JP2980378B2 - Ship water jet propulsion device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a water jet propulsion device for a ship, and more particularly to a propulsion device in which the hull is less likely to roll and cavitation during high-speed cruising and has improved cruising performance.

BACKGROUND ART As a conventional propulsion device for a ship of this type, there is known a device in which a propeller is formed in a leaf shape, a plurality of propellers are disposed on a propeller shaft, and an outer cylinder for pressurization is provided on an outer peripheral portion of the propeller. (For example, Japanese Utility Model Publication No. 1-251717).

Further, a device for providing a rotatable guide blade at a suction port of a suction duct and switching a direction of water flowing into the suction duct is described in Japanese Patent Application Laid-Open No. 5-270486. Further, a device in which guide fins for guiding outside water are provided on fins protruding below the suction port is also described in the specification of Japanese Utility Model Publication No. 1-229200. In addition, a device that removes suspended material by rotating the fork-shaped member backward when suspended material adheres to the suction inlet grid and the thrust is reduced is also known, for example,
No. 56-40078.

Furthermore, a propulsion device that provides a commutation plate at the bottom opening of the steering cylinder and commutates jet water forward with a rotatable flap,
It is described in JP-A-5-278683.

However, the conventional water jet propulsion system enables high-speed cruising, but the wing width of the impeller is short, so that a vortex is generated as the rotation speed of the impeller increases. was there. Also, at high speeds, the amount of water flowing into the suction duct on the forward direction side decreases, creating a low-pressure flow area, causing cavitation on the impeller blade surface, which may cause vibration and noise, as well as rolling. There was also. As a measure to prevent cavitation, a device for providing a movable guide blade at the suction port to switch the direction of flow into the suction duct may obstruct the inflow of water during high-speed traveling. In the case of a device provided with guide vanes outside the suction port, it is possible to increase the amount of inflow to the suction duct, however, the water flow resistance at the time of retreating or turning of the ship causes a rapid change of direction. Could not.

In addition, in a device provided with a grid at the suction port, it has a good ability to remove solids such as driftwood, but flexible floating substances adhere to the grid, or There is a risk that the fluid will flow into the duct and stick to the impeller, resulting in reduced propulsion due to reduced suction performance and the inability to navigate. In the device for removing the adhered suspended matter from the grid, deceleration of the ship and manual operation were required. Further, in a device in which a commutation plate for guiding backward propulsion is provided at the bottom of the steering cylinder, there is a possibility that water flow resistance may occur during high speed traveling. The present invention provides a propulsion device that has improved suction performance and navigation performance, and removes suspended matter adhering to the grid while traveling, and has a small decrease in reverse thrust during backward traveling, and switches between forward and backward. At times, it is an object to provide a water jet propulsion device without sudden braking and skidding.

DISCLOSURE OF THE INVENTION The configuration of the present invention is such that an inlet is opened at the bottom of the ship near the stern, and water sucked from the inlet to the suction duct is pressurized by an impeller provided in the impeller housing, and the stern rearward from the injection duct. In the propulsion device for jetting jet water, a plurality of spiral blades are arranged with a phase shift on an impeller shaft provided in the impeller housing, and the outer peripheral edge of the spiral blade approaches the inner peripheral surface of the impeller housing. As a result, the balance efficiency and volumetric efficiency are increased, and the outer peripheral tip of the spiral wing is extended to the suction side to form a wide suction port, thereby increasing suction performance and floating matters flowing into the suction duct. Is allowed to pass through. Then, a bowl-shaped flow path is formed by the impeller housing and the bearing case of the impeller shaft, and the guide blade provided behind the spiral blade is constituted by a plurality of long twist guide blades, and pressurized by the spiral blade. The swirling flow is guided to a linear flow to improve propulsion efficiency.

