STEERING DEVICE AND SHIP

Abstract

A steering device includes: a flow passage forming member including a first flow passage connecting to a first chamber and a second flow passage connecting to a second chamber; a movable member movable relative to the flow passage forming member; a seal member configured to seal a space between the movable member and the flow passage forming member when the seal member is in contact with the movable member and the flow passage forming member; an operation part capable of rotating an outboard motor; and a resistance reducing part configured to reduce a flow resistance so that a fluid flows between the first and second flow passages even with a pressure generated in the first chamber or the second chamber due to an operation of the operation part by a load equal to or lower than a predetermined load, when sealing is not made by the seal member.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority to Japanese Patent Application No. 2021-009686, filed on Jan. 25, 2021, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a steering device, and a ship.

BACKGROUND OF THE INVENTION

A ship includes a steering device configured to control a traveling direction of a ship body by swinging an outboard motor right and left. For example, JP-A-2020-185885 discloses technology about the steering device. The steering device disclosed in JP-A-2020-185885 includes a cylinder, a motor, a hydraulic source, a main valve, and an oil storage tank. The cylinder is demarcated into a first chamber and a second chamber by a piston. The steering device also includes a check valve that is opened when a hydraulic pressure to the cylinder rapidly increases when supplying an operating oil to a hydraulic circuit so that the piston slides from the first chamber-side toward the second chamber-side. The steering device also includes a check valve that is opened when the hydraulic pressure to the cylinder rapidly increases when supplying the operating oil to the hydraulic circuit so that the piston slides from the second chamber-side toward the first chamber-side. The steering device also includes a manual valve configured to enable manual steering of manually changing the traveling direction of the ship body by opening the valve.

An operation load when manually changing the traveling direction of the ship body is preferably small.

An object of the present invention is to provide a steering device and the like capable of reducing an operation load when manually changing a traveling direction of a ship body.

SUMMARY OF THE INVENTION

According to an aspect of the invention, there is provided a steering device including: a flow passage forming member including a first flow passage connecting to a first chamber in a cylinder and a second flow passage connecting to a second chamber in the cylinder; a movable member provided to be movable relative to the flow passage forming member and capable of being arranged between the first flow passage and the second flow passage; a seal member arranged between the movable member and the flow passage forming member and configured to seal a space between the movable member and the flow passage forming member when the seal member is in contact with the movable member and the flow passage forming member; an operation part capable of rotating an outboard motor when a pressure in the first chamber or the second chamber is increased and capable of applying a pressure to the first chamber or the second chamber to rotate the outboard motor when the operation part is manually operated; and a resistance reducing part configured to reduce a flow resistance so that a fluid flows between the first flow passage and the second flow passage even with a pressure generated in the first chamber or the second chamber due to an operation of the operation part by a load equal to or lower than a predetermined load, when sealing is not made by the seal member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example of a schematic configuration of a ship 100 in accordance with a first embodiment.

FIG. 2 depicts an example of a cylinder 4, an arm 9, a pump unit 3 and the like, as seen in a direction II of FIG. 1.

FIG. 3 depicts an example of a hydraulic circuit of a steering device 1.

FIG. 4 depicts an example of a schematic configuration of a valve unit 50 in accordance with the first embodiment.

FIG. 5 depicts a state where the valve unit 50 is inserted up to a forefront side.

FIG. 6 depicts an example of a schematic configuration of a first valve 41.

FIG. 7 depicts an example of a schematic configuration of a manual valve 243 in accordance with a second embodiment.

FIG. 8 depicts an example of a schematic configuration of a manual valve 343 in accordance with a third embodiment.

FIG. 9 depicts an example of a schematic configuration of a manual valve 443 in accordance with a fourth embodiment.

FIG. 10A depicts an example of a schematic configuration of a second valve 542 in accordance with a fifth embodiment.

FIG. 10B depicts an example of a schematic configuration of a manual valve 543 in accordance with the fourth embodiment.

FIG. 11 depicts an example of a schematic configuration of a valve unit 650 in accordance with a sixth embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Hereinbelow, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that, the embodiments of the present invention to be described below are just exemplary, and the present invention is not limited to the embodiments.

First Embodiment

FIG. 1 depicts an example of a schematic configuration of a ship 100 in accordance with a first embodiment.

FIG. 2 depicts an example of a cylinder 4, an arm 9, a pump unit 3 and the like, as seen in a direction II of FIG. 1.

FIG. 3 depicts an example of a hydraulic circuit of a steering device 1.

The ship 100 includes a ship body 101, an outboard motor 102 mounted to the ship body 101 and configured to generate a propulsion force, and a steering device 1 configured to change a traveling direction of the ship 100 by using an oil that is an example of the fluid. In descriptions below, a traveling direction in a state where the ship 100 travels in a straight line may be referred to as the front, an opposite direction to the traveling direction may be referred to as the rear, the left side with respect to the traveling direction may be referred to as the left, and the right side with respect to the traveling direction may be referred to as the right.

The steering device 1 has a ring-shaped steering wheel 2 provided to a front part of the ship body 101. The steering device 1 also includes a pump unit 3 configured to supply the oil according to rotation of the steering wheel 2, and a cylindrical cylinder 4 into which the oil supplied by the pump unit 3 is caused to flow, which are provided to a rear part of the ship body 101. The steering device 1 also includes a piston 5 by which a space in the cylinder 4 is demarcated into a first chamber Y1 and a second chamber Y2, and a rod 6 axially penetrating the cylinder 4 and holding the piston 5. The steering device 1 also includes a piping 7 connected to the pump unit 3 and the first chamber Y1 of the cylinder 4, and a piping 8 connected to the pump unit 3 and the second chamber Y2 of the cylinder 4. The oil is supplied to any one of the piping 7 and the piping 8, according to a rotation direction of the steering wheel 2. The steering device 1 also includes a flat plate-shaped arm 9 having one end attached to the outboard motor 102, and a link 10 connected to the arm 9 and the cylinder 4.

As shown in FIG. 3, the pump unit 3 has a motor 20, a pump 21 having a pair of gears and configured to be driven to discharge the oil by the motor 20, and a tank 22 in which the oil is stored. A flow passage 31 leading to the first chamber Y1 and a flow passage 32 leading to the second chamber Y2 are formed between the pump 21 and the cylinder 4.

The pump unit 3 includes a main valve 23 arranged to straddle the flow passage 31 and the flow passage 32 and configured to switch a direction of the oil flowing toward the first chamber Y1 or the second chamber Y2.

The pump unit 3 also includes a check valve 24 arranged on a supply path 33 through which the oil is supplied from the tank 22 to the pump 21, and a check valve 25 arranged on a supply path 34 through which the oil is supplied from the tank 22 to the pump 21. The supply path 33 is connected to a flow passage 31A leading from the pump 21 to the main valve 23. The supply path 34 is connected to a flow passage 32A leading from the pump 21 to the main valve 23.

