This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2019-200572, filed on Nov. 5, 2019, the entire contents of which are incorporated herein by reference.
The present invention relates to an outboard engine.
Among outboard engines, there is known an outboard engine including a clamp bracket that is mounted to a hull, and a swivel bracket that swings forward and backward with a clamp shaft supported by the clamp bracket as a fulcrum. The swivel bracket is mounted to an outboard engine main body, and swings forward and backward with the outboard engine main body, with the clamp shaft as the fulcrum. A steering shaft extending in an up-down direction is inserted into the swivel bracket. The steering shaft rotates (swings) integrally with the steering bracket and the outboard engine main body.
Conventionally, there has been proposed an outboard engine including a steering cylinder that is disposed in an upper part of the swivel bracket, above the clamp shaft, and rotates the steering shaft (for example, see U.S. Pat. No. 7,311,571).
Further, there has been also proposed an outboard engine in which a hydraulic cylinder disposed in a lower part of a swivel bracket causes a piston rack meshed with a pinion provided at the steering shaft to move reciprocally by hydraulic pressure and thereby rotates the steering shaft (for example, see U.S. Pat. No. 4,041,889).
When the actuator that rotates the steering shaft is disposed in the upper part of the swivel bracket, above the clamp shaft, as described above, the actuator greatly extends upward and to the left and right of the swivel bracket. Accordingly, in order to avoid contact with the actuator, the size of the outboard engine main body is limited. Further, it is difficult to form an arm portion extending forward, at the steering bracket, and it may become difficult to attach a tie bar that connects arm portions of the steering brackets of a plurality of outboard engines. Furthermore, when seawater is shut off by using a drive component, a boot or the like, the outboard engine is weak to contact and collision from outside. Further, there is the possibility of inflow of seawater when durability of the seal member is low.
When the actuator that rotates the steering shaft is disposed in the lower part of the swivel bracket as described above, the actuator is close to a water surface, and therefore, is easily affected by seawater or the like. Since the actuator is away from the clamp shaft, a moving amount of the actuator following a tilt operation and a trim operation of the outboard engine main body increases. Thereby, the actuator (including pipes of hydraulic pressure or the like connected to the actuator) easily deteriorates. Note that in the structure where the actuator that rotates the steering shaft is disposed between a transom of the hull and the outboard engine main body, serviceability (versatility) and marketability decline unless the influence of the shape or the like on the existing outboard engine main body is suppressed as much as possible. Consequently, a compact shape is required as well as a low-cost structure.
The present invention is made in view of the above circumstances, and has an object to provide an outboard engine in which an actuator that rotates a steering shaft can be compactly disposed, and durability of the actuator is secured.
An outboard engine of the present invention is an outboard engine including an outboard engine main body, a clamp bracket that is mounted to a hull, a clamp shaft that is supported by the clamp bracket, a swivel bracket that is fixed to the outboard engine main body, and swings forward and backward with the outboard engine main body with the clamp shaft as a fulcrum, a tilt/trim unit having a tilt cylinder that is connected to the swivel bracket and causes the swivel bracket to swing forward and backward with the clamp shaft as a fulcrum, a steering shaft that is swingably supported by the swivel bracket and is fixed to the outboard engine main body, and an actuator that rotates the steering shaft, wherein a center of the actuator in side view of the outboard engine main body is at an outboard engine main body side from the clamp shaft and below the clamp shaft, and further is located at a clamp shaft side from the steering shaft, and at the outboard engine main body side from an upper end mounting shaft for mounting the tilt/trim unit and above the upper end mounting shaft.
According to the present invention, the actuator that rotates the steering shaft can be compactly disposed. Further, the outboard engine that secures durability of the actuator can be realized.
Hereinafter, an outboard engine according to an embodiment of the present invention will be described with reference to the drawings.
The outboard engine 1 illustrated in
The outboard engine 1 includes the outboard engine main body 10 and the mounting device 2. The mounting device 2 has a clamp bracket 20, a clamp shaft 30, the swivel bracket 50, the steering bracket 60, a hydraulic cylinder 80 and the like.
The outboard engine main body 10 has an engine cover 11, a drive shaft housing 12, a lower housing 13, the propeller 14, an engine 15, a drive shaft 16, the propeller shaft 17, and a bevel mechanism 18.
The engine cover 11 has an upper cover 11a and a lower cover 11b. The engine cover 11 covers the engine 15 that drives the propeller 14 that is mounted to the lower housing 13 so that the engine 15 is in a hermetically sealed state. The drive shaft 16 of the engine 15 extends to an inside of the lower housing 13 through an inside of the drive shaft housing 12, and transmits power to the propeller shaft 17 connected to the propeller 14 via the bevel gear mechanism 18. A propulsive force by the outboard engine 1 is generated by the propeller 14 rotating.
