JP2021062712A - Steering gear for ship - Google Patents

Abstract

To provide a steering gear for a ship capable of improving mountability of a steering mechanism for a hull.SOLUTION: A steering mechanism 31 of a steering actuator 13 has a housing 40, a ball screw shaft 41, a ball screw nut 42, a sector shaft 44, and a sector gear 45. The ball screw shaft 41 rotates by driving of a motor 33 provided in the housing 40. The ball screw nut 42 is screwed into the ball screw shaft 41 via multiple balls 43. Rack teeth 42a are provided on the outer peripheral surface of the ball screw nut 42. The sector shaft 44 is orthogonal to the ball screw shaft 41 and is rotatably supported by the housing 40. The sector gear 45 is integrally, rotatably connected to the sector shaft 44 and meshes with the rack gear 42a of the ball screw nut 42. The sector gear 45 rocks around the sector shaft 44 as the ball screw nut 42 moves.SELECTED DRAWING: Figure 4

Description

The present invention relates to a marine steering device.

Conventionally, for example, there is a steering device for a ship described in Patent Document 1. This steering device has a steering mechanism (steering mechanism) and a controller. The steering mechanism swings the outboard motor, which is rotatably supported around the steering axis with respect to the stern of the hull, in the left-right direction with respect to the traveling direction of the hull. The controller controls the operation of the steering mechanism according to the operation of the steering wheel provided in the driver's seat of the hull.

The steering mechanism includes a pair of left and right support members, a ball screw shaft, a ball screw nut, and a steering motor provided at the stern. The ball screw shaft is connected between the two support members. The ball screw nut is screwed onto the ball screw shaft. The steering motor has a housing that rotatably accommodates the ball screw nut, and a stator fixed inside the housing. When the stator is energized, the ball screw nut as a rotor rotates.

The housing is provided with a steering arm that extends toward the outboard motor. The steering arm is rotatably connected to the first end of the steering bracket connected to the outboard motor via a connecting pin. The second end of the steering bracket is rotatably supported with respect to a steering shaft provided at the stern.

When the ball screw nut rotates through the drive of the steering motor, the ball screw nut moves in the left-right direction along the ball screw shaft integrally with the housing. As a result, the steering bracket connected to the steering arm swings in the left-right direction around the steering shaft. As a result, the outboard motor connected to the steering bracket is steered in the left-right direction.

JP-A-2010-143413

In the steering device of Patent Document 1, when the outboard motor is steered, the housing moves in the left-right direction along the ball screw axis together with the ball screw nut. Therefore, it is necessary to secure a moving space for the housing on the hull. In addition, it is necessary to eliminate the interfering material from the moving path of the housing. Therefore, there is room for improvement in the mountability of the steering mechanism on the hull.

An object of the present invention is to provide a marine steering device capable of improving the mountability of a steering mechanism on a hull.

A marine steering device capable of achieving the above object includes a steering mechanism for moving a rudder provided at the stern of a ship and a drive source for the steering mechanism. The steering mechanism has a housing fixed to the hull, an output shaft rotatably supported with respect to the housing, and a drive source provided inside the housing to convert the power of the drive source into rotation of the output shaft. It has a first conversion mechanism for converting the rotation of the output shaft into the operation of the rudder, which is provided outside the housing.

As a marine steering device, there is a configuration in which a housing of a steering mechanism is provided so as to be movable with respect to the hull, and the rudder is operated by utilizing the movement of the housing. However, when adopting this configuration, it is necessary to secure a moving space for the housing on the hull. In this regard, according to the above-mentioned ship steering device, the housing of the steering mechanism is fixed to the hull because it is only necessary to rotate the output shaft of the steering mechanism when operating the steering of the ship. Therefore, it is not necessary to secure a moving space for the housing on the hull. Therefore, it is possible to improve the mountability of the steering mechanism on the hull.

In the above-mentioned marine steering device, the first conversion mechanism has a ball screw shaft rotatably supported inside the housing and rotated by the operation of the drive source, and a plurality of balls on the ball screw shaft. It is screwed through the ball screw nut and has rack teeth provided along the axial direction on the outer peripheral surface. The ball screw nut is integrally rotatably connected to the output shaft and is connected to the rack tooth of the ball screw nut. It may have a sector gear that meshes and swings around the output shaft as the ball screw nut moves in the axial direction.

According to this configuration, the power of the drive source can be converted into the rotation of the output shaft via the ball screw shaft, the ball screw nut and the sector gear.
In the above-mentioned marine steering device, the drive source may be a motor. According to this configuration, it is possible to meet the demand for electrification of the steering mechanism.

In the above-mentioned marine steering device, when the drive source is a motor, a speed reducer that decelerates the rotation of the motor and transmits the decelerated rotation to the ball screw shaft may be provided.
According to this configuration, the torque of the motor is increased according to the reduction ratio of the reduction gear, and a larger value torque corresponding to the reduction ratio of the reduction gear is transmitted to the ball screw shaft. Therefore, the rudder can be operated more reliably.

