetermined value. .

In the embodiment described above, the switching valve 102 is provided in the exhaust flow path EC, but a switching mechanism other than the switching valve 102 may be provided. Furthermore, the switching valve 102 may be omitted. Further, in the above embodiment, the lower exhaust port EPl is provided near the center of the propeller 112, but the lower exhaust port EPl may be provided at another position (for example, a position above the propeller 112). In addition to the upper exhaust port EPu and the lower exhaust port EPl, the exhaust flow path EC also includes other exhaust ports (for example, an exhaust port located between the upper exhaust port EPu and the lower exhaust port EPl along the vertical direction). ) may be provided.

In the above embodiment, among the four lower cooling water communication holes 186 formed in the lower component 180, some of the lower cooling water communication holes 186 are asymmetrical in the circumferential direction with respect to the first lower cooling water communication hole 186a. However, all the lower cooling water communication holes 186 may be arranged symmetrically in the circumferential direction with respect to the first lower cooling water communication hole 186a, as in a modification shown in FIG. Column A in FIG. 14 shows the positional relationship (hereinafter simply referred to as "positional relationship") between the lower cooling water communication hole 186 and the upper cooling water communication hole 196 when the steering angle θ1 is 0° in the modified example. ), column B in FIG. 14 shows the positional relationship when the steering angle θ1 is 90° when steering to the right, and column C in FIG. 14 shows the positional relationship when the steering angle θ1 is 180°. It shows the positional relationship when .

In the embodiment described above, by providing a plurality of lower cooling water communication holes 186 in the lower structural member 180 that constitutes the lower storage body 118l, the cooling water flow passage communication area Sc changes according to the steering angle θ1. On the other hand, by providing a plurality of upper cooling water communication holes 196 in the upper component member 190 constituting the upper storage body 118u, the cooling water passage communication area Sc may be changed according to the steering angle θ1.

The aspect of the cooling water passage communication area Sc in the above embodiment (FIG. 13) is just an example, and can be modified in various ways. For example, in the above embodiment, the cooling water flow passage communication area Sc is configured to change according to the steering angle θ1, but instead of the steering angle θ1, or in addition to the steering angle θ1, depending on the rotation speed R1 of the engine 120. It is also possible to adopt a configuration in which the cooling water passage communication area Sc changes. Such a configuration includes, for example, an opening/closing mechanism (for example, in accordance with the rotation speed R1 of the engine 120) that opens and closes between the cooling water pump and the engine 120 (in response to water pressure correlated to the rotation speed R1 of the engine 120). This can be achieved by providing a valve, etc.).

In the above embodiment, the steering axis As of the steering mechanism 170 is the central axis of the drive shaft 132, but even if the steering axis As of the steering mechanism 170 is a different axis from the central axis of the drive shaft 132. good. Further, in the embodiment described above, the outboard motor 100 includes the steering mechanism 170 that rotates the outboard motor lower unit LU around the steering axis As. In addition, a second steering mechanism that rotates the entire outboard motor main body 110 around a second steering axis may be provided.

10: Ship 100: Outboard motor 102: Switching valve 108: Rotating member 109: Through hole 110: Outboard motor body 111: Propeller shaft 112: Propeller 114: Cowl 114a: Upper cowl 114b: Lower cowl 116: Casing 116a: Upper part Casing 116b: Lower casing 118l: Lower housing 118u: Upper housing 120: Engine 124: Crankshaft 130: Transmission mechanism 132: Drive shaft 134: Shift mechanism 150: Suspension device 152: Clamp bracket 152a: Support part 156: Connection bracket 160: Tilt axis 170: Steering mechanism 180: Lower component 181: Flat plate portion 182: Cylindrical portion 183: Through hole 184: Lower exhaust communication hole 186: Lower cooling water communication hole 187: Groove-shaped channel 190: Upper structure Components 191: Flat plate portion 192: Cylindrical portion 193: Box portion 194: Upper exhaust communication hole 196: Upper cooling water communication hole 200: Hull 202: Hull main body portion 204: Living space 206: Space 210: Transom 220: Partition wall 240: Pilot seat 250: Control device 252: Steering wheel 254: Shift/throttle lever 255: Joystick 256: Monitor 258: Input device Ac: Rotation axis Ap: Rotation axis As: Steering axis At: Tilt axis CC: Cooling water flow path CCl: Lower cooling water flow path CCu: Upper cooling water flow path EC: Exhaust flow path ECl: Lower exhaust flow path ECu: Upper exhaust flow path EPl: Lower exhaust port EPu: Upper exhaust port LU: Outboard motor lower unit UU: Outboard Machine upper unit WI: Water intake

