JPH0732383Y2 - Water jet propulsion device nozzle - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle of a water jet propulsion device used for boats and the like.

[0002]

2. Description of the Related Art Water jet propulsion devices are used for propulsion of boats and the like. Conventionally, in a nozzle of a water jet propulsion device, an impeller provided at the bottom of a boat or the like guides a water flow along a passage, and a boat or the like is propelled by a propulsive force when a high-speed jet is ejected from the nozzle.

In the case of giving a turning motion to a watercraft or the like, by rotating a nozzle pivotally supported by a pin or the like at the rear of the water jet propulsion device in the left-right direction with respect to the axial direction of the watercraft or the like, a jet flow is generated. A turning motion is performed by changing the ejection direction.

In order to rotate the nozzle in the left-right direction, the nozzle mounted by the control device and the transmission means provided on the boat and the like is given a kinetic force by the operation of the control device.
The nozzle is rotated to the left and right with respect to the pivot point. For example, a bar handle or the like is used as a control device. As the structure of the nozzle, in order to efficiently eject a high-speed jet, a cylindrical one having a cylindrical inside is used.

[0005]

However, in the nozzle of the above-mentioned conventional water jet propulsion device, when the nozzle is rotated in the left-right direction to change the jetting direction of the jet flow, the nozzle is moved around the pivot point depending on the velocity of the water flow. Since the fluid force acts in the above-mentioned direction, the operator has to hold the steering device so as to oppose the fluid force and maintain the turning motion of the boat or the like. Particularly, when a boat or the like in a high-speed running state is caused to make a turning motion, the fluid force acting on the nozzle is increased to increase the jet velocity from the nozzle, and it is necessary to increase the gripping force of the control device for the operator. To do.

In particular, the above tendency tends to increase with the increase in the size of boats and the like and the increase in the propulsive force of the water jet propulsion device.

Therefore, although a mechanical or hydraulic auxiliary power transmission means is used for the control device and is connected to the nozzle, the structure is complicated.

The present invention solves such a conventional inconvenience, and an object of the present invention is to provide a nozzle of a water jet propulsion device in which the turning force of the nozzle in the left-right direction is reduced.

[0009]

In order to achieve the above-mentioned object, the present invention pivotally supports a cylindrical nozzle which is connected to an end of a throttle portion of a water jet propulsion device and is rotatable in the left-right direction. A concentric cylindrical fluid guide is provided in the nozzle, and the fluid is elongated upstream from the pivot point of the nozzle and short toward the downstream, and is projected respectively.

[0010]

The present invention has the following actions due to the above configuration. That is, when the nozzle is rotated in the left-right direction to change the jetting direction of the jet flow, the water flow causes the portion of the guiding fluid that projects long upstream from the pivot point of the nozzle and the portion of the guiding fluid that projects shortly downstream from the pivot point. Fluid forces with opposite directions of action act between the nozzle and the nozzle, and the unbalanced force during rotation is reduced by itself, so the load of the gripping force of the control device on the operator is reduced. It can be reduced. In particular, the use of auxiliary power transmission means such as a hydraulic device can be omitted.

[0011]

1 to 3 show the structure of an embodiment of the present invention. FIG. 1 is a sectional side view of a main part of a nozzle of a water jet propulsion device. In FIG. 1, reference numeral 10 denotes a water jet propulsion device, which is attached to the bottom of a boat or the like to reduce the running resistance of the hull.

Reference numeral 22 is an impeller, which is attached to a shaft 24 and is rotationally driven by an engine (not shown). Reference numeral 26 denotes a boss portion, which accommodates a bearing that axially supports the shaft 24 inside, and guide vanes 28 are provided outside the duct 18. An inlet 20 is provided on the bottom surface of the end of the duct 18 and the other end is formed as a throttle portion 30,
The nozzle 12 having a cylindrical main part is pivotally supported at the outlet end of the throttle portion 30.

At the pivot point 16 between the throttle portion 30 and the nozzle 12, for example, a pair of upper and lower pins are used to pivotally support both, and the nozzle 12 is rotatable so as to swing in the left and right directions.