An arc-shaped flow guiding member is arranged at the front edge of the front end of the suction port of the suction duct when viewed from the side of the hull, and the running water flowing to the bottom of the ship is sucked in an arc along the flow guiding member. Guide to the mouth,
The water flow uniformly flows into the front part of the suction duct in the traveling direction. Then, a stabilizer is provided at the center of the suction port, and the stabilizer is fixed to the front and rear opening edges of the suction port 4 and protrudes downward from the bottom of the ship, so that the suction water flow to the suction duct is rectified, This is to prevent skidding. A movable grid is arranged in the front-rear direction of the suction port, and a rear end of the movable grid is pivotally connected to a rear end opening edge of the suction port so as to be rotatable. And a rotation speed sensor that detects the rotation speed of the spiral blades, and when the ship's running speed falls below the set value calculated from the rotation speed of the spiral blades, moves the movable grid away from the suction port of the suction duct. A rotating device is provided to remove floating substances adhering from the grid while running and recovering the propulsion performance.

In addition, a steering nozzle is provided behind the injection duct, a reverse injection port is disposed at the bottom of the steering nozzle, and a switching valve having a base end pivotally mounted on the rear opening edge of the reverse injection port is provided,
The reverse jet port and the rear jet port are openable and closable, so that a decrease in reverse thrust during retreat is reduced. When the switching valve is rotated to switch between forward running and backward running, a rotation speed control device for reducing the rotation speed of the spiral blade and returning the rotation speed after a predetermined time is provided. The number control device and the rotating device of the switching valve are interlocked to prevent sudden braking and skidding of the hull.

In the present invention, a plurality of spiral blades are wound around an impeller shaft provided at the stern, and an impeller casing is disposed around the outer periphery of the spiral blade. And, while forming a funnel-shaped suction port, an elliptical main body, and a contracted and opened discharge port in the impeller casing, an inner peripheral surface behind the suction port and an inner peripheral surface in front of the discharge port are formed on the impeller casing. A configuration in which a plurality of straightening plates vertically arranged in the axial direction of the impeller shaft and a plurality of guide vanes for rectifying the swirling flow in the axial direction of the impeller shaft is provided so as not to be affected by a complicated flow of water near the stern. is there. In particular, the thrust is increased by using the spiral blade as a mixed flow blade.

The present invention is configured as described above. When the spiral blade is rotated, water such as seawater is sucked from the suction duct and supplied to the start end of the spiral blade. The inflowing water is accelerated while being pressurized by a series of spiral blade surfaces of the spiral blade, and is transported along the bowl-shaped flow path of the impeller housing. Next, the accelerated spiral swirling flow is
It is guided in the axial direction of the impeller axle along the twisted guide vanes, rectified, and jetted from the jet port to the rear of the stern as jet water. Therefore, the discharge center line and the water surface are substantially the same, the actual head is reduced, and the water flow increased in pressure by the spiral blades can be directly used for propulsion. Also,
By making the blade spiral and extending the outer peripheral tip to the suction side, a wide suction port and a wide flow path to the impeller are formed, improving the suction performance and passing the inflowing floating matter. In addition, it is possible to prevent fibers and the like from being entangled in the spiral wing.

Due to the running of the ship, the water flowing along the bottom of the ship has a low pressure at the rear of the arc-shaped flow guiding member formed at the front edge of the inlet. For this reason, the water flowing along the bottom of the ship is sucked by the low-pressure portion, guided along the outer peripheral surface of the flow guide member, and flows into the suction duct. As the vehicle shifts to high-speed running, the low pressure behind the flow guiding member increases, and the amount of inflow water also increases. Therefore, negative pressure is not generated in the front part of the suction duct, cavitation can be prevented, and the suction performance of the impeller can be maintained. In addition, the stabilizer provided at the central portion of the suction port can prevent disturbance of water flowing into the suction port and also prevent rolling during high-speed running.

Floating matter that is going to flow into the suction duct is blocked or trapped by the grid and is blocked from flowing into the impeller housing. However, as the time elapses, the suction port is blocked by the suspended matter trapped on the grid, and the suction performance decreases and the propulsion performance decreases. Therefore, when the cruising speed of the ship decreases with respect to the rotation speed of the spiral wings and the cruising speed decreases below the set value, the grid is automatically rotated backward from the suction port in the cruising direction, and the The running water flow is used to wash off the suspended matter adhering to the grid, and then the grid is rotated and attached to the suction port. By doing so, the suction performance is increased, and the running speed can be recovered.