In the marine steering device, the drive source is an electric pump that discharges hydraulic oil, and the ball screw nut is slidably provided with respect to the housing, and the inside of the housing is the ball screw nut. A control valve for controlling the supply or discharge of hydraulic oil to the two oil chambers may be provided on the premise that the oil chambers are divided into two oil chambers. In this case, the control valve selectively selects the hydraulic oil discharged from the electric pump to either one of the two oil chambers according to the operation of the handle operated when changing the direction of the hull. The ball screw nut may be moved along the axial direction as a piston by supplying the ball screw nut to the piston.

According to this configuration, the hydraulic oil from the electric pump is selectively supplied to one of the two oil chambers according to the operation of the handle, so that a pressure difference is generated between the two oil chambers. .. In response to this pressure difference, the ball screw nut functions as a piston and is pressed along its axial direction, so that the ball screw nut moves along the ball screw shaft. This movement of the ball screw nut is converted into rotation of the output shaft via the sector gear.

In the above-mentioned ship steering device, the rudder is rotatably provided on the outside of the stern as a propulsion device for a ship about a steering shaft, and can also be used as a rudder for a ship by rotating around the steering shaft. It may be a functioning outboard unit.

In the above-mentioned ship steering device, the rudder may be rotatably provided on the outside of the stern around a support shaft, separately from the ship propulsion device.
In the above-mentioned marine steering device, the rudder may be separated from the power transmission between the rudder and the steering wheel operated when changing the direction of the hull.

In the above-mentioned marine steering device, the rudder may be connected to a handle operated when the hull is turned. In this case, the drive source may generate an assist force that assists the movement of the rudder through the operation of the steering wheel.

According to the marine steering device of the present invention, it is possible to improve the mountability of the steering mechanism on the hull.

FIG. 3 is a plan view of a ship on which the first embodiment of the ship steering device is mounted. A side view of the outboard motor according to the first embodiment. The plan view of the steering actuator in the 1st Embodiment. FIG. 3 is a plan sectional view of the steering actuator according to the first embodiment. The plan view which shows the main part of the steering actuator in 1st Embodiment. FIG. 3 is a plan view of a ship on which a second embodiment of a ship steering device is mounted. FIG. 3 is a plan sectional view of the steering actuator according to the second embodiment. FIG. 6 is a schematic configuration diagram of a power transmission mechanism between the steering wheel and the steering actuator in the second embodiment. The plan view which shows the main part of the steering actuator of another embodiment. The plan view which shows the main part of the steering actuator in another embodiment. FIG. 3 is a perspective view showing an inboard unit of a ship according to another embodiment.

<First Embodiment>
Hereinafter, the first embodiment of the marine steering device will be described.
As shown in FIG. 1, the ship 10 is provided with an outboard motor 12, a steering actuator 13 as a steering device, a steering wheel 14 as a steering wheel, and a control device 15.

The outboard motor 12 is provided at the stern of the hull 10a. The outboard motor 12 is an example of a propulsion device for a ship 10, and has an engine 12a and a propeller 12b that is rotated by driving the engine 12a. The outboard motor 12 can swing in the left-right direction with respect to the traveling direction of the ship 10. The outboard motor 12 also functions as a rudder of the ship 10 by swinging in the left-right direction.

The steering actuator 13 swings the outboard motor 12 in the left-right direction with respect to the traveling direction of the ship 10. The traveling direction of the ship 10 is changed by the outboard motor 12 swinging in the left-right direction.
The steering wheel 14 is provided in the maneuvering seat of the ship 10. The steering wheel 14 is rotatably supported with respect to the hull 10a via the steering shaft 16. The steering shaft 16 is provided with a rotation angle sensor 17. The rotation angle sensor 17 detects the rotation angle of the steering shaft 16 as the steering angle θ, which is the rotation angle of the steering wheel 14.

The control device 15 controls the operation of the steering actuator 13 according to the steering angle θ detected through the rotation angle sensor 17. Incidentally, the output of the engine 12a is controlled by another control device provided separately from the control device 15.

Next, the connection structure between the hull 10a and the outboard motor 12 will be described.
As shown in FIG. 2, the outboard motor 12 has a swivel bracket 21, a steering shaft 22, and a steering bracket 23.

The swivel bracket 21 is for connecting the outboard motor 12 to the hull 10a. The swivel bracket 21 has an L-shape as a whole from the first connecting portion 21a and the second connecting portion 21b. The first connecting portion 21a extends along the front-rear direction (horizontal direction in FIG. 2) of the hull 10a. The second connecting portion 21b extends along the vertical direction of the hull 10a. The first connecting portion 21a is attached between two clamp brackets 24, 24 (see FIG. 1) provided at the stern of the hull 10a. Further, a steering actuator 13 is installed on the upper surface of the first connecting portion 21a. The second connecting portion 21b is provided with a through hole 21c extending along the vertical direction of the hull 10a.

