JPH0941965A - Cooling system of water jet propelled boat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a cooling water passage, simultaneously to make a proper amount of cooling water feedable to engine and an exhaust system and to control the temperature of an engine cooling system. SOLUTION: A hydromotorbike 2 is provided with an engine 6 mounted on a hull 4, an inlet pipe part 10 installing a water inlet port to be opened to a vessel bottom and installed in the rear of the hull 4, a pump part 12 being installed in this inlet pipe part 10 and simultaneously being driven by the engine 6 and inducing water into the inlet pipe part 10 from the water inlet port, and an exhaust system 14 connected to the engine 6, respectively. In addition, two cooling water hoses 16 and 18, being independent from each other, inducing water flowing in a stator 12b of the pump part 12 to the engine 6 and the exhaust system 14 each are installed in a cooling system of this hydromotorbike 2.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cooling device for a water jet propulsion watercraft.

[0002]

2. Description of the Related Art Conventionally, water jet propulsion boats have been widely used for propelling ships by utilizing reaction force generated by water jet. FIG. 4 shows a conventional watercraft as an example of this water jet propulsion boat. FIG. 4 is a view of the watercraft viewed from above and is a configuration diagram of the inside of the hull.

This watercraft a is equipped with an engine c mounted on a hull b, a suction pipe part d provided at the rear of the hull b and having a water suction opening opening to the bottom of the hull, and disposed inside the suction pipe part d. And a pump part e driven by the engine c to introduce water into the suction pipe part d from the water intake port,
An exhaust system f connected to the engine c. In this watercraft a, the water introduced into the suction pipe portion d by the pump portion e is jetted backward by the jet nozzle f to obtain a propulsive force. The pump part e mainly includes an impeller e1 provided at a rear end of a drive shaft g connected to the engine c, and a stator e2 arranged behind the impeller e1 to rectify water.

Normally, in this type of watercraft a, since the water pressure near the stator e2 is high, the high water pressure is used to send the cooling water to the engine c and the exhaust system f. That is, the cooling water hose h is connected to the stator e2, the cooling water hose h is branched into two, and the engine c
And cooling water is supplied to each of the exhaust systems f. The cooling water sent to the engine c passes through the cylinder portion c1 and the cylinder head portion c2, then passes through the cooling water passage i, and is discharged from the side portion of the hull b. On the other hand, the cooling water sent to the exhaust system f cools the exhaust passages of the exhaust manifold j, the exhaust chamber k, and the exhaust muffler m, and is discharged to the outside of the hull b.

[0005]

However, the conventional cooling device for the watercraft a has the following problems. That is, since the cooling water hose h in the stator e2 has only one cooling water inlet, the cooling water supplied to the engine c or the exhaust system f is unlikely to be an appropriate amount on a hot day. Further, even if the cooling water hose h is branched, it becomes difficult to supply an appropriate amount of cooling water to the exhaust system f, and the handling of the cooling water hose h becomes complicated.

Further, since the cooling system of the engine c and the cooling system of the exhaust system f are connected to each other, the cooling systems of the engine c and the exhaust system f are considered separately because of the fact that the cooling water is flowing through the exhaust muffler m. It is not possible. For example, even if a thermostat p is attached to the cylinder head portion c2 as shown in FIG. 4, a large amount of cooling water flows into the exhaust system f when the supply of cooling water to the cooling system of the engine c is stopped, and the exhaust gas is exhausted. Since the resistance may increase and the output of the engine c may be affected, it is difficult to control the temperature of the cooling system of the engine c.

The present invention has been made in view of the above-mentioned conventional problems, and can simplify the cooling water passage and
An object of the present invention is to provide a cooling device for a water jet propulsion watercraft which can supply an appropriate amount of cooling water to an engine and an exhaust system and can control the temperature of a cooling system of an engine without affecting the exhaust system.

