JP2005112150A - Water jet propulsion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a firm and highly efficient water jet propulsion device capable of preventing a problem such as failure by corrosion or vibration and capable of effectively regulating the current. <P>SOLUTION: An impeller drive shaft 23 attached on an impeller 14 arranged in a propulsion water passage 10 is drawn to the outside at a curved tubular shape part of the propulsion water passage 10, the impeller drive shaft 23 drawn is driven, and the impeller 14 is rotated, and thereby water sucked from a suction port 19 is delivered from an outlet port 29 through a nozzle 16 arranged on a downstream side of the impeller 14, and the impeller drive shaft 23 is exposed in the propulsion water passage 10. A regulating plate 40 is suspended from an inner wall surface upper part of the propulsion water passage 10 to a position near the impeller drive shaft 23, a thickness of an edge part of the regulating plate 40 attached to the inner wall surface of the propulsion water passage 10 is thicker than a thickness of a tip part, and a space between a tip side 45 of the regulating plate 40 and the impeller drive shaft 23 is larger on the downstream side than on the upstream side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a water jet propulsion apparatus.

  Conventionally, small planing boats with an engine used for leisure use have a water jet propulsion device installed at the bottom of the stern and sucked from the bottom of the boat by the rotation of an impeller provided in the water channel for propulsion of the water jet propulsion device. It is configured to feed water backward, thereby propelling or turning the hull (see Patent Document 1).

  FIG. 5 is a schematic partial sectional view of these conventional water jet propulsion devices. As shown in the figure, in the water jet propulsion apparatus, an impeller 230 is installed in a propulsion water channel 200 installed at the bottom of the hull near the stern of the hull, and the impeller drive shaft 250 attached to the impeller 230 is driven to drive the impeller 230. , The water sucked from the suction port 201 of the propulsion water channel 200 is discharged from the discharge port 203 of the propulsion water channel via the nozzle 220 installed on the downstream side of the impeller 230 to obtain a propulsive force.

  FIG. 6 is an enlarged cross-sectional view taken along line aa in FIG. As shown in the figure, the portion of the impeller drive shaft 250 located in the propulsion water channel 200 has been conventionally covered with a protective tube 260. Further, in order to reinforce the protective pipe 260 and at the same time rectify the flow of water upstream of the impeller 230, the protective pipe 260 and the upper inner wall of the propulsion water channel 200 are connected by the support plate 270.

However, the protective tube 260 and the support plate 270 frequently have troubles due to problems such as damage due to corrosion or vibration.
JP-A-4-87899

  The present invention has been made in view of the above points, and an object of the present invention is to provide a robust and high-performance water jet propulsion device that is unlikely to cause problems such as damage due to corrosion or vibration and that can perform effective rectification. It is in.

  In the invention according to claim 1 of the present application, the suction side of the propulsion water channel provided in the hull has a bent pipe shape, and the impeller drive shaft attached to the impeller installed in the propulsion water channel is the propulsion water channel at the bent pipe shape portion. The water sucked from the suction port of the propulsion channel is discharged from the discharge port of the propulsion channel through the nozzle installed on the downstream side of the impeller by rotating the impeller by driving the pulled impeller drive shaft. In the water jet propulsion apparatus, the impeller drive shaft in the propulsion water channel is exposed and installed in the propulsion water channel, and the rectifying plate is suspended from the upper inner wall surface of the propulsion water channel to a position near the impeller drive shaft. It is in the water jet propulsion apparatus characterized by this.

  The invention according to claim 2 of the present application is characterized in that the thickness of the bottom portion attached to the inner wall surface of the water channel for propulsion of the rectifying plate is thicker than the thickness of the tip side portion. It is in the jet propulsion device.

  Invention of Claim 3 of this application is that the clearance gap between the front end side of the said baffle plate and the said impeller drive shaft is larger in the downstream rather than the upstream. The water jet propulsion device described.

