JPH01237291A - Water jet propulsion ship - Google Patents

Abstract

PURPOSE:To prevent water from entering toward the portion between the outer periphery on the lower portion of a propulsion device body and a stern board by placing and fixing the propulsion device body onto a placing base which extends rearward from a hull bottom position. CONSTITUTION:On the stern board 12 of a hull 10, a placing base 16 which is integrally extended nearly horizontally to the rear from the position of the ship bottom thereof is provided, and this placing base 16 has a cutout 18 which is opened rearward. A propulsion device body 20 is placed on this placing base 16 so as to be spread over the cutout 18 and a water suction port 22 which is formed slightly projectingly downward on the bottom portion of the propulsion device body 20 is conformed to the cutout 18. Bolt holes 24 for installing the propulsion device body 20 is formed on the stern board 12 while, on the other hand, bolt holes 26 are also formed in the front of the propulsion device body 20, to fix the propulsion device body 20 to the stern board 12 with mounting bolts 28.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a water jet propulsion machine, and particularly to the structure of a so-called outboard motor type water jet propulsion machine in which the thruster body is disposed outside the hull of a ship. Regarding.

[Prior Art] In many conventional water jet propulsion ships, the propulsion unit was installed inside the ship, which caused problems such as loss of space inside the ship and the possibility of water leaking inside the ship. In addition, in this case, since the propulsion device main body is not integrated, there is a problem that the propulsion device main body can only be easily attached and removed.

Therefore, as described in, for example, Japanese Unexamined Patent Publication No. 59-145691, an outboard motor-type watershed propulsion boat has been proposed in which the propulsion unit is provided outside the boat.

[Invention or Problem to be Solved] However, the device described in this publication has a gap between the stern plate of the hull and the front lower part of the propulsion unit, and water flow may enter this gap during sailing. The problem is that the dynamic pressure of the water acts on the outer periphery of the thruster body, creating large running resistance and reducing propulsion efficiency.

The present invention has been made in view of the problems of the prior art, and its purpose is to facilitate installation and removal of the propulsion unit by placing the propulsion unit outside the ship. To provide a water jet propulsion boat in which running resistance is reduced by preventing the interior space from being damaged and by preventing the dynamic pressure of water from acting on the outer periphery of a propulsion device body.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a water jet propulsion vessel in which a propulsion unit is disposed outside the hull, and a propulsion unit located at the bottom of the hull at the stern. A mounting base extending rearward from the base and having a notch is integrally provided, the propulsion unit is stored on this mounting base and fixed to the hull, and the water intake port of the propulsion unit is aligned with the notch of the mounting base. This is what I did.

[Function] In this way, since the storage stand is integrally provided from the bottom of the ship and the propulsion unit is placed on this stand and fixed to the ship, water flows smoothly on the bottom of the storage stand. The liquid is sucked through the notch in the storage stand and into the water intake port on the main unit. Therefore,
Water does not enter the gap between the front lower part of the propulsion unit and the stern plate, and running resistance caused by this can be prevented.

[Example] The present invention will be explained below based on embodiments shown in the drawings.

A first embodiment of the invention is shown in FIGS. 1-3.

The stern plate 12 of the hull 10 is provided with a mounting platform 16 that integrally extends substantially horizontally rearward from the position of the bottom 14 of the ship.
This mounting table 16 has a notch 18 that opens toward the rear. The propulsion device main body 20 is placed on this mounting table 16 so as to straddle the notch 18, and in particular, as shown in FIG. 22 is aligned with the notch 18. Stern board 12
A bolt hole 24 for attaching the propulsion device main body 20 is formed in the propulsion device main body 20, and a bolt hole 26 that matches the bolt hole 24 is formed on the front surface of the propulsion device main body 20, especially the front surface of the upper pump case to be described later. The propulsion unit body 20 is fixed to the stern plate 12 by means of mounting bolts 28 through these bolt holes 24 and 26.

