JP2021172099A - Steering gear for ship - Google Patents

Abstract

To provide a steering gear for a ship capable of maintaining a ship attitude even if a reverse input acts on a rudder.SOLUTION: A steering gear for a ship has a steering actuator 13 including a ball screw shaft 43, a ball screw nut 41, and a sector gear 46. The sector gear 46 swings around a sector shaft 45 in accompany with the movement of the ball screw nut 41 in the axial direction. The ball screw nut 41 is slidably provided with respect to a housing 40. The inside of the housing 40 is partitioned into two oil chambers 40a and 40b by the ball screw nut 41. Oil is sealed in the two oil chambers 40a and 40b. A communication passage 40c to communicate with the two oil chambers 40a and 40b is provided in the housing 40. An electromagnetic valve 49 is provided in the communicating passage 40c. A control device switches the electromagnetic valve 49 from an opened valve state to a closed valve state in the case of the situation where the steering position of an outboard engine is held.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 (steers) 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.

JP-A-2010-143413

In ships, there are concerns about the following. That is, in order to maintain the straight running state or the turning state of the ship, it is necessary to apply a steering holding force to the steering wheel and continue to hold the steering wheel. However, in this case, depending on the magnitude of the reverse input load acting on the outboard motor from the outside of the outboard motor, the steering position of the outboard motor, and eventually the attitude of the ship may not be maintained.

An object of the present invention is to provide a ship steering device capable of maintaining the attitude of a ship even when a reverse input acts on the rudder.

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, a drive source for the steering mechanism, and a control device for controlling the drive source. 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. The first mechanism, the second mechanism provided outside the housing to convert the rotation of the output shaft into the operation of the steering wheel, and the second mechanism provided inside the housing allow the operation of the first mechanism. It has a third mechanism that switches the state between the permissible state to be performed and the regulated state that regulates the operation of the first mechanism. When the control device is in a situation where the position of the rudder should be maintained, the control device switches the state of the third mechanism from the allowable state to the regulated state.

According to this configuration, when the position of the rudder should be maintained, the operation of the first mechanism is regulated by the third mechanism. Therefore, the operation of the output shaft of the steering mechanism and, by extension, the rudder is also regulated. Therefore, for example, the position of the rudder is maintained even when the reverse input acts on the rudder, so that the attitude of the ship can be maintained.

In the above-mentioned marine steering device, the control device may determine whether or not the rudder position should be maintained based on the steering angular velocity of the steering wheel operated when the hull is turned. good.

According to this configuration, it is possible to easily determine whether the rudder position should be maintained based on the steering state of the steering wheel.
In the above-mentioned marine steering device, when the control device is in a situation where the position of the rudder should be maintained and a reverse input load is applied to the rudder, the state of the third mechanism is described. You may switch from the permissible state to the regulated state.

According to this configuration, the position of the rudder should be maintained, and when a reverse input load is applied to the rudder, the operation of the first mechanism is regulated by the third mechanism. That is, even in the situation where the position of the rudder should be maintained, the operation of the first mechanism is permitted when the reverse input load is not applied to the rudder. Therefore, for example, it is possible to respond more quickly to a change in the course of a ship.

In the above-mentioned marine steering device, the control device determines whether or not a reverse input load is acting on the rudder based on the steering torque applied to the steering wheel operated when the hull is turned. You may do so.

The steering torque required to maintain the attitude of the ship differs between when the reverse input load is applied to the rudder and when the reverse input load is not applied to the rudder. Therefore, as described above, it is possible to determine whether or not a reverse input load is acting on the rudder based on the steering torque applied to the steering wheel.

In the above-mentioned marine steering device, the control device is in a situation where the position of the rudder should be maintained, and when the ship is in a turning state, the state of the third mechanism is changed from the permissible state to the regulated state. You may switch.

When the ship is turning, a reverse input load is more likely to be applied to the rudder than when the ship is going straight. Therefore, it is preferable to regulate the movement of the rudder when trying to maintain the turning state of the ship.

In the above-mentioned ship steering device, the control device may determine whether or not the ship is in a turning state based on the steering angle of the steering wheel operated when the hull is turned.

According to this configuration, it is possible to easily determine whether or not the ship is in a turning state based on the steering angle of the steering wheel.
In the marine steering device, the first mechanism includes a ball screw shaft that is rotatably supported inside the housing and rotates according to the operation of the drive source, and a plurality of balls on the ball screw shaft. The ball screw nut is screwed together and has rack teeth provided along the axial direction on the outer peripheral surface, and is integrally rotatably connected to the output shaft and meshes with the rack teeth of the ball screw nut. It may have a sector gear that swings around the output shaft as the ball screw nut moves in the axial direction. In this case, the ball screw nut is provided so as to be slidable with respect to the housing, the inside of the housing is partitioned into two liquid chambers by the ball screw nut, and the two liquid chambers. Is electrically driven to open and close the communication passage as the third mechanism on the premise that the hydraulic fluid is sealed and the housing is provided with a communication passage for communicating the two liquid chambers. A valve is provided, and the movement of the ball screw nut is permitted when the electric drive valve is open, while the movement of the ball screw nut is restricted when the electric drive valve is closed. You may do so.

According to this configuration, when the electrically driven valve is open, the two liquid chambers communicate with each other, so that the hydraulic fluids sealed in the two liquid chambers can move back and forth between the two liquid chambers through the communication passage. .. Therefore, the movement of the ball screw nut is allowed. When the electrically driven valve is closed, the two liquid chambers are shut off from each other, so that the hydraulic fluids sealed in the two liquid chambers cannot move back and forth through the communication passage. Therefore, the movement of the ball screw nut is restricted by the pressure of the hydraulic fluid. By controlling the opening and closing of the electric drive valve in this way, it is possible to allow or regulate the movement of the ball screw nut.

In the above-mentioned marine steering device, the electric drive valve can adjust the opening degree steplessly by controlling the supplied current, and the control device changes the direction of the hull. The current supplied to the electric drive valve may be controlled according to the steering angle speed of the steering wheel operated at the time.

According to this configuration, the opening degree of the electric drive valve is adjusted according to the steering angular velocity of the steering wheel. Therefore, the degree of regulation of the movement of the ball screw nut changes according to the steering angular velocity of the steering wheel. Therefore, it is possible to suppress the influence of the reverse input load acting on the rudder while allowing the operation of the steering wheel.

In the marine steering device, the first mechanism includes a ball screw shaft that is rotatably supported inside the housing and rotates according to the operation of the drive source, and a plurality of balls on the ball screw shaft. The ball screw nut is screwed together and has rack teeth provided along the axial direction on the outer peripheral surface, and is integrally rotatably connected to the output shaft and meshes with the rack teeth of the ball screw nut. It may have a sector gear that swings around the output shaft as the ball screw nut moves in the axial direction. In this case, the third mechanism is the first rotation restricting member fixed to the end of the ball screw shaft and the first rotation restricting member in a state where rotation around the axis of the ball screw shaft is restricted. A second rotation regulation that moves between a first position that is separated from the rotation regulation member and a second position that engages with the first rotation regulation member and regulates the rotation of the ball screw shaft. It may have a member and.

According to this configuration, when the position of the rudder should be maintained, the second rotation restricting member moves from the first position to the second position and engages with the first rotation regulating member. Restricts the operation of the first mechanism. Therefore, the operation of the output shaft of the steering mechanism and, by extension, the rudder can be regulated.