The pump unit 3 also includes a first valve 41 that opens when a pressure in a flow passage 31B leading from the main valve 23 to the first chamber Y1 becomes equal to or higher than a preset pressure, thereby relieving the oil in the flow passage 31B to a flow passage 32B leading from the main valve 23 to the second chamber Y2. The pressure in the flow passage 31B becomes equal to or higher than the preset pressure when an external force is applied to the outboard motor 102 and the piston 5 is thus rapidly moved toward the first chamber Y1, for example.

The pump unit 3 also includes a second valve 42 that opens when a pressure in the flow passage 32B becomes equal to or higher than a preset pressure, thereby relieving the oil in the flow passage 32B to the flow passage 31B. The pressure in the flow passage 32B becomes equal to or higher than the preset pressure when an external force is applied to the outboard motor 102 and the piston 5 is thus rapidly moved toward the second chamber Y2, for example.

The pump unit 3 also includes a manual valve 43 that is arranged on an flow passage between the flow passage 31B and the flow passage 32B and can be manually opened and closed by a user.

The pump unit 3 also includes a housing 30 (refer to FIG. 2) in which the pump 21, the main valve 23, the check valve 24, the check valve 25, the first valve 41, the second valve 42 and the manual valve 43 are accommodated. The housing 30 is formed with the flow passage 31A and the flow passage 32A. The housing 30 is connected to the piping 7 and the piping 8. A part of the flow passage 31B is constituted by the piping 7, and the flow passage 31B from the main valve 23 to the piping 7 is formed in the housing 30. A part of the flow passage 32B is constituted by the piping 8, and the flow passage 32B from the main valve 23 to the piping 8 is formed in the housing 30.

In the steering device 1 configured as described above, when the steering wheel 2 is rotated in a clockwise direction, the oil is supplied to the second chamber Y2 by the pump 21, so that a pressure in the second chamber Y2 is increased. Thereby, the cylinder 4 is moved leftward with respect to the piston 5 whose position is fixed via the rod 6, so that the outboard motor 102 is rotated in an A direction (counterclockwise direction) shown in FIG. 1. As a result, the ship body 101 travels rightward. On the other hand, when the steering wheel 2 is rotated in a counterclockwise direction, the oil is supplied to the first chamber Y1 by the pump 21, so that a pressure in the first chamber Y1 is increased. Thereby, the cylinder 4 is moved rightward with respect to the piston 5, so that the outboard motor 102 is rotated in a B direction (clockwise direction) shown in FIG. 1. As a result, the ship body 101 travels leftward.

In the below, the first valve 41, the second valve 42, and the manual valve 43 are described.

(Valve Unit 50)

FIG. 4 depicts an example of a schematic configuration of a valve unit 50 in accordance with the first embodiment.

The pump unit 3 of the first embodiment includes a valve unit 50 where the second valve 42 and the manual valve 43 are integrally constituted.

The valve unit 50 includes a spherical valve body 51, a movable member 52 on which the valve body 51 is seated, a holding member 53 configured to hold the valve body 51, a coil-shaped spring 54, and a cap 55 for plugging a through-hole 35 formed in the housing 30. The valve unit 50 also includes a handle 57 that is gripped for operation with a hand by a user, and an annular seal member 58 configured to seal a gap between the movable member 52 and the housing 30.

In the valve unit 50, the movable member 52 is press-fitted into the cap 55 and is thus integrated in a state where the spring 54, the holding member 53 and the valve body 51 are accommodated in the cap 55. The handle 57 is mounted to the cap 55. The valve unit 50 is inserted in the through-hole 35 formed in the housing 30 from the movable member 52-side. The valve unit 50 is arranged so that the movable member 52 is on the front side and the handle 57 is on the rear side with respect to the ship body 101.

The movable member 52 has a cylindrical first part 521 provided on the forefront side, a cylindrical second part 522 provided behind the first part 521, a cylindrical third part 523 provided behind the second part 522, and a cylindrical fourth part 524 provided behind the third part 523.

The first part 521 is formed with a through-hole 525 for communicating an inside and an outside. The through-hole 525 may be one or may be formed in plural with equal intervals in a circumferential direction.

An inner diameter of the second part 522 is the same as an inner diameter of the first part 521, and an outer diameter of the second part 522 is larger than an outer diameter of the first part 521.

An inner diameter of the third part 523 is larger than the inner diameter of the second part 522, and an outer diameter of the third part 523 is the same as the outer diameter of the second part 522.

An inner diameter of the fourth part 524 is the same as the inner diameter of the third part 523, and an outer diameter of the fourth part 524 is smaller than the outer diameter of the third part 523.

An end portion on a rear side of the fourth part 524 is formed with a concave portion 526 recessed from an inner peripheral surface. An end portion on a front side of the concave portion 526 is formed with a seating surface 527 on which the valve body 51 is seated and which is inclined relative to a center line C1.

The holding member 53 is a columnar member having an outer diameter smaller than an inner diameter of the spring 54. The holding member 53 has a protrusion part 531 provided at an end portion on a front side and protruding outward from an outer peripheral surface. An outer diameter of the protrusion part 531 is larger than a center diameter of the spring 54, and is equal to or smaller than the outer diameter of the fourth part 524 of the movable member 52. The protrusion part 531 supports an end portion on a front side of the spring 54.

The cap 55 has a cylindrical tubular part 551 provided on a front side, a columnar first pillar-shaped part 561 provided behind the tubular part 551, and a columnar second pillar-shaped part 562 provided behind the first pillar-shaped part 561.

An inner diameter of the tubular part 551 is larger than the outer diameter of the spring 54 and the outer diameter of the protrusion part 531 of the holding member 53, so that the spring 54, the holding member 53 and the valve body 51 are accommodated in the tubular part 551.

The inner diameter of the tubular part 551 is smaller than the outer diameter of the fourth part 524 of the movable member 52, and an outer diameter of the tubular part 551 is substantially the same as the outer diameter of the third part 523 of the movable member 52. The tubular part 551 and the movable member 52 are fitted (press-fitted) by interference-fit.

In the tubular part 551, a through-hole 553 for communicating an inside and an outside is formed behind a part in which the fourth part 524 of the movable member 52 is fitted. In the tubular part 551, a male screw 554 that is fastened to a female screw 355 formed in the through-hole 35 is formed at a part behind the through-hole 553.

The first pillar-shaped part 561 is formed with a groove 563 recessed from an outer peripheral surface over an entire circumference. In the groove 563, an O-ring 564 for sealing a space between an outer peripheral surface of the cap 55 and an inner peripheral surface of the through-hole 35 is fitted.