Next, the water pressurized and accelerated by the spiral wings is jetted from the rear end of the steering nozzle, and the ship runs by the reaction force of the discharge pressure. Then, when stopping or retreating the ship, if the switching valve closing the reverse ejection port of the steering nozzle is rotated in the direction of the ejection port, the ejection port is blocked by the switching valve, and the pressurized water is oblique in the forward direction. It is jetted downward, and can respond immediately from full speed advance to stop or full speed retreat. In addition, when switching between forward running and backward running by the rotation control device of the spiral wing, the rotation speed of the spiral wing can be reduced for a predetermined time, so that sudden braking of the hull is avoided, and the use of a stabilizer is also used. Thus, thrust of the ship can be prevented. Further, since the propulsion switching device is located inside the steering nozzle, there is no resistance to water flow during forward movement. In addition, there is no dispersion of the jet water at the time of retreat, and there is no decrease in propulsion.

Further, in the present invention, when the spiral wing is rotated, water such as seawater is sucked from the suction port of the impeller casing and supplied to the start end of the spiral wing along the straightening plate,
It is transported along a series of twisted guide surfaces of the helical wing and accelerates while being pressurized by the guide surfaces. Next, the accelerated water flow is rectified in the axial direction of the impeller axle by the guide blade, and is jetted out as a jet stream from the discharge opening which has been contracted and opened further, and the hull is propelled by the reaction force. You. Therefore, it is possible to prevent the water flow from diffusing and causing a complicated flow of the water flow near the stern.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cutaway side view of a boat provided with a water jet propulsion device.

FIG. 2 is a side sectional view of the water jet propulsion device according to the present invention.

FIG. 3 is a side view showing a guide blade of an impeller of the propulsion device according to the present invention taken out of a housing.

FIG. 4 is a side sectional view showing an operation state of a suction duct and a movable grid provided in the suction duct of the main part of the propulsion device according to the present invention.

FIG. 5 is a bottom view showing a state in which a movable grid is attached to the suction port of the suction duct of the propulsion device according to the present invention.

FIG. 6 is a block diagram of a schematic configuration of a control device according to the suspended matter removing device and the cruise switching device according to the present invention.

FIG. 7 is a flowchart of the processing operation of the suspended matter removing device according to the present invention.

FIG. 8 is a side view of the propulsion switching device according to the present invention.

FIG. 9 is a flowchart of the processing operation of the propulsion switching device according to the present invention.

FIG. 10 is a schematic side sectional view showing another propulsion device for a ship according to the present invention.