In the marine steering device, the portion of the housing corresponding to the first rotation restricting member is opened toward the direction along the axis of the ball screw shaft, and the opened portion is the housing. Assuming that the cover is closed by the cover as a part of the ball screw shaft, the cover is along the axis of the ball screw shaft in a state where the relative rotation about the axis of the ball screw shaft is restricted with respect to the housing. The second rotation restricting member may be fixed to the inside of the cover so as to be relatively movable back and forth.

According to this configuration, when the position of the rudder should be maintained, the second rotation restricting member moves from the first position to the second position together with the cover and engages with the first rotation restricting member. By doing so, the operation of the first mechanism is restricted.

In the above-mentioned marine steering device, the ball is provided on the opposite side of the second rotation-regulating member from the first rotation-regulating member, and the rotation around the axis of the ball screw shaft is restricted. A first cam member that moves integrally with the second rotation restricting member in a direction along the axis of the screw shaft and a first cam member that faces the first cam member in a direction along the axis of the ball screw shaft. , The second cam member that rotates about the axis of the ball screw shaft in a state where the movement of the ball screw shaft in the direction along the axis is restricted, the first cam member, and the second cam. It may have a plurality of balls held between the members. In this case, as the second cam member rotates, the first cam member moves in a direction away from the second cam member via the ball, so that the second rotation regulating member May be engaged with the first rotation restricting member.

According to this configuration, when the position of the rudder should be maintained, the first cam member moves in a direction away from the second cam member through the rotation of the second cam member. The second rotation restricting member is engaged with the first rotation regulating member.

In the above-mentioned marine steering device, assuming that the drive source is a motor, a worm connected to the output shaft of the motor and a worm wheel provided so as to be rotatable integrally with the ball screw shaft and mesh with the worm. The third mechanism may be provided at the end of the worm on the opposite side of the motor as the worm instead of the ball screw shaft whose rotation is restricted.

According to this configuration, when the position of the rudder should be maintained, the state of the third mechanism changes from the allowable state of allowing the rotation of the worm, which is the object of rotation regulation, to the regulated state of restricting the rotation of the worm. Switch. By restricting the rotation of the worm, the operation of the first mechanism can be regulated.

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 is connected to a handle that is operated when the hull is turned, and the drive source is an assist force that assists the movement of the rudder through the operation of the handle. May be generated.

According to the ship steering device of the present invention, the attitude of the ship can be maintained even when the reverse input acts on the rudder.

The plan view of the 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. (A) is a schematic diagram showing the configuration of the solenoid valve in the first embodiment, and (b) is a schematic diagram showing the configuration of the solenoid valve in another embodiment. The flowchart which shows the processing procedure of the control apparatus in 1st Embodiment. The graph which shows the map which defines the relationship between the steering angular velocity and the current supplied to a solenoid valve in 2nd Embodiment. (A) is a graph showing a map defining the relationship between the steering angular velocity and the first reverse input determination threshold value in the third embodiment, and (b) is the steering angular velocity and the second in the third embodiment. A graph showing a map that defines the relationship with the reverse input judgment threshold value of. The flowchart which shows the processing procedure of the control apparatus in 3rd Embodiment. The flowchart which shows the processing procedure of the control apparatus in 4th Embodiment. FIG. 5 is a plan sectional view of a steering actuator according to a fifth embodiment. FIG. 5 is a cross-sectional view of a main part of a steering actuator showing a state in which a clutch is connected according to a fifth embodiment. (A) is a cross-sectional view of a main part of the steering actuator showing a state in which the clutch is disengaged in the sixth embodiment, and (b) is a steering actuator showing a state in which the clutch is connected in the sixth embodiment. Sectional view of the main part of. (A) is a cross-sectional view of a main part of the steering actuator showing a state in which the clutch is disengaged in the seventh embodiment, and (b) is a steering actuator showing a state in which the clutch is connected in the seventh embodiment. Sectional view of the main part of. FIG. 3 is a perspective view of a speed reducer provided with a clutch according to the eighth embodiment. The perspective view which shows the inboard motor of the ship in 9th 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 (left-right 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 speed reducer 32 has a housing 50. The housing 50 is connected to the steering mechanism 31. 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 43. 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 (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.

The steering mechanism 31 has a housing 40. Inside the housing 40, a ball screw nut 41, a bottomed tubular closing member 42, a ball screw shaft 43, a plurality of balls 44, a sector shaft 45 as an output shaft, and a sector gear 46 are provided.

The ball screw nut 41 is slidably provided with respect to the housing 40 (more accurately, the cylinder portion thereof) in the direction along the axis thereof. Rack teeth 41a are provided on the outer peripheral surface of the ball screw nut 41 along the axial direction thereof.

The closing member 42 is fitted without a gap to the first end portion (left end portion in FIG. 4) of the ball screw nut 41. The closing member 42 moves integrally with the ball screw nut 41.
The ball screw shaft 43 is screwed into the ball screw nut 41 via a plurality of circulatory balls 44. The first end portion (left end portion in FIG. 4) of the ball screw shaft 43 is inserted inside the closing member 42. A predetermined gap is provided between the first end of the ball screw shaft 43 and the bottom wall of the closing member 42. The ball screw nut 41 is movable relative to the ball screw shaft 43 along the axial direction within the range of the gap between the ball screw shaft 43 and the bottom wall of the closing member 42. The second end portion (right end portion in FIG. 4) of the ball screw shaft 43 protrudes from the second end portion (right end portion in FIG. 4) of the ball screw nut 41. The second end of the ball screw shaft 43 is integrally rotatably connected to the second end (left end in FIG. 4) of the shaft 51 of the speed reducer 32.

The sector shaft 45 extends along a direction orthogonal to the axis of the ball screw nut 41 (direction orthogonal to the paper surface in FIG. 4). The sector shaft 45 is rotatably supported with respect to the housing 40 via bearings (not shown).

The sector gear 46 is provided so as to be integrally rotatable with respect to the sector shaft 45. The teeth 46a of the sector gear 46 mesh with the rack teeth 41a of the ball screw nut 41. The upper end of the sector shaft 45 is exposed to the outside of the housing 40. An end portion of the steering bracket 23 opposite to the steering shaft 22 is rotatably connected to the upper end portion of the sector shaft 45 via a lever 47 and a link 48 (see FIG. 3).

The inside of the housing 40 is divided into a first oil chamber 40a and a second oil chamber 40b by a ball screw nut 41, a closing member 42, and a speed reducer 32. The first oil chamber 40a is located on the speed reducer 32 side with respect to the ball screw nut 41. The second oil chamber 40b is located on the opposite side of the speed reducer 32 with respect to the ball screw nut 41. As shown in FIG. 4 with a shading consisting of a large number of dots, oil as a hydraulic fluid is sealed inside the first oil chamber 40a and the second oil chamber 40b. Further, the housing 40 is provided with a communication passage 40c that communicates between the first oil chamber 40a and the second oil chamber 40b. The communication passage 40c is provided with a solenoid valve (SV) 49 as an electrically driven valve, which is an electrically driven valve. The solenoid valve 49 opens and closes the communication passage 40c.