As shown in FIGS. 2 and 3, the propulsion unit of the propulsion main body 20 has an integral structure constructed by stacking a plurality of cast blocks. That is, the lower pump case 3, which is the first block, has the water intake port 22 at the lowermost end.
0 is formed and as shown in FIG.
It is placed above. Here, the tli surfaces of the front part and both side parts of the notch 18 are in close contact with the lower pump casing 30. A middle pump case 32 serving as a second block is connected to one of the lower pump cases 30 , and the middle pump case 32 accommodates the impeller 34 and forms the lower half of the swirl chamber 36 . An upper pump case 38 as a third block is connected above the middle pump case 32, and this upper pump case 38 forms the upper half of the swirl chamber 36 and has the bolt holes 26. A nozzle 40 is provided connected to the outlet of the swirl chamber 36, and a deflector nozzle 42 that can be rotated from side to side is connected to this nozzle 40. 4
4 is a reverse gate that rotates to cover the deflector nozzle 42 to obtain a reverse thrust.

Bottom cowling 46 is on top of upper pump case 3B.
is placed on the engine 5 along with the upper cowling 48.
It stores 0. In FIG. 43, 52 is an exhaust port, and in FIG. 2, 54 is a tail pipe for raising the exhaust flow discharged from the exhaust port 52 in one direction higher than the exhaust port 52 immediately before the exhaust flow.

With this configuration, the propulsion device body 20 is first mounted outside the boat, so that the presence of the propulsion device body 20 in the prior art prevents the inboard space from being wasted. Since the propulsion device main body 20 is placed and fixed on the mounting table 16, especially as shown in FIG. 2, the propulsion device main body 20
The space between the front lower part of the main body 20 and the stern plate 12 is covered by the storage stand 16, and the dynamic pressure of the water flow does not act on the outer periphery of the propulsion device body 20. Rather, the water flow flows along the bottom surface of the mounting table 16 and is smoothly guided to the water intake port 22.

Also, since the propulsion unit and engine are integrated, the recommendation for the hull lO is a41! The main body 20 can only be easily attached or removed. In particular, in this embodiment, the propulsion unit is formed by stacking YJ block blocks, and the exhaust passage from the engine is formed by the wall surface of the flock along the swirl chamber of the shedding water flow, so that the overall length of the exhaust passage is lengthened. Since it can be expected that the exhaust gas will be treated more efficiently and smoothly, it will be possible to improve the performance of the engine. Furthermore, since the exhaust passage is formed along the vortex chamber, exhaust cooling is achieved by the shet water flow flowing through the vortex chamber, and there is no need to create a separate cooling channel. In addition, just before the exhaust is discharged to the outside, the tail vibe 54 causes the exhaust to rise higher than the exhaust port 52, so that when the engine is stopped, etc.
It is possible to prevent backflow from 2 into the engine. Furthermore, since the exhaust passage and the P1 winding chamber are integrally formed by the wall surface of the flock, the entire unit can be made lightweight and compact.

Next, FIG. 4 shows a second embodiment of the present invention, and the difference between this embodiment and the first embodiment is the means for attaching the propulsion unit main body 20 to the hull 10. That is, in this second embodiment, the propulsion unit main body 20 is fixed to the stern plate 12 of the hull lO via a clamp bracket 58 instead of the mounting bolts used in the first embodiment. Placing the propulsion device main body 20 on the mounting table 16k is the same as in the first embodiment. In this case, the propulsion device main body 20 is
i. Since the structure is such that it is placed on the mounting stand 16h, it is preferable to leave a predetermined gap 60 between the clamp bracket 58 and the upper end of the ship J-board 12.

[Effects] As described above, according to the present invention, the main body of the propulsion unit is mounted on the stand a that extends rearward from the bottom of the hull. Since the structure is fixed in place, water is borrowed between the lower outer periphery of the propulsion unit and the stern plate by l/j1, which suppresses the generation of running resistance and improves propulsion efficiency. It has an excellent effect of being able to improve things.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of essential parts showing a first embodiment of a water jet propulsion vessel according to the present invention, FIG. The right side view of FIG. 2 and FIG. 4 are schematic diagrams showing a second embodiment of the present invention. 10...Hull 12...Stern plate 14...Bottom 16...Placement stand 18...Notch 20...Propulsion unit body 28...Mounting bolt 58...Clamp bracket agent Patent attorney Yoshiyuki Inaba

Claims (1)

[Claims] (1) In a waterjet propulsion boat of the type in which the propulsion machine body is placed outside the hull, a mounting table that extends rearward from the bottom of the hull and has a notch is integrally provided at the stern, and the propulsion machine body A waterjet propulsion vessel in which a water jet propulsion vessel is mounted on this storage stand and fixed to the hull, and the water intake port of the propulsion unit is aligned with the notch in the storage stand.