JP4275188B1 - Hull with side thrusters - Google Patents

Abstract

An object of the present invention is to provide a hull with a side thruster capable of reducing resistance during navigation through a tunnel of a side thruster and improving a fuel consumption rate.
A lid 17 that opens and closes a tunnel 9 of a side thruster, a shaft 19A that is fixed to the lid 17 and is rotatably supported on a ship bottom 7, and the lid 17 is rotated by rotation of the shaft 19A. A rotation axis L2 of the shaft portion 19A extends in a direction orthogonal to the tunnel axis L1 of the tunnel 9 and is offset with respect to the tunnel axis L1, and opens the tunnel 9 The surface 17a of the lid portion 17 at this time is closer to the tunnel axis L1 than when the rotation axis L2 intersects the tunnel axis L1.
[Selection] Figure 2

Description

  The present invention relates to a hull having a side thruster.

  2. Description of the Related Art Hulls equipped with side thrusters are conventionally known for facilitating landing and leaving of a hull. The side thruster includes a tunnel penetrating across the ship bottom and a screw disposed in the tunnel. Usually, the side thrusters are provided on each of the bow side and the stern side, and serve as a propulsive force when the hull moves sideways. The hull with a side thruster eliminates the need for a tugboat when berthing and improves operability.

  The side thruster tunnel is in the water under the draft of the hull, and the tunnel opening (entrance / exit) formed on the side of the hull acts as a resistance to navigation, affecting the navigation speed and maneuvering, and reducing the fuel consumption rate. . Thus, for example, a technique has been developed in which a lid structure that opens and closes the entrance and exit of the tunnel is provided and the resistance is reduced by closing the tunnel during normal navigation (see Patent Document 1). This type of lid structure has a structure similar to a butterfly valve, and includes a circular plate corresponding to the shape of the inner peripheral surface of the tunnel and a shaft portion for rotating the circular plate. The axis (rotation axis) of the shaft portion is arranged to intersect the center line (tunnel axis) of the tunnel, and when the shaft portion is rotated, the circular plate also rotates. When standing up, the circular plate closes the tunnel and closes the tunnel. On the other hand, when the circular plate falls down and lies horizontally, the tunnel is fully opened. The side thruster is operated with the tunnel fully open.

JP 59-45198 A

  The circular plate of the lid structure has a surface facing outward when the tunnel is closed and a back surface facing inward. The axis of rotation of the lid structure intersects the tunnel axis, but the surface of the circular plate and the axis of rotation are substantially separated, so when the circular plate is tilted to open the tunnel, the surface of the circular plate Also shifts downward. Therefore, it is necessary to make a clearance that allows this deviation in the tunnel. This escape portion becomes a gap that cannot be closed even when the circular plate stands up, and becomes resistance during navigation. However, in conventional hulls with side thrusters, the lid that closes the tunnel usually has its rotational axis intersecting the tunnel axis, and in particular, the occurrence of resistance due to the gaps described above is taken into consideration. However, it was insufficient in terms of improving the fuel consumption rate by reducing the resistance.

  An object of the present invention is to provide a hull with a side thruster that can reduce resistance during navigation through a tunnel of a side thruster and can improve a fuel consumption rate.

  The present invention relates to a hull with a side thruster having a cylindrical tunnel passing through the bottom of the ship and a screw disposed in the tunnel, a lid that opens and closes the entrance and exit of the tunnel, and is fixed to the lid and rotates to the bottom of the ship A shaft portion that is freely supported, and a drive portion that causes the lid portion to stand up and close the tunnel by rotation of the shaft portion, and that opens the tunnel by tilting the lid portion. When closed, it has a surface facing the outside of the tunnel and a back surface facing the inside of the tunnel, the axis of rotation of the shaft extends in a direction perpendicular to the tunnel axis of the tunnel, and the tunnel axis The surface of the lid when the tunnel is opened is closer to the tunnel axis than when the rotation axis intersects the tunnel axis.

  In the present invention, the driving portion rotates the shaft portion, thereby erecting the lid portion to close the tunnel, and tilting the lid portion to open the tunnel. Since the lid portion has a substantial thickness, there is a predetermined distance between the rotation axis of the shaft portion and the surface of the lid portion. For this reason, when the lid portion is tilted to open the tunnel, the surface of the lid portion is displaced downward, for example, from the rotational axis. When the tunnel is closed, the widest part of the surface of the lid part exists on the tunnel axis, but when the lid is tilted and the tunnel is opened, this widest part is larger than the tunnel axis. Also come down. Therefore, in order to avoid interference with the surface of the lid when the tunnel is opened, it is necessary to form a relief on the inner peripheral surface near the entrance / exit of the tunnel. In conventional hulls, it has been common to intersect the axis of rotation of the shaft and the tunnel axis. However, in the present invention, the axis of rotation of the shaft portion extends in a direction orthogonal to the tunnel axis and is offset with respect to the tunnel axis. Therefore, when the tunnel is opened, the conventional general hull That is, the surface of the lid portion is closer to the tunnel axis than the hull in which the rotation axis of the shaft portion that opens and closes the lid portion intersects the tunnel axis, and the size of the clearance gap can be made smaller than that of the conventional hull. Even if the lid is stood up and the tunnel is closed, the clearance gap cannot be covered by the lid portion, and this clearance gap becomes a resistance in normal navigation. Therefore, if the clearance can be reduced, the gap generated between the inner peripheral surface of the tunnel and the lid portion is reduced when the tunnel is closed, the navigation resistance is reduced, and the fuel consumption rate is improved. be able to.