When the solenoid valve 49 is in the valve open state, the ball screw nut 41 is allowed to move in the axial direction. For example, when the ball screw nut 41 tries to move to the left in FIG. 4, the oil in the second oil chamber 40b is pushed by the ball screw nut 41 and the closing member 42 and is pushed through the communication passage 40c. It flows into the oil chamber 40a of 1. As a result, the ball screw nut 41 can move to the left in FIG. Further, when the ball screw nut 41 tries to move to the right in FIG. 4, the oil in the first oil chamber 40a is pushed by the ball screw nut 41 and the second oil is pushed through the communication passage 40c. It flows into the chamber 40b. As a result, the ball screw nut 41 can be moved to the right in FIG.

When the solenoid valve 49 is in the closed state, the movement of the ball screw nut 41 along the axial direction is restricted. For example, when the ball screw nut 41 tries to move to the left in FIG. 4, the oil in the second oil chamber 40b cannot escape to the first oil chamber 40a through the communication passage 40c. Further, when the ball screw nut 41 tries to move to the right in FIG. 4, the oil in the first oil chamber 40a cannot escape to the second oil chamber 40b through the communication passage 40c. Therefore, the pressure of the oil restricts the ball screw nut 41 from moving along its axial direction.

As shown in FIG. 5A, the solenoid valve 49 is maintained in the open state when the solenoid is in a non-energized state in which power is not supplied to the solenoid. When the solenoid valve 49 is in the open state, the first oil chamber 40a and the second oil chamber 40b communicate with each other. The solenoid valve 49 is maintained in a closed state when it is in an energized state in which electric power is supplied to its solenoid. When the solenoid valve 49 is in the closed state, the communication between the first oil chamber 40a and the second oil chamber 40b is cut off.

Next, the operation of the steering actuator 13 will be described. However, the solenoid valve 49 is maintained in the open state.
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. By the way, the control device 15 transfers to the motor 33 based on the rotation angle of the sector shaft 45, 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 43 via the speed reducer 32. As the ball screw shaft 43 rotates, the ball screw nut 41 and the closing member 42 function as pistons and move along the ball screw shaft 43. As the ball screw nut 41 moves, the sector gear 46 that meshes with the rack teeth 41a swings in the left-right direction around the sector shaft 45. With the swing of the sector gear 46, the sector shaft 45 rotates in the same direction as the swing direction of the sector gear 46 and according to the swing amount of the sector gear 46.

The lever 47 swings in the left-right direction around the sector shaft 45 in conjunction with the rotation of the sector shaft 45. The swing of the lever 47 is transmitted to the steering bracket 23 via the link 48, so that the steering bracket 23 swings in the left-right direction about the steering shaft 22. Since the steering shaft 22 is fixed to the steering bracket 23, torque around the shaft is applied to the steering shaft 22 as the steering bracket 23 swings. Since the steering shaft 22 is fixed to the case 12c of the outboard motor 12, the outboard motor 12 swings in the left-right direction about the steering shaft 22 as the steering shaft 22 rotates.

The ball screw nut 41, the ball screw shaft 43, and the ball 44 form a ball screw mechanism. Further, the ball screw mechanism (41, 43, 44) and the sector gear 46 provide a first mechanism for converting the power of the motor 33, which is the drive source of the steering actuator 13, into the rotation of the sector shaft 45, which is the output shaft. Constitute. Further, the lever 47 and the link 48 form a second mechanism that converts the rotation of the sector shaft 45, which is an output shaft, into the steering operation of the outboard motor 12. Further, the solenoid valve 49 constitutes a third mechanism for switching between a permissible state that allows the operation of the ball screw nut 41 and a regulated state that regulates the operation of the ball screw nut 41.

Here, in a ship provided with an outboard motor 12, there are concerns about the following. That is, when the steering wheel 14 is held in order to keep the ship in a straight-ahead state or a turning state, the steering position of the outboard motor 12 may be changed depending on the magnitude of the reverse input such as the water pressure acting on the outboard motor 12. It may not be possible to maintain. Therefore, when the control device 15 is in a situation where the steering position of the outboard motor 12 should be maintained, that is, when the operator is holding the steering wheel 14 with the intention of holding the steering wheel, the outboard motor 12 In order to suppress the influence of the reverse input on the steering position, the following processing is executed at a predetermined calculation cycle.

As shown in the flowchart of FIG. 6, the control device 15 acquires the steering angle information (step S101). That is, the control device 15 captures the steering angle θ detected through the rotation angle sensor 17. Further, the control device 15 calculates the steering angular velocity ω of the steering wheel 14 by differentiating the steering angle θ detected through the rotation angle sensor 17.

Next, the control device 15 determines whether or not the steering wheel 14 is in a steered state (step S102).
As shown by the following equation (A), the control device 15 determines the steering state of the steering wheel 14 by comparing the steering angular velocity ω calculated in step S101 with the angular velocity threshold value ω _th. The angular velocity threshold value ω _th is a reference for determining whether or not the steering wheel 14 is in a steered state.

│ ω │ <ω _th … (A)
Controller 15, when the absolute value of the steering angular velocity omega is not a value smaller than the angular velocity threshold omega _th (NO at step S102), opens the solenoid valve 49 (step S103), and ends the process. In this case, the steering wheel 14 is in a state of being rotated. Further, by opening the solenoid valve 49, the ball screw nut 41 is allowed to move along the axial direction, and the outboard motor 12 is allowed to steer. Therefore, the outboard motor 12 steers according to the steering angle θ of the steering wheel 14.

When the absolute value of the steering angular velocity ω _{is smaller than the angular velocity threshold value ω th} (YES in step S102), the control device 15 closes the solenoid valve 49 (step S104) and ends the process. In this case, the steering wheel 14 is in a state of being held. Further, by closing the solenoid valve 49, the movement of the ball screw nut 41 along the axial direction and the steering operation of the outboard motor 12 are restricted. Therefore, even when the reverse input acts on the outboard motor 12, the rudder position, that is, the steering position of the outboard motor 12 is maintained.

Therefore, according to the first embodiment, the following effects can be obtained.
(1) When the steering state of the steering wheel 14 is in the steered state, the solenoid valve 49 is switched from the valve open state to the valve closed state. As a result, the oil sealed in the first oil chamber 40a and the second oil chamber 40b cannot move back and forth between the first oil chamber 40a and the second oil chamber 40b. Therefore, the movement of the ball screw nut 41 along the axial direction and the steering operation of the outboard motor 12 are restricted. Therefore, when the steering wheel 14 is held in order to keep the ship in a straight-ahead state or a turning state, the outboard motor 12 rolls even when a larger reverse input load is applied to the outboard motor 12. The steering position can be maintained.

(2) Further, the inside of the housing 40 of the steering mechanism 31 is filled with oil. Therefore, the ball screw mechanism (41, 43, 44) can be kept in a better lubricated state.

<Second Embodiment>
Next, a second embodiment of the marine steering device will be described. This embodiment basically has the same configuration as the first embodiment shown in FIGS. 1 to 5. This embodiment differs from the first embodiment in that for controlling the energization to the electromagnetic valve 49 without performing a comparison between the steering angular velocity omega and the angular velocity threshold omega _th of the steering wheel 14.