The steering shaft 22 serves as the swing center of the outboard motor 12. The steering shaft 22 is inserted into the through hole 21c of the second connecting portion 21b of the swivel bracket 21. The steering shaft 22 is rotatable relative to the swivel bracket 21. The upper end of the steering shaft 22 projects from the upper part of the second connecting portion 21b of the swivel bracket 21. The upper end of the steering shaft 22 is connected to the steering actuator 13 via the steering bracket 23. The portion of the steering shaft 22 between the steering bracket 23 and the swivel bracket 21 is fixed to the case 12c of the outboard motor 12 via the bracket 25. The lower end of the steering shaft 22 projects from the lower part of the swivel bracket 21. The lower end of the steering shaft 22 is fixed to the case 12c of the outboard motor 12 via the bracket 26. The two brackets 25 and 26 are fixed to the steering shaft 22, respectively. Since the relative rotation of the steering shaft 22 with respect to the brackets 25 and 26 is restricted, the outboard motor 12 can rotate relative to the swivel bracket 21 around the steering shaft 22.

Next, the configuration of the steering actuator 13 will be described in detail.
As shown in FIG. 3, the steering actuator 13 includes a steering mechanism 31, a speed reducer 32, a motor 33 as a drive source, and a rotation angle sensor 34. As the steering mechanism 31, a so-called RBS (recirculating ball type steering gear) is adopted. The motor 33 and the rotation angle sensor 34 are connected to the steering mechanism 31 via the speed reducer 32.

As shown in FIG. 4, the steering mechanism 31 has a housing 40. Inside the housing 40, a ball screw shaft 41, a ball screw nut 42, a plurality of balls 43, a sector shaft 44 as an output shaft, and a sector gear 45 are provided. The ball screw shaft 41 is rotatably supported with respect to the housing 40 via two bearings 46 and 47. The ball screw nut 42 is screwed onto the ball screw shaft 41 via a plurality of circulatory balls 43. Rack teeth 42a are provided on the outer peripheral surface of the ball screw nut 42 along the axial direction thereof. The sector shaft 44 extends along a direction orthogonal to the axis of the ball screw nut 42 (direction orthogonal to the paper surface in FIG. 4). The sector shaft 44 is rotatably supported with respect to the housing 40 via bearings (not shown). The sector gear 45 is provided so as to be integrally rotatable with respect to the sector shaft 44. The teeth 45a of the sector gear 45 mesh with the rack teeth 42a of the ball screw nut 42.

As shown in FIG. 3, the upper end portion of the sector shaft 44 is exposed to the outside of the housing 40. The first end of the lever 48 is fixed to the upper end of the sector shaft 44. A first end of the link 49 is rotatably pivotally supported at the second end of the lever 48. At the second end of the link 49, an end of the steering bracket 23 provided on the outboard motor 12 opposite to the steering shaft 22 is rotatably supported.

As shown in FIG. 4, the speed reducer 32 has a housing 50. The housing 50 is connected to the housing 40 of the steering mechanism 31. The insides of these housings 40 and 50 communicate with each other. A motor 33 is attached to the outside of the housing 50. The output shaft 33a of the motor 33 extends along a direction orthogonal to the axis of the ball screw shaft 41. The output shaft 33a of the motor 33 penetrates the peripheral wall of the housing 50 and is inserted into the peripheral wall of the housing 50. A rotation angle sensor 34 is attached to a portion of the housing 50 opposite to the steering mechanism 31.

A shaft 51, a worm wheel 52, and a worm 53 are provided inside the housing 50. The shaft 51 is rotatably supported with respect to the housing 50 via two bearings 54, 55. The first end portion (left end portion in FIG. 4) of the shaft 51 is integrally rotatably connected to the ball screw shaft 41. The second end portion (right end portion in FIG. 4) of the shaft 51 is rotatably supported with respect to the case in which the detection element of the rotation angle sensor 34 is housed. The rotation angle sensor 34 detects the rotation angle of the shaft 51. The worm wheel 52 is provided so as to be integrally rotatable with respect to the shaft 51. The worm 53 is provided so as to be integrally rotatable with respect to the output shaft 33a of the motor 33. The worm 53 meshes with the worm wheel 52.

Next, the operation of the steering actuator 13 will be described.
The control device 15 executes steering control for steering the outboard motor 12 according to the amount of operation of the steering wheel 14 through the drive control of the motor 33. The control device 15 calculates a target value of the steering amount of the outboard motor 12 based on the steering angle θ of the steering wheel 14 detected through the rotation angle sensor 17. Further, the control device 15 calculates the steering amount of the outboard motor 12 based on the rotation angle of the shaft 51 detected through the rotation angle sensor 34. Then, the control device 15 obtains a difference between the target value of the steering amount of the outboard motor 12 and the actual steering amount of the outboard motor 12, and controls the power supply to the motor 33 so as to eliminate the difference. Incidentally, the control device 15 transfers to the motor 33 based on the rotation angle of the sector shaft 44, which is one of the state variables reflecting the steering amount of the outboard motor 12, instead of the steering amount of the outboard motor 12. The power supply may be controlled.

As shown in FIG. 4, the rotation of the motor 33 is transmitted to the ball screw shaft 41 via the speed reducer 32. As the ball screw shaft 41 rotates, the ball screw nut 42 moves along its axis direction. As the ball screw nut 42 moves, the sector gear 45 that meshes with the rack tooth 42a swings in the left-right direction about the sector shaft 44. With the swing of the sector gear 45, the sector shaft 44 rotates in the same direction as the swing direction of the sector gear 45 and according to the swing amount of the sector gear 45.