  In addition, the width of the part of the ship bottom where the tunnel is provided is narrower on the lower side than the upper side, and the lid stands up diagonally following the outer peripheral surface of the ship bottom around the tunnel entrance and closes the tunnel The axis of rotation of the shaft is offset upward with respect to the tunnel axis, and the portion of the surface of the lid that has the widest width in the direction of the axis of rotation is the axis of rotation when the tunnel is opened. It is preferable that the distance is closer to the tunnel axis than in the case of intersecting with. Since the lid portion stands up obliquely following the outer peripheral surface of the ship bottom around the entrance of the tunnel and closes the tunnel, the resistance at the time of navigation with the entrance of the tunnel closed can be reduced. Further, the axis of rotation of the shaft portion is shifted upward with respect to the tunnel axis, and the portion of the surface of the lid that has the widest axial width of the shaft portion is located on the shaft portion when the tunnel is opened. It is closer to the tunnel axis than when the axis intersects the tunnel axis. It is necessary to form a tunnel relief in accordance with this widest portion. By making the widest part close to the tunnel axis, it is possible to reliably reduce the escape compared to the case where the axis of rotation of the shaft intersects the tunnel axis, reduce the resistance during navigation, and improve the fuel consumption rate. Can be planned.

  Furthermore, it is preferable that the lid portion has a wing shape in which the front surface and the back surface are convex curved surfaces. When the tunnel is opened by tilting the lid, and the screw is driven in this state, the resistance of the fluid passing through the tunnel is reduced, and the fuel consumption rate can be improved.

  Furthermore, it is preferable that there are a pair of shaft portions fixed to the lid portion, and the pair of shaft portions are arranged independently on both sides of the lid portion. Since the pair of shaft portions are provided independently of each other, repair and maintenance accompanying damage to one shaft portion and the like are facilitated.

  Furthermore, it is preferable that the drive unit opens and closes the lid using hydraulic pressure. By using the hydraulic pressure, it is possible to obtain a large output while being small in size, and further, the friction loss is small and efficient.

  Further, the drive unit projects from each of the pair of shaft portions and extends in a direction intersecting the rotation axis of the shaft portion, and is connected to each of the pair of arm portions. It is preferable to include a pair of cylinder parts that rotate the part and a hydraulic pump that applies hydraulic pressure to both of the pair of cylinder parts. The cylinder portion acts to tilt the arm portion, and the shaft portion rotates by the tilt of the arm portion to open and close the lid portion. Therefore, the lid portion can be efficiently opened and closed with a small force.

  Furthermore, it is preferable that the drive unit further includes a detection unit that is provided in the cylinder unit and detects at least one of an open position and a closed position of the lid unit to stop the operation of the hydraulic pump. When the detection unit detects the open position of the lid, the lid moving from the closed position to the open position can be reliably stopped at the open position. When the detection unit detects the closed position of the lid, the lid moving from the open position to the closed position can be reliably stopped at the closed position.

  Furthermore, it is preferable to further include a locking portion that maintains the hydraulic pressure applied to the cylinder portion and holds the lid portion in a predetermined position when the lid portion closes the tunnel. Since the lid portion can be held in a predetermined position (for example, a closed position or an open position), it is possible to stably reduce the resistance that can be generated at the entrance and exit of the tunnel by eliminating the influence of the blur of the lid portion.

  Furthermore, it is preferable to further include an overload prevention part that releases the holding of the cover part by the locking part when an external force is applied to the cover part with the cover part closing the tunnel entrance. When the lid is overloaded with an external force, the holding of the lid by the locking portion is released, so that damage to the lid and the drive due to overload is avoided.

  Further, it is preferable that a tunnel of a side thruster is provided on both the front part on the bow side and the rear part on the stern side, and the lid part opens and closes the entrance / exit of at least the front tunnel. During normal navigation, the fuel consumption rate is likely to be reduced by the resistance of the side thruster tunnel on the bow side. Therefore, at least the entrance and exit of the front tunnel is opened and closed with a lid to effectively reduce the fuel consumption rate. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the resistance at the time of navigation by the tunnel of a side thruster can be reduced, and the improvement of a fuel consumption rate can be aimed at.

  Hereinafter, a preferred embodiment of a hull with a side thruster according to the present invention will be described with reference to the drawings. FIG. 1 is a view schematically showing a hull with side thrusters (hereinafter referred to as “hull”) 1, wherein (a) is a side view and (b) is a bottom view.

  The hull 1 is provided with side thrusters 3 and 5 at both the front part on the bow 1a side and the rear part on the stern 1b side. The side thruster 3 on the bow 1a side is commonly called a bow thruster 3, and the side thruster 5 on the stern 1b side is commonly called a stern thruster 5. In recent large passenger ships and the like, there are some which have three bow thrusters 3 and three stern thrusters 5, but in this embodiment, a hull which has one stern thruster 5 and one bow thruster 3. 1 is illustrated. The bow thruster 3 and the stern thruster 5 are convenient because they can be easily maneuvered without calling for support such as a tugboat when landing on the quay, and are also economical.

  2 is a cross-sectional view taken along the line II-II in FIG. 1, and is an enlarged view of the bow raster 3. FIG. 3 is an enlarged view of the cross section of the lid portion shown in FIG. is there. FIG. 4 is an enlarged view of a hydraulic cylinder that opens and closes the lid, and FIG. 5 is a plan view of the lid. Hereinafter, the side thruster will be described with reference to FIGS. 2 to 5, but in this embodiment, the bow thruster 3 and the stern thruster 5 have substantially the same configuration. The explanation of the Stern raster 5 is omitted.