Inside the nozzle 12, a fluid guide 14 is integrally provided, for example, and the fluid guide 14 is formed in a concentric cylindrical shape with respect to the nozzle 12, and the fluid guide 14 is provided upstream by the pivot point 16. The length is increased, the length is shortened downstream from the pivot point 16, and the protrusions are provided. It is also possible to form one end of the fluid guide 14 with a contour that follows the streamlined shape of the end of the boss 26, and make the inlet that is one end of the fluid guide 14 into a bell mouth shape. The fluid resistance is being reduced.

A fitting (not shown) is provided on the outside of the nozzle 12, and is connected by being guided from a steering device such as a boat to a conduction means, and the nozzle 12 is operated as described above by the operator operating the steering device. Is rotatable about the pivot point 16 in the left-right direction.

In the above embodiment, when the impeller 22 is rotated by driving the engine, water is sucked from the inlet 20, a water flow is generated in the duct 18, the flow is rectified by the guide vanes 28, and the high speed is supplied from the nozzle 12 via the throttle portion 30. The jet of water is ejected, and the propulsive force of the jet is used to propel a watercraft such as a water jet.

FIG. 2 is a cross-sectional plan view showing an essential part of the nozzle, which is a cross-sectional plan view taken along the line II of FIG. Figure 2
In FIG. 3, the fluid guide 14 is projected forward from the pivot point 16 of the nozzle 12 to indicate that the fluid guide 14 is provided in the nozzle 12, and the dotted line indicates the rotation of the nozzle 12 to the right.

As shown by the solid line of the nozzle 12, the throttle unit 3
When the water flow from the throttle portion 30 is pivotally supported at a position that coincides with the center direction of 0, the water flow goes straight in the nozzle 12 and jets a high-speed jet. In this case, the water flow proceeds straight to the nozzle portion behind the fluid guide 14 and the pivot 16 without generating a fluid force around the pivot 16.

As indicated by the dotted line, when the nozzle 12 is rotated, the center direction of the nozzle 12 is pivotally supported by being rotated to a position inclined to the left, for example, on a horizontal plane when viewed from the center direction of the narrowed portion 30. , The water flow from the throttle 30 is the nozzle 1
Bend in 2 and eject a high-speed jet. In this case, the fluid-conducting fluid 1 that has long projected upstream from the pivot 16 of the nozzle 12
4 between the portion of No. 4 and the portion of the fluid guide 14 that projects shortly downstream from the pivot point 16 and the nozzle 12 portion.
Of it respectively to generate fluid force M ₁ and M ₂ around, so the direction of the fluid force M _1, M ₂ is the opposite directions, to significantly reduce the imbalance forces in around the pivot point 16 at their own Therefore, the load of the gripping force of the control device on the operator can be reduced. Moreover, since it is possible to omit the use of the power transmission means, it is possible to reduce the weight of the boat.

FIG. 3 is a sectional front view of the main part of the fluid guide.
In FIG. 3, the fluid guide 14 has a cylindrical body, and is concentrically provided inside the nozzle 12. Reference numeral 15 is a fitting for connecting the nozzle 12 and the fluid guide 14. With this configuration, the cross section of the nozzle 12 is divided into concentric cylinders to allow the water flow to pass therethrough, thereby preventing the non-uniform flow of the water flow and effectively applying the fluid force of the fluid guide 14. The reduction of the unbalanced force can be enhanced.

The aspect of the present invention is not limited to the above embodiment, and many aspects can be adopted.

[0022]

As is apparent from the above embodiment, the present invention is an improvement of the nozzle of the water jet propulsion device, which uses the fluid force in the nozzle to turn the nozzle to the left and right. Since the unbalanced force is reduced by itself, the load of the gripping force of the control device on the operator can be reduced.

Further, the use of auxiliary power transmission means and the like can be omitted. Moreover, it has practical effects such as making it possible to reduce the weight of boats and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view of essential parts of a nozzle of a water jet propulsion device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional plan view of an essential part of the nozzle.

FIG. 3 is a fluid guide in the nozzle.

[Explanation of symbols]

 10 Water Jet Propulsion Device 12 Nozzle 14 Fluid Guide 16 Pivot

Claims (1)

[Scope of utility model registration request] 1. A cylindrical nozzle which is connected to an end of a throttle portion of a water jet propulsion device and is rotatable in the left-right direction,
A nozzle for a water jet propulsion device, characterized in that a concentric cylindrical guiding fluid is provided in the nozzle, and the guiding fluid is projected to the upstream side and the downstream side from the pivot point of the nozzle so as to project respectively.