As illustrated in
The left bracket 21 and the right bracket 22 support the clamp shaft 30 illustrated in
A tilt/trim unit 40 illustrated in
The tilt cylinder 41 has a bearing portion 41a, a piston rod 41b, and a piston 41c.
The bearing portion 41a supports the lower shaft 91 between a lower end of the left bracket 21 and a lower end of the right bracket 22.
The piston 41c advances and retreats the piston rod 41b up and down by sliding in the tilt cylinder 41 by hydraulic pressure, and makes a position of the upper end mounting shaft 43 connected to an upper end of the piston rod 41b to the lower shaft 91 changeable.
The upper end mounting shaft 43 is inserted into a pair of left and right mounting bearing portions 51 of the swivel bracket 50 illustrated in
Note that swing of the outboard engine main body 10 that is performed by drive of the tilt cylinder 41 is referred to as a tilt operation, and swing of the outboard engine main body 10 that is performed by drive of the trim cylinder 42 is referred to as a trim operation. The tilt operation is performed in a case where the outboard engine main body 10 is greatly tilted and a part including the propeller 14 is raised on a water surface while the ship is stopped or when the hull is unloaded, or the like. The trim operation is performed in a case where a tilt angle (trim angle) of the outboard engine main body 10 in the up-down direction is adjusted to change a traveling attitude in a state where the propeller 14 is under water, or the like. The pair of left and right trim cylinders 42 that operate to perform the trim operation also cause the swivel bracket 50, the outboard engine main body 10 by extension in the front-back direction. Note that the pair of left and right trim cylinders 42 are located on both a left and right sides of the tilt cylinder 41, but as described above,
As illustrated in
The steering bracket 60 is fixed to the steering shaft 71, and therefore swings integrally with the steering shaft 71. Further, since the steering bracket 60 is fixed to the outboard engine main body 10 in the connection portions 63, and the steering shaft 71 is fixed to the outboard engine main body 10 in the mounting portion 12a, the outboard engine main body 10 turns (swings) left and right by rotation of the steering shaft 71.
The hydraulic cylinder 80 is an example of an actuator that rotates the steering shaft 71. The actuator may be another actuator such as a motor as long as the actuator rotates the steering shaft 71.
As illustrated in
The piston rack 81 is disposed between the left cylinder body 82 and the right cylinder body 83. The piston rack 81 slides in the left cylinder body 82 and the right cylinder body 83 in the left-right direction by hydraulic pressure. Note that oil in the hydraulic cylinder 80 can be supplied from pipes connected to the left cylinder body 82 and the right cylinder body 83 via the left nipple 84 and the right nipple 85.
A rear portion of the piston rack 81 is meshed with a pinion 72 provided at an upper part of the steering shaft 71. Therefore, the steering shaft 71 rotates (swings) by the piston rack 81 sliding in the left-right direction in the left cylinder body 82 and the right cylinder body 83. Note that a spline 72a that is meshed with an upper spline 71a provided on an outer peripheral surface of the steering shaft 71 is formed on an inner peripheral surface of the pinion 72, and thereby the steering shaft 71 and the pinion 72 are fixed. In this manner, the steering shaft 71 and the pinion 72 can be fixed with splines, serrations and the like.
As illustrated in
The left cylinder body 82 and the right cylinder body 83 illustrated in
As illustrated in
The left nipple 84 (and the right nipple 85) extends diagonally along a close upper portion of the left bracket 21 (right bracket 22) in the state where the swivel bracket 50 and the outboard engine main body 10 do not tilt as illustrated in
As illustrated in
As illustrated in
As illustrated in
In the present embodiment described above, the outboard engine 1 includes the outboard engine main body 10, the clamp bracket 20, the clamp shaft 30, the tilt/trim unit 40, the swivel bracket 50, the steering shaft 71, and the hydraulic cylinder 80 that is an example of the actuator. The clamp bracket 20 is mounted to a hull. The clamp shaft 30 is supported by the clamp bracket 20. The swivel bracket 50 is fixed to the outboard engine main body 10, and swings forward and backward with the outboard engine main body 10, with the clamp shaft 30 as the fulcrum. The tilt/trim unit 40 has the tilt cylinder 41. The tilt cylinder 41 is connected to the swivel bracket 50 in the upper end mounting shaft 43, and causes the swivel bracket 50 to swing forward and backward with the clamp shaft 30 as the fulcrum. The steering shaft 71 is swingably supported by the swivel bracket 50, and is fixed to the outboard engine main body 10. The hydraulic cylinder 80 rotates the steering shaft 71. The center C of the hydraulic cylinder 80 in side view of the outboard engine main body 10 is at the outboard engine main body 10 side (back side) from the clamp shaft 30 and below the clamp shaft 30, and is at the clamp shaft 30 side (front side) from the steering shaft 71. Further, the center C is located at the outboard engine main body 10 side (back side) from the upper end mounting shaft 43 and above the upper end mounting shaft 43.