An end portion on a rear side of the second pillar-shaped part 562 is formed with a female screw 565. A bolt 59 is fastened to the female screw 565, so that the handle 57 is attached to the second pillar-shaped part 562.

The seal member 58 has an inner diameter that is larger than the outer diameter of the first part 521 of the movable member 52, and an outer diameter that is substantially the same as the outer diameter of the second part 522.

The through-hole 35 has a columnar first hole 351 formed on a front side and a columnar second hole 352 formed on a rear side and having a diameter larger than a diameter of the first hole 351. The first hole 351 communicates with the flow passage 32B. The second hole 352 communicates with the flow passage 31B via a connection hole 353 formed in a direction of intersecting with the center line C1 of the second hole 352. Note that, an opening on a front side, which is opposite to a side in which the valve unit 50 is inserted, of the through-hole 35 is closed.

The valve unit 50 configured as described above is mounted to the housing 30 by operating the handle 57 to fasten the male screw 554 of the cap 55 to the female screw 355 formed in the through-hole 35. The seal member 58 is attached to an outer side of the first part 521 of the movable member 52, and the seal member 58 is arranged between the second part 522 of the movable member 52 and the housing 30.

FIG. 5 depicts a state where the valve unit 50 is inserted up to the innermost side.

The user can change a screwing depth of the valve unit 50 to the housing 30 by operating the handle 57. As shown in FIG. 5, the user can insert forward the valve unit 50 until the seal member 58 comes into contact with the second part 522 of the movable member 52 and the housing 30. On the other hand, the user can move rearward the valve unit 50 until an end face on the rear side of the first pillar-shaped part 561 of the cap 55 is butted against a clip 354 attached to the housing 30.

In a state (hereinbelow, also referred to as ‘first state’) where the seal member 58 is in contact with the second part 522 of the movable member 52 and the housing 30, the seal member 58 seals the gap between the movable member 52 and the housing 30. For this reason, in the first state, the oil is difficult to flow between the flow passage 31B and the flow passage 32B through a ring-shaped flow passage R1 between an outer peripheral surface of the first part 521 of the movable member 52 and an inner peripheral surface of the first hole 351 of the through-hole 35 of the housing 30.

In addition, in the first state, the valve body 51 is applied with a spring force of the spring 54 via the holding member 53 and is thus seated on the seating surface 527 of the movable member 52, so that the valve body 51 is not opened unless the pressure in the flow passage 32B becomes equal to or higher than a preset pressure. The preset pressure is set as a value that the pressure in the flow passage 32B is difficult to reach simply by manually operating the arm 9.

As a result, it is difficult to rotate the outboard motor 102 by manually operating the arm 9 in a direction in which the piston 5 moves toward the second chamber Y2-side.

Note that, in the first state, when the pressure in the flow passage 32B becomes equal to or higher than the preset pressure, the valve body 51 moves rearward against the spring force of the spring 54, so that a gap is formed between the valve body 51 and the seating surface 527 of the movable member 52. For this reason, the oil flows from the flow passage 32B to the flow passage 31B through an inside of the movable member 52, the gap between the valve body 51 and the seating surface 527 of the movable member 52, and the through-hole 553 of the tubular part 551 of the cap 55.

On the other hand, as shown in FIG. 4, in a state (hereinbelow, also referred to as ‘second state’) where the seal member 58 is not in contact with the second part 522 of the movable member 52 and the housing 30, the seal member 58 does not seal the gap between the movable member 52 and the housing 30. Therefore, the oil can easily flow between the flow passage 31B and the flow passage 32B through the ring-shaped flow passage R1. As a result, when the user unfastens the male screw 554 and takes out the valve unit 50 rearward, it is possible to rotate the outboard motor 102 more easily by manually operating the arm 9, as compared to the first state.

In addition, when the valve unit 50 is moved until the through-hole 525 formed in the first part 521 of the movable member 52 is located behind the first hole 351 of the housing 30, the oil flows from the flow passage 32B to the flow passage 31B through the through-hole 525. An area of the through-hole 525 is greater than a flow area of the ring-shaped flow passage R1. As a result, since a flow resistance of the oil flowing between the flow passage 31B and the flow passage 32B is reduced, an operation load is reduced when manually changing the traveling direction of the ship body 101 by operating the arm 9.

From the above, the valve body 51, the movable member 52, the holding member 53, the spring 54, the cap 55, the seal member 58 and the housing 30 constitute the second valve 42. The movable member 52, the cap 55, the handle 57, the seal member 58 and the housing 30 constitute the manual valve 43 that can open and close the flow passage between the flow passage 31B and the flow passage 32B by the user's operation.

Note that, the clip 354 is provided in a position where the end face on the rear side of the first pillar-shaped part 561 of the cap 55 is butted when the end portion on the front side of the first part 521 of the movable member 52 is located in the first hole 351 of the housing 30. This is to locate the seal member 58 on the outer side of the first part 521 even when the male screw 554 is unfastened and the valve unit 50 is taken out rearward by the user.

(First Valve 41)

FIG. 6 depicts an example of a schematic configuration of the first valve 41.

The first valve 41 includes a spherical valve body 61, a movable member 62 on which the valve body 61 is seated, a holding member 63 configured to hold the valve body 61, a coil-shaped spring 64, and a cap 65 for plugging a through-hole 36 formed in the housing 30. The first valve 41 also includes an annular seal member 68 for sealing a gap between the movable member 62 and the housing 30.

Since the valve body 61, the movable member 62, the holding member 63 and the spring 64 are each similar to the valve body 51, the movable member 52, the holding member 53 and the spring 54 of the valve unit 50, the detailed descriptions thereof are omitted.

The cap 65 is different from the cap 55, in that it does not have the second pillar-shaped part 562 and the handle 57 is not attached thereto.

The first valve 41 is inserted in the through-hole 36. The through-hole 36 has a columnar first hole 361 formed on a rear side and a columnar second hole 362 formed on a front side and having a diameter larger than a diameter of the first hole 361. The first hole 361 is configured to communicate with the flow passage 31B. The second hole 362 is configured to communicate with the flow passage 32B via a connection hole (not shown) formed in a direction of intersecting with a center line of the second hole 362.

The first valve 41 is inserted in the through-hole 36 until the seal member 68 comes contact with the movable member 62 and the housing 30. The valve body 61 is applied with a spring force of the spring 64 via the holding member 63 and is thus in contact with a seating surface 627 of the movable member 62. When the pressure in the flow passage 31B becomes equal to or higher than the preset pressure, the valve body 61 separates from the seating surface 627. When the pressure in the flow passage 31B becomes equal to or higher than the preset pressure, the valve body 61 is moved forward against the spring force of the spring 64, so that a gap is formed between the valve body 61 and the seating surface 627 of the movable member 62. As a result, the oil flows from the flow passage 31B to the flow passage 32B through an inside of the movable member 62, the gap between the valve body 61 and the seating surface 627 of the movable member 62, and a through-hole 653 of a tubular part 651 of the cap 65.

