JPS62247997A - Trim control device for water injection type vessel screw - Google Patents

Abstract

PURPOSE:To make it possible to control the trim of a vessel automatically responding to the vessel speed, by furnishing a variable nozzle slidable up and down as well through a cylinder mechanism and linking an intake to input the dynamic power of the water of the vessel responding to the vessel's speed to the cylinder mechanism. CONSTITUTION:A sliding member 54 is reciprocated along a rail 52 by the reciprocation of a piston rod 64, and a variable nozzle 28 is swayed up and down against a fixed nozzle 26 around a spherical joint 50 as the center. The pressure chamber 72 of the first piston 68 is linked to the position of a rectifying wing 21 in a casing 22, i.e., at the rear side of an impeller 20, in order to push out the piston rod 64 to the left side by the pressure at the rear side of the impeller 20. On the other hand, the pressure chamber 76 of the second piston 70 is linked to a Pitot tube 80 through a hose 78, the Pitot tube 80 is opened to the right side, a pressure responding to the vessel's speed is led to the pressure chamber 76 thereby, and the piston rod 64 is moved to the right side.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a water-injection marine propulsion system, and in particular to a trim mechanism for a water-injection marine propulsion system that adjusts the attitude or trim of a ship according to the ship's speed. Regarding.

[Prior Art] Conventionally, in not only outboard motors but also water-injection marine propulsion systems, it has been necessary to adjust the sailing attitude of a ship in response to changes in ship speed, and to achieve the best sailing performance with appropriate trim. Various trim adjustment devices have been proposed for the purpose of obtaining economical fuel consumption rates. One of these examples is Utility Model 60-4879.
There is a water jet propulsion system for small boats described in the publication.

The trim adjustment device described herein is one in which a movable nozzle is manually swung up and down to obtain an appropriate trim angle.

Another example is an automatic trim adjustment device for a jet propulsion watercraft described in Japanese Utility Model Publication No. 54-40636. This is intended to automatically swing the movable nozzle up and down depending on the ship's speed to obtain an appropriate trim angle. However, in the case described here, the cover located on the bottom of the ship is placed so as to protrude below the keel line and is attached so that it can swing up and down, and the water resistance acting on this cover causes this cover to move. It has a structure that moves up and down, so the trim angle can be adjusted constantly to avoid water resistance against the boat.

Problems to be Solved by the Invention As described above, conventional trim adjustment devices for water-injection marine propulsion systems have been manually adjusted, for example.
Furthermore, the structure is such that it actively receives the resistance of the water acting on the ship, and the trim is adjusted using this resistance, so it is not possible to obtain the best sailing performance.

The present invention has been made in view of the problems of the prior art, and its purpose is to provide a water jet type ship that automatically responds to the ship's speed and is free from water resistance as much as possible. To provide a trim adjustment device for propulsion machines.

[Means for Solving the Problems] The present invention provides a water injection type marine propulsion device that obtains propulsive force by injecting a jet of water generated by the rotation of an impeller toward the rear of a ship through a movable nozzle that can swing left and right. In this method, the movable nozzle is made vertically swingable via a cylinder mechanism, and an intake 11 is provided on the ship to take in the dynamic pressure of water around the ship corresponding to the speed of the ship, and the intake port is connected to the pressure chamber of the piston of the cylinder mechanism. The purpose of the present invention is to achieve the above object by means of a trim adjustment device for a water-injected marine propulsion device, which is configured so that the higher the pressure in the pressure chamber, the closer the nozzle is to the water force.

[Function] With this configuration of the present invention, when the ship is in a low speed range or accelerates from low speed to high speed, the pressure of the water around the ship taken in from the intake port is low, so the movable nozzle is moved diagonally downward. The movable nozzle is swung to an almost horizontal position, and the water is swung diagonally downward, raising the stern and improving acceleration performance. to obtain efficient propulsion.

[Example] Hereinafter, the present invention will be described based on an example shown in the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a small water jet leisure boat. This water injection type small leisure boat as a whole has a water injection unit 12 at the rear lower part of the hull 10, an engine 14 at the front center of the engine room 11 of the hull, and a fuel tank 16 further forward from the engine 14. ing. The water injection unit 12 mainly includes a propeller shaft 1B driven by an engine 14, and a propeller shaft 1B driven by an engine 14.
an impeller 20.8 driven by an impeller 20.8 which pushes water from the water suction port 24 rearward; It consists of a rectifier fi21 provided behind the impeller 20, a casing 22 with a water suction port 24 formed below and housing the impeller 20 and the rectifier i21, and a fixed nozzle 26 and a movable nozzle 28, which will be described in detail later.