The control device 15 controls the energization of the solenoid valve 49 by using the map M1 shown in the graph of FIG. 7. The map is stored in the storage device of the control device 15.
As shown in the graph of FIG. 7, the map M1 is a two-dimensional map in which the horizontal axis is the absolute value of the steering angular velocity ω and the vertical axis is the value of the current I supplied to the solenoid valve 49, and has the following characteristics. That is, as shown in the region R1 in the graph of FIG. 7, the period during which the absolute value of the steering angular velocity ω is a small value (a value near “0” or “0”) that is considered to be in the steering holding state. The value of the current I slightly increases as the absolute value of the steering angular velocity ω increases. However, the value of the current I during this period is maintained at a small value (a value close to "0" or "0") so that the solenoid valve 49 does not operate. As shown in the area R2 in the graph of FIG. 7, the rate of change of the value of the current I with respect to the absolute value of the steering angular velocity ω at the timing when the absolute value of the steering angular velocity ω reaches a value that is considered to be the cut-in steering state. (Inclination of the characteristic line shown in FIG. 7) increases sharply, and the value of the current I reaches a value at which the solenoid valve 49 operates.

By controlling the energization of the solenoid valve 49 based on the map M1, the absolute value of the steering angular velocity ω becomes larger. The solenoid valve 49 is maintained in the open state during the incision steering, while the absolute value of the steering angular velocity ω is ". The solenoid valve 49 is maintained in the closed state when the steering is maintained at a value close to "0" or "0".

Therefore, according to the second embodiment, the same effects as those of (1) and (2) of the first embodiment can be obtained.
Incidentally, as shown in FIG. 5B, a proportional control valve may be used as the solenoid valve 49. The proportional control valve can adjust the opening degree steplessly between 0% and 100% by controlling the supplied current. By controlling the power supply to the solenoid valve 49 based on the map M1, the opening degree of the solenoid valve 49 is adjusted according to the steering angular velocity ω. Therefore, the degree of restricting the movement of the ball screw nut 41 can be changed according to the steering angular velocity ω. Therefore, when the proportional control valve is used as the solenoid valve 49, the influence of the reverse input load acting on the outboard motor 12 can be suppressed while allowing the operation of the steering wheel 14.

<Third embodiment>
Next, a third embodiment of the marine steering device will be described. This embodiment basically has the same configuration as the first embodiment shown in FIGS. 1 to 5. The present embodiment is different from the first embodiment mainly in the processing procedure for suppressing the influence of the reverse input on the steering position of the outboard motor 12.

As shown by the alternate long and short dash line in FIG. 4, a torque sensor 60 is provided inside the housing 40 of the steering mechanism 31. The torque sensor 60 detects the torque applied to the sector shaft 45.

The control device 15 controls the energization of the solenoid valve 49 by using not only the steering angular velocity ω but also the torque detected through the torque sensor 60. In the control device 15, when the steering wheel 14 is in a steered state, a reverse input load acts on the outboard motor 12 by comparing the torque detected through the torque sensor 60 with the reverse input determination threshold value. It is determined whether or not the solenoid valve 49 is open and closed, and the opening and closing of the solenoid valve 49 is controlled according to the determination result.

The control device 15 calculates the _first reverse input determination threshold value T1 using the map M2 shown in the graph of FIG. 8A. The first reverse input determination threshold value T ₁ determines whether or not the direction of the reverse input load with respect to the outboard motor 12 is opposite to the steering direction of the outboard motor 12 (steering direction of the steering wheel 14). It is for judging. As shown in the graph of FIG. 8 (a), the map M2 defines the absolute value and the first relationship between the reverse input determination threshold T ₁ of the steering angular velocity omega. The first reverse input determination threshold value T ₁ gradually increases as the absolute value of the steering angular velocity ω increases. The map M2 is stored in the storage device of the control device 15.

The control device 15 calculates the _second reverse input determination threshold value T2 using the map M3 shown in the graph of FIG. 8B. The second reverse input determination threshold value T ₂ is for determining whether or not the direction of the reverse input load with respect to the outboard motor 12 is the same as the steering direction of the outboard motor 12. The map M3 is stored in the storage device of the control device 15.

As shown in the graph of FIG. 8 (b), the map M3 defines the absolute value and the second reverse input determination between the threshold T ₂ of the steering angular velocity omega. The second reverse input determination threshold value T ₂ is set to a value smaller than _{the first reverse input determination threshold value T 1} regardless of the absolute value of the steering angular velocity ω. _{The second reverse input determination threshold value T 2} is maintained at “0” during the period until the absolute value of the steering angular velocity ω reaches a predetermined value based on “0”. After the absolute value of the steering angular velocity ω reaches a predetermined value based on “0”, the second reverse input determination threshold value T ₂ gradually increases as the absolute value of the steering angular velocity ω increases.

Next, a processing procedure for suppressing the influence of the reverse input on the steering position of the outboard motor 12 executed by the control device 15 will be described with reference to the flowchart of FIG. The processing of the flowchart of FIG. 9 is executed at a predetermined calculation cycle.

As shown in the flowchart of FIG. 9, the control device 15 acquires the steering angle information (step S201). That is, the control device 15 captures the steering angle θ detected through the rotation angle sensor 17. Further, the control device 15 calculates the steering angular velocity ω of the steering wheel 14 by differentiating the steering angle θ detected through the rotation angle sensor 17.

Next, the control device 15 determines whether or not the steering wheel 14 is in a steered state (step S202). As shown in the above equation (A), the control device 15 determines the steering state of the steering wheel 14 by comparing the steering angular velocity ω calculated in step S201 with the angular velocity threshold value ω _th.

When the absolute value of the steering angular velocity ω _{is not smaller than the angular velocity threshold value ω th} (NO in step S202), the control device 15 opens the solenoid valve 49 (step S203) and ends the process. In this case, the steering wheel 14 is in a state of being rotated. Further, by opening the solenoid valve 49, the ball screw nut 41 is allowed to move along the axial direction, and the outboard motor 12 is allowed to steer. Therefore, the outboard motor 12 steers according to the steering angle θ of the steering wheel 14.

The control device 15 acquires torque information when the absolute value of the steering angular velocity ω _{is smaller than the angular velocity threshold value ω th} (YES in step S202) (step S204). That is, the control device 15 takes in the torque T detected through the torque sensor 60.

Next, the control device 15 calculates the reverse input determination threshold value (step S205). Based on the maps M2 and M3 shown in the graphs of FIGS. 8A and 8B above, the control device 15 has a first reverse input determination threshold value T1 and a _first reverse input determination threshold value T1 according to the absolute value of the steering angular velocity ω. The reverse input determination threshold value T ₂ of 2 is calculated.

Next, the control device 15 determines whether the steering direction of the steering wheel 14 and the steering direction of the outboard motor 12 are directions corresponding to each other.
The control device 15 determines whether or not both of the following two conditions B1 and B2 are satisfied (step S206). Incidentally, for example, the signs of the steering angular velocity ω and the torque T when the ship is turning right with respect to the straight-ahead direction are positive.

ω> 0… (B1)
T> 0 ... (B2)
When both of the two conditions B1 and B2 are satisfied (YES in step S206), the control device 15 determines whether or not the reverse input load from the outboard motor 12 is acting on the steering mechanism 31 (step S207). .. That is, the control device 15 determines, for example, whether the following condition B3 is satisfied.

