JP4197416B2 - Water vehicle jet propulsion machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a jet pump used in a water vehicle driven by water jet injection (a small planing boat such as a water motorcycle or other water vehicle).
[0002]
[Prior art]
A water vehicle jet propulsion machine uses an impeller attached to a drive shaft that rotates by driving of a drive source such as an engine to suck water from a water intake at the bottom of the ship and to suck up water taken along a jet waterway equipped with the impeller. The water vehicle is driven by the propulsive force generated by the reaction force. The water flowing through the jet channel is swirled by the impeller, rectified by a stationary blade provided behind the impeller and a fin provided on the inner wall of the nozzle corresponding to the stationary blade, and jetted from a jet outlet at the rear end of the nozzle. Spouts as water. The diameter of the nozzle is narrowed from the inlet (impeller connecting portion) toward the rear end outlet, and the nozzle is tapered to increase the injection pressure.
[0003]
The rear end of the drive shaft is covered with a taper-shaped (tapered) cap inside the nozzle. This cap is fixed to the rear of the impeller together with the stationary blade, and is attached to protect each component such as a bearing provided on the drive shaft. The cap has a smooth convexly curved conical shape (tapered shape) in order to avoid turbulent flow action and resistance loss as much as possible with respect to the water flow in the nozzle.
[0004]
On the other hand, in order to raise the bottom end of the ship during running and reduce resistance from the water surface, the nozzle jet outlet is formed somewhat obliquely upward, thereby improving speed and acceleration. In the nozzle of such a water vehicle, the axis of the nozzle connecting the center of the nozzle inlet and the center of the outlet (jet outlet) is inclined upward toward the rear.
[0005]
[Problems to be solved by the invention]
However, in the conventional water vehicle jet propulsion device, the axis of the conical cap that covers the rear end of the drive shaft in the nozzle is aligned with the axis of the drive shaft and is formed coaxially and straight. Accordingly, since the upward cap to the axis of the nozzle is disposed horizontally, the resistance by the cap relative to the water flow in the nozzle does not coincide in the axial direction of the water flow direction and the cap of the nozzle is large.
[0006]
Increasing water flow resistance increases the load on the engine and increases energy loss. For this reason, the dynamic pressure recovery rate which changes the dynamic pressure given to a water flow by engine rotation into a propulsive force falls. Therefore, the output is substantially reduced, and the effect of improving the speed and accelerating performance by raising the nozzle outlet is not sufficiently obtained.
[0007]
The present invention has been made in consideration of the above-described prior art, and aims to provide a water vehicle jet propulsion device that reduces the resistance loss in the jet water channel, suppresses the decrease in output of the driving source, and increases the propulsive force. To do.
[0008]
[Means for Solving the Problems]
To achieve the above object, according to the present invention, a drive shaft connected to a drive source, an impeller composed of a plurality of blades connected to the drive shaft, and a plurality of stationary blades provided behind the impeller And a nozzle provided in the rear of the stationary blade, and a substantially conical cap provided in the nozzle and covering a rear end portion of the drive shaft, the nozzle facing the rear outlet The water jet jet propulsion is shaped so that the diameter is narrowed, and the axis of the nozzle connecting the center of the nozzle inlet and the center of the jet outlet is inclined upward toward the axis of the drive shaft. in machine, the axis of the conical cap is a straight line connecting the center and the cone apex of the conical bottom surface formed at an angle relative to the axis of the match to the drive shaft and the axis of the nozzle To provide a jet propulsion personal watercraft, characterized in that.
[0009]
According to this configuration, since the direction of the axis of the conical cap (the straight line connecting the center of the cone bottom and the apex of the cone) is inclined to coincide with the axis of the nozzle, the cap matches the direction of the water flow flowing through the jet channel. Arranged. For this reason, it is suppressed that a cap becomes resistance of a jet water flow, the output fall by an energy loss can be suppressed, and the improvement of the speed by the increase in thrust and the improvement of acceleration can be aimed at.
[0010]
In a preferred configuration example, a fin is attached to the outer periphery of the cap corresponding to the position of the stationary blade.
[0011]
According to this structure, the rectification | straightening effect | action with respect to the jet water flow in a nozzle is heightened with the fin with which the outer periphery of a cap is equipped, and a turbulent flow suppression and a fall of resistance loss are achieved.
[0012]
In a preferred configuration example, the tip of the cap is in the vicinity of the position where the diameter of the nozzle is stopped or in the rear thereof.