FIG. 11 is a side sectional view showing an arrangement state of an impeller casing and a spiral wing of a main part of the propulsion device shown in FIG.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail with reference to the drawings.
Reference numeral 1 denotes a ship, in which a water jet propulsion device 3 is connected to an engine 2 arranged at the stern of the ship 1,
Water is sucked from below the bottom of the hull, jet water is jetted toward the rear of the stern at an increased pressure, and the marine vessel 1 is propelled by the reaction force. The propulsion device 3 will be described in detail with reference to FIG. 2. A suction duct 5 having a suction port 4 is provided at the bottom of the boat 1 so as to be inclined in the forward direction, and from the suction port 4 as the traveling speed increases. The amount of suction water such as seawater has been increased. Reference numeral 6 denotes an impeller housing connected to the suction duct 5, and an impeller shaft 7 horizontally disposed on the impeller housing 6
Are connected to the drive shaft 8. As shown in FIG. 3, three helical blades 10 are wound around the hub 9 provided on the impeller shaft 7 with a phase shift of 120 degrees in a symmetrically spiral manner. The water flow is pressurized and increased in the spiral centrifugal direction on the surface 10a. Each spiral wing 10
As shown in FIG. 3, the outer peripheral edge portion 10b has an impeller shaft 7
, And extend obliquely across the hub 9 in a side view, and the outer peripheral tip 10c projects forward from the hub 9. The outer peripheral edge of each spiral wing 10 that is inclined and protrudes in this manner.
The volume efficiency and the balance efficiency are improved by bringing the 10b closer to the inner peripheral surface of the impeller housing 6 and providing a plurality of such spiral blades 10 as shown in FIG. Also, the outer peripheral tip 10c of the spiral blade 10
Is extended to the suction side to widen the suction port of the spiral blade 10 to improve the suction performance, and at the same time, prevent the floating material flowing into the suction duct 5 from being clogged in the suction part of the spiral blade 10. .
Further, since the width of the spiral blade surface 10a is long, the inflowing fibers and the like are prevented from being entangled. The number of the spiral wings 10 may be four depending on the size of the hull. As shown in FIG. 2, the inner peripheral surface of the impeller housing 6 forms a gentle parabola, and the impeller housing 6, the hub 9 provided on the impeller shaft 7, and the bearing case 11 of the impeller shaft 7 form a pot shape. A channel is formed. In the flow path behind the spiral blade 10, four long twisted guide blades 12 having both ends connected by the impeller housing 6 and the bearing case 11 of the impeller shaft 7 are provided. This guide vane 12
As shown in FIG. 3, the start end side is spirally formed like the spiral blade 10, and the end side is arranged so as to be parallel to the axis of the impeller shaft 7, and the pressure is increased by the spiral blade 10. The accelerated spiral swirling flow is parabolically guided at the start end of the guide vane 12, and at the end end of the guide vane 12, a rectifying flow path for exchange to a linear flow is formed, and a reduced opening injection duct. Pressurized water is taken out from the thirteen injection ports 14.

As shown in FIG. 2 and FIG. 4, an arc-shaped flow guiding member is provided at the opening edge of the front end of the suction port 4 of the suction duct 5.
15 are formed. The water flow flowing below the bottom of the ship is sucked behind the flow guiding member 15 which is reduced in pressure by the traveling water flow by the flow guiding member 15, and is guided by the surface of the flow guiding member 15 to generate a low pressure region. Water can be supplied to the front part in the traveling direction of the suction duct 5 which is easy to operate. Further, a stabilizer 16 is provided at the center of the suction port 4 at both ends thereof at front and rear opening edges of the suction port 4 so as to project in the front-rear direction below the bottom of the ship. The stabilizer 16 prevents the turbulence of the water flowing into the suction duct 5, prevents the sway at the time of high-speed cruising, and also prevents the skid at the time of turning the direction of the ship. As shown in FIGS. 4 and 5, the inlet 4 is provided with a plurality of fixed grids 17 that are parallel to the stabilizer 16 and that are bridged to the opening edges before and after the inlet 4. In addition, movable grids 18 are provided between the fixed grids 17 so as to prevent floating substances from flowing into the suction port 4. A bearing 20 is provided at the rear end opening edge of the suction port 4. This bearing 20
As shown in FIG. 5, a support punch 19 to which the base end of the movable grid 18 is fixed is rotatably supported. And
One end of the support punch 19 is connected to one end of the crankshaft 21, and the other end of the crankshaft 21 is connected to a piston 23 of the working cylinder 22. When the piston 23 is extended, the movable grid 18 separates from the suction port 4 of the suction duct 5 and rotates backward in the forward direction of the ship, so that floating matters are washed out of the movable grid 18 by the running water flow. It is. When the piston 23 is contracted, a movable grid is placed on the suction port 4.
18 are to be coalesced.