The preset pressure at which the valve body 61 starts to move is set as a value that the pressure in the flow passage 31B is difficult to reach simply by manually operating the arm 9.

As a result, it is difficult to rotate the outboard motor 102 by manually operating the arm 9 in a direction in which the piston 5 moves toward the first chamber Y1-side.

However, as shown in FIG. 4, the user unfastens the male screw 554 to take out the valve unit 50 rearward, and causes the seal member 58 not to seal the gap between the movable member 52 and the housing 30, thereby enabling the oil to easily flow between the flow passage 31B and the flow passage 32B. Thereby, it is possible to easily rotate the outboard motor 102 by manually operating the arm 9.

As described above, the steering device 1 includes the housing 30 as an example of the flow passage forming member where the flow passage 31B as an example of the first flow passage connecting to the first chamber Y1 in the cylinder 4 and the flow passage 32B as an example of the second flow passage connecting to the second chamber Y2 in the cylinder 4 are formed. The steering device 1 also includes the movable member 52 as an example of the movable member provided to be movable relative to the housing 30 and capable of being arranged between the flow passage 31B and the flow passage 32B. The steering device 1 also includes the seal member 58 arranged between the movable member 52 and the housing 30 and sealing a space between the movable member 52 and the housing 30 when the seal member 58 is in contact with the movable member 52 and the housing 30. The steering device 1 also includes the arm 9 as an example of the operation part capable of rotating the outboard motor 102 when the pressure in the first chamber Y1 or the second chamber Y2 is increased and applying a pressure to the first chamber Y1 or the second chamber Y2 to rotate the outboard motor 102 when it is manually operated. The steering device 1 also includes the through-hole 525 as an example of the resistance reducing part that reduces a flow resistance so that the oil as an example of the fluid flows between the flow passage 31B and the flow passage 32B, when the sealing is not made by the seal member 58.

Here, an area S (cm²) of the through-hole 525 of the first part 521 of the movable member 52 is determined so that a manual steering load F of the arm 9 is equal to or lower than a preset upper limit load Fm. More specifically, the area S is calculated using following equations (1), (2) and (3). Note that, the upper limit load Fm may be 100(N), for example.

$\begin{array}{cc}Q=C*S\sqrt{\frac{2*G*\left(P_1-P_2\right)}{r}}& \left(1\right)\end{array}$

Q is a flow rate (cm³/sec) of the oil to flow per a unit time and is determined by the equation (2). P₁ is a pressure (MPa) on a high pressure-side (for example, the pressure in the flow passage 32B when the arm 9 is steered so that the piston 5 moves toward the second chamber Y2) and is a value determined by the equation (3). C is a resistance coefficient of a flow passage, G is the acceleration of gravity (=980 cm/sec), P₂ is a pressure (MPa) on a lower pressure-side, and r is a specific gravity (Kgf/cm³).

Q=Sp×Lp/t  (2)

Lp is a stroke (cm) of the piston 5, and t is an operating time (sec) of the arm 9 (piston 5).

P ₁ =k×Fm/Sp  (3)

k is a coefficient corresponding to a length of the arm 9 and Sp is a sectional area (cm²) of the piston 5.

Note that, in a case of Fm=100 (N), C=0.7, P₂=0 (MPa), r=0.000851 (Kgf/cm³), Sp=36.32 (cm²), Lp=3.79 (cm), t=3 (sec) and k=6.9, the area S is 0.0322 (cm²).

In the case of the area S=0.0322 (cm²), when the through-hole 525 is one, the hole diameter is 0.202 (cm), and when the through-hole 525 is two, the hole diameter is 0.143 (cm). When the two through-holes 525 are provided and the hole diameter is set to 0.15 (cm), the manual steering load F can be made equal to or lower than the upper limit load Fm.

As described above, when the sealing is not made by the seal member 58, the through-hole 525 of the first part 521 of the movable member 52 reduces the flow resistance so that the oil flows between the flow passage 31B and the flow passage 32B even with the pressure generated in the first chamber Y1 or the second chamber Y2 due to the operation of the arm 9 with the load equal to or lower than the upper limit load Fm.

The flow resistance reducing function of the through-hole 525 is exhibited as the through-hole 525 is provided as described above. That is, in the steering device 1, the movable member 52 has the first part 521 as an example of the cylindrical part that is fitted in the first hole 351 as an example of the hole formed in the housing 30 and communicating with the flow passage 32B. When the sealing is made by the seal member 58, the through-hole 525 is located inside the first hole 351, and when the sealing is not made by the seal member 58, the through-hole 525 is located outside the first hole 351 so that the fluid flows between the flow passage 31B and the flow passage 32B via the through-hole 525.

In the steering device 1, the movable member 52 is cylindrical, and has the seating surface 527 provided at the end portion on the opposite side to the flow passage 32B in the direction of the center line C1 and being in contact with the spherical valve body 51. The steering device 1 has the cap 55 configured to accommodate therein the valve body 51, the holding member 53 as an example of the pressing part for pressing the valve body 51 to the seating surface 527 and the spring 54 together with the movable member 52, and having the through-hole 553 formed on a further opposite side to the flow passage 32B than the valve body 51 and provided as an example of the communication hole for communicating an inside and an outside. In other words, the steering device 1 includes the valve unit 50 where the second valve 42 and the manual valve 43 are integrally provided. For this reason, as compared to a configuration where the second valve 42 and the manual valve 43 are provided as separate bodies, the steering device 1 has a simpler configuration and is more lightweight.

Second Embodiment

FIG. 7 depicts an example of a schematic configuration of a manual valve 243 in accordance with a second embodiment.

A steering device 200 of the second embodiment is different from the steering device 1 of the first embodiment, in a manual valve 243 corresponding to the manual valve 43. The manual valve 243 is different from the manual valve 43, in a movable member 252 corresponding to the movable member 52. Hereinbelow, differences from the steering device 1 are described. The parts having the same functions between the steering device 1 and the steering device 200 are denoted with the same reference signs, and the detailed descriptions thereof are omitted.

The movable member 252 is different from the movable member 52 of the first embodiment, in a first part 2521 corresponding to the first part 521. The first part 2521 is not formed with the through-hole 525 that is formed in the first part 521. An outer diameter of the first part 2521 is smaller than the outer diameter of the first part 521. For this reason, in the manual valve 243, a flow area of a ring-shaped flow passage R2 between an outer peripheral surface of the first part 2521 and the inner peripheral surface of the first hole 351 of the through-hole 35 of the housing 30 is greater than the flow area of the ring-shaped flow passage R1 of the first embodiment.