[0013]
According to this structure, since the distance which a jet water flow flows along the cap which has a smooth conical curved surface becomes long compared with the past, the higher rectification | straightening effect | action of a jet water flow can be obtained.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic view of an entire water vehicle according to the present invention.
This water vehicle 19 has a handle 21 at the upper center of the hull composed of the hull 13 and the deck 20. A seat 22 on which the driver sits is provided behind the handle 21. An engine room 43 is provided at the center of the hull, and an engine 23 is provided inside. A jet propulsion machine 1 is provided at the lower rear of the hull.
[0015]
The drive shaft 2 is coupled to the crankshaft 24 of the engine 23 via a coupling 26. An impeller 3 is fastened to the rear end portion of the drive shaft 2, and a stationary vane 4 for rectification is provided behind the impeller 3. The impeller 3 is mounted in the jet water channel 10. The jet water channel 10 is formed between the water intake 9 at the bottom of the ship and the nozzle 5 at the stern. The impeller 3 has its shaft coupled to the end of the drive shaft 2 and its housing attached to the plate transom 12 together with the stationary blade 4. The plate transom 12 is a rectangular frame, and a hole through which the jet water channel 10 and the drive shaft 2 are inserted is opened at the center.
[0016]
The water sucked up from the water intake 9 is ejected as a swirling flow backward by the impeller 3, rectified by the stationary blade 4, and ejected from the nozzle 5. A deflector 7 is attached to the jet outlet 63 at the rear end of the nozzle 5. The deflector 7 can rotate left and right around a steering shaft (not shown), and changes the traveling direction of the water vehicle by changing the injection direction in conjunction with the handle 21.
[0017]
As will be described later, the axis of the nozzle 5 is slightly inclined upward, and the jet port 63 is provided upward. A cap 64 that covers the rear end of the drive shaft 2 is fixed in the nozzle 5 as described later.
[0018]
FIG. 2 is a schematic view of a water vehicle jet propulsion apparatus according to the present invention, and FIG. 3 is a schematic view seen from the direction AA of FIG.
[0019]
The jet propulsion device 1 includes an impeller 3 attached to an end of a drive shaft 2 that rotates by driving of an engine 23 (FIG. 1) via a boss 18, a stationary blade 4 provided behind the impeller 3, and a rear thereof And the nozzle 5 provided in The impeller 3 includes a plurality of blades 3 a fixed to the boss 18 and is housed in the housing 6. The housing 6 is fixed to the plate transom 12 through four intermediate bolts 14 (two in the figure) via an intermediate housing 27. The plate transom 12 has a square ring shape, and a jet water channel 10 is opened in the ring, and the drive shaft 2 is inserted in the center thereof.
[0020]
The stationary blade 4 is fixed to the housing 6 by four (two in FIG. 2) bolts 11. The stationary blade 4 is composed of a plurality of blades, and rectifies the water flow which is swirled by the impeller 3 and ejects it backward. A nozzle 5 is fixed behind the housing 4 a of the stationary blade 4. The stationary blade 4 is integrated with the housing of the impeller 3 and the intermediate housing 27 together with the nozzle 5 to form a cylindrical body. After the impeller 3 is attached to the drive shaft 2, the integrated cylindrical body is put on the impeller 3 and fixed to the plate transom 12. Behind the nozzle 5 is provided with a deflector (rudder) 7 and a reverse bucket 8 for backing the hull. The jet propulsion device 1 is fixed to the above-described substantially square ring-shaped plate transom 12 fixed to the hull 13 by four (two in FIG. 2) bolts 14.
[0021]
As the impeller 3 rotates, water is sucked into the jet water channel 10 from the water intake 9, and water is jetted rearward from the jet outlet 63 at the rear end of the nozzle 5 to obtain propulsive force. The deflector 7 is attached to the hull 4 so as to be rotatable left and right around the steering shaft 25. By operating this deflector 7 and changing the direction, a turning force is generated to steer the ship.
[0022]
The water sucked from the water intake 9 is removed from foreign matter in the water flow by a grid-like screen intake 15 provided near the inlet of the water intake 9, and is then directed to the impeller 3 in the jet water channel 10 in front of the impeller 3. It flows as a straight flow, turns into a swirl flow that flows backward by the impeller 3, and turns into a swirl flow rectified by the stationary blade 4 and is injected linearly (in the axial direction) toward the rear.