The engine 14 mainly consists of a cylinder block 30° cylinder head 32. Crankcase 34, exhaust expansion chamber 36 located above the cylinder head. and an exhaust passage 38, the output of which is transmitted to the propeller shaft 18 via a coupling 40. Furthermore, code 42
1 is a cooling water hose that introduces cooling water into a two-way jacket (not shown) of the engine, 44 is an exhaust pipe, and 46 is a spark plug. Further, reference numeral 48 indicates a handle device, and this handle device 48 is connected to the city recordable nozzle 28.
As a result, the movable nozzle 28 is swung left and right, thereby controlling the steering of the ship.

FIG. 2 shows the structure of the water injection unit 12 in an enlarged manner. The movable nozzle 28 is attached to the fixed nozzle 26 via a spherical joint 50 at its lower part so as to be swingable in the horizontal and horizontal directions. See also Figure 3,
A part of the fixed nozzle 26 is formed thick and has a protruding rail 52 extending along the axial direction.
It is smoothly curved toward the left end in the figure so as to gradually approach the axis. A sliding member 54 is placed on the rail 52 so as to straddle the rail 52, and a shaft portion 56 is integrally protruded from the sliding member 54 in a substantially perpendicular direction. This shaft portion 56 passes through the upper part of the movable nozzle 28, and a nut 58 is screwed into this penetration portion. Thereby, the movable nozzle 28 is supported around the shaft portion 56 so as to be swingable in the left-right direction of the ship. A bracket 60 is integrally provided on the nut 58, and this bracket 6
0 is connected to a piston rod 64 via a pin 62. Therefore, as the piston rod 64 reciprocates, the sliding member 54 reciprocates along the rail 52, thereby making the movable nozzle 28 swing up and down about the spherical joint 50 as a spade. The piston rod 6
4 protrudes from a cylinder 66 formed integrally with the fixed nozzle 26, and this piston opening/end 64
In the cylinder 66, a pair of pistons 68.7
0 is attached. For more details, see cylinder 66
has a shape in which a small diameter part 66A and a large diameter part 66B are integrally arranged in series, and a small diameter first piston 68 is connected to the small diameter part 66A at the tip of the piston rod 64, and a large diameter part 86B A second piston 70 having a diameter of about 100 mm is connected to the piston rod 64 at a substantially intermediate position. The pressure chamber 72 of the piston 68 of E7'S1 is connected to the hose 7
4, the position of the rectifier ff21 in the casing 22, that is, the rear side of the impeller 20, is communicated with the position of the rectifier ff21 in the casing 22, thereby introducing 20% pressure of the impeller, and this pressure pushes the piston rod 64 to the left in FIG. It looks like this.

Further, the pressure chamber 76 of the second piston 70 is communicated with a pitot tube 80 via a hose 78. This pitot tube 8
0 is attached to the bottom plate 82 that covers the bottom of the water injection unit 12, and its tip is located at the front of the ship in the axial direction, that is, the second
The opening is opened toward the right in the figure, whereby pressure corresponding to the speed of the ship is introduced into the pressure chamber 76 to press the second piston 70, thereby moving the piston rod 64 to the right in FIG. It looks like this. Note that reference numeral 84 is an air vent passage for communicating the space between both pistons 68 and 70 with the atmosphere.

The operation of this embodiment will be explained below.1 Normally, especially in a water injection type marine propulsion system, the relationship between the water pressure generated by the impeller 20 and the pressure taken out from the pitot tube 80 corresponding to the ship speed is shown in FIG. It will look like the one shown below. In this FIG. 4, P+ is the pressure of water behind the impeller 20 taken out by the aforementioned hose 74, and P2
is the pressure of water taken out from the pitot tube 80 corresponding to the speed of the ship. As can be seen from this figure, the pressure P2 corresponding to the ship speed rises more slowly than the water injection pressure P1 by the impeller 20 and is always lower due to running resistance due to water and the like. Here, as described above, the second pressure chamber 76 connected to the pitot tube 80 is divided into two
The piston 70 has a larger pressure receiving area than the first piston 68 that defines the first pressure chamber 72 into which the pressure behind the impeller 20 is introduced. By doing this, the force for moving the piston rod 64 will be reduced by the amount corresponding to the difference in the pressure receiving area of the pressure P in FIG. 4, and the state will be exactly as shown by the dotted line in FIG. 4. . In other words, the pressure P is the piston port "r)' 64
The pressure P1, indicated by the one-dot line, causes the movable nozzle 28 to swing in the water flow direction by moving the piston rod 64 to the left in FIG. This is the force that moves P6 downward. Therefore, when the ship's speed is low, P,' is larger than P2, and the movable nozzle 28 swings downward to inject the jet below the ship.
It acts to increase the ship's acceleration. As the ship's speed gradually increases, the pressures PI' and 22 become the same at the point shown by C in the figure, and then P2 becomes a higher pressure than P, °, and as a result, the orifice nozzle is in a horizontal position. It is possible to obtain efficient and high-speed sailing conditions.