As shown in FIG. 5, the lever 48 swings in the left-right direction about the sector shaft 44 as the sector shaft 44 rotates. For example, when the sector shaft 44 rotates counterclockwise, the lever 48 rotates counterclockwise about the sector shaft 44. Along with this, the link 49 tries to rotate clockwise around the connecting portion with the lever 48. As the link 49 rotates clockwise, the steering bracket 23 rotates counterclockwise around the steering shaft 22. Since the steering shaft 22 is fixed to the steering bracket 23, torque is applied to the steering shaft 22 in the counterclockwise direction as the steering bracket 23 rotates in the counterclockwise direction. Since the steering shaft 22 is fixed to the case 12c of the outboard motor 12, the outboard motor 12 rotates counterclockwise around the steering shaft 22 as the steering shaft 22 rotates in the counterclockwise direction. Rotate towards.

When the sector shaft 44 rotates clockwise, the steering bracket 23 rotates via the sector gear 45, the lever 48, and the link 49, as when the sector shaft 44 rotates counterclockwise. By rotating clockwise around the steering shaft 22, torque is applied to the steering shaft 22 in the clockwise direction. As the steering shaft 22 rotates clockwise, the outboard motor 12 rotates clockwise around the steering shaft 22.

The ball screw shaft 41, the ball screw nut 42, and the ball 43 form a ball screw mechanism. Further, the ball screw mechanism (41 to 43) and the sector gear 45 constitute a first conversion mechanism that converts the power of the motor 33, which is the drive source of the steering actuator 13, into the rotation of the sector shaft 44, which is the output shaft. To do. Further, the lever 48 and the link 49 form a second conversion mechanism that converts the rotation of the sector shaft 44, which is an output shaft, into the steering operation of the outboard motor 12.

<Effect of embodiment>
Therefore, according to the present embodiment, the following effects can be obtained.
(1) The steering mechanism 31 converts the rotation of the motor 33 into the rotation of the sector gear 45, and transmits the rotation of the sector gear 45 as torque to the steering shaft 22 of the outboard motor 12. Here, there is a configuration in which the housing of the steering mechanism is provided so as to be movable with respect to the hull together with the ball screw nut, and the outboard motor is steered by using the movement of the housing. It is necessary to secure a moving space for the housing on the hull. In this regard, according to the steering mechanism 31 of the present embodiment, when the outboard motor 12 is steered, it is only necessary to rotate the sector shaft 44. Since it is not necessary to move the housing 40 of the steering mechanism 31 with respect to the hull 10a, the housing 40 is fixed to the hull 10a. Therefore, it is not necessary to secure a space in the hull 10a for the housing 40 of the steering mechanism 31 to move. Therefore, the mountability of the steering mechanism 31 on the hull 10a can be improved.

(2) The rotation of the sector gear 45 is transmitted to the steering shaft 22 which is the rotation center of the outboard motor 12 via the sector shaft 44, the lever 48, the link 49 and the steering bracket 23. Since the outboard motor 12 rotates around the steering shaft 22, torque for steering the outboard motor 12 can be efficiently applied to the steering shaft 22. Incidentally, as described above, a configuration in which the linear motion of the housing of the steering mechanism is converted into a rotational motion centered on the steering axis of the outboard unit is conceivable. However, when this configuration is adopted, the torque with respect to the steering shaft 22 is applied. There is a concern that the transmission efficiency will be lower than that of the steering mechanism 31 of the present embodiment.

(3) As the steering actuator 13, a configuration is adopted in which the rotation of the sector gear 45 is transmitted to the steering shaft 22 which is the rotation center of the outboard motor 12 via the sector shaft 44, the lever 48, the link 49 and the steering bracket 23. Has been done. Therefore, as compared with the case of adopting the above-mentioned configuration in which the linear motion of the housing of the steering mechanism is converted into the rotational motion of the steering shaft, there is less unnecessary operation of the steering mechanism 31. Further, the operating range of the lever 48 and the link 49 interlocking with the sector gear 45 can be set to a narrower range than the moving range of the housing when the housing of the steering mechanism is linearly moved. Since it is not necessary to move the lever 48 and the link 49 significantly, the installation space of the steering mechanism 31 can be set narrower.

(4) A motor 33 is adopted as a drive source for the steering mechanism 31. Therefore, it is possible to meet the demand for electrification of the steering actuator 13. In addition, higher responsiveness and stable steering force can be obtained regardless of the speed (low speed to high speed) of the ship 10 and the environment (wave, wind). For example, when a hydraulic pump driven by an engine is adopted as a drive source for the steering mechanism 31, the discharge amount of the hydraulic pump and the steering force applied to the outboard motor 12 may fluctuate depending on the speed and environment of the ship 10. There is.

(5) By electrifying the steering actuator 13, it is not necessary to provide a hydraulic pipe for supplying and discharging hydraulic oil to the hull 10a, unlike the case where a hydraulic device is adopted as a drive source of the steering mechanism 31. Therefore, the configuration of the steering actuator 13 can be simplified. Further, the space in the hull 10a can be saved because it is not necessary to provide the hydraulic piping.