As shown in FIG. 4, a pitot tube type boat speed sensor 24 is provided at the bottom of the boat 1 so as to detect the running speed of the boat 1. A rotational speed sensor 25 is provided on the drive shaft 8 of the engine 2 so as to detect the rotational speed of the spiral blade 10. The detection signals of the boat speed sensor 24 and the rotation speed sensor 25 are transmitted to a central processing unit (CPU) as shown in FIG. In this central processing unit, the running speed of the ship 1 is calculated from the number of revolutions of the spiral blade 10, the allowable damping speed of the clogging of the grids 17 and 18 of the suction port 4 is set, and this set value is stored. A program memory (ROM) is provided, and when an abnormality is detected, the output control output signal is transmitted to the working cylinder 22. As shown in FIG. 7, the control data stored in the arithmetic memory includes a standard cruising speed V1 calculated based on the rotation speed of the spiral wing 10 as an initial setting, and the actual cruising speed of the ship 1. Speed V2 and grid 17,18
There is an allowable limit speed V when the traveling speed decreases due to the attachment of suspended matter to the vehicle. Then, the detection signal of the traveling speed of the boat speed sensor 24 and the detection signal of the rotation speed sensor 25 of the spiral blade 10 are compared and calculated, and the preset difference speed is V> V1−V
2, i.e., when within the permissible limits, grids of suspended matter 17,18
The cruise continues as it is without clogging.
When V <V1-V2, that is, when the value exceeds the permissible limit, the command signal is transmitted to the solenoid valve of the hydraulic circuit, the piston 23 of the working cylinder 22 is extended, and the movable grid 18 is rotated backward in the traveling direction. Then, the floating matter adhering to the fixed grid 17 is peeled off, and dust and the like are washed out of the movable grid 18 by the water flow resistance. Thereafter, after a set time, the solenoid valve is operated to contract the piston 23, rotate the movable grid 18, and attach the movable grid 18 to the suction port 4. In this way, with this device,
Suspensions can be removed from the grids 17,18. At the rear end of the injection duct 13, as shown in FIG.
A steering nozzle 26 is provided so as to surround the thirteen outlets 14. The steering nozzle 26 jets the pressurized water jetted from the jet duct 13 from its jet port 27 as a jet stream, and propels the ship by its reaction force. Steering nozzle
A reverse jet 28 is provided on the bottom surface of 26, and the jet 27
And a switching valve 29 that can open and close the and the reverse injection port 28.

The base end of the switching valve 29 is rotatably supported by a support punch 30 provided at the rear end edge of the opening of the reverse jet port 28, and one end of a link punch 31 is connected thereto. The other end of the link punch 31 is pivotally connected to the tip of the piston 33 of the working cylinder 32. When the piston 33 is contracted, the switching valve 29 closes the reverse jet port 28 of the steering nozzle 26, jets jet water from the jet port 27, and makes the ship travel forward. On the other hand, when trying to retreat the ship 1 that is moving forward, the contracted piston 33 is extended, the switching valve 29 is rotated, and the jet port 27 is closed. In this manner, the jet water is jetted obliquely downward in the forward direction from the reverse jet port 28 to switch the marine vessel 1 from forward to backward. Here, the switching valve 29 is in close contact with the bottom portion of the steering nozzle 26 when the ship is moving forward, so that the switching valve 29 does not affect the jet of the water flow. Since the direction of the jet water is switched inside the nozzle, there is no dispersion of the jet water.

Operating cylinder 32 of switching valve 29 inscribed in steering nozzle 26
Is provided with an operation detector 34 as shown in FIG. This operation detector 34 is an operation punch connected to a piston 33.
When the start of sliding of 35 is detected, as shown in FIG. 6, the detection signal is transmitted to the central processing unit (CPU). On the other hand, the central processing unit is provided with a program memory (ROM) that reduces the rotation speed of the spiral blade 10 when the start of sliding of the piston 33 is detected and returns the rotation speed after a predetermined time.
Then, as shown in FIG. 9, first, when the forward / reverse lever is switched from the forward operation to the reverse operation, the operating cylinder 32
Is detected by the operation detector 34, and this detection signal is transmitted to the central processing unit. Based on this signal, the opening of the fuel injection nozzle is adjusted, the rotation speed of the spiral wing 10 is reduced, and the ship is decelerated. At the same time, the switching valve 29 rotates in the direction of the ejection port 27 of the steering nozzle 26. Then, the ejection port 27 is closed. next,
The fuel injection nozzle is opened again, and the rotation speed of the spiral blade 10 increases. Then, jet water is jetted obliquely downward with respect to the forward traveling direction, and the vehicle retreats backward. Thus, in this device, the rotational speed of the spiral wing 10 is reduced at the time of forward / reverse switching, thereby preventing sudden braking and thrust from occurring on the hull. Reference numeral 36 denotes an operating cylinder for rotating the steering nozzle 26 left and right to switch the traveling direction of the boat.