[0008]

The present invention has the following configuration to achieve the above object. That is, the invention of claim 1 is that an engine mounted on a hull, a suction pipe portion provided at a rear portion of the hull, which includes a water inlet opening to a bottom of the hull, the suction pipe portion disposed inside the suction pipe portion, and the engine. And a pump part for introducing water into the suction pipe part from the water suction port, and an exhaust system connected to the engine, and the water introduced into the suction pipe part by the pump part is injected backward In a water jet propulsion watercraft that propels water by propelling water, a cooling device for a water jet propulsion water boat is provided with two independent cooling water passages that guide water flowing through the pump section to the engine and the exhaust system, respectively. is there.

According to a second aspect of the present invention, a cooling system for a water jet propulsion watercraft according to the first aspect is characterized in that a cooling system of the engine communicating with the cooling water passage for the engine is provided with a thermostat. Is.

According to the first aspect of the invention, the two cooling water passages for guiding the water flowing through the pump portion to the engine and the exhaust system are independent of each other. Therefore, the absolute amount of cooling water can be increased, and an appropriate amount of cooling water can be supplied to the engine and the exhaust system. Further, since the cooling water passage is not branched, the arrangement of the members forming the cooling water passage is also simplified.

According to the second aspect of the present invention, the temperature of the cooling system in the engine can be controlled by the thermostat, and at the same time, the two cooling water passages leading to the engine and the exhaust system are independent from each other. Regardless of the open / closed state of the engine cooling system, an appropriate amount of cooling water is supplied to the exhaust system.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a watercraft according to the present embodiment, FIG. 2 is a plan view of the watercraft, and FIG. 3 is a view of the watercraft viewed from above, which is a configuration diagram inside a hull.

As shown in FIG. 1, a watercraft 2 (one example of a water jet propulsion boat) of the present embodiment is equipped with an engine 6 mounted on a hull 4 and a water intake port 8 opening to the bottom of the hull 4. Suction pipe part 10 provided at the rear part and suction pipe part 1
And a pump unit 12 driven by the engine 6 to introduce water into the suction pipe unit 10 through the water intake port 8 and an exhaust system 14 (see FIG. 3) connected to the engine 6. , Suction section 10 by pump section 12
The water introduced therein is jetted backward by the jet nozzle 11 to propel it.

The cooling device according to this embodiment includes
As shown in FIG. 3, two independent cooling water hoses (corresponding to cooling water passages) 16 and 18 for guiding the water flowing through the pump unit 12 to the engine 6 and the exhaust system 14 are provided. A thermostat 20 is provided in the cooling system of the engine 6 that communicates with the cooling water hose 16 for the engine 6.

The configuration of each part of this embodiment will be described below. As shown in FIG. 1 and FIG. 2, the hull 4 is provided with footrests 4a, 4a on both left and right sides.
A sheet 22 is provided between a and 4a. A steering wheel 24 is provided at the front of the hull 4, and the driver can change the jetting direction of water by operating the steering wheel 24.

As shown in FIG. 1, the engine 6 is a two-cycle engine which is mounted inside the hull 4 positioned directly below the handle 24 and installed vertically. The engine 6 includes a cylinder portion 6a and the cylinder portion 6a.
and a cylinder head portion 6b mounted and fixed on a. As shown in FIG. 3, the exhaust system 14 includes an exhaust manifold 14a connected to an exhaust port of the engine 6, an exhaust chamber 14b connected to a downstream end of the exhaust manifold 14a, and an exhaust chamber 14b connected to the exhaust chamber 14b. It is mainly composed of an exhaust muffler 14c that silences the exhaust sound of the exhaust gas that has been exhausted, and an exhaust pipe 14d that extends laterally in the hull 4 from the exhaust muffler 14c and exhausts the exhaust from the rear end of the hull 4 toward the rear. It

The suction pipe section 10 is, as shown in FIG.
It is formed in the lower rear portion of the hull 4 and has a shape that after sucking water from the water suction port 8 rearward and upward, the sucked water is guided substantially horizontally to the rear end opening. A drive shaft 26 connected to the crank shaft of the engine 6 projects from the front wall of the suction pipe portion 10 which is inclined rearward toward the inside of the suction pipe portion 10.

As shown in FIG. 1, the pump portion 12 is fixed to the rear end of the drive shaft 26, and an impeller 12a for sucking water from the water suction port 8 to suck it into the pipe portion 10 and pressurizing it, and immediately after this impeller 12a. And a stator 12b for rectifying the water that is disposed and rectifies the water pressurized by the impeller 12a. Immediately after the stator 12b, the injection nozzle 11 that ejects the water rectified by the stator 12b toward the rear of the hull 4 is provided.