(6) The output shaft 33a of the motor 33 is connected to the ball screw shaft 41 of the steering mechanism 31 via the speed reducer 32. Therefore, the torque of the motor 33 is increased according to the reduction ratio of the speed reducer 32, and a larger value torque corresponding to the reduction ratio is transmitted to the ball screw shaft 41. Since the force required to steer the outboard motor 12 can be obtained, the outboard motor 12 can be steered more reliably.

<Second embodiment>
Next, a second embodiment of the marine steering device will be described. The present embodiment is different from the first embodiment in that a hydraulic steering actuator is adopted instead of the electric steering actuator.

As shown in FIG. 6, the ship 10 is provided with an outboard motor 12, a steering wheel 14, a control device 15, and a hydraulic steering actuator 60. The steering actuator 60 has an electric pump 61 and a reservoir tank 62 as drive sources. Further, the steering actuator 60 has a steering mechanism 71 and a control valve 72 provided on the swivel bracket 21 at the stern.

Hydraulic oil is stored in the reservoir tank 62. The reservoir tank 62 is connected to the electric pump 61 via a suction pipe 63. The electric pump 61 is connected to the pump port of the control valve 72 via a discharge pipe 64. Further, the tank port of the control valve 72 is connected to the reservoir tank 62 via the discharge pipe 65.

The control device 15 controls the electric pump 61 based on the steering angle θ detected through the rotation angle sensor 17. By driving the electric pump 61, the hydraulic oil in the reservoir tank 62 is supplied to the control valve 72 via the discharge pipe 64. The hydraulic oil discharged from the control valve 72 is returned to the reservoir tank 62 via the discharge pipe 65.

Next, the configuration of the steering mechanism 71 will be described in detail.
As shown in FIG. 7, the steering mechanism 71 has a housing 80. Inside the housing 80, a ball screw shaft 81, a ball screw nut 82, a plurality of balls 83, a sector shaft 84, a sector gear 85, and a bottomed tubular closing member 86 are provided.

The ball screw nut 82 is slidably provided with respect to the housing 80 (to be exact, the cylinder portion thereof) in the direction along the axis thereof. Rack teeth 82a are provided on the outer peripheral surface of the ball screw nut 82 along the axial direction thereof.

The closing member 86 is fitted without a gap to the first end portion (left end portion in FIG. 7) of the ball screw nut 82. The closing member 86 moves integrally with the ball screw nut 82.
The ball screw shaft 81 is screwed into the ball screw nut 82 via a plurality of circulatory balls 83. The first end portion (left end portion in FIG. 7) of the ball screw shaft 81 is inserted inside the closing member 86. A predetermined gap is provided between the first end of the ball screw shaft 81 and the bottom wall of the closing member 86. The ball screw nut 82 is movable relative to the ball screw shaft 81 along the axial direction within the range of the gap between the ball screw shaft 81 and the bottom wall of the closing member 86. The second end of the ball screw shaft 81 (right end in FIG. 7) protrudes from the second end of the ball screw nut 82 (right end in FIG. 7). The second end of the ball screw shaft 81 is connected to the control valve 72.

The sector shaft 84 extends along a direction orthogonal to the axis of the ball screw nut 82 (direction orthogonal to the paper surface in FIG. 7). The sector shaft 84 is rotatably supported with respect to the housing 80 via bearings (not shown).

The sector gear 85 is provided so as to be integrally rotatable with respect to the sector shaft 84. The teeth 85a of the sector gear 85 mesh with the rack teeth 82a of the ball screw nut 82. The upper end of the sector shaft 84 is exposed to the outside of the housing 80. An end portion of the steering bracket 23 opposite to the steering shaft 22 is connected to the upper end portion of the sector shaft 84 via a lever 48 and a link 49 (see FIG. 2).

The inside of the housing 80 is divided into a first oil chamber 87 and a second oil chamber 88 by a ball screw nut 82 and a closing member 86. The first oil chamber 87 is located on the control valve 72 side with respect to the ball screw nut 82. The second oil chamber 88 is located on the opposite side of the control valve 72 with respect to the ball screw nut 82.

Hydraulic oil is supplied to the first oil chamber 87 and the second oil chamber 88 via the control valve 72. By selectively supplying the hydraulic oil from the electric pump 61 to either one of the first oil chamber 87 and the second oil chamber 88 via the control valve 72, the first oil chamber 87 and the first oil chamber 87 A pressure difference is generated between the oil chamber 88 and the second oil chamber 88. When the ball screw nut 82 and the closing member 86 are pressed along their axial directions in response to this pressure difference, the ball screw nut 82 and the closing member 86 function as a piston and move along the ball screw shaft 81. To do. As the ball screw nut 82 moves, the sector gear 45 swings in the left-right direction around the sector shaft 84. With the swing of the sector gear 45, the sector shaft 44 rotates in the same direction as the swing direction of the sector gear 45.

Next, the configuration of the control valve 72 will be described in detail.
As shown in FIG. 7, the control valve 72 has a housing 90. The housing 90 is connected to the housing 80 of the steering mechanism 71. Inside the housing 90, a hollow input shaft 91, a torsion bar 92, an inner valve 93, and an outer valve 94 are provided.