For this reason, when the male screw 554 (refer to FIG. 4) is unfastened by the user and the seal member 58 does not seal the gap between the movable member 252 and the housing 30, the resistance when the oil flows between the flow passage 31B and the flow passage 32B through the ring-shaped flow passage R2 is reduced, as compared to the resistance when the oil flows through the ring-shaped flow passage R1. As a result, even when the first part 2521 is not formed with a through-hole corresponding to the through-hole 525, the operation load when manually operating the arm 9 is reduced.

Here, a gap h2 (cm) (=(the outer diameter d (cm) of the first part 2521−the diameter (D) (cm) of the first hole 351)/2) between the outer peripheral surface of the first part 2521 and the inner peripheral surface of the first hole 351 of the through-hole 35 of the housing 30 is determined so that the manual steering load F of the arm 9 is equal to or lower than the upper limit load Fm. More specifically, the gap h2 is calculated using a following equation (4).

$\begin{array}{cc}Q=\frac{\pi \left(D-2\mathrm{h2}\right){\mathrm{h2}}^3}{12\mu }\times \frac{\left(P_1-P_2\right)}{L}& \left(4\right)\end{array}$

Q and P₁ are values determined by the above equations (2) and (3). μ is a viscosity (Pa·sec) of the oil, and L is a wrap length (cm) of the first part 2521 and the first hole 351.

In a case of Fm=100 (N), D=0.325 (cm), P₂=0 (MPa) and L=0.1 (cm), the gap h2=0.062 (cm) is calculated, and d0=0.201 (cm) is calculated using an equation of d0 (cm)=D−2×h2. The outer diameter d of the first part 2521 is set smaller than d0, so that the manual steering load F can be made equal to or lower than the upper limit load Fm.

As described above, in the steering device 200, the movable member 252 has the first part 2521 as an example of the cylindrical part that is fitted in the first hole 351 formed in the housing 30 and communicating with the flow passage 32B. The ring-shaped flow passage R2 between the outer peripheral surface of the first part 2521 and the inner peripheral surface of the first hole 351 functions as the resistance reducing part that reduces the flow resistance so that the oil flows between the flow passage 31B and the flow passage 32B even with the pressure generated in the first chamber Y1 or the second chamber Y2 due to the operation of the arm 9 with the load equal to or lower than the upper limit load, when the sealing is not made by the seal member 58.

Since the inner diameter of the first part 2521 is the same as the inner diameter of the first part 521, the resistance when the oil passes through the inside of the first part 2521 can be made to be the same as the resistance when the oil passes through the inside of the first part 521. For this reason, also in the second embodiment, the second valve 42 is opened when the pressure in the flow passage 32B becomes equal to or higher than the preset pressure, so that the oil in the flow passage 32B can be relived to the flow passage 31B. In the meantime, the inner diameter of the first part 2521 may be set small within a range in which the second valve 42 can be opened when the pressure in the flow passage 32B becomes equal to or higher than the preset pressure.

Note that, the first part 2521 may also be formed with a through-hole corresponding to the through-hole 525. Thereby, as compared to the configuration where the movable member 252 is used, the resistance when the oil flows between the flow passage 31B and the flow passage 32B is reduced. As a result, the operation load when manually operating the arm 9 is reduced.

Third Embodiment

FIG. 8 depicts an example of a schematic configuration of a manual valve 343 in accordance with a third embodiment.

A steering device 300 of the third embodiment is different from the steering device 1 of the first embodiment, in a manual valve 343 corresponding to the manual valve 43. The manual valve 343 is different from the manual valve 43, in a movable member 350 corresponding to the movable member 52 and a housing 330 corresponding to the housing 30. Hereinbelow, differences from the steering device 1 are described. The parts having the same functions between the steering device 1 and the steering device 300 are denoted with the same reference signs, and the detailed descriptions thereof are omitted.

The movable member 350 is different from the movable member 52, in a first part 3521 corresponding to the first part 521. The first part 3521 is not formed with the through-hole 525 that is formed in the first part 521.

The housing 330 is different from the housing 30, in a through-hole 335 corresponding to the through-hole 35. The through-hole 335 has a columnar first hole 3351 corresponding to the first hole 351, and the second hole 352. A diameter of the first hole 3351 is larger than the diameter of the first hole 351.

For this reason, in the manual valve 343, a flow area of a ring-shaped flow passage R3 between an outer peripheral surface of the first part 3521 and an inner peripheral surface of the first hole 3351 of the through-hole 335 of the housing 330 is greater than the flow area of the ring-shaped flow passage R1 of the first embodiment.

For this reason, when the male screw 554 (refer to FIG. 4) is unfastened by the user and the seal member 58 does not seal the gap between the movable member 350 and the housing 330, the resistance when the oil flows between the flow passage 31B and the flow passage 32B through the ring-shaped flow passage R3 is reduced, as compared to the resistance when the oil flows through the ring-shaped flow passage R1. As a result, even when the first part 3521 is not formed with a through-hole corresponding to the through-hole 525, the operation load when manually operating the arm 9 is reduced.

Here, a gap h3 (cm) (=(the outer diameter d (cm) of the first part 3521−the diameter (D) (cm) of the first hole 3351)/2) between the outer peripheral surface of the first part 3521 and the inner peripheral surface of the first hole 3351 of the through-hole 335 of the housing 330 is determined so that the manual steering load F of the arm 9 is equal to or lower than the upper limit load Fm. More specifically, the gap h3 is calculated using a following equation (5).

$\begin{array}{cc}Q=\frac{\pi \mathrm{dh}{3}^3}{12\mu }\times \frac{\left(P_1-P_2\right)}{L}& \left(5\right)\end{array}$

Q and P₁ are values determined by the above equations (2) and (3). μ is a viscosity (Pa·sec) of the oil, and L is a wrap length (cm) of the first part 3521 and the first hole 3351.

In a case of Fm=100 (N), D=0.325 (cm), P₂=0 (MPa) and L=0.1 (cm), the gap h3=0.053 (cm) is calculated, and D0=0.431 (cm) is calculated using an equation of D0 (cm)=d+2×h2. The outer diameter D of the first hole 3351 is set larger than D0, so that the manual steering load F can be made equal to or lower than the upper limit load Fm.

As described above, in the steering device 300, the movable member 350 has the first part 3521 as an example of the cylindrical part that is fitted in the first hole 3351 formed in the housing 330 and communicating with the flow passage 32B. The ring-shaped flow passage R3 between the outer peripheral surface of the first part 3521 and the inner peripheral surface of the first hole 3351 functions as the resistance reducing part that reduces the flow resistance so that the oil flows between the flow passage 31B and the flow passage 32B even with the pressure generated in the first chamber Y1 or the second chamber Y2 due to the operation of the arm 9 with the load equal to or lower than the upper limit load, when the sealing is not made by the seal member 58.

