JP2652052B2 - Ship propulsion device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine vessel propulsion device that can change the pitch of a propeller by a hydraulic mechanism.

<Prior Art> Conventionally, in a propulsion device for a ship, a so-called variable pitch propeller capable of changing a propulsion speed by changing a twist angle (pitch) of a propeller has been proposed (Japanese Patent Laid-Open Publication No. Sho.
Nos. 54-146394, 60-88696 and 56-14798. The use of the variable pitch propeller is advantageous because the propulsion speed can be changed while operating the prime mover for rotating the propeller under certain conditions.

Each of the above techniques is configured so that the pitch of the propeller can be changed by linearly driving the crosshead by linear driving means such as a hydraulic cylinder.

In each of the above technologies, a clutch for connecting and disconnecting power for propelling a ship or a switch for switching pressure oil supplied to a hydraulic cylinder is provided inside a casing containing a propeller shaft and a hydraulic cylinder. Means are not housed.

<Problems to be Solved by the Invention> In the above-mentioned prior art, when the hull is large to some extent, such as an inboard / outboard motor or an inboard motor, the clutch and the hydraulic pressure switching means are housed inside the hull and these clutches are used. And the switching means can be remotely controlled.

However, in an outboard motor in which an engine, a power transmission system, and the like are housed in a single casing, it is necessary to house the clutch, the switching means, and the like in the casing and to make the overall structure compact. Even for an inboard / outboard motor or an inboard motor, it is advantageous to make the structure of the marine vessel propulsion device compact from the viewpoint of improving the loading efficiency of the hull.

An object of the present invention is to switch between connection and disconnection of power for propelling a ship and switching of pressure oil for changing the pitch of a propeller.
An object of the present invention is to provide a ship propulsion device which can be operated by a rod and has a compact structure.

<Means for Solving the Problems> In order to solve the above problems, a marine vessel propulsion apparatus of the present invention includes a propeller for propelling a marine vessel and rotates a pitch changing means for changing a pitch of the propeller. Power transmission means including a propeller means to be inserted as much as possible, a propeller shaft transmitting power for propelling a ship to the propeller means, a clutch means provided in the power transmission means, and a power transmission means provided in the power transmission means. Linear drive means driven by pressure oil, transmission means for transmitting the reciprocating linear motion of the linear drive means to the pitch changing means, and switching means for switching the supply direction of the pressure oil supplied to the linear drive means. A marine propulsion device having switching means, comprising a first cam for operating the clutch means and a second cam for operating the switching means. And a rod.

In the marine vessel propulsion device, the first cam operates the clutch means in accordance with the axial movement of the rod, and the second cam operates the switching means in accordance with the rotation of the rod. It is preferred that

<Operation> According to the above-described means, power can be transmitted to the propeller means via the power transmission means, and the propeller can be driven to drive the propeller. Further, the power transmitted to the propeller means can be connected and disconnected by the clutch means provided in the power transmission means, so that the boat can be propelled or stopped.

Changing the pitch of the propeller by driving the linear drive means provided on the power transmission means with the pressure oil and transmitting the reciprocating linear motion of the linear drive means to the pitch change means rotatably fitted to the propeller means. Can be done. Further, by switching the pressure oil supplied to the linear driving means by the switching means, the direction of movement of the linear driving means can be selected, and thereby the pitch of the propeller can be changed to a desired value.

Since a rod having a cam for operating the clutch means and the pressure oil switching means is provided, it is possible to operate the clutch means and the switching means simultaneously or selectively by operating one rod. I can do it. The cam formed on the rod is preferably composed of a first cam mechanism that operates in accordance with the axial movement of the rod and a second cam mechanism that operates in accordance with the rotation of the rod.

Thus, the clutch means for connecting and disconnecting the propulsion power of the ship transmitted to the propeller means, and the switching means for switching the pressure oil supplied to the linear drive means for generating the power for changing the pitch of the propeller, Can be operated by one rod, and the boat propulsion device can be made compact.

<Embodiment> An embodiment of a ship propulsion device to which the above-described means is applied will be described below with reference to the drawings.

1 is an explanatory sectional view of the marine propulsion device, FIG. 2 is an II-II sectional view of FIG. 1, and FIGS. 3 (A) and 3 (B) are explanatory views of a clutch cam.

First, an outline of the overall configuration of the ship propulsion device will be described.