  The bottom 7 of the hull 1 is designed in consideration of various factors such as underwater resistance and ship maneuverability during drafting. The ship bottom 7 according to the present embodiment is substantially streamlined (see FIG. 1B) in order to reduce fluid resistance during navigation. A tunnel 9 for the bow thruster 3 is provided on the ship bottom 7. The tunnel 9 has a cylindrical shape with a circular cross section, and penetrates the ship bottom 7 along the left-right direction orthogonal to the front-rear direction. A screw 11 for drawing and discharging a fluid such as seawater into the tunnel 9 is provided at the approximate center in the left-right direction of the tunnel 9. The screw 11 is rotated by driving of the drive motor 13, and the drive motor 13 is disposed in a chamber 15 provided in the ship bottom 7.

  The bottom 7 has a lower width B1 narrower than an upper width B2 in the portion where the tunnel 9 is provided (see FIG. 2). Therefore, the outer peripheral surface 7 a of the ship bottom 7 around the left and right entrances 9 a of the tunnel 9 is a convex curved surface inclined obliquely with respect to the center line (tunnel axis) L 1 of the tunnel 9. The left and right entrances 9 a of the tunnel 9 are provided with lid portions 17 that open and close the entrance 9 a. The lid portion 17 has a structure similar to a butterfly valve that opens and closes by the rotation of the shaft portions 19A and 19B, but the shape of the lid portion 17 in plan view is not a circular shape close to a perfect circle, but rather an oval shape close to an ellipse. (See FIG. 5). The shape of the lid portion 17 corresponds to the shape generated when the tunnel 9 is cut obliquely following the shape of the outer peripheral surface 7a of the ship bottom 7 around the entrance 9a of the tunnel 9.

  The lid portion 17 has a front surface 17 a facing the outside of the tunnel 9 and a back surface 17 b facing the inside of the tunnel 9 when the entrance 9 a of the tunnel 9 is closed. The lid portion 17 has a wing shape in which the front surface 17a and the back surface 17b are convex curved surfaces, and has a convex lens shape. The lid portion 17 can close the entrance / exit 9a of the tunnel 9 with a single wing-shaped plate body.

  As shown in FIG. 4, a pair of independent shaft portions 19 </ b> A and 19 </ b> B are provided on both sides of the lid portion 17 (both sides in the front-rear direction of the hull 1). The shaft portions 19A and 19B are supported by a boss portion 21 fixed to the ship bottom 7 around the tunnel 9 by welding or the like. A bearing portion (not shown) that rotatably supports the shaft portions 19A and 19B and a seal ring (not shown) constituting a watertight mechanism are incorporated in the boss portion 21. Since the pair of shaft portions 19A and 19B are independent on both sides of the lid portion 17, assembly and disassembly are easy, and the shaft portions 19A and 19B are inserted into the boss portion 21 or pulled out. The external space can be smaller than the case where the lid portion is rotatably supported by a single shaft portion that crosses the lid portion.

  Of the pair of shaft portions 19A and 19B, one shaft portion 19A is fixed to the lid portion 17 on the base end side. The tip of the shaft portion 19A protrudes from the boss portion 21, and an arm portion 23 that protrudes and extends in a direction orthogonal to the rotation axis L2 of the shaft portion 19A is fixed to the tip. The arm part 23 is connected to the piston rod 25a of the hydraulic cylinder 25A via a pin. The arm portion 23 tilts around the shaft portion 19A by the reciprocating motion of the piston rod 25a, and the shaft portion 19A rotates as the arm portion 23 tilts. The other shaft portion 19B is the same, and is rotatably supported by a boss portion 21 fixed to the ship bottom 7, and an arm portion 23 is connected to a piston rod 25a. The arm portion 23 is tilted by the reciprocating motion of the piston rod 25a of the hydraulic cylinder 25B, and the shaft portion 19B is rotated by the tilting of the arm portion 23. A stopper member (not shown) corresponding to the closed position of the lid portion 17 is provided at the end when the piston rod 25a moves forward, and the piston rod 25a moves forward by contacting the stopper member. Be regulated.

  A pair of piston rods 25a connected to both shaft portions 19A and 19B reciprocate synchronously, and rotate both shaft portions 19A and 19B in synchronization. The lid portion 17 opens and closes with the rotation of the shaft portions 19A and 19B. The lid portion 17 closes the entrance / exit 9a of the tunnel 9 in a state of standing up obliquely following the outer peripheral surface 7a of the ship bottom 7 around the entrance / exit 9a of the tunnel 9 and closes the entrance / exit 9a of the tunnel 9 in a state of lying down horizontally. Fully open.

  The lid 17 is opened and closed by a driving device (driving unit) 24 using hydraulic pressure. FIG. 6 shows a hydraulic circuit constituting the driving device 24. As shown in FIG. 6, the driving device 24 includes hydraulic cylinders (cylinder portions) 25A and 25B that reciprocate the piston rod 25a. A pair of hydraulic cylinders 25 </ b> A and 25 </ b> B are provided corresponding to the shaft portions 19 </ b> A and 19 </ b> B of the lid portion 17, and are arranged so as to sandwich the lid portion 17.

  The hydraulic circuit of the driving device 24 is provided with a first oil path 51 and a second oil path 52 that communicate from the oil tank 31 to the electromagnetic direction switching valve 41. The first oil passage 51 is a line for supplying hydraulic oil, and the second oil passage 52 is a line for returning the hydraulic oil to the oil tank 31.