In addition, since the movable member 62 and the movable member 350 of the first valve 41 can be made to be the same, it is possible to reduce the number of components of the steering device 300.

Note that, the first part 3521 may also be formed with a through-hole corresponding to the through-hole 525. Thereby, as compared to the configuration where the movable member 350 is used, the resistance when the oil flows between the flow passage 31B and the flow passage 32B is reduced.

In addition, the movable member 252 of the second embodiment may also be used instead of the movable member 350. Thereby, as compared to the configuration where the movable member 350 is used, the resistance when the oil flows between the flow passage 31B and the flow passage 32B is reduced. As a result, the operation load when manually operating the arm 9 is reduced.

Fourth Embodiment

FIG. 9 depicts an example of a schematic configuration of a manual valve 443 in accordance with a fourth embodiment.

A steering device 400 of the fourth embodiment is different from the steering device 1 of the first embodiment, in a manual valve 443 corresponding to the manual valve 43. The manual valve 443 is different from the manual valve 43 of the first embodiment, in a movable member 452 corresponding to the movable member 52, a seal member 458 corresponding to seal member 58 and a housing 430 corresponding to the housing 30. Hereinbelow, differences from the steering device 1 are described. The parts having the same functions between the steering device 1 and the steering device 400 are denoted with the same reference signs, and the detailed descriptions thereof are omitted.

The movable member 452 is different from the movable member 52, in a second part 4522 corresponding to the second part 522. An outer diameter of the second part 4522 is smaller than the outer diameter of the second part 522. That is, the outer diameter of the second part 4522 is smaller than the outer diameter of the third part 523, and the outer diameters are larger in order of the first part 521, the second part 4522 and the third part 523 in the flow direction of the oil from the flow passage 32B toward the flow passage 31B.

An outer diameter of the seal member 458 is smaller than the outer diameter of the seal member 58 and is substantially the same as the outer diameter of the second part 4522.

The housing 430 is different from the housing 30, in a through-hole 435 corresponding to the through-hole 35. The through-hole 435 has the first hole 351, and a second hole 4352 corresponding to the second hole 352. The through-hole 435 is also formed with a columnar first intermediate hole 4353 having a diameter larger than the diameter of the first hole 351 and a truncated conical second intermediate hole 4354 formed behind the first intermediate hole 4353 and having an outer diameter that becomes larger in the flow direction of the oil from the flow passage 32B toward the flow passage 31B, between the first hole 351 and the second hole 4352. That is, the diameter of the through-hole 435 becomes larger in order of the first hole 351, the first intermediate hole 4353, the second intermediate hole 4354 and the second hole 4352 in the flow direction of the oil from the flow passage 32B toward the flow passage 31B.

For this reason, when the male screw 554 (refer to FIG. 4) is unfastened by the user and the seal member 458 does not seal a gap between the movable member 452 and the housing 430, the oil flows in a direction inclined relative to the center line C1 while the oil flows between the flow passage 31B and the flow passage 32B, particularly, while the oil flows through the second intermediate hole 4354. In addition, a gap between an outer peripheral surface of the second part 4522 of the movable member 452 and an inner peripheral surface of the second hole 4352 is greater than the gap between the outer peripheral surface of the second part 522 of the movable member 52 of the first embodiment and the inner peripheral surface of the second hole 352. For this reason, the resistance when the oil flows between the flow passage 31B and the flow passage 32B is reduced, as compared to the resistance in the first embodiment. As a result, the operation load when manually operating the arm 9 is reduced.

As described above, in the steering device 400, the movable member 452 has the second part 4522 as an example of the first protrusion, which protrudes to have an outer diameter larger than the outer diameter of the first part 521 and is in contact with the seal member 458, on a further downstream side than the first part 521 in the flow direction of the oil from the flow passage 32B toward the flow passage 31B. The movable member 452 also has the third part 523 as an example of the second protrusion, which protrudes to have an outer diameter larger than the outer diameter of the second part 4522, on a further downstream side than the second part 4522 in the flow direction of the oil from the flow passage 32B toward the flow passage 31B. For this reason, according to the steering device 400, since the oil is likely to flow in the direction inclined relative to the center line C1, the flow resistance is reduced, as compared to a configuration where the oil flows in a direction orthogonal to the center line C1 and then flows in a direction parallel to the center line C1, so that the operation load when manually operating the arm 9 is reduced.

Further, the steering device 400 is provided with the second intermediate hole 4354 as an example of the truncated conical connection path formed concentrically with the flow passage 32B on a further downstream side than the flow passage 32B in the flow direction of the oil from the flow passage 32B toward the flow passage 31B and having an outer diameter that becomes larger in the flow direction. For this reason, according to the steering device 400, since the oil is likely to flow in the direction inclined relative to the center line C1, the flow resistance is reduced, as compared to a configuration where the oil flows in a direction orthogonal to the center line C1 and then flows in a direction parallel to the center line C1, so that the operation load when manually operating the arm 9 is reduced.

Fifth Embodiment

FIG. 10A depicts an example of a schematic configuration of a second valve 542 in accordance with a fifth embodiment. FIG. 10B depicts an example of a schematic configuration of a manual valve 543 in accordance with the fourth embodiment.

A steering device 500 of the fifth embodiment is different from the steering device 1 of the first embodiment, in a second valve 542 and a manual valve 543 corresponding to the second valve 42 and the manual valve 43. The second valve 542 and the manual valve 543 are different from the second valve 42 and the manual valve 43 of the first embodiment, in that the second valve 542 and the manual valve 543 are separate bodies. Hereinbelow, differences from the steering device 1 are described. The parts having the same functions between the steering device 1 and the steering device 500 are denoted with the same reference signs, and the detailed descriptions thereof are omitted.

Similarly to the first valve 41 described with reference to FIG. 6, the second valve 542 has the valve body 61, the movable member 62, the holding member 63, the spring 64, the cap 65, and the seal member 68. The second valve 542 is inserted in a through-hole 37 formed in the housing 30. The through-hole 37 is formed in parallel to the through-hole 35, and has a columnar first hole 371 formed on a front side and a columnar second hole 372 formed on a rear side and having a diameter larger than a diameter of the first hole 371. The first hole 371 communicates with the flow passage 32B, and the second hole 372 communicates with the flow passage 31B.

The manual valve 543 has a cap 570 for plugging the through-hole 35 formed in the housing 30, the handle 57, and the annular seal member 58 for sealing a gap between the cap 570 and the housing 30.

The cap 570 has a first part 571 corresponding to the first part 521 of the movable member 52, and a second part 572 corresponding to the second part 522 of the movable member 52. The cap 570 also has a first pillar-shaped part 573 corresponding to the first pillar-shaped part 561 of the cap 55, and a second pillar-shaped part 574 corresponding to the second pillar-shaped part 562 of the cap 55. The cap 570 also has a columnar third pillar-shaped part 575 having substantially the same diameter as an outer diameter of the second part 572 and a columnar fourth pillar-shaped part 576 having a diameter larger than the diameter of the third pillar-shaped part 575 between the second part 572 and the first pillar-shaped part 573.