T> T ₁ ... (B3)
When the condition B3 is satisfied (YES in step S207), the control device 15 closes the solenoid valve 49 (S208) and ends the process. When the value of the torque T is larger than the first reverse input determination threshold value T _1, a reverse input load in the direction opposite to the original steering direction of the outboard motor 12 is applied to the steering mechanism 31. It can be said that this is the situation.

When the condition B3 is not satisfied (NO in step S207), the control device 15 opens the solenoid valve 49 (S209) and ends the process. When the value of the torque T is not larger than the first reverse input determination threshold value T ₁ , it can be said that the steering wheel 14 in the steering holding state is operated by the operator.

In the previous step S206, when at least one of the two conditions B1 and B2 is not satisfied (NO in step S206), the control device 15 determines whether or not both of the following two conditions B4 and B5 are satisfied (NO). Step S210). Incidentally, for example, the signs of the steering angular velocity ω and the torque T when the ship is turning left with respect to the straight-ahead direction are negative.

ω <0 ... (B4)
T <0 ... (B5)
When both of the two conditions B1 and B2 are satisfied (YES in step S210), the control device 15 shifts the process to the previous step S207.

When at least one of the two conditions B1 and B2 is not satisfied (NO in step S210), the control device 15 determines, for example, whether the next condition B6 is satisfied (step S211).

T <T ₂ ... (B6)
When the condition B6 is satisfied (YES in step S211), the control device 15 closes the solenoid valve 49 (S212) and ends the process. When the value of the torque T is smaller than the second reverse input determination threshold value T _2, a reverse input load in the same direction as the original steering direction of the outboard motor 12 is applied to the steering mechanism 31. It can be said that this is the situation.

When the condition B6 is not satisfied (NO in step S211), the control device 15 opens the solenoid valve 49 (S213) and ends the process. When the value of the torque T is not smaller than the second reverse input determination threshold value T ₂ , it can be said that the steering wheel 14 in the steering holding state is operated by the operator.

Therefore, according to the third embodiment, the following effects can be obtained in addition to the effects (1) and (2) of the first embodiment.
(3) When the steering wheel 14 is in the steering holding state, it is determined whether or not the reverse input load from the outboard motor 12 is applied to the steering mechanism 31 based on the torque T detected through the torque sensor 60, and the determination is made. The opening and closing of the solenoid valve 49 is controlled based on the result. Therefore, even though the reverse input load from the outboard motor 12 does not act on the steering mechanism 31, it is possible to prevent the solenoid valve 49 from being accidentally closed.

<Fourth Embodiment>
Next, a fourth embodiment of the marine steering device will be described. This embodiment basically has the same configuration as the first embodiment shown in FIGS. 1 to 5. The present embodiment is different from the first embodiment in the processing procedure for suppressing the influence of the reverse input on the steering position of the outboard motor 12.

The processing procedure for suppressing the influence of the reverse input on the steering position of the outboard motor 12 executed by the control device 15 will be described with reference to the flowchart of FIG. The processing of the flowchart of FIG. 10 is executed at a predetermined calculation cycle.

As shown in the flowchart of FIG. 10, the control device 15 acquires the steering angle information (step S301). That is, the control device 15 captures the steering angle θ detected through the rotation angle sensor 17. Further, the control device 15 calculates the steering angular velocity ω of the steering wheel 14 by differentiating the steering angle θ detected through the rotation angle sensor 17.

Next, the control device 15 determines whether or not the steering wheel 14 is in a steered state (step S302). As shown in the above equation (A), the control device 15 determines the steering state of the steering wheel 14 by comparing the steering angular velocity ω calculated in step S301 with the angular velocity threshold value ω _th.

When the absolute value of the steering angular velocity ω _{is not smaller than the angular velocity threshold value ω th} (NO in step S302), the control device 15 opens the solenoid valve 49 (step S303) and ends the process. In this case, the steering wheel 14 is in a state of being rotated. Further, by opening the solenoid valve 49, the ball screw nut 41 is allowed to move along the axial direction, and the outboard motor 12 is allowed to steer. Therefore, the outboard motor 12 steers according to the steering angle θ of the steering wheel 14.

When the absolute value of the steering angular velocity ω _{is smaller than the angular velocity threshold value ω th} (YES in step S302), the control device 15 determines whether or not the following condition C1 is satisfied (step S304).

│ θ │ ＞ θ ₁ … (C1)
However, “θ” is the steering angle detected through the rotation angle sensor 17, and “θ ₁ ” is the turning determination threshold value. The turning determination threshold value θ ₁ is set with reference to a steering angle at which the ship can be said to turn.

When the condition C1 is satisfied (YES in step S304), the control device 15 closes the solenoid valve 49 (step S305) and ends the process. When the absolute value of the steering angle θ _{is larger than the turning determination threshold value θ 1,} it can be said that the ship is turning to the left or right with respect to the traveling direction.

When the condition C1 is not satisfied (NO in step S304), the control device 15 opens the solenoid valve 49 (step S306) and ends the process. When the absolute value of the steering angle θ is a value equal to _{or less than the turning determination threshold value θ 1} , it can be said that the ship is traveling straight.

Therefore, according to the fourth embodiment, the following effects can be obtained in addition to the effects (1) and (2) of the first embodiment.
(4) When the steering wheel 14 is in the steering holding state, it is determined whether the ship is in the turning state or the straight running state based on the steering angle θ detected through the rotation angle sensor 17, and the solenoid valve is determined based on the determination result. The opening and closing of 49 is controlled. When the steering wheel 14 is in the steering holding state, the steering of the outboard motor 12 is restricted by closing the solenoid valve 49 when the ship is turning. Further, even when the steering wheel 14 is in the steering holding state, the solenoid valve 49 is opened when the ship is traveling straight. This is because when the ship is traveling straight, a situation in which a reverse input load from the outboard motor 12 is applied to the steering mechanism 31 is less likely to occur than when the ship is turning. Rather, it is preferable to maintain the outboard motor 12 in a state where it can be steered immediately in preparation for steering of the steering wheel 14 by the operator.

<Fifth Embodiment>
Next, a fifth embodiment of the marine steering device will be described. This embodiment basically has the same configuration as the first embodiment shown in FIGS. 1 to 3 above. The present embodiment is different from the first embodiment in that the configuration for suppressing the influence of the reverse input on the steering position of the outboard motor 12 is suppressed. This embodiment may be applied to the second to fourth embodiments.

As shown in FIG. 11, no oil is sealed inside the housing 40 of the steering mechanism 31. The ball screw shaft 43 is rotatably supported with respect to the housing 40 via two bearings 61 and 62. The ball screw nut 41 moves along the axial direction in a non-contact state with respect to the housing 40 as the ball screw shaft 43 rotates. The ball screw nut 41 does not function as a piston.

A clutch 70 is provided in a portion of the ball screw shaft 43 opposite to the speed reducer 32 inside the housing 40. The clutch 70 has a first friction plate 71 and a second friction plate 72. The first friction plate 71 and the second friction plate 72 face each other in the axial direction of the ball screw shaft 43. The first friction plate 71 is fixed to the end of the ball screw shaft 43 opposite to the speed reducer 32. The second friction plate 72 is provided inside the housing 40 so as to be movable along the axis direction of the ball screw shaft 43 in a state where the rotation around the axis of the ball screw shaft 43 is restricted.