In the case of an outboard motor, it is arranged at the upper part of the casing, and in the case of an inboard / outboard motor or an inboard motor, the power of a motor such as an engine (not shown) arranged inside the hull is:
The power is transmitted from the vertical shaft 1 to the transmission shaft 2 constituting the power transmission means via the dog clutch 4. The power is transmitted from the transmission shaft 2 via the torque limiter 8 to the intermediate shaft 22 constituting the power transmission means, and further transmitted via the hydraulic cylinder 23 to the propeller shaft 25, and is transmitted to the propeller boss 30 attached to the shaft 25. Is transmitted. When the propeller boss 30 rotates, the propeller 32 supported by the boss 30 rotates to propel the ship.

In the power transmission path, a dog clutch 4 is provided on the outer periphery of the transmission shaft 2. This dog clutch 4
Is for connecting and disconnecting the power transmitted to the vertical shaft 1 to the transmission shaft 2 at all times. The torque limiter 8 is provided between the transmission shaft 2 and the intermediate shaft 22. This torque limiter 8 is for preventing the overload from being transmitted to the prime mover when an overload occurs in the path after the intermediate shaft 22. Further, between the intermediate shaft 22 and the propeller shaft 25, a hydraulic cylinder 23 serving as a linear drive means is provided.
Are formed, and the cylinder portion of the hydraulic cylinder 23 is configured as a coupling.

Thus, the power transmission means consists of the vertical shaft 1, the dog clutch
4, transmission shaft 2, torque limiter 8, intermediate shaft 22, and propeller shaft
Consists of 25.

A gear pump 17 is formed on the outer circumference of the transmission shaft 2, and is driven by a bevel gear 3 rotatably mounted on the shaft 2. The pressure oil generated by the gear pump 17 is supplied to the hydraulic cylinder 23 through the inside of the spool 20 provided through the transmission shaft 2 and the intermediate shaft 22 to linearly move the piston 24 in the axial direction. The movement of the piston 24 is converted into a rotational movement by a spiral spline 28. For this reason, the transmission sleeve 29 serving as the transmission means integrally formed with the screw spline 28 rotates, and this rotation is transmitted to the screw shaft 33 constituting the pitch changing means rotatably fitted to the propeller boss 30. . When the screw shaft 33 rotates, the crosshead 35 constituting the pitch changing means screwed to the screw shaft 33 moves in the axial direction, and the propeller 32 rotates the rotating shaft 34.
The propeller 32 is rotated about a, thereby changing the pitch of the propeller 32.

The spool 20 for selectively supplying pressure oil to the chambers 23 a and 23 b formed in the hydraulic cylinder 23 is driven by the cam plate 7. That is, the spool 20 is moved in the axial direction according to the shape of the cam plate 7 rotated by the clutch cam 6, and along with this movement, pressure oil is supplied to the hydraulic cylinder 23 to move the piston 24 in a desired direction. Thus, the pitch of the propeller 32 can be changed to a desired value.

 Next, the above components will be described in detail.

The vertical shaft 1 is a shaft for transmitting the power of an engine (not shown) to the transmission shaft 2, and is rotatably supported by the casing A. A bevel gear 1a is fixed to an end of the vertical shaft 1.

The transmission shaft 2 is arranged orthogonal to the vertical shaft 1.
At substantially the center of the transmission shaft 2, a bevel gear 3 which is always meshed with the bevel gear 1a is rotatably mounted between the transmission shaft 2 and the shaft 2 via a bearing.

A spline 2 a is formed on the front side of the transmission shaft 2, and a dog clutch 4 is mounted on the spline 2 a so as to be slidable in the axial direction of the transmission shaft 2. The dog clutch 4 is always urged in one direction (to the right in the figure) by a compression spring 4a attached to the outer periphery of the transmission shaft 2. A clutch pin 4c is fitted in a ring groove 4b formed on the outer periphery of the dog clutch 4. Claws 4d are formed on a surface of the dog clutch 4 facing the bevel gear 3.

The rod 5 is provided in parallel with the vertical axis 1. The rod 5 is configured to be rotatable by a lever (not shown) and to be slidable in the axial direction. FIGS. 3 (A) and 3 (B)
The clutch cam 6 configured as shown in FIG. That is, a spline 6a is formed at the tip of the clutch cam 6, and a cam surface serving as a first cam mechanism is formed on a central side surface.
6b is formed. A cam plate 7 serving as a second cam mechanism fitted in a groove formed in the casing A is provided on the spline 6a.
Are slidably mounted.