[0023]
The nozzle 5 is tapered toward the rear and formed into a tapered shape, and a jet port 63 is formed somewhat upward. By jetting the jet water flow upward at the rear of the hull in this way, the rear side of the hull sinks and the front side of the running hull is lifted by the reaction, so that the water resistance can be reduced. A blade-like fin 62 is provided on the inner wall of the nozzle 5 corresponding to the position of the stationary blade 4. Thereby, the rectification effect of the jet water flow by the stationary blade 4 is improved. A cap 64 for sealing the connection structure of the drive shaft 2 and the stationary blade 4 and enhancing the rectifying effect is fitted into the rear end portion of the drive shaft 2. The shape of the cap 64 will be described later.
[0024]
In the flow path of the nozzle 5, for example, a bilge pipe 55 made of stainless steel protrudes. The bilge pipe 55 communicates with a bilge portion at the bottom of the engine room 43 through a bilge drain pipe such as a hose. The water accumulated in the bilge part is drained from the bilge pipe 55 by the negative pressure of the jet water flow.
[0025]
A spout pipe 60 is provided on the upper part of the nozzle 5, and a part of the jet water flow is ejected from here, improving the visibility from other water vehicles, ships, etc. and appealing to the existence of the self, thereby improving safety.
[0026]
As shown in FIG. 3, when the nozzle 63 of the nozzle 5 is viewed from the rear, the nozzle 5 has an axial line inclined upward, so that the nozzle 63 at the rear end of the nozzle is somewhat above the cap 64 inside. Is provided. The cap 64 is fixed to the stationary blade side with three bolts 65. As will be described later, the apex 64a of the cap 64 is displaced upward with respect to the bottom edge 64b of the cap 64 when viewed from the rear.
[0027]
4A is a side view of the cap structure around the stationary blade and the nozzle according to the present invention, and FIG. 4B is a rear view of the stationary blade portion.
[0028]
As described above, the nozzle 5 is attached to the rear of the housing 4a of the stationary blade 4. The nozzle 5 has a tapered shape with a diameter that decreases toward the rear and becomes smaller. Further, the axis C of the nozzle 5 is formed so as to incline upward toward the rear, and the jet outlet 63 is formed to be somewhat upward. A cap 64 having a substantially conical shape is fitted into the stationary blade 4 from the nozzle side, and a conical bottom edge 64 b portion is fixed by three bolts 65.
[0029]
The cap 64 has a substantially conical shape with a convex curved side surface, and is inclined slightly upward in accordance with the angle of the axis of the nozzle. That is, the axis of the conical cap 64 coincides with the axis C of the nozzle 5. Therefore, the vertex 64 a of the cap 64 is on the axis C that is the center of the cross section of the nozzle 5. Six fins 66 are formed on the outer peripheral surface of the cap 64 corresponding to the positions of the six stationary blades 4. By these fins 66, a rectifying action is added to the jet water flow which is swirled by the impeller (see FIG. 2) together with the fins 62 provided on the inner surfaces of the stationary blade 4 and the nozzle 5. Furthermore, since the cap 64 has a substantially conical shape with a smooth convex curved surface and its axis is inclined upward in line with the axis C of the nozzle 5, the cap 64 is prevented from becoming a resistance to jet water flow. The As a result, it is possible to suppress a decrease in output due to energy loss of the drive source and increase the propulsive force. In the example of FIG. 4, the vertex 64 a of the cap 64 is in the vicinity of the front end of the throttle end (taper end) of the throttle portion of the nozzle 5.
[0030]
FIG. 5A is a side view of a cap structure around a stationary blade and a nozzle, showing another example according to the present invention, and FIG. 5B is a rear view of the stationary blade portion.
[0031]
In this example, as shown in the drawing, the apex 64a at the rear end of the cap 64 protrudes to a portion where the taper of the nozzle 5 finishes being squeezed (two-point difference line in the figure). The angle of the cap 64 is formed somewhat upward in accordance with the axis C of the nozzle as in the example of FIG. Therefore, as shown in (B), the apex 64a of the cap 64 is biased upward when viewed from the rear. As the cap apex 64a extends rearward in this manner, the taper inclination becomes loose, the resistance of the cap 64 to the jet water flow is reduced, and the generation of turbulent flow is suppressed along the cap 64 inclined according to the nozzle. Jet water flow smoothly.
[0032]
FIG. 6 is a side view and a rear view showing another embodiment of the cap structure of the present invention.