As described above, this water jet propulsion device
The blade has a spiral shape, and the suction port of the impeller is enlarged, so that the suction performance is improved. The pressure is increased by increasing the pressure of the blade surface connected in series, so that high-speed traveling is possible. That is, in the conventional water jet propulsion device, when the rotation speed of the impeller is increased, the width of the blade surface of the impeller is narrow, so that a vortex flow and a low pressure region of the water flow flowing into the suction duct are generated, and cavitation phenomenon occurs on the blade surface. However, in the present invention, the outer peripheral edge of the spiral wing is brought closer to the inner peripheral surface of the impeller housing, and the outer peripheral tip is extended to the suction side. Therefore, the suction port of the spiral blade becomes large, the suction performance is improved, and the amount of suction is increased by the inducer action of the blade surface following the spiral series, so that high-speed traveling can be obtained. In addition, since the flow path is formed in a bowl shape and the long twisted guide vanes for rectification are disposed behind the spiral blade, the spiral swirling flow can be directly guided to the flow to improve propulsion efficiency. Things. And, since the arc-shaped flow guiding member is provided at the opening edge of the front end of the suction port, the voyage water flow is guided to the front part of the suction duct, which tends to be a low pressure flow area, and the water flow uniformly flows into the suction duct, preventing cavitation You can do it. Further, the stabilizing plate at the suction port can regulate the flow of the suction water to the suction duct, and can prevent the ship from rolling and slipping at the time of turning.

In the present invention, when suspended matter adheres to the grid and the suction performance is reduced, dust can be automatically removed from the grid. That is, in the conventional device that provided the grid in the conventional suction duct,
It was necessary to stop or decelerate the ship to remove suspended matter from the grid, but in the present invention, the difference between the standard traveling speed and the actually measured traveling speed was calculated and the movable speed was calculated. By turning the grid backward and running water flow,
Since the dust and the like adhering to the grid can be washed away to the rear, there is no need for deceleration cruising, and the work for removing suspended matters is not required. Further, in the present invention, the forward and backward movement can be performed by operating the switching valve provided inside the steering nozzle. That is, in the conventional device, there is a switching device that becomes a water flow resistance during forward running, but in the present invention, since there is no switching device that becomes a water flow resistance during traveling, thrust is reduced. Can be moved forward or backward without any decrease in And when switching the cruise,
After reducing the rotation speed of the impeller for a predetermined time and decelerating the ship,
By switching between forward and reverse, it is possible to prevent sudden braking and side slip thrust of the ship.

Next, another embodiment of the present invention will be described. FIG. 10 and FIG. 11 show an example in which the propulsion device is provided outside the hull instead of being incorporated in the hull. In FIG. 10, reference numeral 41 denotes a hull, and an engine 42 is disposed at the stern thereof,
A drive shaft 43 of the engine 42 is connected to an impeller shaft 45 projecting outboard through a coupling 44. As shown in FIG. 11, a conical hub 46 is provided at the tip of the impeller shaft 45, and the conical top is connected to the impeller shaft 45. The hub 46 is provided with a plurality of spiral blades 47. The spiral blades 47 are attached with their base ends shifted in phase at equal intervals in the circumferential direction. In the embodiment, two spiral wings 47 are wound, but this spiral wing 47 is
When the number of sheets is four, the balance efficiency is increased and the vibration can be reduced.

An impeller housing 48 is provided on the outer peripheral portion of the spiral blade 47, and the outer peripheral edge of the spiral blade 47 is provided close to the inner peripheral surface of the impeller housing 48. The impeller housing 48 has a suction port 48a formed in a funnel shape, so that water can flow in according to the flow velocity due to the suction force of the rotating spiral blade 47. The main body 48b of the impeller housing 48 has an elliptical swelling shape, and the pressure of the water flow is increased by the centrifugal force of the spiral blade 47 along the conical hub 46 and the main body 48b of the impeller housing 48. The volume efficiency increases as the number of spiral blades 47 increases to three or four, and the amount of inflow into the impeller housing 48 increases.
The discharge pressure also increases.