Claims (18)

An outboard motor,
engine and
propeller shaft,
a propeller attached to the propeller shaft;
a transmission mechanism that transmits rotation of the engine to the propeller shaft;
an upper container housing at least a portion of the engine;
a lower container housing at least a portion of the propeller shaft;
a steering mechanism that rotates the lower housing relative to the upper housing about a steering axis;
Equipped with
The upper housing body has an upper exhaust port and an upper exhaust flow path that communicates with the engine,
A lower exhaust flow path having a lower exhaust port is formed in the lower housing,
The upper exhaust flow path and the lower exhaust flow path are configured to switch between a communicating state in which they communicate with each other and a non-communicating state in which they do not communicate with each other, depending on the steering angle of the steering mechanism. ,Outboard motor. The outboard motor according to claim 1,
The upper exhaust flow path and the lower exhaust flow path are in the communicating state when the steering angle is less than or equal to a predetermined value, and are in the non-communicating state when the steering angle is larger than the predetermined value. It consists of an outboard motor. The outboard motor according to claim 1,
One of the upper exhaust flow path and the lower exhaust flow path has a first communication port,
The other of the upper exhaust flow path and the lower exhaust flow path is a second communication port extending along a part of the circumferential direction around the steering shaft, and in the communication state, the second communication port is connected to the first communication port. An outboard motor having a second communication port that communicates with the first communication port and that does not communicate with the first communication port in the non-communication state. The outboard motor according to claim 3,
The second communication port rotates relative to the first communication port around the steering shaft as the steering mechanism turns the outboard motor. The outboard motor according to claim 3,
In the outboard motor, the area of the second communication port is larger than the area of the first communication port. The outboard motor according to claim 5,
In the communication state, the outboard motor includes the first communication port entirely included in the second communication port when viewed in a vertical direction. The outboard motor according to claim 1, further comprising:
An outboard motor comprising a switching mechanism that restricts the flow of exhaust gas from the upper exhaust flow path to the lower exhaust flow path when the rotational speed of the engine is below a predetermined value. The outboard motor according to claim 7,
In an outboard motor, the switching mechanism is a switching valve. The hull and
The outboard motor according to claim 1, which is attached to the rear of the hull;
A ship equipped with An outboard motor,
engine and
propeller shaft,
a propeller attached to the propeller shaft;
a transmission mechanism that transmits rotation of the engine to the propeller shaft;
an upper container housing at least a portion of the engine;
a lower container housing at least a portion of the propeller shaft;
a steering mechanism that rotates the lower housing body around a steering axis with respect to the upper housing body;
Equipped with
The upper housing body has an upper exhaust port and an upper exhaust flow path that communicates with the engine,
A lower exhaust flow path having a lower exhaust port is formed in the lower housing,
The upper exhaust flow path and the lower exhaust flow path are in a communicating state in which they communicate with each other and in a non-communicating state in which they do not communicate with each other, depending on at least one of the steering angle of the steering mechanism and the rotation speed of the engine; An outboard motor configured to switch between The outboard motor according to claim 10,
The upper exhaust flow path and the lower exhaust flow path are in the communicating state when the steering angle is less than or equal to a predetermined value, and are in the non-communicating state when the steering angle is larger than the predetermined value. It consists of an outboard motor. The outboard motor according to claim 10,
One of the upper exhaust flow path and the lower exhaust flow path has a first communication port,
The other of the upper exhaust flow path and the lower exhaust flow path is a second communication port extending along a part of the circumferential direction around the steering shaft, and in the communicating state, the other communicates with the first communication port. An outboard motor, the outboard motor having a second communication port that communicates with the first communication port and that does not communicate with the first communication port in the non-communication state. The outboard motor according to claim 12,
In an outboard motor, the second communication port rotates relative to the first communication port around the steering shaft as the steering mechanism turns the steering mechanism. The outboard motor according to claim 12,
In the outboard motor, the area of the second communication port is larger than the area of the first communication port. The outboard motor according to claim 14,
In the communication state, the outboard motor includes the first communication port entirely included in the second communication port when viewed in a vertical direction. The outboard motor according to claim 10, further comprising:
An outboard motor comprising a switching mechanism that restricts the flow of exhaust gas from the upper exhaust flow path to the lower exhaust flow path when the rotational speed of the engine is below a predetermined value. The outboard motor according to claim 16,
In an outboard motor, the switching mechanism is a switching valve. The hull and
The outboard motor according to claim 10, which is attached to the rear of the hull;
A ship equipped with

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