In the above embodiment, the pitot tube 8 is connected to the second pressure chamber 76.
The dynamic pressure of the water around the vessel taken out by 0 is introduced, but there is no need to limit it to this, and in fact,
What is necessary is to take in the dynamic pressure of water around the ship that corresponds to the speed of the ship.

An example of this is shown in FIG. 5, the difference from the first embodiment is that the hose 78 in contact with the second pressure chamber is connected to a pressure intake port 86 opened in the water intake port 24 of the casing 22. There are only points.

The other parts are exactly the same as the previous embodiment. The pressure of the water taken in by this pressure intake port 86 is the dynamic pressure of the water around the ship corresponding to the speed of the ship, similar to the pressure of the water taken in by the pitot tube in the previous embodiment. It can have exactly the same effect.

Furthermore, various modifications can be considered for the pressure introduced into the first pressure chamber 72 in the first embodiment, and FIGS. 6 and 7 show the modifications. The one shown in FIG. 6 eliminates the first piston 68, hose 74 and air vent passage 84 in the first embodiment, and has a first pressure chamber 7.
2 is a sealed chamber, and this first pressure chamber 7
The pressure of 2 presses one side of the piston 70, while the pressure of the second
The structure is such that dynamic pressure corresponding to the speed of the ship introduced into the pressure chamber 76 of the piston 70 presses the other surface of the piston 70.

Furthermore, what is shown in FIG. 7 is the first example in the first embodiment.
The piston 68 and hose 74 of the piston rod 6 are eliminated, and the injection pressure from the rear of the impeller is introduced into the first pressure chamber 72, and a spring 88 is inserted in the first pressure chamber 72.
4 is biased toward the left in the figure. These Figure 6,
The embodiment shown in FIG. 7 can also provide substantially the same effect as that shown in the first embodiment.

[Effects] According to the present invention, it is possible to automatically adjust the trim of the ship according to the speed of the ship, and therefore, there is an excellent effect that it is possible to exhibit efficient sailing properties.

[Brief explanation of drawings]

FIG. 1 shows a trim WJ of a water injection type marine propulsion device according to the present invention.
Fig. 2 is an enlarged sectional view showing the water injection unit in the same embodiment; Fig. 3 is an enlarged sectional view taken along the line ■-■ in Fig. 2; , 4th
The figure is a graph showing a comparison between the water injection pressure behind the impeller and the pressure in the pitot tube corresponding to the ship speed. Fig. 5 shows another embodiment of the present invention, in particular the pressure introduced into the second pressure chamber. FIG. 6 is a cross-sectional view of the main part showing another example of the first pressure chamber, FIG. 7 is a cross-sectional view of the main part showing another example of the first pressure chamber, and FIG.
FIG. 3 is a sectional view showing another embodiment of the pressure chamber of FIG. 12... Water injection unit 20... Impeller 24... Water suction port 26... Fixed nozzle 28... Movable nozzle 66... Cylinder 68.70... Piston 72.76... Pressure Chamber 86...pressure intake

Claims (1)

[Claims] A water injection type marine propulsion system that obtains propulsive force by injecting a jet of water generated by the rotation of an impeller toward the rear of the ship through a movable nozzle that can swing left and right.The movable nozzle can also be moved up and down via a cylinder mechanism. A ship is provided with an intake port that can swing and takes in the dynamic pressure of water around the ship corresponding to the speed of the ship, and the intake port is communicated with the pressure chamber of the piston of the cylinder mechanism, so that the pressure in this pressure chamber increases. A trim adjustment device for a water-injection marine propulsion device configured so that the movable nozzle becomes nearly horizontal.