The input shaft 91 penetrates the housing 90. The input shaft 91 is rotatably supported with respect to the housing 90 via a bearing 95. The first end portion (left end portion in FIG. 7) of the input shaft 91 is provided with respect to the recess 81a as an insertion portion provided in the second end portion (right end portion in FIG. 7) of the ball screw shaft 81. It is inserted so that it can rotate relative to each other. A rotation angle sensor 34 is provided at the second end (right end in FIG. 7) of the input shaft 91.

The torsion bar 92 penetrates the input shaft 91. The first end (left end in FIG. 7) of the torsion bar 92 is fixed to the bottom of the recess 81a provided in the second end (right end in FIG. 7) of the ball screw shaft 81. .. The second end portion (right end portion in FIG. 7) of the torsion bar 92 is fixed to the second end portion (right end portion in FIG. 7) of the input shaft 91.

The inner valve 93 is provided on the outer periphery of the input shaft 91 inside the housing 90. The outer valve 94 is provided on the inner circumference of the housing 90.
The torsion bar 92 is twisted according to the torque applied to the input shaft 91, and the positional relationship (relative angle) between the inner valve 93 and the outer valve 94 in the rotation direction changes with the twisting of the torsion bar 92. The control valve 72 switches the flow path of the hydraulic oil by utilizing the change in the positional relationship between the inner valve 93 and the outer valve 94 in the rotational direction. Further, the control valve 72 forms a throttle according to the difference (valve operating angle) between the rotation angle of the input shaft 91, that is, the inner valve 93 and the rotation angle of the outer valve 94, thereby forming the first oil chamber 87 and the second oil chamber 87 and the second. The flow rate of the hydraulic oil supplied to the oil chamber 88 of the above is adjusted.

The hydraulic oil supplied from the electric pump 61 via the discharge pipe 64 is either the first oil chamber 87 or the second oil chamber 88 according to the relative angular displacement between the inner valve 93 and the outer valve 94. It is distributed to one side. Here, when the input shaft 91 is directed clockwise when viewed from the axial direction of the input shaft 91, the electric pump 61 and the first oil chamber 87 communicate with each other. On the other hand, when the input shaft 91 rotates counterclockwise when viewed from the axial direction of the input shaft 91, the electric pump 61 and the second oil chamber 88 communicate with each other.

For example, when the hydraulic oil is supplied to the second oil chamber 88, the ball screw nut 82 and the closing member 86 move toward the first oil chamber 87 side under the pressure of the hydraulic oil. As the ball screw nut 82 moves, the hydraulic oil inside the first oil chamber 87 is pushed out from the first oil chamber 87. The hydraulic oil extruded from the first oil chamber 87 is discharged to the reservoir tank 62 via the discharge pipe 65.

When the hydraulic oil is supplied to the first oil chamber 87, the ball screw nut 82 and the closing member 86 move toward the second oil chamber 88 side under the pressure of the hydraulic oil. As the ball screw nut 82 moves, the hydraulic oil inside the second oil chamber 88 is pushed out from the second oil chamber 88. The hydraulic oil extruded from the second oil chamber 88 is discharged to the reservoir tank 62 via the discharge pipe 65.

In this way, the supply or discharge of hydraulic oil to the first oil chamber 87 and the second oil chamber 88 is controlled according to the torque applied to the input shaft 91, that is, the rotation of the input shaft 91.
By the way, the input shaft 91 rotates in conjunction with the operation of the steering wheel 14. For example, the following configuration is adopted as a configuration for transmitting power from the steering wheel 14 to the input shaft 91.

As shown in FIG. 8, the steering shaft 16 is provided with a drive pulley 101 that can rotate integrally. Further, a driven pulley 102 is provided on the input shaft 91 of the control valve 72 so as to be integrally rotatable. The drive pulley 101 and the driven pulley 102 are connected to each other by two operation cables 103 and 104. The driven pulley 102 and the input shaft 91 rotate in conjunction with the rotation of the drive pulley 101.

The two operation cables 103 and 104 are in a state where their first ends are fixed to two side surfaces facing each other in the axial direction of the drive pulley 101, and a spiral groove provided on the outer peripheral surface of the drive pulley 101. In a state of being wound in a direction approaching each other along the above, the drive pulley 101 is pulled out in a direction intersecting the axis of the drive pulley 101.

Further, the second ends of the two operation cables 103 and 104 are fixed to two side surfaces facing each other in the axial direction of the driven pulley 102, similarly to the first ends of the operation cables 103 and 104. In a state of being wound in a direction of approaching each other along a spiral groove provided on the outer peripheral surface of the driven pulley 102, the driven pulley 102 is pulled out in a direction intersecting the axis of the driven pulley 102.

When the steering wheel 14 is operated when the ship 10 is turned, the drive pulley 101 rotates in conjunction with the operation of the steering wheel 14. As the drive pulley 101 rotates, one of the two operation cables 103 and 104 wound around the drive pulley 101 is pulled, and the other operation cable is loosened. As a result, the rotation of the drive pulley 101 is transmitted to the driven pulley 102. The input shaft 91 of the control valve 72 rotates in conjunction with the rotation of the driven pulley 102, and the sector gear 85 swings according to the rotation of the input shaft 91. The swing of the sector gear 85 is transmitted to the steering shaft 22 via the sector shaft 84, the lever 48, the link 49, and the steering bracket 23, so that the outboard motor 12 is steered.