A support shaft 73 is fixed to a side surface (left side surface in FIG. 11) of the second friction plate 72 opposite to the first friction plate 71. The end of the support shaft 73 opposite to the second friction plate 72 penetrates the housing 40. The support shaft 73 is provided so as to be movable relative to the housing 40 and along the axial direction of the ball screw shaft 43. The support shaft 73 receives a driving force generated by a drive source 74 provided outside the housing 40, and moves back and forth integrally with the second friction plate 72 along the axial direction of the ball screw shaft 43.

The second friction plate 72 moves between the first position P1 shown in FIG. 11 and the second position P2 shown in FIG. 12 through the drive of the drive source 74. The first position P1 is a position where the second friction plate 72 is separated from the first friction plate 71. When the second friction plate 72 is held at the first position P1, the rotation of the ball screw shaft 43 and the movement of the ball screw nut 41 are allowed. The second position P2 is a position where the first friction plate 71 and the second friction plate 72 are frictionally engaged with each other by pressing the second friction plate 72 against the first friction plate 71. .. When the second friction plate 72 is held at the first position P1, the rotation of the ball screw shaft 43 and the movement of the ball screw nut 41 are restricted.

The control device 15 switches the state of the clutch 70 between the connected state and the disconnected state through the control of the drive source 74. The connected state of the clutch 70 is a state in which the second friction plate 72 is connected to the first friction plate 71, that is, the second friction plate 72 moves from the first position P1 to the second position P2. It means a state in which the friction plate 71 is engaged with the first friction plate 71. The disengaged state of the clutch 70 is a state in which the second friction plate 72 is disengaged with respect to the first friction plate 71, that is, the second friction plate 72 is held at the second position P2 and the first friction. A state of being separated from the plate 71.

The first friction plate 71 corresponds to the first rotation regulating member constituting the third mechanism. Further, the second friction plate 72 corresponds to a second rotation restricting member constituting the third mechanism.
When the present embodiment is applied to the first or second embodiment, the control device 15 is a process for suppressing the influence of the reverse input on the steering position of the outboard motor 12, as shown in FIG. A process similar to the process shown in the flowchart of the above is executed at a predetermined calculation cycle. However, the process of step S103 (“opening the solenoid valve 49”) in the flowchart of FIG. 6 is read as “disengaging the clutch 70”. Further, the process of step S104 (“closing the solenoid valve 49”) in the flowchart of FIG. 6 is read as “connecting the clutch 70”.

When the present embodiment is applied to the third embodiment, the control device 15 is shown in the flowchart of FIG. 9 as a process for suppressing the influence of the reverse input on the steering position of the outboard motor 12. The same processing as the processing shown is executed at a predetermined calculation cycle. However, the process of steps S208 and S212 (closing the solenoid valve 49) in the flowchart of FIG. 9 is read as "connecting the clutch 70". Further, the process of steps S209 and S213 (opening the solenoid valve 49) in the flowchart of FIG. 9 is read as "disengaging the clutch 70".

When the present embodiment is applied to the fourth embodiment, the control device 15 is shown in the flowchart of FIG. 10 as a process for suppressing the influence of the reverse input on the steering position of the outboard motor 12. The same processing as the processing shown is executed at a predetermined calculation cycle. However, the process of step S305 (closing the solenoid valve 49) in the flowchart of FIG. 10 is read as "connecting the clutch 70". Further, the process of step S306 (opening the solenoid valve 49) in the flowchart of FIG. 10 is read as "disengaging the clutch 70".

Therefore, according to the fifth embodiment, the following effects can be obtained.
(5) When the present embodiment is applied to the first or second embodiment, when the steering state of the steering wheel 14 is in a steered state, the clutch 70 is changed from the disengaged state to the clutch 70. Is switched to the connected state. The rotation of the ball screw shaft 43 is restricted by the frictional engagement of the second friction plate 72 with the first friction plate 71. Therefore, the movement of the ball screw nut 41 in the axial direction and the steering operation of the outboard motor 12 are restricted. Therefore, when the steering wheel 14 is held in order to keep the ship in a straight-ahead state or a turning state, the outboard motor 12 rolls even when a larger reverse input load is applied to the outboard motor 12. The steering position can be maintained.

(6) When the present embodiment is applied to the third embodiment, when the steering wheel 14 is in the steering holding state, the reverse from the outboard motor 12 is based on the torque T detected through the torque sensor 60. It is determined whether or not the input load is applied to the steering mechanism 31, and the engagement and disengagement of the clutch 70 is controlled based on the determination result. When the steering wheel 14 is in the steering holding state, the clutch 70 is switched from the disengaged state to the connected state when the reverse input load from the outboard motor 12 is applied to the steering mechanism 31. When the steering wheel 14 is in the steering holding state, the clutch 70 is maintained in the disengaged state when the reverse input load from the outboard motor 12 is not applied to the steering mechanism 31. Therefore, the state of the clutch 70 can be more appropriately switched between the disengaged state and the connected state based on whether or not the reverse input load from the outboard motor 12 is applied to the steering mechanism 31. Further, even though the reverse input load from the outboard motor 12 does not act on the steering mechanism 31, it is possible to prevent the clutch 70 from being erroneously connected.

(7) When the steering wheel 14 is in the steering holding state, it is determined whether the ship is in the turning state or the straight running state based on the steering angle θ detected through the rotation angle sensor 17, and the clutch 70 is determined based on the determination result. The contact and separation of is controlled. When the steering wheel 14 is in the steering holding state, the steering of the outboard motor 12 is restricted by switching the clutch 70 from the disengaged state to the connected state when the ship is turning. Further, even when the steering wheel 14 is in the steering holding state, the clutch 70 is maintained in the disengaged state when the ship is traveling straight. This is because when the ship is traveling straight, a situation in which a reverse input load from the outboard motor 12 is applied to the steering mechanism 31 is less likely to occur than when the ship is turning. Rather, it is preferable to maintain the outboard motor 12 in a state where it can be steered immediately in preparation for steering of the steering wheel 14 by the operator.

<Sixth Embodiment>
Next, a fifth embodiment of the marine steering device will be described. This embodiment basically has the same configuration as the fifth embodiment shown in FIG. 11 above. The fifth embodiment is described in terms of a configuration for suppressing the influence of the reverse input on the steering position of the outboard motor 12, more specifically, a configuration for moving the second friction plate 72. Different from the embodiment. This embodiment may be applied to the second to fourth embodiments.

As shown in FIG. 13, the portion of the housing 40 opposite to the speed reducer 32 is open. The open portion of the housing 40 is closed by a bottomed cylindrical cover 75 as a part of the housing 40. The cover 75 is fitted on the outer surface of the open portion of the housing 40. The cover 75 is provided so as to be movable back and forth along the axial direction of the ball screw shaft 43 in a state where the relative rotation of the ball screw shaft 43 with respect to the housing 40 is restricted. A second friction plate 72 is fixed to the inner bottom surface of the cover 75.

The cover 75 receives a driving force generated by a driving source 74 provided outside the housing 40, and moves back and forth along the axial direction of the ball screw shaft 43 integrally with the second friction plate 72. The second friction plate 72 moves between the first position P1 shown in FIG. 13 (a) and the second position P2 shown in FIG. 13 (b) through the drive of the drive source 74. The first position P1 is a position where the second friction plate 72 is separated from the first friction plate 71. The second position P2 is a position where the first friction plate 71 and the second friction plate 72 are frictionally engaged with each other.