  A hydraulic pump 27 is provided in the first oil passage 51. The hydraulic pump 27 is activated by the activation of the electric motor 29, sucks hydraulic oil from the oil tank 31, and discharges it from the discharge port 27a. Further, the first oil passage 51 is provided with a filter 33 for protecting the hydraulic pump 27 on the upstream side of the hydraulic pump 27, that is, on the oil tank 31 side. Further, a check valve 35 and a stop valve 39 are provided in the first oil passage 51 on the downstream side of the hydraulic pump 27.

  Further, the first oil passage 51 is provided with a bypass passage 53 that branches between the check valve 35 and the stop valve 39 and communicates with the second oil passage 52. A relief valve 37 that holds the inside of the circuit at a constant pressure is provided.

  The electromagnetic direction switching valve 41 is switched to either the open position Po or the closed position Pc when excited from the neutral position Pn, and returns to the neutral position Pn when demagnetized. The open position Po is a position where hydraulic oil is supplied so that the piston rod 25a is protruded (advanced) and the lid portion 17 is moved in the opening direction. The closed position Pc is a position where hydraulic oil is supplied so that the piston rod 25a is retracted (retracted) and the lid portion 17 is moved in the closing direction. The neutral position Pn is a position where the supply of hydraulic oil to the hydraulic cylinder 25 is stopped. The electromagnetic direction switching valve 41 is electrically connected to the lid closing position detection switches 47A and 47B and the lid opening position detection switches 49A and 49B. The electromagnetic direction switching valve 41 switches the open position Po, the intermediate position Pn, or the closed position Pc based on detection signals from the lid closed position detection switches 47A and 47B or the lid open position detection switches 49A and 49B.

  The electromagnetic direction switching valve 41 is connected to a third oil path 54 and a fourth oil path 55 that communicate with the pair of hydraulic cylinders 25A and 25B. When the electromagnetic direction switching valve 41 is in the open position Po, the hydraulic oil supplied from the first oil passage 51 is supplied to the third oil passage 54 and the hydraulic oil returning from the fourth oil passage 55 is the second oil. Is returned to the oil tank 31 through the oil passage 52. When the electromagnetic direction switching valve 41 is in the closed position Pc, the hydraulic oil supplied from the first oil passage 51 is supplied to the fourth oil passage 55, and the hydraulic oil returning from the third oil passage 54 is the second oil passage. Is returned to the oil tank 31 through the oil passage 52. When the electromagnetic direction switching valve 41 is in the neutral position Pn, even if hydraulic fluid is supplied from the first oil passage 51, it is not supplied to the third oil passage 54 and the fourth oil passage 55, It is returned to the oil tank 31 through the second oil passage 52.

  The third oil passage 54 is branched, and each branch passage is connected to a pair of hydraulic cylinders 25A and 25B. The fourth oil passage 55 is branched, and each branch passage is connected to a pair of hydraulic cylinders 25A and 25B. Since the pair of hydraulic cylinders 25A and 25B have the same configuration, the connection between the third oil passage 54 and the fourth oil passage 55 and the hydraulic cylinders 25A and 25B will be described by taking one hydraulic cylinder 25A as an example. To do. The hydraulic cylinder 25A is a double-acting cylinder, and two ports 25c and 25d for supplying hydraulic oil are provided so as to sandwich the piston 25b. The third oil passage 54 is connected to the port 25c on the side where the piston rod 25a is advanced, and the fourth oil passage 55 is connected to the port 25d on the side where the piston rod 25a is retracted. When hydraulic oil is supplied from the third oil passage 54, the hydraulic oil is discharged from the fourth oil passage 55, and when hydraulic oil is supplied from the fourth oil passage 55, the third oil passage The hydraulic oil is discharged from 54.

  The third oil passage 54 and the fourth oil passage 55 are provided with a locking circuit (locking portion) 43. The locking circuit 43 includes pilot check valves 43a and 43b provided in the third oil passage 54 and the fourth oil passage 55, respectively. The pilot check valve 43a provided in the third oil passage 54 allows the flow of hydraulic oil from the electromagnetic direction switching valve 41 side and restricts the flow of hydraulic oil from the hydraulic cylinder 25 side. The pilot check valve 43b provided in the fourth oil passage 55 allows the flow of hydraulic oil from the electromagnetic direction switching valve 41 side and restricts the flow of hydraulic oil from the hydraulic cylinder 25 side. The locking circuit 43 suppresses the backflow of hydraulic oil from the hydraulic cylinder 25 when the lid portion 17 reaches the open position or the closed position and the electromagnetic direction switching valve 41 is switched to the neutral position Pn, and the piston rod 25a. Is held at a predetermined position, and as a result, the movement of the lid portion 17 is stopped and the lid portion 17 is held at a predetermined position.

  Further, the pilot check valve 43a provided in the third oil passage 54 is supplied with hydraulic oil from the electromagnetic direction switching valve 41 side, and when the hydraulic pressure is applied, the pilot check valve 43b provided in the fourth oil passage 55 is provided. open. As a result, in the fourth oil passage 55, hydraulic oil from the hydraulic cylinder 25 side is discharged toward the electromagnetic direction switching valve 41 side. As a result, when supplying hydraulic oil from the third oil passage 54, the hydraulic oil from the fourth oil passage 55 is smoothly discharged. Further, the pilot check valve 43b provided in the fourth oil passage 55 is supplied with hydraulic oil from the electromagnetic direction switching valve 41 side and applied with hydraulic pressure, the pilot check valve 43a provided in the third oil passage 54 is provided. open. As a result, in the third oil passage 54, the hydraulic oil from the hydraulic cylinder 25 side is discharged toward the electromagnetic direction switching valve 41 side. As a result, when supplying hydraulic oil from the fourth oil passage 55, the hydraulic oil from the third oil passage 54 is smoothly discharged.