At the rear end of the impeller housing 48, there is provided a discharge port 48c which is contracted and opened, and further accelerates the water flow pressurized and accelerated by the spiral wing 47, and jets it as a jet stream behind the stern. The hull is propelled by force.

Also, behind the suction port 48a of the impeller housing 48,
On the inner peripheral surface in front of the discharge port 48c, there are provided a plurality of rectifying plates 49 which are suspended in the axial direction of the impeller shaft and guide vanes 50 which rectify the swirling flow in the axial direction of the impeller shaft. The water flow sucked into the housing 48 is supplied to the start end of the spiral blade 47 along the axial direction of the impeller shaft, and the swirling flow pressurized and accelerated from the terminal end of the spiral blade 47 in the axial direction of the impeller shaft. It is discharged as rectification along. Reference numeral 51 denotes a suspended blade having an impeller housing 48 suspended from the hull 41. The suspended blade 51 is disposed in parallel with the axis of the impeller shaft, and regulates a complicated flow of water near the stern. I have to do it. Reference numeral 52 denotes a cap for fixing the spiral blade 47, but the lower end of the guide blade 50 may be connected to use the cap 52 as a support metal for the impeller shaft 45. Reference numeral 53 denotes a rudder for running the hull 41.

In such a propulsion device, when the spiral wing 47 is rotated, water such as seawater flows into the suction port 48 of the impeller housing 48.
Sucked from a. Then, the water is supplied to the start end of the spiral wing 47 along the flow straightening plate 49, is transported along a series of twisted guide surfaces of the spiral wing 47, and is accelerated while being pressurized by the guide surface. Next, the accelerated water flow is
The flow is rectified in the axial direction of the rotation shaft by 50, and is jetted out as a jet stream from the discharge port 48c which has been contracted and opened to a further increased speed, and the hull is propelled by the reaction force. Therefore,
Prevent the water flow from diffusing and causing a complicated flow of the water flow near the stern, increase the pressure without escaping the water flow in all directions,
It can squirt backwards to increase propulsion. Furthermore,
Since the impeller housing is provided on the outer periphery of the spiral wing, the water flow near the stern is not agitated, and vibration and noise can be reduced.

──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application Hei 7-332803 (32) Priority date Heisei 7 (1995) November 27 (33) Priority claim country Japan (JP) (58) Field (Int.Cl. ⁶ , DB name) B63H 11/01 B63H 11/08

Claims (12)