The first part 571 is formed with a through-hole 577 corresponding to the through-hole 525 of the movable member 52. The fourth pillar-shaped part 576 is formed with a male screw 578 that is fastened to the female screw 355 formed in the through-hole 35. An end portion on a rear side of the second pillar-shaped part 574 is formed with a female screw 579, and the bolt 59 is fastened to the female screw 579, so that the handle 57 is attached.

Also in the manual valve 543 configured as described above, when the male screw 578 is unfastened by the user and thus the seal member 58 does not seal the gap between the cap 570 and the housing 30, the oil flows between the flow passage 31B and the flow passage 32B through the through-hole 577 formed in the first part 571 of the cap 570. As a result, similarly to the manual valve 43 of the first embodiment, the operation load when manually operating the arm 9 is reduced.

Note that, the outer diameter of the first part 571 may be set small, like the outer diameter of the first part 2521 of the second embodiment. In this case, the through-hole 577 may not be provided.

Alternatively, the diameter of the first hole 351 of the through-hole 35 may be set large, like the diameter of the first hole 3351 of the third embodiment. In this case, the through-hole 577 may not be provided.

Alternatively, like the second part 4522 of the fourth embodiment, a cylindrical part having an outer diameter larger than the outer diameter of the first part 571 and smaller than the outer diameter of the second part 572 may be provided between the first part 571 and the second part 572 of the cap 570. In addition, the through-hole 35 of the housing 30 may be formed to have a similar shape to the through-hole 435 of the housing 430 of the fourth embodiment.

Sixth Embodiment

FIG. 11 depicts an example of a schematic configuration of a valve unit 650 in accordance with a sixth embodiment.

A steering device 600 of the sixth embodiment is different from the steering device 1 of the first embodiment, in a valve unit 650 corresponding to the valve unit 50. The valve unit 650 is different from the valve unit 50, in that a first valve 641, a second valve 642, and a manual valve 643 of the sixth embodiment are integrally provided. The parts having the same functions between the steering device 1 and the steering device 600 are denoted with the same reference signs, and the detailed descriptions thereof are omitted.

The valve unit 650 has the valve body 51, the movable member 52, the holding member 53, the handle 57, the seal member 58, the valve body 61, and the holding member 63. The valve unit 650 also has a coil-shaped spring 654 for applying a spring force to the valve body 51 via the holding member 53 and applying the spring force to the valve body 61 via the holding member 63, and a cap 655 for plugging a through-hole 38 formed in the housing 30.

The through-hole 38 has a columnar first hole 381 formed on a front side, and a columnar second hole 382 formed behind the first hole 381 and having a diameter larger than a diameter of the first hole 381. The through-hole 38 also has a columnar third hole 383 formed behind the second hole 382 and having a diameter larger than the diameter of the second hole 382, and a columnar fourth hole 384 formed behind the third hole 383 and having a diameter larger than the diameter of the third hole 383. The first hole 381 communicates with the flow passage 32B. The second hole 382 communicates with the flow passage 31B. The third hole 383 communicates with the flow passage 32B. The fourth hole 384 communicates with the flow passage 31B.

The cap 655 has a cylindrical first tubular part 661 provided on a front side, a cylindrical second tubular part 662 provided behind the first tubular part 661, and a cylindrical third tubular part 663 provided behind the second tubular part 662. The cap 655 also has a columnar first pillar-shaped part 664 provided behind the third tubular part 663 and a second pillar-shaped part 665 provided behind the first pillar-shaped part 664.

The first tubular part 661 is similar to the tubular part 551 of the cap 55 and is formed with the through-hole 553, and the movable member 52 is press-fitted therein.

An outer diameter of the second tubular part 662 is larger than an outer diameter of the first tubular part 661. The second tubular part 662 is formed with a groove 666 recessed from an outer peripheral surface over an entire circumference. In the groove 666, an O-ring 667 for sealing a space between an outer peripheral surface of the second tubular part 662 and an inner peripheral surface of the second hole 382 of the through-hole 38 is fitted.

An outer diameter of the third tubular part 663 is larger than the outer diameter of the second tubular part 662. An outer peripheral surface of the third tubular part 663 is formed with a male screw 668 that is fastened to a female screw 385 formed in the through-hole 38. In the third tubular part 663, a seating surface 669 on which the valve body 61 is seated is formed. In the third tubular part 663, a through-hole 670 that communicates an inside and the fourth hole 384 of the through-hole 38 located at an outside is formed in a direction of intersecting with the center line C1.

The first pillar-shaped part 664 is formed with a groove 671 recessed from an outer peripheral surface over an entire circumference. In the groove 671, an O-ring 672 for sealing a space between an outer peripheral surface of the first pillar-shaped part 664 and an inner peripheral surface of the fourth hole 384 of the through-hole 38 is fitted.

The second pillar-shaped part 665 is similar to the second pillar-shaped part 562 of the cap 55, and is formed with a female screw 565 to which the bolt 59 for attaching the handle 57 is fastened.

In the valve unit 650 configured as described above, the valve body 61, the holding member 63, the spring 654, the cap 655 and the housing 30 constitute the first valve 641. The valve body 51, the movable member 52, the holding member 53, the spring 654, the cap 655, the seal member 58 and the housing 30 constitute the second valve 642. The movable member 52, the cap 655, the handle 57, the seal member 58 and the housing 30 constitute the manual valve 643.

Also in the manual valve 643 configured as described above, when the male screw 668 is unfastened by the user and thus the seal member 58 does not seal the gap between the cap 655 and the housing 30, the oil flows between the flow passage 31B and the flow passage 32B through the through-hole 525 formed in the first part 521 of the movable member 52. As a result, similarly to the manual valve 43 of the first embodiment, the operation load when manually operating the arm 9 is reduced.

Note that, the outer diameter of the first part 521 of the movable member 52 may be set small, like the outer diameter of the first part 2521 of the second embodiment. In this case, the through-hole 525 may not be provided.

Alternatively, the diameter of the first hole 381 of the through-hole 38 may be set large, like the diameter of the first hole 3351 of the third embodiment. In this case, the through-hole 525 may not be provided.

Alternatively, like the second part 4522 of the fourth embodiment, a cylindrical part having an outer diameter larger than the outer diameter of the first part 571 and smaller than the outer diameter of the second part 572 may be provided between the first part 521 and the second part 522 of the movable member 52. In addition, the through-hole 38 of the housing 30 may be formed to have a similar shape to the through-hole 435 of the housing 430 of the fourth embodiment.