The control device 15 switches the state of the clutch 70 between the connected state and the disconnected state through the control of the drive source 74, as in the fifth embodiment.
Therefore, according to the sixth embodiment, the same effects as those of (5), (6), and (7) of the fifth embodiment can be obtained.

<7th embodiment>
Next, a seventh embodiment of the marine steering device will be described. This embodiment basically has the same configuration as the fifth embodiment shown in FIG. 11 above. The fifth embodiment is described in terms of a configuration for suppressing the influence of the reverse input on the steering position of the outboard motor 12, more specifically, a configuration for moving the second friction plate 72. Different from the embodiment. This embodiment may be applied to the second to fourth embodiments.

As shown in FIG. 14A, a cam mechanism 80 is provided between the second friction plate 72 of the clutch 70 and the support shaft 73. The cam mechanism 80 includes a first cam member 81, a second cam member 82, and a plurality of balls 83.

A second friction plate 72 is fixed to the side surface of the first cam member 81 on the clutch 70 side (the right side surface in FIG. 14A). The first cam member 81 is provided so as to be movable back and forth along the axial direction of the ball screw shaft 43 in a state where the relative rotation of the ball screw shaft 43 with respect to the housing 40 around the axis is restricted. A plurality of cam groove portions 81b are provided on the side surface of the first cam member 81 opposite to the second friction plate 72 by providing a plurality of cam protrusions 81a. The cam protrusions 81a and the cam groove 81b are alternately provided around the axis of the first cam member 81. The cam protrusion 81a and the cam groove 81b are smoothly continuous around the axis of the first cam member 81.

The second cam member 82 has the same configuration as the first cam member 81. A plurality of cam groove portions 82b are provided on the side surface of the second cam member 82 on the first cam member 81 side by providing the plurality of cam protrusions 82a. The second cam member 82 is in a state where the movement of the ball screw shaft 43 with respect to the housing 40 in the axial direction is restricted, and relative rotation of the ball screw shaft 43 with respect to the housing 40 about the axis is allowed. It is provided in a closed state. A support shaft 73 is fixed to a side surface (left side surface in FIG. 14A) of the second cam member 82 opposite to the first cam member 81.

The ball 83 is provided between the first cam member 81 and the second cam member 82. The size of the ball 83 is set to a size that fits into the cam groove portion 81b of the first cam member 81 and the cam groove portion 82b of the second cam member 82.

The driving force generated by the driving source 74 is applied as torque to the support shaft 73. The second cam member 82 rotates about the support shaft 73 by applying torque via the support shaft 73.

The second cam member 82 rotates between the first rotation position P11 shown in FIG. 14A and the second rotation position P12 shown in FIG. 14B.
As shown in FIG. 14A, at the first rotation position P11, the cam protrusion 82a of the second cam member 82 is the cam protrusion 81a of the first cam member 81 in the axial direction of the ball screw shaft 43. It is a position facing the. Further, the first rotation position P11 is also a position where the cam groove portion 82b of the second cam member 82 faces the cam groove portion 81b of the first cam member 81 in the axial direction of the ball screw shaft 43. When the rotation position of the second cam member 82 is held at the first rotation position P11, the ball 83 is surrounded by the cam groove portion 81b of the first cam member 81 and the cam groove portion 82b of the second cam member 82. It is maintained in a state of being housed in the space.

As shown in FIG. 14B, in the second rotation position P12, the cam protrusion 82a of the second cam member 82 is formed in the cam groove portion 81b of the first cam member 81 in the axial direction of the ball screw shaft 43. It is the opposite position. The second rotation position P12 is also a position where the cam groove portion 82b of the second cam member 82 faces the cam protrusion 81a of the first cam member 81 in the axial direction of the ball screw shaft 43.

When torque is applied to the second cam member 82 held at the first rotation position P11 through the drive of the drive source 74, the second cam member 82 tries to rotate about the support shaft 73. .. Along with this, the cam protrusion 82a of the second cam member 82 gradually guides the ball 83 relative to the surface of the ball 83 held by the cam groove 81b of the first cam member 81. I will get on.

Here, the movement of the first cam member 81 in the axial direction is permitted, while the movement of the second cam member 82 in the axial direction is restricted. Therefore, as the cam protrusion 82a of the second cam member 82 rides on the ball 83, the first cam member 81 moves away from the second cam member 82 via the ball 83 (FIG. 14 (a). ), (B) to the right). As a result, the first cam member 81 moves away from the second cam member 82, while the second friction plate 72 moves toward the first friction plate 71. Eventually, the second friction plate 72 reaches the second position where it engages with the first friction plate 71 at the timing when the rotation position of the second cam member 82 reaches the second rotation position P12.

The control device 15 switches the state of the clutch 70 between the connected state and the disconnected state through the control of the drive source 74, as in the fifth embodiment.
Therefore, according to the seventh embodiment, the same effects as those of (5), (6), and (7) of the fifth embodiment can be obtained. The first cam member 81, the second cam member 82, and the ball 83 form a third mechanism.

<Eighth Embodiment>
Next, an eighth embodiment of the marine steering device will be described. This embodiment is different from the fifth embodiment in that the clutch 70 is installed. This embodiment may be applied to the second to fourth embodiments.

As shown in FIG. 15, the clutch 70 is provided at the end of the speed reducer 32 on the worm 53 opposite to the motor 33. Rotation of the worm 53 is allowed while the clutch 70 is maintained in the disengaged state. Therefore, the rotation of the motor 33 is also allowed. When the clutch 70 is kept engaged, the rotation of the worm 53 is restricted. Therefore, the rotation of the motor 33 is also regulated. Further, since the rotation of the worm wheel 52 and the ball screw shaft 43 is also restricted, the movement of the ball screw nut 41 along the axial direction and the steering operation of the outboard motor 12 are restricted.

Therefore, according to the eighth embodiment, in addition to the same effects as the effects of (5), (6), and (7) of the fifth embodiment, the following effects can be obtained.
(8) The clutch 70 is provided at the end of the worm 53 on the opposite side of the motor 33. That is, when regulating the steering operation of the outboard motor 12, the clutch 70 regulates the rotation of the worm 53, that is, the rotation of the motor 33 before being decelerated by the speed reducer 32. Therefore, it is possible to reduce the frictional engagement force of the clutch 70 as compared with the case where the clutch 70 regulates the rotation of the ball screw shaft 43.

<9th embodiment>
Next, a ninth embodiment of the marine steering device will be described. This embodiment differs from the first embodiment in that the type of ship 10 on which the steering actuator 13 is mounted is different. The present embodiment may be applied to the second to eighth embodiments.

In the first embodiment, the steering actuator 13 is applied to the ship 10 on which the outboard motor 12 is mounted, but it may be applied to the ship 10 having an inboard motor, for example.
As shown in FIG. 16, an engine 12a is provided as an inboard motor inside the hull 10a. The output of the engine 12a is transmitted to the propeller 126 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 126 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, a steering actuator 13 is provided near the stern of the hull 10a. The lever 47 of the steering actuator 13 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 47. The second end, which is the end of the link 124 opposite to the lever 47, 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 47 in the left-right direction about the sector shaft 45 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 actuator 13 may be applied to the ship 10 on which the inboard / outboard unit is mounted. The inboard / 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 shaft 45 of the steering mechanism 31 of the steering actuator 13 to the drive unit as a steering force for steering the drive unit.