A clutch pin 4c is in contact with the cam surface 6b. Then, by moving the rod 5 in the direction of arrow a,
The clutch pin 4c is moved in the axial direction (left-right direction in the figure) of the pin 4c according to the shape of the cam surface 6b, whereby the dog clutch 4 is moved in the axial direction along the transmission shaft 2 to thereby engage the pawl 4d. Is engaged with or released from the pawl 3a formed on the bevel gear 3, and the transmission of the power of the vertical shaft 1 to the transmission shaft 2 is disconnected.

By operating the lever to rotate the rod 5 in the direction of arrow b, the cam plate 7 mounted on the spline 6a is rotated, and a spool 20 described later is rotated via a pin 21 abutting on the cam plate 7. Move in the axial direction and pressurized oil to hydraulic cylinder
By selectively supplying the chamber 23a or the chamber 23b, the transmission sleeve 29 is rotated, and the pitch of the propeller 32 is changed.

In the rod 5 configured as described above, when the rod 5 is moved in the direction of arrow a to connect and disconnect the dog clutch 4 and the bevel gear 3, the cam plate 7 can slide on the spline 6 a of the clutch cam 6. Rod 5
Does not affect the cam plate 7. When the rod 5 is rotated in the direction of the arrow b to change the pitch of the propeller 32, the cross-sectional shape of the cam surface 6b is changed as shown in FIG.
As shown in the figure, the rotation of the rod 5 does not affect the position of the clutch pin 4c which comes into contact with the cam surface 6b, since it is formed to have the same diameter in the circumferential direction.

When the rod 5 is simultaneously moved and rotated in the axial direction, the operation of the dog clutch 4 and the operation of the spool 20 can be performed simultaneously. Therefore, the connection and disconnection of the power by the dog clutch 4 and the change of the pitch of the propeller 32 can be performed simultaneously.

An inner collar 9 constituting a torque limiter 8 is fixed to a rear side portion of the transmission shaft 2 by a nut.
A friction member 10 made of a material having a large friction coefficient, such as rubber, is attached to the outer periphery of the inner collar 9. An outer collar 11 fixed to an intermediate shaft 22 by a nut is mounted on the outer periphery of the friction member 10.

As described above, the torque limiter 8 has the inner collar 9,
A friction member 10 and an outer collar 11 are used to transfer power from the transmission shaft 2 to the inner collar 9 and the friction member.
It is configured to be able to transmit to the intermediate shaft 22 by contact friction with the friction member 10 and contact friction between the friction member 10 and the outer collar 11.

The bearing case 12a that supports the transmission shaft 2 via the bevel gear 3 has a surface facing the torque limiter 8,
An oil seal 13a for sealing between the transmission shaft 2 and the case 12a is attached, and thereby a watertight oil chamber 14a is formed in the casing A. The oil chamber 14a is filled with lubricating oil for smoothly engaging the bevel gear 1a and the bevel gear 3 and sliding the dog clutch 4 with the transmission shaft 2. This lubricating oil also serves as hydraulic oil supplied to a hydraulic cylinder 23 described later.

An inner gear 15 is fixed to the boss side of the bevel gear 3. An outer gear 16 meshing with the inner gear 15 is provided on the bearing case 12a so as to be eccentric from the axis of the transmission shaft 2 and rotatable with respect to the bearing case 12a. Therefore, the outer gear 16 is driven by the inner gear 15, and these gears 15, 16 constitute a gear pump 17.

A passage 18 for the pressure oil generated by the gear pump 17 is formed in the bearing case 12a. A relief valve 19 is provided in the middle of the passage 18.
In this configuration, the pressure oil that has risen to a predetermined pressure or more can escape to the oil chamber 14a.

A through hole 2b is formed in the axis of the transmission shaft 2.
A spool 20 for selectively supplying pressure oil to the hydraulic cylinder 23 and a pin 21 having one end in contact with the spool 20 and the other end in contact with the cam plate 7 are provided in the through hole 2b in the axial direction. It is slidably housed. Therefore, operate the lever,
When the cam plate 7 is rotated in the direction of arrow b by the clutch cam 6, the spool 20 is moved in the axial direction (left and right directions in the figure) via the pin 21 according to the outer peripheral shape of the cam plate 7. is there.