According to the present invention, it is possible to reduce an operation load when manually changing the traveling direction of the ship body.

Claims

1. A steering device comprising: a flow passage forming member including a first flow passage connecting to a first chamber in a cylinder and a second flow passage connecting to a second chamber in the cylinder;a movable member provided to be movable relative to the flow passage forming member and capable of being arranged between the first flow passage and the second flow passage;a seal member arranged between the movable member and the flow passage forming member and configured to seal a space between the movable member and the flow passage forming member when the seal member is in contact with the movable member and the flow passage forming member;an operation part capable of rotating an outboard motor when a pressure in the first chamber or the second chamber is increased and capable of applying a pressure to the first chamber or the second chamber to rotate the outboard motor when the operation part is manually operated; anda resistance reducing part configured to reduce a flow resistance so that a fluid flows between the first flow passage and the second flow passage even with a pressure generated in the first chamber or the second chamber due to an operation of the operation part by a load equal to or lower than a predetermined load, when sealing is not made by the seal member.

2. The steering device according to claim 1, wherein the movable member has a cylindrical part that is fitted in a hole formed in the flow passage forming member and communicating with the second flow passage,the resistance reducing part is a through-hole formed in the cylindrical part, andwhen sealing is made by the seal member, the through-hole is located inside the hole, and when sealing is not made by the seal member, the through-hole is located outside the hole so that the fluid flows between the first flow passage and the second flow passage via the through-hole.

3. The steering device according to claim 1, wherein the movable member has a cylindrical part that is fitted in a hole formed in the flow passage forming member and communicating with the second flow passage, andthe resistance reducing part is a ring-shaped flow passage formed between an outer peripheral surface of the cylindrical part and an inner peripheral surface of the second flow passage.

4. The steering device according to claim 2, wherein the movable member has a first protrusion, which protrudes to have an outer diameter larger than an outer diameter of the cylindrical part and is in contact with the seal member, on a further downstream side than the cylindrical part in a flow direction from the second flow passage toward the first flow passage, and a second protrusion, which protrudes to have an outer diameter larger than the outer diameter of the first protrusion, on a further downstream side than the first protrusion in the flow direction.

5. The steering device according to claim 3, wherein the movable member has a first protrusion, which protrudes to have an outer diameter larger than an outer diameter of the cylindrical part and is in contact with the seal member, on a further downstream side than the cylindrical part in a flow direction from the second flow passage toward the first flow passage, and a second protrusion, which protrudes to have an outer diameter larger than the outer diameter of the first protrusion, on a further downstream side than the first protrusion in the flow direction.

6. The steering device according to claim 4, further comprising a truncated conical connection path formed concentrically with the second flow passage on a further downstream side than the second flow passage in the flow direction and having an outer diameter that becomes larger toward a downstream side in the flow direction.

7. The steering device according to claim 5, further comprising a truncated conical connection path formed concentrically with the second flow passage on a further downstream side than the second flow passage in the flow direction and having an outer diameter that becomes larger toward a downstream side in the flow direction.

8. The steering device according to claim 1, wherein the movable member is cylindrical and has a seating surface provided at an end portion on an opposite side to the second flow passage in a center line direction, a spherical valve body being contacted to the seating surface, and the steering device further comprising a cap configured to accommodate therein the valve body and a pressing part for pressing the valve body to the seating surface, together with the movable member, and having a communication hole provided on a further opposite side to the second flow passage than the valve body and configured to communicate an inside and an outside of the cap.

9. A ship comprising: a ship body; andthe steering device configured to change a traveling direction of the ship body according to claim 1.

10. The steering device according to claim 2, wherein the movable member is cylindrical and has a seating surface provided at an end portion on an opposite side to the second flow passage in a center line direction, a spherical valve body being contacted to the seating surface, and the steering device further comprising a cap configured to accommodate therein the valve body and a pressing part for pressing the valve body to the seating surface, together with the movable member, and having a communication hole provided on a further opposite side to the second flow passage than the valve body and configured to communicate an inside and an outside of the cap.

11. A ship comprising: a ship body; andthe steering device configured to change a traveling direction of the ship body according to claim 2.

12. The steering device according to claim 3, wherein the movable member is cylindrical and has a seating surface provided at an end portion on an opposite side to the second flow passage in a center line direction, a spherical valve body being contacted to the seating surface, and the steering device further comprising a cap configured to accommodate therein the valve body and a pressing part for pressing the valve body to the seating surface, together with the movable member, and having a communication hole provided on a further opposite side to the second flow passage than the valve body and configured to communicate an inside and an outside of the cap.

13. A ship comprising: a ship body; andthe steering device configured to change a traveling direction of the ship body according to claim 3.

14. The steering device according to claim 4, wherein the movable member is cylindrical and has a seating surface provided at an end portion on an opposite side to the second flow passage in a center line direction, a spherical valve body being contacted to the seating surface, and the steering device further comprising a cap configured to accommodate therein the valve body and a pressing part for pressing the valve body to the seating surface, together with the movable member, and having a communication hole provided on a further opposite side to the second flow passage than the valve body and configured to communicate an inside and an outside of the cap.

15. A ship comprising: a ship body; andthe steering device configured to change a traveling direction of the ship body according to claim 4.

16. The steering device according to claim 5, wherein the movable member is cylindrical and has a seating surface provided at an end portion on an opposite side to the second flow passage in a center line direction, a spherical valve body being contacted to the seating surface, and the steering device further comprising a cap configured to accommodate therein the valve body and a pressing part for pressing the valve body to the seating surface, together with the movable member, and having a communication hole provided on a further opposite side to the second flow passage than the valve body and configured to communicate an inside and an outside of the cap.

17. A ship comprising: a ship body; andthe steering device configured to change a traveling direction of the ship body according to claim 5.

18. The steering device according to claim 6, wherein the movable member is cylindrical and has a seating surface provided at an end portion on an opposite side to the second flow passage in a center line direction, a spherical valve body being contacted to the seating surface, and the steering device further comprising a cap configured to accommodate therein the valve body and a pressing part for pressing the valve body to the seating surface, together with the movable member, and having a communication hole provided on a further opposite side to the second flow passage than the valve body and configured to communicate an inside and an outside of the cap.

19. A ship comprising: a ship body; andthe steering device configured to change a traveling direction of the ship body according to claim 6.

20. The steering device according to claim 7, wherein the movable member is cylindrical and has a seating surface provided at an end portion on an opposite side to the second flow passage in a center line direction, a spherical valve body being contacted to the seating surface, and the steering device further comprising a cap configured to accommodate therein the valve body and a pressing part for pressing the valve body to the seating surface, together with the movable member, and having a communication hole provided on a further opposite side to the second flow passage than the valve body and configured to communicate an inside and an outside of the cap.