  The third oil passage 54 and the fourth oil passage 55 are provided with an overload prevention circuit (overload prevention portion) 45 on the hydraulic cylinder 25 side with respect to the locking circuit 43. The overload prevention circuit 45 is provided with a return oil passage 56 connected to the second oil passage 52. A safety valve (relief valve) 57 is provided in the return oil passage 56. On the upstream side of the safety valve 57 in the return oil passage 56, that is, on the side close to the locking circuit 43, the first bypass passage 56 a connected to the third oil passage 54 and the fourth oil passage 55 connected to the fourth oil passage 55 are provided. 2 bypass paths 56b. Furthermore, on the downstream side of the safety valve 57 in the return oil passage 56, a third bypass passage 56 c connected to the third oil passage 54 and a fourth bypass passage 56 d connected to the fourth oil passage 55 are provided. Is provided. The first bypass path 56a is provided with a check valve 56e for restricting the flow from the third oil path 54 to the return oil path 56, and the second bypass path 56b is connected with the fourth oil path 55. A check valve 56 f that restricts the flow to the return oil passage 56 is provided. The third bypass passage 56c is provided with a check valve 56g for guiding the high-pressure oil in the third oil passage 54 to the safety valve 57, and the high-pressure oil in the fourth oil passage 55 is supplied to the fourth bypass passage 56d. A check valve 56h leading to the safety valve 57 is provided. The check valve 56 g prevents the flow from the fourth oil passage 55 to the third oil passage 54. The check valve 56 h prevents the flow from the third oil passage 54 to the fourth oil passage 55.

  The overload prevention circuit 45 applies an external overload such as wave force to the lid portion 17 that closes the tunnel 9, and as a result, the piston rod 25a, the fourth oil passage 55, and the check valve When a hydraulic pressure of a predetermined pressure or more is applied to the safety valve 57 via 56h, the safety valve 57 is opened, and the working oil is guided to the fourth oil passage 54 via the check valve 56e. At the same time, the shortage of the oil amount caused by the effective area difference between the pistons 25 b of the hydraulic cylinders 25 A and 25 B is supplied from the oil tank 31 through the second oil passage 52. As a result, the lid portion 17 moves in the opening direction, and an excessive load is not applied to the lid portion 17 and the driving device 24, thereby preventing damage. The safety valve 57 is set to a higher pressure than the relief valve 6.

  The driving device 24 includes lid closing position detection switches 47A and 47B for detecting a state in which the piston rod 25a is retracted and retracted, that is, a state in which the lid portion 17 closes the entrance 9a of the tunnel 9, and a piston rod A pair of lid opening position detection switches 49A and 49B for detecting a state in which 25a has advanced and protruded, that is, a state in which the lid portion 17 opens (fully opens) the entrance 9a of the tunnel 9, are provided. The lid closing position detection switches 47A and 47B and the lid opening position detection switches 49A and 49B are provided in the pair of hydraulic cylinders 25A and 25B, respectively, and close to the end of the reciprocating track of the piston rod 25a of the hydraulic cylinders 25A and 25B. It is arranged at the position to do. The lid closing position detection switches 47A and 47B and the lid opening position detection switches 49A and 49B are electrically connected to the electric motor 29 and the electromagnetic direction switching valve 41 so that detection signals can be transmitted.

  In the hull 1 according to the present embodiment, the rotation axis L2 of the shaft portions 19A and 19B for opening and closing the lid portion 17 extends in a direction orthogonal to the tunnel axis L1 and is shifted upward with respect to the tunnel axis L1. Hereinafter, an operation and an effect produced when the rotation axis L2 of the shaft portions 19A and 19B is deviated from the tunnel axis L1 will be described with reference to FIG. 3, FIG. 7, and FIG.

  FIG. 7 exemplifies a conventional side thruster and is an enlarged cross-sectional view centering on a lid. FIG. 8 is a view schematically showing a lid for comparing the conventional side thruster and the side thruster according to the present embodiment. FIG. 8A is a cross-sectional view of the lid according to the present embodiment. FIG. 4B is a front view of the lid according to the present embodiment, and FIG. 8C is a cross-sectional view of the lid portion according to the conventional example, FIG. 8D is a front view of the lid portion according to the conventional example, and (c) and (d) are in a correspondence relationship.

  As shown in FIGS. 8C and 8D, in the conventional example, the rotation axis L3 of the shaft portion 119 intersects the tunnel axis L1. Since the lid portion 117 has a substantial thickness, there is a predetermined distance between the rotation axis L3 of the shaft portion 119 and the surface 117a of the lid portion 117. Therefore, when the lid portion 117 is tilted to open the tunnel 109, the surface 117a of the lid portion 117 is shifted downward from the rotation axis L3. In the state where the lid portion 117 closes the tunnel 109, the widest portion Pb of the surface 117a of the lid portion 117 exists on the tunnel axis L1, but when the lid portion 117 is tilted, this widest portion Pb is present. The wide portion Pb comes below the tunnel axis L1. Therefore, in order to avoid interference with the surface 117a of the lid portion 117 when the tunnel 109 is opened, it is necessary to form a relief Rb on the inner peripheral surface near the entrance / exit of the tunnel 109. Even if the lid portion 117 is erected and the tunnel 9 is closed, the gap serving as the relief Rb cannot be covered by the lid portion 117, so that the clearance Rb becomes a resistance during normal navigation.