  According to the invention described in claim 1 of the present application, the impeller drive shaft is exposed and installed in the propulsion water channel, and the current plate is suspended from the upper inner wall surface of the propulsion water channel to a position near the impeller drive shaft. Therefore, troubles such as corrosion and damage due to vibration of the protective tube and the support plate supporting the same as when the periphery of the impeller drive shaft is covered with the protective tube do not occur at all. In addition, since the flow straightening plate performs the flow straightening action around the impeller drive shaft, which has been conventionally performed by the support plate, the flow is not disturbed and effective flow straightening can be performed.

  According to the invention described in claim 2 of the present application, since the thickness of the skirt portion of the rectifying plate is made larger than the thickness of the tip side portion, the rectifying plate can be easily fixed to the propulsion water channel, and vibration can be caused. Damage can be effectively prevented.

  According to the invention described in claim 3 of the present application, since the gap dimension between the tip side of the current plate and the impeller drive shaft is formed so that the gap on the downstream side is larger than the gap on the upstream side. It is possible to easily prevent foreign matters in the water flowing in from the upstream side from being clogged in the gap.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic partial sectional view of a water jet propulsion apparatus according to an embodiment of the present invention. As shown in the figure, this water jet propulsion apparatus is constructed by installing a propulsion water channel 10 at the bottom of the hull near the stern of the hull and housing an impeller 14 therein.

  Here, the propulsion water channel 10 is configured by connecting a suction pipe 11, an impeller housing 13, a discharge bowl 15, a nozzle 16 and a bucket 17 from the upstream side (front side of the hull). The suction pipe 11 has a bent pipe shape, the upstream side (right side in FIG. 1) is bent downward, and the suction port 19 at the tip thereof faces downward (boat bottom). A strainer 21 is attached in the vicinity of the suction port 19 in the suction pipe 11 so as to prevent foreign matter in the water sucked from the suction port 19 from flowing into the propulsion water channel 10. An impeller drive shaft 23 is installed in the suction pipe 11, an impeller 14 installed in the impeller housing 13 is attached to one end on the downstream side, and the other end is connected to the outside from the bent pipe-shaped portion of the suction pipe 11. The drawn-out portion is pivotally supported by the bearing 27, and the tip side is connected to the engine 25. Guide vanes 28 are fixed in the discharge bowl 15. The bucket 17 is attached so as to be swingable in the horizontal direction, and changes the direction of water for propulsion ejected from the nozzle 16 to the left and right. The end of the bucket 17 is a water discharge port 29.

  In this water jet propulsion apparatus, the impeller drive shaft 23 in the propulsion water channel 10 is exposed and installed in the propulsion water channel 10. That is, the protective tube 260 shown in FIG. 5 and the support plate 270 that supports the protective tube 260 are not provided. At the same time, in this water jet propulsion device, the rectifying plate 40 is suspended from the upper part of the inner wall surface of the propulsion water channel 10 (suction pipe 11) to a position near the impeller drive shaft 23.

  2 is an enlarged schematic cross-sectional view showing the vicinity of the rectifying plate 40 of the suction pipe 11, FIG. 3 is an enlarged cross-sectional view of the AA line portion of FIG. 1, and FIG. 4 is a schematic perspective view of the rectifying plate 40 and the vicinity thereof. FIG. As shown in FIGS. 3 and 4, the rectifying plate 40 is formed in a streamline shape so as to rectify the flow of fluid that is about to be disturbed by the impeller driving shaft 23 at the upper part (downstream side) of the impeller driving shaft 23, And as mentioned above, it hangs from the inner wall surface upper part of the suction pipe 11, and is installed. And as shown in FIG. 3, the thickness of the base part 41 attached to the inner wall surface of the water channel 10 for a rectifying plate 40 of the rectifying plate 40 is made wider than the thickness of the tip side part 43, thereby the rectifying plate 40 is connected to the suction pipe 11. The mounting strength is strengthened. On the other hand, as shown in FIG. 2, the tip side 45 of the rectifying plate 40 is such that the gap between the tip side 45 and the impeller drive shaft 23 is smaller in the downstream gap dimension L2 than in the upstream gap dimension L1. It is configured to be inclined obliquely so as to increase.

