JPH05139379A - Water jet propelling device - Google Patents

Abstract

PURPOSE:To provide a water jet propelling machine which can be reduced in weight and manufacturing cost by providing a liner formed of a cylindrically rounded stainless steel plate or synthetic resin plate, and insertedly attaching the liner to the inner peripheral stepped part of an impeller housing. CONSTITUTION:An impeller housing 3 and a nozzle 4 are connected to the rear side of an intake duct 1, and an impeller 7 connected to the rear end of a driving shaft 5 rotatably constructed through the intake duct 1 is arranged inside an impeller housing 3, and hard alumite treatment is executed on the surface of the impeller housing 3 cylindrically cast of light alloy, and a liner 10 formed of a cylindrically rounded stainless steel plate or a synthetic resin plate is inserted into the inner peripheral stepped part 9 of the impeller housing 3 and attached to the stepped part 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water jet propulsion machine used for a small boat such as a pleasure boat.

[0002]

2. Description of the Related Art In a small boat such as a pleasure boat, an impeller is attached to the rear end of a drive shaft that is rotated by an engine, and the water sucked from the bottom of the boat is jetted by the rotation of the impeller to the stern side, and the reaction force is generated by the reaction force. A water jet propulsion machine that advances the hull is used.

A cylindrical impeller housing for accommodating the impeller is cast from a light alloy, and a stainless steel liner is integrally inserted inside. And
After casting, the inner circumference of the liner is cut to a predetermined size for finishing. See, for example, Japanese Utility Model Laid-Open No. 60-60397.

[0004]

The mold is expensive to insert the liner into the impeller housing. Further, it takes time to cut the inner circumference of the liner into a predetermined size after casting, because stainless steel is hard and the workability is poor. Further, the rigidity of the impeller housing is increased so as to improve the accuracy during cutting, so that the impeller housing becomes thick and heavy. In addition, if the impeller housing has cavities, seawater causes rust, which causes a problem of separation from the liner.

In view of the above point, the present invention provides a liner formed by rolling a stainless steel plate or a synthetic resin plate into a cylindrical shape, and inserts and adheres the liner into the step portion of the inner periphery of the impeller housing to reduce the weight and to process it. The purpose is to obtain a water jet propulsion machine that can reduce costs.

[0006]

In order to achieve the above-mentioned object, a water jet propulsion machine of the present invention has a rear end of a drive shaft in which an impeller housing and a nozzle are connected to a rear side of an intake duct and which is axially mounted on the intake duct. The impeller connected to the end is placed inside the impeller housing, and the surface of the impeller housing, which is cast in a tubular shape with light alloy, is hard-anodized, and a stainless steel plate or a synthetic resin plate is placed on the inner peripheral step of the impeller housing. It is that a liner rolled into a shape was inserted and adhered.

[0007]

[Function] Since the liner is formed by rolling a stainless steel plate into a cylindrical shape of a synthetic resin plate, the inner diameter accuracy can be obtained by controlling the inner diameter of the step portion of the inverter housing and the plate thickness of the stainless steel plate or the synthetic resin plate. Since the liner is not cut, it is easy to process and the weight of the liner can be reduced. Then, electrolytic corrosion can be prevented by treating the impeller housing with a hard alumite treatment.

[0008]

Embodiments of the present invention will be described below with reference to FIGS. The intake duct 1 communicates with the rear side from the lower suction port, and connects the tubular impeller housing 3 to the rear side of the intake duct 1. The tapered nozzle 4 is connected to the rear side of the impeller housing 3. A drive shaft 5 is inserted in the front and rear in the center of the intake duct 1, and the drive shaft 5 is rotatably mounted by a bearing 6. The front end of the drive shaft 5 is connected to the output shaft of the engine, and the impeller 7 is connected to the rear end of the drive shaft 5. Impeller 7
It is arranged inside the impeller housing 3. A rudder 8 is attached to the rear side of the nozzle 4 so that the rudder 8 can be pivoted left and right on the vertical axis.

The impeller housing 3 is cast from a light alloy into a tubular shape. Then, the step portion 9 is formed on the inner circumference by cutting, and the surface is hard-anodized. The liner 10 is made of a stainless steel plate or a synthetic resin plate having good water resistance and abrasion resistance and having a thickness of 1 to 1.5 mm, and is roll-formed so as to be rolled into a tubular shape. Inner diameter of liner 10 and impeller 7
If the gap between the outer circumferences of 0.1 to 0.3 mm is used, the rotational force can be efficiently converted into the propulsive force, and the inner diameter of the stepped portion 9 is set in consideration of the thickness of the liner 10. .. If the step 9 is provided with an inner flange only on the rear side and no inner flange is provided on the front side, the liner 10 can be easily inserted. Then, the liner 10 may be formed into a roll having a size larger than the inner diameter of the step 9 by 2 to 5 mm, and the roll may be contracted and inserted. The liner 10 is thinly coated with an adhesive on the surface of the liner 10 in contact with the outer step portion 9, and the liner 10 is inserted and bonded. As shown in FIG. 4, the liner 10 may be separated only from the bearing 6 of the impeller 7 and has a large amount of runout, and may be only the latter half portion. Further, as shown in FIG. 5, the liner 10 can be cut at the cut portion when algae or the like enters by making the cut portion of the mating portion oblique.

When the impeller 7 is rotated at a high speed in the engine, the water sucked from the lower intake port 2 of the intake duct 1 is injected to the rear side, and the tapered nozzle 4 pressurizes and accelerates and injects it to the rear side. This reaction force advances the hull. Ladder 8
Can be steered in the advancing direction of the ship by changing the direction of the water to be jetted by rotating right and left.

[0011]

As described above, since the present invention is configured as described above, the surface of the impeller housing can be made to have an insulating property by hard alumite treatment, and electrolytic corrosion can be prevented. .. In addition, the liner is made by rolling a stainless steel plate or synthetic resin plate and rolling it into the impeller housing, so that the liner can be made thinner, and the stepped inner diameter of the impeller housing and the liner thickness can be reduced. You can manage with. For this reason, the cutting process of the liner is unnecessary, the processing cost can be reduced, and the weight can be reduced. Also, casting of the impeller housing is simpler and less expensive than inserting a liner. Since the impeller housing itself does not have the liner cut, it can be made thin and lightweight.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part showing an embodiment of the present invention.

FIG. 3 is an exploded perspective view of an impeller housing and a liner showing an embodiment of the present invention.

FIG. 4 is an enlarged vertical cross-sectional view of a main part showing another embodiment of the present invention.

FIG. 5 is an exploded perspective view of an impeller housing and a liner showing another embodiment of the present invention.

[Explanation of symbols]

 1 Intake duct 3 Impeller housing 4 Nozzle 5 Drive shaft 7 Impeller 9 Step section 10 Liner

Claims (1)

[Claims] 1. An impeller housing and a nozzle are connected to a rear side of the intake duct, and an impeller connected to a rear side of a drive shaft axially mounted on the intake duct is arranged inside the impeller housing, and cast in a light alloy into a tubular shape. A water jet propulsion machine characterized in that the surface of the impeller housing is hard-anodized, and a liner formed by rolling a stainless steel plate or a rigid resin plate into a tubular shape is inserted and adhered to the inner peripheral step of the impeller housing.