In this example, two fins 66 are attached vertically on the outer peripheral surface of the cap 64 in FIG. These fins 66 are formed substantially corresponding to the positions of the upper and lower two of the six stationary blades 4. These fins 66 further enhance the rectifying effect. Other configurations and operational effects are the same as in the example of FIG.
[0033]
FIG. 7 is a side view and a rear view showing still another embodiment of the cap structure of the present invention.
In this example, three fins 66 are attached to the outer peripheral surface of the cap 64 shown in FIG. These fins 66 are formed corresponding to the position of the stationary blade 4. Thereby, the rectification effect is further enhanced. Other configurations and operational effects are the same as in the example of FIG. Note that any number of fins 66 may be formed according to the number of the stationary blades 4. Further, the cap apex 64a may extend beyond the throttle part of the nozzle 5 to the rear (jet port side).
[0034]
【The invention's effect】
As described above, in the present invention, since the direction of the axis of the conical cap (the straight line connecting the center of the cone bottom and the apex of the cone) is inclined in accordance with the axis of the nozzle, the direction of the water flow through which the cap flows in the jet channel It is arranged according to. For this reason, it is suppressed that a cap becomes resistance of a jet water flow, the output fall by an energy loss can be suppressed, and the improvement of the speed by the increase in thrust and the improvement of acceleration can be aimed at.
[0035]
Further, according to the configuration in which the fin is attached to the outer periphery of the cap corresponding to the position of the stationary blade, the rectifying action for the jet water flow in the nozzle is enhanced by the fin provided on the outer periphery of the cap, thereby suppressing turbulent flow and resistance. Loss can be reduced.
[0036]
Furthermore, according to the configuration in which the tip of the cap is near or behind the position where the diameter of the nozzle finishes squeezing, the distance that the jet water flow flows along the cap having a smooth conical curved surface is longer than before, Higher jet water flow rectification can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic view of an entire water vehicle according to the present invention.
FIG. 2 is a schematic view of a water vehicle jet propulsion device according to the present invention.
FIG. 3 is a schematic view seen from the AA direction in FIG. 2;
4A is a side view of a cap structure around a stationary blade and a nozzle according to the present invention, and FIG. 4B is a rear view of the stationary blade portion.
FIG. 5A is a side view of a cap structure of a stationary blade and a nozzle peripheral portion showing another example according to the present invention, and FIG. 5B is a rear view of the stationary blade portion.
6A and 6B are a side view and a rear view showing another embodiment of the cap structure of the present invention.
FIGS. 7A and 7B are a side view and a rear view showing still another embodiment of the cap structure of the present invention. FIGS.
[Explanation of symbols]
1: Jet propulsion machine 2: Drive shaft 3: Impeller
4: Static blade, 5: Nozzle, 6: Housing, 7: Deflector,
8: Reverse bucket, 9: Water intake, 10: Jet waterway, 11: Bolt,
12: Plate transom, 13: Hull, 15: Screen intake
18: Boss, 19: Water vehicle, 20: Deck, 21: Handle
22: Seat, 23: Engine, 24: Crankshaft, 25: Steering shaft,
26: coupling, 27: intermediate housing,
43: Engine room, 55: Bilge pipe, 60: Spout pipe,
62: Fins, 63: Spout, 64: Cap, 64a: Apex,
64b: bottom edge, 65: bolt, 66: fin.

Claims (3)

A drive shaft coupled to the drive source;
An impeller comprising a plurality of blades connected to the drive shaft;
A plurality of stationary blades provided behind the impeller;
A nozzle provided behind the stationary blade;
A substantially conical cap provided in the nozzle and covering a rear end of the drive shaft;
The diameter of the nozzle is narrowed toward the rear outlet, and the axis of the nozzle connecting the center of the nozzle inlet and the center of the outlet is inclined upward toward the rear with respect to the axis of the drive shaft. In the water vehicle jet propulsion machine formed as follows:
A jet propulsion for a water vehicle characterized in that the axis of the conical cap, which is a straight line connecting the center of the cone bottom and the apex of the cone, is formed obliquely with respect to the axis of the drive shaft so as to coincide with the axis of the nozzle Machine.   The water vehicle jet propulsion apparatus according to claim 1, wherein fins are attached to an outer periphery of the cap so as to correspond to positions of the stationary blades.   The water vehicle jet propulsion device according to claim 1 or 2, wherein a tip of the cap is located near or behind a position where the diameter of the nozzle is stopped.

Images