The intermediate shaft 22 has an outer collar 11 constituting the torque limiter 8 fixed to a front side portion, and a cylinder wall 22a constituting a hydraulic cylinder 23 formed at a rear end portion. Also, inside the intermediate shaft 22, a spool 20 and a piston
A through hole 22b having a step portion for accommodating the 24 shaft 24a is formed. The intermediate shaft 22 is rotatably supported by a bearing housed in a bearing case 12b at substantially the center.

The cylinder wall 22a and a flange 25a formed on the front side of a propeller shaft 25, which will be described later, are fastened by bolts, thereby constituting the hydraulic cylinder 23. The hydraulic cylinder 23 is configured to have a function as a coupling. Therefore, the power transmitted from the transmission shaft 2 via the torque limiter 8 is transmitted to the hydraulic cylinder 23
Is transmitted to the propeller shaft 25 via the

The bearing case 12b has an intermediate shaft
An oil seal 13b is provided for sealing the space between the oil seal 22 and the oil seal 22. The oil seal 13b and the bearing case 1
A cooling chamber 26 for cooling heat generated in the torque limiter 8 is formed between the oil chamber 13a and the oil seal 13a. Above the cooling chamber 26, the water taken in from intake A ₁ formed in the casing A is introduced through the intake port A _2. Further, a water intake pipe of a water pump (not shown) is connected to the cooling chamber 26, and the engine and the like are cooled by water pumped by the pump.

A piston 24 is housed inside the hydraulic cylinder 23. In the center of the piston 24, a through hole 22 of the intermediate shaft 22 is provided.
A shaft 24a that fits with b, and a rod 24b that fits with a hole 25e of the propeller shaft 25 are formed to protrude. A hole 24c for fitting the spool 20 is formed inside the piston 24, and conduction holes 24d and 24e for conducting the hole 24c and the cylinder chambers 23a and 23b are formed.

A shifter 27 is mounted on the rod 24b of the piston 24. This shifter 27 is formed by forming a linear spline on the inner surface and forming a spiral spline on the outer surface, and the reciprocating linear motion of the piston 24 together with the spiral spline 28 provided on the propeller shaft 25 side. This is converted into rotational motion.

The propeller shaft 25 has a flange 25a constituting the hydraulic cylinder 23 formed on the front side, and a spline 25b formed near the flange 25a. A screw portion 25c is formed at the rear end of the propeller shaft 25, and a spline 25d is formed continuously with the screw portion 25c. Propeller shaft 2
Inside of 5, a hole 25e for accommodating the rod 24b of the piston 24 is formed. The propeller shaft 25 is rotatably supported by a bearing housed in the bearing case 12c via a transmission sleeve 29.

On the rear side of the bearing case 12c, an oil seal for sealing between the case 12c and the transmission sleeve 29 is provided.
An oil chamber 14b is formed between the seal 13c and the oil seal 13b.

A shifter 27 is mounted on a spline 25b formed on the front side of the propeller shaft 25 so as to be non-rotatable and slidable in the axial direction. On the outer periphery of the propeller shaft 25, a transmission sleeve 29 provided with a spiral spline 28 for engaging with the shifter 27 is fitted. A propeller boss 30 is mounted on a spline 25d formed on the rear side of the propeller shaft 25. The boss 30 is fixed to the propeller shaft 25 by screwing a nut 31 into a screw portion 25c.

A spline 29a that engages with a spline 33b of the screw shaft 33 described later is formed on the inner surface of the rear end of the transmission sleeve 29.

As shown in FIG. 2, the propeller boss 30 is provided with a predetermined number (three in this embodiment) of propellers 32 mounted around the propeller bosses 30 and forms a sleeve changing means for changing the pitch of the propellers 32. The screw shaft 33 is rotatably fitted and attached to the propeller shaft 25.

Inside the propeller boss 30, there are formed chambers 30a corresponding to the number of the propellers 32. A crank 34 is rotatably fitted in the chamber 30a. The crank 34 is provided such that a shaft 34a serving as a rotation center of the crank 34 is orthogonal to the axis of the propeller shaft 25. And this crank 34
, A propeller 32 is fastened by bolts 32a.

A projection 34b is formed inside the crank 34, that is, at a position eccentric from the shaft 34a on the propeller shaft 25 side.
The projection 34b is fitted in a groove 35a formed in the crosshead 35 that is screwed with the screw shaft 33. The protrusion 34b is driven by a crosshead 35 that moves in the axial direction with the rotation of the screw shaft 33, whereby the crank 34 rotates about the shaft 34a, and changes the pitch of the propeller 32.