  As shown in FIGS. 8A and 8B, in the present embodiment, the rotation axis L2 of the shaft portion 19A is shifted upward with respect to the tunnel axis L1. Therefore, when the tunnel 9 is opened, the surface 17a (the widest portion Pa) of the lid portion 17 is closer to the tunnel axis L1 than in the conventional example, and the dimension of the gap that becomes the clearance Ra is set to the conventional hull. Can be smaller than If the clearance Ra can be reduced, the gap generated between the inner peripheral surface of the tunnel 9 and the lid portion 17 when the tunnel 9 is closed is reduced, the navigation resistance is reduced, and the fuel consumption rate is reduced. Can be improved.

  Subsequently, the operation method of the side thruster will be described focusing on the operation procedure of the lid portion 17 that opens and closes the tunnel 9 of the bow thruster 3. When normal navigation ends and the berth arrives at the quay at the destination, the operator who operates the boat pushes the release switch to perform the opening operation. Then, the electric motor 29 is activated and the hydraulic pump 27 is activated. When the electric motor 29 reaches the rated rotation, the electromagnetic direction switching valve 41 is switched to the open position Po.

  In this state, the hydraulic oil passing through the third oil passage 54 is supplied to the hydraulic cylinders 25A and 25B, while the hydraulic oil from the hydraulic cylinder 25 is discharged via the fourth oil passage 55. Then, the piston rod 25a moves forward to rotate the shaft portions 19A and 19B, and the lid portion 17 falls and starts to open the entrance 9a of the tunnel 9. When the lid open position detection switches 49A and 49B detect the piston rod 25a, the electromagnetic direction switching valve 41 is demagnetized and switched to the neutral position Pn, and the electric motor 29 is stopped and the operation of the hydraulic pump 27 is stopped. Here, the locking circuit 43 functions to prevent the backflow of hydraulic oil from the hydraulic cylinders 25A and 25B and hold the piston rod 25a in a predetermined position. As a result, the lid portion 17 is held in the open position where the entrance 9a of the tunnel 9 is fully opened.

  When the tunnel 9 is opened, the drive motor 13 is activated to rotate the screw 11 of the bow thruster 3. When the screw 11 disposed in the tunnel 9 rotates, a propulsive force in the lateral direction acts on the hull 1. As a result, the hull 1 moves laterally without a tugboat and berths.

  Next, an operation procedure when the entrance / exit 9a of the tunnel 9 is closed by the lid portion 17 will be described. The operator performs the closing operation by pressing the closing switch. Then, the electric motor 29 is activated and the hydraulic pump 27 is activated. When the electric motor 29 reaches the rated rotation, the electromagnetic direction switching valve 41 is excited to switch from the neutral position Pn to the closed position Pc.

  In this state, the hydraulic oil passing through the fourth oil passage 55 is supplied to the hydraulic cylinders 25A and 25B, while the hydraulic oil is discharged from the hydraulic cylinders 25A and 25B through the third oil passage 54. Then, the piston rod 25a moves backward to rotate the shaft portions 19A and 19B, and the lid portion 17 rises to start closing the entrance 9a of the tunnel 9. When the lid opening position detection switches 49A and 49B are released and the lid closing position detection switches 47A and 47B detect the piston rod 25a, the electromagnetic direction switching valve 41 is demagnetized and switched to the neutral position Pn, and the motor 29 stops. Thus, the operation of the hydraulic pump 27 is stopped. Here, the locking circuit 43 functions to prevent the backflow of hydraulic oil from the hydraulic cylinder 25 and hold the piston rod 25a in a predetermined position. As a result, the lid portion 17 is held in the closed position where the entrance 9a of the tunnel 9 is closed.

  Next, a safety function in the case where an external overload is applied to the lid portion 17 during navigation while the lid portion 17 closes the entrance 9a of the tunnel 9 will be described. When an external overload such as wave force acts on the lid portion 17 and the lid portion 17 receives a force in a direction to open the entrance 9 a of the tunnel 9, an excessive force acts on the piston rod 25 a in the forward direction. become. Then, the hydraulic oil in the hydraulic cylinder 25 applies an excessive hydraulic pressure equal to or higher than a predetermined pressure to the overload prevention circuit 45 through the fourth oil passage 55.

  In the overload prevention circuit 45, when excessive hydraulic pressure is applied through the fourth oil passage 55 and the fourth bypass passage 56d, the safety valve 57 is opened and discharged to the return oil passage 56. On the other hand, hydraulic oil is supplied to the third oil passage 54 via the first bypass passage 56a of the overload prevention circuit 45, and the amount of oil generated due to the effective area difference between the pistons 25b of the hydraulic cylinders 25A and 25B. The shortage is supplied from the oil tank 31 via the second oil passage 52. As a result, the piston rod 25a moves forward and protrudes, and the lid portion 17 is opened to eliminate the overload state.

  When either of the lid closing position detection switches 47A and 47B is brought into a non-detection state due to the advancement of the piston rod 25a, a non-detection signal is notified to the electric motor 26 and the electromagnetic direction switching valve 41. Upon receipt of non-detection signals from the lid closing position detection switches 47A and 47B, the electric motor 29 operates the hydraulic pump 27, the electromagnetic direction switching valve 41 switches from the neutral position Pn to the closed position Pc, and the lid 17 once opened Again, it operates in the direction of closing the entrance 9a of the tunnel 9.