  In the water jet propulsion apparatus configured as described above, when the engine 25 is driven, the impeller 14 is rotated by the impeller drive shaft 23, whereby water sucked from the suction port 19 of the propulsion water channel 10 passes through the strainer 21 to the suction pipe. 11, the impeller housing 13, the discharge bowl 15, and the nozzle 16 are discharged from the discharge port 29 at the tip of the bucket 17 to give a propulsive force to the hull in which this water jet propulsion device is installed. If the direction of the water for propulsion ejected from the nozzle 16 by the bucket 17 is changed to the left and right, the hull can turn and be steered.

  On the other hand, in this water jet propulsion apparatus, since the impeller drive shaft 23 is exposed in the suction pipe 11, the protection pipe and the support plate that supports the same are corroded or vibrated as if the periphery of the impeller drive shaft 23 is covered with the protection pipe. No troubles such as damage due to. Conventionally, the rectifying action around the impeller drive shaft 23 performed by the support plate is performed by the rectifying plate 40, so that the flow is not disturbed. Further, as described above, since the rectifying plate 40 is thickened at the bottom portion 41 so as to strengthen the attachment strength to the suction pipe 11, there is no fear of breakage due to vibration.

  Further, as described above, the gap between the tip side 45 of the current plate 40 and the impeller drive shaft 23 is larger in the downstream gap dimension L2 than in the upstream gap dimension L1, and therefore flows in from the upstream side. Even if the foreign matter in the water is once clogged on the upstream side of the gap, it is removed by being pushed downstream, and the clogging can be easily released.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims and the technical idea described in the specification and drawings. Deformation is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited. For example, in the above embodiment, the current plate 40 is a single sheet, but a plurality of sheets may be used. Needless to say, the shape of the current plate 40 can be variously modified.

1 is a schematic partial cross-sectional view of a water jet propulsion device according to an embodiment of the present invention. FIG. 3 is an enlarged schematic cross-sectional view showing a portion near the rectifying plate 40 of the suction pipe 11. It is an expanded sectional view of the AA line part of FIG. It is a schematic perspective view of the baffle plate 40 and its vicinity part. It is a general | schematic fragmentary sectional view of the conventional water jet propulsion apparatus. It is a cross-sectional enlarged view of the aa line part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Propulsion water channel 11 Suction pipe 13 Impeller housing 14 Impeller 15 Discharge bowl 16 Nozzle 17 Bucket 19 Suction port 21 Strainer 23 Impeller drive shaft 25 Engine 27 Bearing 28 Guide vane 29 Discharge port 40 Rectifier plate 41 Slip portion 43 Tip side portion 45 Tip Side L1, L2 Clearance dimension

Claims (3)

The suction side of the propulsion water channel provided in the hull has a bent pipe shape, and the impeller drive shaft attached to the impeller installed in the propulsion water channel is pulled out of the propulsion water channel at the bent pipe shape part, and the impeller drive shaft pulled out is In the water jet propulsion apparatus that drives and rotates the impeller, and discharges water sucked from the suction port of the propulsion channel from the discharge port of the propulsion channel through a nozzle installed on the downstream side of the impeller.
The impeller drive shaft in the propulsion channel is exposed and installed in the propulsion channel,
A water jet propulsion apparatus, wherein a rectifying plate is suspended from an upper part of an inner wall surface of the water channel for propulsion to a position near the impeller drive shaft.   2. The water jet propulsion apparatus according to claim 1, wherein a thickness of a skirt portion attached to an inner wall surface of the water channel for propulsion of the rectifying plate is thicker than a thickness of a tip side portion.   3. The water jet propulsion apparatus according to claim 1, wherein a gap between a front end side of the current plate and the impeller drive shaft is larger on the downstream side than on the upstream side.

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