At a predetermined position on the outer periphery of the screw shaft 33, a screw portion 33a having a length capable of setting the pitch of the propeller 32 to a desired value is formed. On the front side of the screw shaft 33, a spline 33b that engages with a spline 29a formed on the transmission sleeve 29 is formed.

At both open ends of the chamber 30a formed in the propeller bolt 30,
Oil seals 13d and 13e for sealing between the boss 30 and the screw shaft 33 are mounted, whereby the chamber 30a has a watertight structure. The chamber 30a is filled with lubricating oil for screwing the screw shaft 33 and the crosshead 35 and smoothly rotating the propeller 32 with respect to the propeller boss 30. In the figure, 30b is an O-ring groove.

Next, the operation of the marine vessel propulsion device configured as described above will be described.

First, the vertical shaft 1 is constantly rotating by power generated by an engine or the like. Therefore, the bevel gear 3 meshed with the bevel gear 1a also rotates at all times, thereby causing the inner gear to rotate.
The gear pump 17 constituted by the outer gear 15 and the outer gear 16 always operates to generate pressure oil using the lubricating oil in the oil chamber 14a as operating oil. When the pitch of the propeller 32 is not changed, that is, when the spool 20 is at the neutral position, the pressure oil circulates through the relief valve 19 and the oil chamber 14a.

When the ship is propelled, the lever 5
By pressing the clutch cam 6 in the direction of the arrow a.
The clutch pin 4c is moved in the axial direction (to the left in the figure) according to the shape of the cam surface 6b of the clutch cam 6. With the movement of the clutch pin 4c, the dog clutch 4 moves in the axial direction.
The power of the vertical shaft 1 is transmitted to the transmission shaft 2 by meshing with the claw 3a of the transmission.

The power is transmitted from the transmission shaft 2 to the intermediate shaft 22 via the torque limiter 8, and further transmitted to the propeller shaft 25 via a hydraulic cylinder 23 composed of the intermediate shaft 22 and a propeller shaft 25. Then, the propeller boss 30 attached to the propeller shaft 25 rotates, whereby the propeller attached to the boss 30 is rotated.
32 rotates to propel the ship.

When the pitch of the propeller 32 is not changed, that is, when the boat is propelled at a constant speed, the above state may be maintained.

In the above operation state, no pressure oil is supplied to the hydraulic cylinder 23, and the piston 24 maintains a fixed position. Therefore, the rotation of the propeller shaft 25 is transmitted to the transmission sleeve 29 from the spline 25b via the shifter 27 and the spiral spline. Therefore, the propeller shaft 25 and the transmission sleeve 29 rotate at the same rotation speed. Therefore, the screw shaft 33 to which the rotation of the transmission sleeve 29 is transmitted has the same rotation as the propeller boss 30, and the screw 33 does not generate a relative speed difference with respect to the propeller boss 30, so that the propeller 32 has a constant pitch. Hold.

To change the pitch of the propeller 32, the lever is rotated to rotate the rod 5, and the rotation causes the cam plate 7 to rotate in the direction of arrow b. In accordance with the rotation of the cam plate 7, the pin 21 which comes into contact with the cam plate 7 moves in the axial direction (left-right direction in the drawing), and accordingly, the spool 20 moves in the axial direction. At this time, the pressure oil generated by the gear pump 17 passes through a through hole inside the spool 20 and a conduction hole formed in the piston 24.
It is selectively supplied to the chamber 23a or 23b of the hydraulic cylinder 23 through 24a or 24b.

For example, when the pressure oil is supplied to the chamber 23a of the hydraulic cylinder 23, the piston 24 moves to the left in the drawing. With the movement of the piston 24, the shifter 27 is moved leftward by the linearly formed spline 25b. The linear movement of the shifter 27 is converted into a rotational movement by the spiral spline 28, and the transmission sleeve 29 attached to the spiral spline 28 is rotated according to the spiral shape.
Accordingly, the rotation of the transmission sleeve 29 has a state where the rotation speed is increased or reduced with respect to the rotation of the propeller shaft 25, that is, has a relative rotation.