(57) [Claims] 1. A water jet for a marine vessel that sucks water from the bottom of the ship by an inducer action, turns and pressurizes the sucked water, rectifies the water to generate a water jet, and jets the water jet to the rear of the stern for propulsion. In the propulsion device, an inclined suction duct portion having a water suction port opened to the bottom of the ship, an impeller housing portion connected to the suction duct portion and having an inner peripheral surface forming a gentle curve, and connected to the impeller housing portion, A duct member having an injection duct portion provided with a water jet injection port directed toward the stern; a bearing case provided in the impeller housing portion of the duct member; one end supported by the bearing case; An impeller shaft having the other end outside the duct member, a hub provided on the impeller shaft, A plurality of spiral wings around which an inner peripheral portion is wound, an outer peripheral edge portion is close to an inner peripheral surface of the impeller housing portion, and a plurality of spiral wings for turning and pressurizing water sucked through the suction duct portion; Both ends in the radial direction are connected to the bearing case, the axial start end is spiral and the end is extended in parallel with the axis of the impeller shaft, and the plurality of spiral blades rectifies water swirled and pressurized. A guide vane, wherein an outer peripheral edge of the spiral blade is inclined with respect to the blade axle,
The hub extends diagonally across the side as viewed from the side, and the outer peripheral tip projects toward the suction duct portion more than the hub,
A water jet propulsion device for a ship, wherein the spiral wing has an inducer action. 2. A water jet propulsion device for a ship according to claim 1, further comprising an arc-shaped flow guiding member at a bottom portion of a front edge side of a suction port of said suction port duct portion. A water jet propulsion device for a ship, comprising: 3. The water jet propulsion device for a ship according to claim 1, further comprising: a grid member pivotally attached to a bottom of the suction duct at a rear edge side of a suction port of the suction duct. And a drive mechanism for driving a member to open and close the suction port. 4. A water jet propulsion device for a ship according to claim 3, further comprising: a ship speed sensor for detecting a running speed of said ship; and a rotation speed sensor for detecting a rotation speed of said spiral blade. A control unit for controlling a driving mechanism of the grid member based on a traveling speed of the ship and a rotation speed of the spiral blade detected by these sensors. 5. A suction port is opened at the bottom of the stern near the stern, and water sucked into the suction duct from the suction port is pressurized by an impeller provided in the impeller housing, and jet water is jetted rearward from the injection duct to the stern. In a water jet propulsion device for a ship, a plurality of spiral blades are arranged with a phase shift on an impeller provided in the impeller housing, and the outer peripheral edge of the spiral blade approaches the inner peripheral surface of the impeller housing. Let me
The outer peripheral tip of the spiral wing extends to the suction side, and furthermore, a guide vane for rectification is provided in a flow path behind the spiral wing, and an arc-like shape as viewed from the side at the front end opening edge of the suction port. A water jet propulsion device for a ship, wherein the water guiding member is disposed. 6. A water jet propulsion device for a ship according to claim 5, wherein the impeller housing and the bearing case of the impeller shaft form a bowl-shaped flow path, and a plurality of flow paths behind the spiral blade are formed. A water jet propulsion device for a ship, comprising a plurality of long torsional guide blades for guiding a spiral swirling flow pressurized by a spiral blade into a linear flow. 7. The water jet propulsion device for a ship according to claim 5, wherein a movable grid is arranged in a front-rear direction of the suction port, and a rear end of the movable grid is connected to a rear end of the suction port. A water jet propulsion device for a ship, wherein the water jet propulsion device is pivotally attached to an opening edge. 8. A water jet propulsion device for a ship according to claim 7, further comprising a ship speed sensor for detecting a running speed of the ship and a rotation speed sensor for detecting a rotation speed of the spiral blade. A water jet propulsion device for a ship, comprising a rotating device for moving the movable grid away from the suction port when the running speed falls below a set value calculated from the rotational speed of the spiral blade. 9. A suction port is opened at the bottom of the stern near the stern, and water sucked into the suction duct from the suction port is pressurized by an impeller provided in the impeller housing, and jet water is jetted from the jet duct toward the rear of the stern. In a water jet propulsion device for a ship, a plurality of spiral blades are arranged with a phase shift on an impeller provided in the impeller housing, and the outer peripheral edge of the spiral blade approaches the inner peripheral surface of the impeller housing. Let me
The tip of the outer periphery of the spiral blade is extended to the suction side, and a guide vane for rectification is further provided in a flow path behind the spiral blade, and a movable grid is arranged in the front-rear direction of the suction port. A water jet propulsion device for a ship, wherein a rear end of the water jet propulsion device is rotatably connected to a rear end opening edge of the suction port. 10. A water jet propulsion device for a ship according to claim 9, wherein a bowl-shaped flow path is formed by said impeller housing and a bearing case of an impeller shaft.
A water jet propulsion device for a ship, wherein a plurality of long twist guide vanes are arranged in a flow path behind a spiral blade to guide a spiral swirling flow pressurized by the spiral blade into a linear flow. . 11. A waterjet propulsion device for a ship according to claim 9 or 10, wherein a speed sensor for detecting a running speed of the ship and a speed sensor for detecting a speed of the spiral blade are provided. Provided, when the running speed of the ship falls below the set value calculated from the rotation speed of the spiral wing,
A water jet propulsion device for a ship, comprising a rotating device for moving a movable grid away from an inlet. 12. A plurality of spiral blades are wound around a blade axle provided at the stern, and an impeller housing is disposed around the outer periphery of the spiral blade, wherein the spiral blade is a mixed flow blade. Water-jet propulsion device for ships.