  The effect by the hull 1 which concerns on this embodiment is demonstrated. When the tunnel 9 is closed by the lid portion 17, the widest portion Pa (see FIGS. 8A and 8B) of the surface 17a of the lid portion 17 exists on the tunnel axis L1, When the lid portion 17 is tilted, the widest portion Pa comes below the tunnel axis L1. In order to avoid interference with the widest portion Pa, it is necessary to form a relief Ra on the inner peripheral surface in the vicinity of the entrance / exit 9a of the tunnel 9. In the hull 1, the rotation axis L2 of the shaft portions 19A and 19B extends in a direction orthogonal to the tunnel axis L1 and is offset from the tunnel axis L1, so that the conventional general hull (FIG. 7 8 (c) and 8 (d)), that is, the surface 17a of the lid 17 is closer to the tunnel axis L1 than the hull in which the rotation axis L3 of the shaft 119 that opens and closes the lid 117 intersects the tunnel axis L1. The size of the gap that becomes closer and becomes the clearance Ra can be made smaller than the size of the clearance Rb of the conventional hull. Even if the lid portion 17 is erected and the tunnel 9 is closed, the gap that becomes the relief Ra cannot be covered by the lid portion 17, so that the clearance Ra becomes a resistance in normal navigation. However, in the hull 1, the clearance Ra can be reduced as compared with the conventional hull. Therefore, when the tunnel 9 is closed, a gap generated between the inner peripheral surface of the tunnel 9 and the lid portion 17 is reduced. The resistance is reduced, and the fuel consumption rate can be improved. In particular, in the hull 1, when the lid portion 17 is tilted down, the widest portion Pa is closer to the tunnel axis L1 than in the conventional hull, so the escape Ra can be reliably reduced and the resistance during navigation is reduced. This can improve the fuel consumption rate.

  Further, in the hull 1, the width of the portion provided with the tunnel 9 in the bottom 7 is narrower in the lower width B 1 than in the upper width B 2, and the lid portion 17 is provided around the entrance 9 a of the tunnel 9. The tunnel 9 is closed by standing up obliquely following the outer peripheral surface 7 a of the ship bottom 7. As a result, a step or the like is unlikely to occur between the outer peripheral surface 7a of the ship bottom 7 and the surface 17a of the lid portion 17, and resistance during navigation can be reduced.

  Furthermore, since the lid portion 17 according to the present embodiment has a wing shape in which the front surface 17a and the back surface 17b are convex curved surfaces, the lid portion 17 is tilted to open the tunnel 9, and in that state, the screw 11 is driven. In this case, the resistance of fluid such as seawater passing through the tunnel 9 is reduced, and the fuel consumption rate can be improved.

  Further, in the present embodiment, there are a pair of shaft portions 19A and 19B fixed to the lid portion 17, and the pair of shaft portions 19A and 19B are disposed independently on both sides of the lid portion 17, respectively. Repair and maintenance associated with damage to the shaft portions 19A and 19B are facilitated.

  Furthermore, since the driving device 24 according to the present embodiment uses the hydraulic pressure to open and close the lid portion 17, the driving device 24 can obtain a large output while being small in size, and further has low friction loss and high efficiency.

  In particular, the drive device 24 protrudes from each of the pair of shaft portions 19A and 19B and extends in a direction intersecting the rotation axis L2 of the shaft portions 19A and 19B, and each of the pair of arm portions 23. A pair of hydraulic cylinders 25A and 25B that are connected to tilt the arm portion 23 to rotate the shaft portions 19A and 19B, and a hydraulic pump 27 that applies hydraulic pressure to both the pair of hydraulic cylinders 25A and 25B are provided. The hydraulic cylinders 25A and 25B act to tilt the arm portion 23, and the tilting of the arm portion 23 causes the shaft portions 19A and 19B to rotate to open and close the lid portion 17. Therefore, the lid portion 17 can be efficiently opened and closed with a small force. be able to.

  Further, in the present embodiment, lid closing position detection switches 27A and 27B and lid opening position detection switches 29A and 29B are provided. When the piston rod 25a is detected by the lid opening position detection switches 29A and 29B, hydraulic pressure is detected. The operation of the pump 27 is stopped. Further, when the lid opening position detection switches 29A and 29B are released and the piston rod 25a is detected by the lid closing position detection switches 27A and 27B, the operation of the hydraulic pump 27 is stopped. As a result, the lid portion 17 can be reliably stopped at the open position or the closed position.

  Furthermore, in this embodiment, since the locking circuit 43 (locking part) is provided, the lid part 17 can be held in a predetermined position, for example, a closed position or an open position. As a result, it is possible to stably reduce the resistance that can be generated at the entrance / exit 9a of the tunnel 9 by eliminating the influence of the shaking of the lid portion 17. In particular, since the lid portion 17 can be held in the closed position, it is possible to suppress the occurrence of resistance due to the shaking of the lid portion 17 during navigation, and since the lid portion 17 can be held in the open position, the side thrusters 3 and 5 are operated. It is possible to suppress the generation of resistance due to the shaking of the lid portion 17 at the time of hitting.

  Further, the present embodiment includes an overload prevention circuit 45 (overload prevention unit), and when the lid 17 is overloaded with external force, the holding of the lid 17 by the locking circuit 43 is released. Damage to the lid 17 due to the load is avoided.

  Further, a bow thruster 3 and a stern thruster 5 are provided on the ship bottom 7, and a lid portion 17 is provided in each tunnel 9 of the bow thruster 3 and the stern thruster 5. During normal navigation, the fuel consumption rate is likely to be reduced by the resistance of the tunnel 9 of the side thruster (bow thruster 3) on the bow 1a side. However, since the lid portion 17 is provided in the tunnel 9 of the bow thruster 3, normal navigation is performed. At this time, at least the entrance / exit 9a of the tunnel 9 of the bow thruster 3 is closed by the lid portion 17, so that the reduction of the fuel consumption rate can be efficiently suppressed.