Therefore, according to the ninth embodiment, even when the steering actuator 13 is mounted on the ship 10 having the inboard motor or the inboard motor, the same effect as that of the first to eighth embodiments is obtained. Obtainable.

<Other embodiments>
In addition, each embodiment may be changed and carried out as follows.
-In each embodiment, an electric valve may be adopted as the electric drive valve instead of the solenoid valve 49. The electric valve drives the valve body by a motor.

-In each embodiment, as the clutch 70, a multi-plate electromagnetic clutch in which a plurality of clutch plates are alternately stacked may be adopted. The multi-plate electromagnetic clutch has an exciting coil. Power is interrupted through the interruption of energization of the exciting coil. The control device 15 switches the engagement and disengagement of the clutch 70 through the interruption and disengagement control of the energization of the exciting coil of the clutch 70. By adopting a multi-plate electromagnetic clutch as the clutch 70, it is possible to make the outer diameter of the clutch 70 smaller while maintaining the allowable amount of torque transmission (total frictional engagement force). In addition, it is possible to further alleviate the impact caused by the frictional change before and after the clutch plates are frictionally engaged.

-In each embodiment, a friction clutch is used as the clutch 70, but a meshing clutch may be used. In this case, instead of the two friction plates, two clutch members having teeth or claws that mesh with each other are used.

-In the first to seventh embodiments, 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.

-In each 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 each embodiment, the control device 15 may control both the steering actuator 13 and the engine 12a in the outboard motor 12.

-In each 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 manual operation of the outboard motor 12 is performed. It may be embodied as an auxiliary power steering device. 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 ship 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.

10 ... Ship 10a ... Hull 12 ... Outboard motor (rudder)
12d ... Handle 13 ... Steering actuator (steering device for ships)
14 ... Steering wheel (steering wheel)
15 ... Control device 22 ... Steering shaft,
31 ... Steering mechanism 33 ... Motor (drive source)
40, 50 ... Housing 40a ... First oil chamber (liquid chamber)
40b ... Second oil chamber (liquid chamber)
40c ... Communication passage 41 ... Ball screw nut forming the first mechanism 41a ... Rack tooth 43 ... Ball screw shaft forming the first mechanism 44 ... Ball 45 forming the first mechanism 45 ... Sector shaft (output shaft)
46 ... Sector gear constituting the first mechanism 47 ... Lever constituting the second mechanism 48 ... Link forming the second mechanism 49 ... Solenoid valve as an electric drive valve (third mechanism)
53 ... Warm 54 ... Worm wheel 71 ... First friction plate constituting the third mechanism (first rotation regulating member)
72 ... Second friction plate (second rotation restricting member) constituting the third mechanism
75 ... Cover 81 ... First cam member constituting the third mechanism 82 ... Second cam member constituting the third mechanism 83 ... Ball 122 constituting the third mechanism 122 ... Rudder

Claims (16)

A rudder mechanism that moves the rudder installed at the stern of a ship,
The drive source of the steering mechanism and
A control device for controlling the drive source 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 mechanism provided inside the housing to convert the power of the drive source into rotation of the output shaft,
A second mechanism provided outside the housing to convert the rotation of the output shaft into the operation of the rudder,
It has a third mechanism that is provided inside the housing and switches between a permissible state that allows the operation of the first mechanism and a regulated state that regulates the operation of the first mechanism.
The control device is a marine steering device that switches the state of the third mechanism from the allowable state to the regulated state when the position of the rudder should be maintained. The marine steering device according to claim 1, wherein the control device determines whether or not the rudder position should be maintained based on the steering angular velocity of the steering wheel operated when the hull is turned. The control device is in a situation where the position of the rudder should be maintained, and when a reverse input load is applied to the rudder, the state of the third mechanism is switched from the allowable state to the regulated state. The marine steering device according to claim 1 or 2. The ship according to claim 3, wherein the control device determines whether or not a reverse input load is acting on the rudder based on a steering torque applied to a steering wheel operated when the hull is turned. Steering device. The control device is in a situation where the position of the rudder should be maintained, and when the ship is in a turning state, claim 1 or claim 2 switches the state of the third mechanism from the allowable state to the regulated state. The marine steering device according to. The ship steering device according to claim 5, wherein the control device determines whether or not the ship is in a turning state based on the steering angle of a steering wheel operated when the hull is turned. The first 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. Have and
The ball screw nut is slidably provided with respect to the housing, the inside of the housing is partitioned into two liquid chambers by the ball screw nut, and the hydraulic fluid is contained in the two liquid chambers. Is enclosed, and the housing is provided with a communication passage for communicating the two liquid chambers.
As the third mechanism, an electric drive valve for opening and closing the communication passage is provided, and the ball screw nut is allowed to move when the electric drive valve is open, while the electric drive valve is allowed to move. The marine steering device according to any one of claims 1 to 6, wherein the movement of the ball screw nut is restricted when the valve is closed. The electric drive valve can adjust the opening degree steplessly by controlling the supplied current.
The marine steering device according to claim 7, wherein the control device controls a current supplied to the electric drive valve according to a steering angular velocity of a steering wheel operated when the hull is turned. The first 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. Have and
The third mechanism includes a first rotation restricting member fixed to the end of the ball screw shaft.
The ball screw engages with the first rotation regulating member and the first position separated from the first rotation regulating member in a state where the rotation around the axis of the ball screw shaft is restricted. The marine steering device according to any one of claims 1 to 6, further comprising a second rotation regulating member that moves between and a second position that regulates the rotation of the shaft. The portion of the housing corresponding to the first rotation restricting member is opened in a direction along the axis of the ball screw shaft, and the opened portion is closed by a cover as a part of the housing. Assuming that
The cover is provided so as to be able to move forward and backward relative to the housing along the axis of the ball screw shaft in a state where the relative rotation about the axis of the ball screw shaft is restricted. The marine steering device according to claim 9, wherein the rotation restricting member is fixed to the inside of the cover. A direction along the axis of the ball screw shaft while being provided on the side opposite to the first rotation restricting member of the second rotation regulating member and in a state where rotation around the axis of the ball screw shaft is restricted. A first cam member that moves integrally with the second rotation restricting member,
With the axis of the ball screw shaft as the center in a state of facing the first cam member in the direction along the axis of the ball screw shaft and restricting the movement of the ball screw shaft in the direction along the axis of the ball screw shaft. The second rotating cam member and
It has a plurality of balls held between the first cam member and the second cam member.
As the second cam member rotates, the first cam member moves in a direction away from the second cam member via the ball, so that the second rotation regulating member becomes the second. The marine steering device according to claim 9, which is engaged with the rotation restricting member of 1. Assuming that the drive source is a motor
The worm connected to the output shaft of the motor and
It has a worm wheel that is integrally rotatable with the ball screw shaft and meshes with the worm.
The third mechanism is any one of claims 9 to 11 provided at the end of the worm on the opposite side of the worm as the worm instead of the ball screw shaft whose rotation is restricted. The marine steering device according to the section. 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 12. The ship steering device according to any one of claims 1 to 12, 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 14, 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 14, 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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