Therefore, according to the second embodiment, the same effects as those of (1) to (3) of the first embodiment can be obtained. Further, the electric pump 61 is adopted as the hydraulic pump. Therefore, although it is necessary to provide a hydraulic pipe at 10a on the hull, the same effect as in (4) of the first embodiment can be obtained.

<Other embodiments>
The first and second embodiments may be modified as follows.
-In the first embodiment, the control device 15 is provided at an appropriate position on the hull 10a, but the control device 15 may be provided integrally with the motor 33.

-In the first embodiment, a worm reducer having a worm 53 and a worm wheel 52 is adopted as the reducer 32, but a belt transmission mechanism may be adopted instead of the worm reducer. That is, as shown in FIG. 10, the motor 33 is attached to the housing 50 of the speed reducer 32 in a posture in which its output shaft 33a is parallel to the shaft 51 of the speed reducer 32. A drive pulley 111 is provided on the output shaft 33a of the motor 33 so as to be integrally rotatable. Further, a driven pulley 112 is provided on the shaft 51 of the speed reducer 32 so as to be integrally rotatable. An endless belt 113 is wound between the drive pulley 111 and the driven pulley 112. The rotation of the motor 33 is transmitted to the shaft 51 and thus to the ball screw shaft 41 via the drive pulley 111, the belt 113 and the driven pulley 112.

In the second embodiment, a drive pulley 101, a driven pulley 102, and two operation cables 103 and 104 are adopted as a configuration for transmitting power from the steering wheel 14 to the input shaft 91 of the control valve 72. However, a motor may be adopted instead of these. In this case, the output shaft of the motor may be integrally rotatably connected to the input shaft 91, or torque can be transmitted to the input shaft 91 via a worm reducer or a speed reducer such as a belt transmission mechanism. It may be connected. The control device 15 controls the power supply to the motor according to the steering angle θ detected through the rotation angle sensor 17. Since the motor is used only for rotating the input shaft 91, a smaller and lower output motor can be adopted.

-In the first and second embodiments, the control device 15 may control both the steering actuators 13 and 60 and the engine 12a in the outboard motor 12.
-In the first and second embodiments, the rotation of the sector shaft 44 is transmitted to the steering bracket 23 via the lever 48 and the link 49, but the power transmission between the sector shaft 44 and the steering bracket 23 is performed. The following configuration may be adopted as the mechanism.

As shown in FIG. 9, on the upper surface of the sector gear 45 (the surface on the front side of the paper surface in FIG. 9), an interlocking shaft 44a is provided at a position near the teeth 45a. The interlocking shaft 44a is parallel to the sector shaft 44. Therefore, the interlocking shaft 44a swings in the left-right direction around the sector shaft 44 in conjunction with the sector gear 45. The upper end of the interlocking shaft 44a penetrates the housings 40 and 80 and is exposed to the outside. The upper end of the interlocking shaft 44a is slidably engaged with the elongated hole 23a provided in the steering bracket 23. Therefore, the steering bracket 23 swings in the left-right direction about the interlocking shaft 44a in conjunction with the sector gear 45. As a result, the outboard motor 12 is steered in the left-right direction around the steering shaft 22. By doing so, the configuration of the steering actuator 13 can be made simpler by adopting a configuration in which the lever 48 and the link 49 are omitted as the steering actuator 13.

-In the first and second embodiments, the steering actuators 13 and 60 are applied to the ship 10 on which the outboard motor 12 is mounted, but may be applied to the ship 10 having an inboard motor, for example.
As shown in FIG. 11, an engine 12a is provided as an inboard unit inside the hull 10a. The output of the engine 12a is transmitted to the propeller 12b via the propeller shaft 121 extending from the engine 12a toward the stern. The end of the propeller shaft 121 on the opposite side of the engine 12a penetrates the bottom of the hull 10a and is located outside the hull 10a. A propeller 12b is integrally rotatably connected to an end of the propeller shaft 121 on the opposite side of the engine 12a. A rudder 122 is rotatably supported at the stern of the hull 10a via a support shaft 123. Further, steering actuators 13 and 60 are provided near the stern of the hull 10a. The lever 48 of the steering actuators 13 and 60 is connected to the support shaft 123 via two links 124 and 125. The link 124 extends in the left-right direction with respect to the traveling direction of the ship 10. The link 125 extends along the front-rear direction of the hull 10a. The first end of the link 124 is rotatably connected to the lever 48. The second end, which is the end of the link 124 opposite to the lever 48, is rotatably connected to the first end of the link 125. The second end of the link 125 is fixed to the support shaft 123 of the rudder 122. Therefore, the swing of the lever 48 in the left-right direction about the sector shafts 44 and 84 is converted into the rotation of the support shaft 123 via the two links 124 and 125. The rudder 122 swings in the left-right direction about the support shaft 123, so that the traveling direction of the ship 10 is changed.