As shown in FIG. 3, the cooling water intakes 16a and 18a of the two cooling water hoses 16 and 18 are provided on both left and right sides of the stator 12b. Each of the two cooling water hoses 16 and 18 has a cooling water intake 16
a, 18a extends forward in a unique path, one cooling water hose 16 is connected to a predetermined portion of the cylinder portion 6a, and the other cooling water hose 18 is connected to the exhaust manifold 14a, Each cooling water hose 16,1
8 communicates with the cooling systems of the engine 6 and the exhaust system 14, respectively.

As shown in FIG. 3, the thermostat 20 is installed in the cylinder head portion 6b of the engine 6, and for example, the temperature of the cooling system in the engine 6 (cylinder portion 6a and cylinder head portion 6b) is below a set value. At this time, the supply of cooling water into the engine 6 is stopped. After passing through the thermostat 20 of the cylinder head portion 6b, the cooling water in the engine 6 is guided to the side portion of the hull 4 through the cooling water passage 28 and discharged to the outside of the hull 4. The cooling water guided to the exhaust manifold 14a by the cooling water hose 18 flows through the exhaust chamber 14b, the exhaust muffler 14c, and the exhaust pipe 14d after cooling the exhaust manifold 14a, and is discharged backward together with the exhaust. It

According to the watercraft 2 of the present embodiment having the above-mentioned structure, the cooling water hose 16 for the engine 6 is provided.
Since the cooling water hose 18 for the exhaust system 14 and the cooling water hose 18 are independent of each other, the absolute amount of the cooling water is increased and an appropriate amount of cooling water can be supplied to the engine 6 and the exhaust system 14. Moreover, since the cooling water hoses 16 and 18 are not branched, the handling of the cooling water hoses 16 and 18 can be simplified.

Further, the temperature of the cooling system in the engine 6 can be controlled by the thermostat 20, and at the same time, since the two cooling water hoses 16 and 18 are independent of each other, the thermostat 20 opens and closes the cooling system of the engine 6. Regardless, an appropriate amount of cooling water can be constantly supplied to the exhaust system 14.

The present embodiment is a preferred embodiment of the present invention, and the technical scope of the present invention is not limited to this embodiment.

[0024]

As described above, according to the present invention, the cooling water passage can be simplified and an appropriate amount of cooling water can be supplied to the engine and the exhaust system. Moreover, it is possible to manage the temperature of the cooling system of the engine without affecting the exhaust resistance.

[Brief description of drawings]

FIG. 1 is a side view of a watercraft according to this embodiment.

FIG. 2 is a plan view of the watercraft according to the present embodiment.

FIG. 3 is a view of the watercraft according to the present embodiment as seen from above, which is a configuration diagram of the inside of the hull.

FIG. 4 is a view of a watercraft according to a conventional example seen from above, and is a configuration diagram of the inside of a hull.

[Explanation of symbols]

 2 Water bike (an example of water jet propulsion boat) 4 Hull 6 Engine 8 Water inlet 10 Suction pipe part 12 Pump part 14 Exhaust system 16 Cooling water hose for engine (equivalent to cooling water passage) 18 Cooling water hose for exhaust system (Equivalent to cooling water passage) 20 Thermostat

Claims (2)

[Claims] 1. An engine mounted on a hull, a suction pipe portion provided at a rear portion of the hull, having a water inlet opening to a bottom of the hull, a suction pipe portion disposed inside the suction pipe portion, and driven by the engine. A pump unit that introduces water into the suction pipe unit through the water suction port and an exhaust system that is connected to the engine are provided, and the water introduced into the suction pipe unit by the pump unit is jetted backward to propel the water. The water jet propulsion watercraft is provided with two independent cooling water passages for guiding water flowing through the pump section to the engine and the exhaust system, respectively. 2. The cooling system for a water jet propulsion watercraft according to claim 1, wherein a cooling system of the engine communicating with the cooling water passage for the engine is provided with a thermostat.