Thereby, the hydraulic cylinder 80 can be assembled with a simple structure inside an upper part of the swivel bracket 50 as compared with a mode in which the hydraulic cylinder 80 is disposed in the swivel bracket 50 above the clamp shaft 30, and therefore, cost of the hydraulic cylinder 80 can be reduced. Further, since the hydraulic cylinder 80 can be disposed compactly, it is also possible to avoid the shape of the outboard engine main body 10 from being limited. Thereby, it is also possible to mount the hydraulic cylinder 80 (swivel bracket 50) to the existing outboard engine main body 10 easily, and therefore the present invention is also excellent in serviceability. Since the arm portion 62 extending forward is easily formed at the steering bracket 60, it becomes easy to attach a tie bar that connects the arm portions 62 of the steering brackets 60 of a plurality of outboard engines 1. Since the hydraulic cylinder 80 is disposed inside the upper part of the swivel bracket 50, the hydraulic cylinder 80 hardly receives seawater while the ship is traveling, and is strong to contact and collision from outside.
Further, as compared with a mode where the hydraulic cylinder 80 is disposed in a lower part of the swivel bracket 50, the hydraulic cylinder 80 is apart from a water surface, and is hardly affected by seawater or the like including when the ship is at anchor. Further, a distance from the clamp shaft 30 to be the swing fulcrum is short, a moving amount of the hydraulic cylinder 80 following the tilt operation and the trim operation of the outboard engine main body 10 decreases. Accordingly, durability of the hydraulic cylinder 80 (including the pipes connected to the left nipple 84 and the right nipple 85) can be improved.
As above, according to the present embodiment, it is possible to dispose the hydraulic cylinder 80 that rotates the steering shaft 71 compactly and to improve durability of the hydraulic cylinder 80, and it is possible to realize the outboard engine 1 including durability.
Further, in the present embodiment, the hydraulic cylinder 80 is a hydraulic cylinder that operates the piston rack 81 meshed with the pinion 72 provided at the steering shaft 71 by hydraulic pressure. Therefore, it is possible to dispose the actuator (hydraulic cylinder 80) that rotates the steering shaft 71 compactly. Note that it is also possible to improve durability and reliability of the piston rack 81 and the pinion 72 by the inside of the hydraulic cylinder 80 being filled with oil.
Further, in the present embodiment, the hydraulic cylinder 80 has the air vent 87 that is located at the uppermost portion of the hydraulic cylinder 80 in the state where the swivel bracket 50 and the outboard engine main body 10 tilt at a predetermined angle by operation of the tilt/trim unit 40. Therefore, the air vent 87 is away from the water surface, and thereby is hardly affected by seawater or the like.
Further, in the modification of the present embodiment, the outboard engine 1 includes the steering bracket 60 and the hydraulic pump 94. The steering bracket 60 is fixed to the steering shaft 71, and swings left and right with the outboard engine main body 10. The hydraulic pump 94 is located above the clamp shaft 30 and below the steering bracket 60 (arm 62), and supplies hydraulic pressure to the hydraulic cylinder 80. Further, as described above, the center C of the hydraulic cylinder 80 is located at the outboard engine main body 10 side (back side) from the clamp shaft 30 and below the clamp shaft 30. Accordingly, it is possible to dispose the hydraulic pump 94 between the steering bracket 60 and the clamp shaft 30.
Further, the present embodiment has the structure in which the clamp bracket 20 is the left bracket 21 and the right bracket 22 that support the clamp shaft 30 at both the left and right sides of the swivel bracket 50, and at least a part of the hydraulic cylinder 80 is located between the left bracket 21 and the right bracket 22 in the state where the outboard engine main body 10 does not tilt. Therefore, the hydraulic cylinder 80 can be compactly disposed.
Note that the present invention can be carried out by being variously changed without being limited to the above described embodiment. It is possible to properly change the components, control and the like illustrated in the accompanying drawings within the range in which the effect of the present invention is exhibited without being limited to the components, control and the like illustrated in the accompanying drawings. In addition, it is possible to carry out the present invention by properly changing the present invention within the range without departing from the object of the present invention.
Number | Date | Country | Kind |
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JP2019-200572 | Nov 2019 | JP | national |
Number | Name | Date | Kind |
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4041889 | Blanchard | Aug 1977 | A |
7311571 | Swan et al. | Dec 2007 | B1 |
20090084299 | Mizutani | Apr 2009 | A1 |
20090149091 | Baros | Jun 2009 | A1 |
Number | Date | Country | |
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20210129964 A1 | May 2021 | US |