  As mentioned above, although this invention was concretely demonstrated based on the embodiment, this invention is not limited to the said embodiment. For example, in the above-described embodiment, the case where the surface of the lid portion is located below the tunnel axis when the lid portion is tilted has been described, but the same applies to the case where the surface is located above the tunnel axis. In this case, by shifting the rotation axis of the lid part below the tunnel axis, when the lid part is opened compared to the conventional hull where the rotation axis intersects the tunnel axis, the surface of the lid part becomes the tunnel axis. Get closer.

  In the above embodiment, the wing-shaped lid has been described as an example, but a flat lid may be used. Moreover, in the said embodiment, although the drive device using a hydraulic pressure was demonstrated to the example as a drive part which opens and closes a cover part, the apparatus which opens and closes a cover part by mechanical structure may be sufficient. In the above embodiment, the detection unit has been described by taking two switches (lid closed position detection switch, lid open position detection switch) as an example for detecting the open position and the closed position of the cover, respectively. It is also possible to provide only the detection unit that performs the detection, or only the detection unit that detects the closed position.

It is a figure which shows the hull with a side thruster which concerns on embodiment of this invention, (a) is a side view, (b) is a bottom view. It is sectional drawing along the II-II line of FIG. It is a side view which expands and shows a hydraulic cylinder. It is a front view which shows the state which the cover part has closed the entrance / exit of the tunnel. It is a top view of a cover part. It is a figure which shows the hydraulic circuit of a drive device. It is sectional drawing of the cover part which concerns on a prior art example. It is a typical figure for comparing this embodiment with a conventional example, (a) is a sectional view of a lid concerning this embodiment, (b) is a front view of a lid concerning this embodiment, ( (c) is sectional drawing of the cover part which concerns on a prior art example, (d) is a front view of the cover part which concerns on a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Hull (hull with a side thruster), 3 ... Bow thruster (side thruster), 5 ... Stern thruster (side thruster), 7 ... Ship bottom, 9 ... Tunnel, 9a ... Tunnel entrance / exit, 11 ... Screw, 17 ... Lid , 17a ... front surface, 17b ... back surface, 19A, 19B ... shaft portion, 23 ... arm portion, 24 ... drive device (drive portion), 25A, 25B ... hydraulic cylinder (cylinder portion), 27 ... hydraulic pump, 43 ... locking circuit (Locking part), 45 ... overload prevention circuit (overload prevention part), 47A, 47B ... lid closing position detection switch (detection part), 49A, 49B ... lid opening position detection switch (detection part), L1 ... tunnel axis , L2... Axis of rotation of the shaft portion, Pa... The portion having the widest surface width of the lid portion.

Claims (10)

In a hull with a side thruster having a cylindrical tunnel penetrating the ship bottom and a screw disposed in the tunnel,
A lid for opening and closing the entrance of the tunnel;
A shaft portion fixed to the lid portion and rotatably supported on the ship bottom;
A drive unit that erects the lid part to close the tunnel by rotating the shaft part, and that opens the tunnel by tilting the lid part;
The lid portion has a surface facing the outside of the tunnel and a back surface facing the inside of the tunnel when the tunnel is closed;
The axis of rotation of the shaft extends in a direction perpendicular to the tunnel axis of the tunnel and is offset from the tunnel axis;
The hull with a side thruster, wherein the surface of the lid when the tunnel is opened is closer to the tunnel axis than when the rotation axis intersects the tunnel axis. The width of the part of the ship bottom provided with the tunnel is narrower on the lower side than on the upper side,
The lid portion stands up obliquely following the outer peripheral surface of the ship bottom around the tunnel entrance and closes the tunnel,
The axis of rotation of the shaft is shifted upward with respect to the tunnel axis,
Of the surface of the lid portion, the widest portion in the direction of the rotation axis is closer to the tunnel axis when the tunnel is opened than when the rotation axis intersects the tunnel axis. The hull with a side thruster according to claim 1.   The hull with a side thruster according to claim 1 or 2, wherein the lid portion has a wing shape in which a front surface and a back surface are convex curved surfaces. The shaft portion has a pair,
The hull with a side thruster according to any one of claims 1 to 3, wherein the pair of shaft portions are independently arranged on both sides of the lid portion.   The hull with a side thruster according to claim 4, wherein the driving unit opens and closes the lid using hydraulic pressure. The drive unit is
A pair of arm portions projecting from each of the pair of shaft portions and extending in a direction intersecting the rotation axis of the shaft portion;
A pair of cylinder parts coupled to each of the pair of arm parts and tilting the arm part to rotate the shaft part;
A hydraulic pump that applies hydraulic pressure to both of the pair of cylinder parts;
The hull with a side thruster according to claim 5.   The said drive part is further provided in the said cylinder part, and further has a detection part which detects the at least one of the open position of the said cover part, and a closed position, and stops the action | operation of the said hydraulic pump. Hull with side thrusters as described.   8. The device according to claim 5, further comprising a locking portion that maintains a hydraulic pressure applied to the cylinder portion and holds the lid portion in a predetermined position when the lid portion closes the tunnel. The hull with the side thruster described in the paragraph.   In the state where the lid portion closes the entrance / exit of the tunnel, the lid portion further includes an overload prevention portion that releases the holding of the lid portion by the locking portion when an external force is applied to the lid portion. The hull with a side thruster according to claim 8. In the ship bottom, the tunnel of the side thruster is provided in both the front part on the bow side and the rear part on the stern side,
The hull with a side thruster according to any one of claims 1 to 9, wherein the lid part opens and closes at least an entrance / exit of the tunnel at the front part.

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