Incidentally, the steering actuators 13 and 60 may be applied to the ship 10 on which the inboard / outboard unit is mounted. The inboard and outboard unit consists of an integrated engine and drive unit. The drive unit is an integrated mechanism for transmitting the output of the outboard propeller and the engine to the propeller. The engine is installed near the stern inside the ship. The drive unit is provided so as to protrude outboard with respect to the stern. The drive unit can swing in the left-right direction with respect to the hull 10a and also functions as a rudder of the ship 10. The drive unit can be steered by transmitting the rotation of the sector shafts 44 and 84 of the steering mechanisms 31 and 71 of the steering actuators 13 and 60 to the drive unit as a steering force for steering the drive unit.

-In the first embodiment, the marine steering device is embodied as a bi-wire type steering actuator 13 in which the power transmission between the steering wheel 14 and the outboard motor 12 is separated, but the outboard motor 12 is manually operated. It may be embodied as a power steering device that assists the operation. In this case, it is possible to adopt a configuration in which the steering wheel 14, the steering shaft 16, and the rotation angle sensor 17 are omitted as the ship 10. As shown by the alternate long and short dash line in FIG. 2, the case 12c of the outboard motor 12 is integrally provided with a handle 12d extending toward the front of the hull 10a. The operator steers the outboard motor 12 by operating the handle 12d in the left-right direction. Further, the outboard motor 12 or the steering wheel 12d is provided with a torque sensor that detects the steering torque applied to the steering wheel 12d. The control device 15 controls the power supply to the motor 33 according to the steering torque detected through the torque sensor. The torque of the motor 33 is transmitted to the steering shaft 22 as an assist force via the reduction gear 32 and the steering mechanism 31, so that the outboard motor 12 is assisted in steering via the steering wheel 12d. Incidentally, the steering actuator 60 of the second embodiment can be embodied as a power steering device. In this case, the control device 15 controls the power supply to the electric pump 61 according to the steering torque detected through the torque sensor.

10 ... Ship, 10a ... Hull, 12 ... Outer unit (steering, propulsion device), 13, 60 ... Steering actuator (steering device for ships), 14 ... Steering wheel (steering wheel), 15 ... Control device, 22 ... Rolling Steering wheel, 23 ... Steering bracket, 31,71 ... Steering mechanism, 32 ... Reducer, 33 ... Motor (drive source), 40, 50 ... Housing, 41 ... Ball screw shaft constituting the first conversion mechanism, 42 ... Ball screw nuts constituting the first conversion mechanism, 42a ... rack teeth, 43 ... balls constituting the first conversion mechanism, 44 ... sector shafts (output shafts), 45 ... sector gears constituting the first conversion mechanism , 48 ... Lever constituting the second conversion mechanism, 49 ... Link constituting the second conversion mechanism, 61 ... Electric pump (drive source), 72 ... Control valve, 87 ... First oil chamber, 88 ... First 2 oil chambers, 122 ... steering wheels, 123 ... support shafts.

Claims (9)

A rudder mechanism that moves the rudder installed at the stern of a ship,
The driving source of the steering mechanism is provided.
The steering mechanism includes a housing fixed to the hull and
An output shaft rotatably supported with respect to the housing
A first conversion mechanism provided inside the housing to convert the power of the drive source into rotation of the output shaft, and
A marine steering device provided outside the housing and having a second conversion mechanism for converting the rotation of the output shaft into the operation of the rudder. The first conversion mechanism is
A ball screw shaft that is rotatably supported inside the housing and rotates with the operation of the drive source.
A ball screw nut that is screwed onto the ball screw shaft via a plurality of balls and has rack teeth provided along the axial direction on the outer peripheral surface.
A sector gear that is integrally rotatably connected to the output shaft and meshes with the rack teeth of the ball screw nut and swings around the output shaft as the ball screw nut moves in the axial direction. The marine steering device according to claim 1. The marine steering device according to claim 1 or 2, wherein the drive source is a motor. The drive source is a motor
The marine steering device according to claim 2, further comprising a speed reducer that decelerates the rotation of the motor and transmits the decelerated rotation to the ball screw shaft. The drive source is an electric pump that discharges hydraulic oil, and the ball screw nut is slidably provided with respect to the housing, and the inside of the housing is partitioned into two oil chambers by the ball screw nut. Assuming that
It has a control valve that controls the supply or discharge of hydraulic oil to the two oil chambers.
The control valve selectively supplies hydraulic oil discharged from the electric pump to one of the two oil chambers in response to an operation of a handle operated when changing the direction of the hull. The marine steering device according to claim 2, wherein the ball screw nut is moved along the axial direction as a piston. The rudder is an outboard unit that is rotatably provided on the outside of the stern as a propulsion device for a ship and also functions as a rudder for a ship by rotating around the rudder shaft. The marine steering device according to any one of items 1 to 5. The ship steering device according to any one of claims 1 to 5, wherein the rudder is rotatably provided on the outside of the stern around a support shaft separately from the ship propulsion device. The marine steering device according to any one of claims 1 to 7, wherein the rudder is separated from the power transmission between the rudder and the steering wheel operated when the hull is turned. A handle that is operated when changing the direction of the hull is connected to the rudder.
The marine steering device according to any one of claims 1 to 7, wherein the drive source generates an assist force that assists the movement of the rudder through the operation of the steering wheel.

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