The rotation of the transmission sleeve 29 is transmitted to the screw shaft 33 fitted to the propeller boss 30 via splines 29a and 33b, and rotates the screw shaft 33 at the same rotation speed as the transmission sleeve 29. Therefore, the screw shaft 33 has the propeller shaft 25 and the propeller boss 3
As a result, the cross head 35 screwed to the screw shaft 33 moves in the axial direction of the propeller shaft 25. And, with the movement of the crosshead 35,
The protrusion 3 of the crank 34 fitted in the groove 35a of the crosshead 35
4b is driven to rotate the crank 34 about the shaft 34a. The rotation of the crank 34 causes the propeller 32 to rotate about the shaft 34a, thereby changing the pitch of the propeller 32.

When the rotation of the lever is stopped when the pitch of the propeller 32 reaches a desired value, the axial movement of the piston 24 causes the through-holes formed in the spool 20 and the through-holes 24d, 24e.
And the supply of the pressure oil to the chamber 23a of the hydraulic cylinder 23 is stopped. Therefore, the movement of the piston 24 stops, and the pitch of the propeller 32 maintains the position.

In the above embodiment, the chamber formed in the propeller boss 30
Since there is no insert from outside in 30a, the internal volume is constant. As a result, there is no change in the internal pressure, and therefore, various problems caused by the change in the internal pressure, such as leakage of the lubricating oil or a change in the power for driving the screw shaft 33, do not occur. It becomes possible to drive with.

<Effects of the Invention> As described in detail above, according to the marine vessel propulsion apparatus of the present invention, power can be transmitted to the propeller means via the power transmission means, and the marine vessel can be propelled by driving the propeller. . Further, the power transmitted to the propeller means can be connected and disconnected by the clutch means provided in the power transmission means, so that the boat can be propelled or stopped.

Further, the linear drive means is driven by the pressure oil, and the reciprocating linear motion of the linear drive means is transmitted to the pitch change means rotatably fitted to the propeller means, whereby the pitch of the propeller can be changed. Further, by switching the pressure oil supplied to the linear driving means by the switching means, it is possible to select the direction of movement of the linear driving means, thereby changing the pitch of the propeller to a desired value.

Since a rod having a cam for operating the clutch means and the pressure oil switching means is provided, by operating one rod, the clutch means and the switching means can be operated simultaneously or selectively. . The cam formed on the rod is preferably composed of a first cam mechanism that operates in accordance with the axial movement of the rod and a second cam mechanism that operates in accordance with the rotation of the rod.

Thus, the clutch means for connecting and disconnecting the propulsion power of the ship transmitted to the propeller means, and the switching means for switching the pressure oil supplied to the linear drive means for generating the power for changing the pitch of the propeller, Can be operated by a single rod, so that the boat propulsion device can be made compact.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view of a ship propulsion device, and FIG.
FIGS. 3 (A) and 3 (B) are explanatory views of the clutch cam. A is a casing, 1 is a vertical shaft, 1a and 3 are bevel gears, 2 is a transmission shaft, 4 is a dog clutch, 5 is a rod, 6 is a clutch cam, 6a is a spline, 6b is a cam surface, 7 is a cam plate, 8
Is a torque limiter, 9 is an inner collar, 10 is a friction member, 11 is an outer collar, 14a and 14b are oil chambers, 15 is an inner gear, 16 is an outer gear, 17 is a gear pump, 20 is a spool, 21 is a pin, and 22 is a pin. Intermediate shaft, 23 is a hydraulic cylinder, 24 is a piston, 25 is a propeller shaft, 27 is a shifter, 28
Is a spiral spline, 29 is a transmission sleeve, 30 is a propeller boss, 32 is a propeller, 33 is a screw shaft, 34 is a crank, 34a is a shaft, and 35 is a crosshead.

Claims (2)

(57) [Claims] 1. A propeller means for mounting a propeller for propelling a boat and rotatably inserting pitch changing means for changing a pitch of the propeller, and a power for propelling the boat to the propeller means. Power transmission means including a propeller shaft for transmitting power, a clutch means provided in the power transmission means, a linear drive means provided in the power transmission means and driven by pressure oil, and a reciprocating linear movement of the linear drive means And a switching means for switching a supply direction of the pressure oil supplied to the linear drive means, the transmission means for transmitting the pressure change to the pitch changing means, and the switching means for operating the clutch means. A boat propulsion device comprising a rod having a first cam and a second cam for operating the switching means. 2. A marine vessel propulsion device according to claim 1, wherein the first cam operates the clutch means in accordance with the axial movement of the rod, and the second cam operates the clutch of the rod. A marine vessel propulsion device, wherein the switching means is operated according to rotation.