JP2002220090A - Small-sized ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure prescribed engine performance and stabilize an exhaust gas value by suppressing fluctuation in pressure of cooling water supplied to an engine and maintaining a sufficiently constant cooling temperature in accordance with the operating state of the engine. SOLUTION: A small-sized ship 1, which comprises a propeller 30 driven by the engine 20 and leads cooling water supplied by the propeller 30 to the engine 20 to cool it, includes an engine cooling water path 50 for supplying the cooling water to the engine 20, and a branch cooling water path 52 having a pressure control valve 53 opened or closed upstream of the engine 20 in accordance with the pressure of the cooling water in the engine cooling water path 50 so as to control the flow rate of the cooling water in the engine cooling water path 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small boat equipped with a propulsion device driven by an engine.

[0002]

2. Description of the Related Art Conventionally, some small boats have, for example, a propulsion device driven by an engine, and guide cooling water supplied from the propulsion device to the engine for cooling. In this way, the outside water is guided to the engine, and the cooling water whose temperature has increased by cooling the engine is discharged to the outside of the engine.

[0003]

As described above, in a small boat, the temperature of the cooling water is lower than that of the engine mounted on the vehicle because the outside water is guided to the engine and cooled. Outside water is supplied as cooling water according to the output of.

Therefore, for example, it is conceivable to provide a thermostat for opening and closing the engine cooling water path to control the temperature of the cooling water to be constant. However, since external water is supplied as cooling water in accordance with the output of the propulsion device. The pressure fluctuation of the cooling water is large. For this reason, a large cooling water pressure is applied to the thermostat to cause malfunction, or the temperature control by the thermostat alone cannot sufficiently maintain a constant cooling temperature in accordance with the operating state of the engine. There are problems that performance cannot be obtained, or combustion in the engine is not stable, and the exhaust gas value is not stable.

SUMMARY OF THE INVENTION The present invention has been made to solve the conventional problem, and suppresses fluctuations in the pressure of cooling water supplied to an engine to maintain the cooling temperature sufficiently constant according to the operating state of the engine. It is another object of the present invention to provide a small boat capable of obtaining a predetermined engine performance and further stabilizing an exhaust gas value.

[0006]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention has the following constitution.

[0007] The invention described in claim 1 is a small boat that includes a propulsion device driven by an engine and guides cooling water supplied from the propulsion device to the engine to cool the engine. A branch cooling water having an engine cooling water path to be supplied and a pressure control valve which can be opened and closed in accordance with the pressure of the cooling water in the engine cooling water path at a stage preceding the engine and can control a flow rate of the cooling water in the engine cooling water path; A small vessel comprising a path. ].

According to the first aspect of the present invention, the pressure control valve opens and closes in front of the engine in accordance with the pressure of the cooling water in the engine cooling water path to control the flow rate of the cooling water supplied to the engine. Therefore, the pressure of the cooling water supplied to the engine can be suppressed, and the cooling temperature can be sufficiently maintained constant in accordance with the operating state of the engine, thereby obtaining a predetermined engine performance and stabilizing the exhaust gas value. Can be.

According to a second aspect of the present invention, there is provided a thermostat for opening and closing the engine cooling water passage, wherein the valve opening pressure of the thermostat is higher than the valve opening pressure of the pressure control valve. 2. The small boat according to 1. ].

According to the second aspect of the present invention, there is provided a thermostat for opening and closing the engine cooling water path, and by setting the valve opening pressure of the thermostat higher than the valve opening pressure of the pressure control valve, an excessively large amount of heat is generated in the thermostat. The pressure of the cooling water is not applied, and the temperature of the cooling water can be controlled with high accuracy.

According to a third aspect of the present invention, there is provided a small boat according to the second aspect, wherein the thermostat is provided on a cooling water outlet side of the engine. ].

According to the third aspect of the present invention, by providing the thermostat on the cooling water outlet side of the engine,
The cooling temperature of the engine can be maintained substantially constant by the thermostat.

According to a fourth aspect of the present invention, there is provided an exhaust system cooling water path for supplying cooling water to an exhaust system separately from the engine. A small vessel as described in. ].

According to the fourth aspect of the present invention, an exhaust system cooling water path for supplying cooling water to the exhaust system separately from the engine is provided, and the exhaust system can be cooled.

According to a fifth aspect of the invention, there is provided a lubrication system cooling water path for supplying cooling water to a lubrication system separately from the engine. A small vessel as described in. ].

According to the fifth aspect of the present invention, a lubrication system cooling water path for supplying cooling water to the lubrication system separately from the engine is provided, and the lubrication system can be cooled.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a small boat according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view of the jet propulsion boat, and FIG. 2 is a plan view of the jet propulsion boat.

The small boat of this embodiment is constituted by a jet propulsion boat 1. In this jet propulsion boat 1, a hull 2 is composed of a hull member 3 and a deck member 4. A steering handle 5 is provided on an upper portion of the deck member 4, and a seat table 4 rising upward from the deck member 4 is provided on an upper portion of the deck member 4 behind the steering handle 5.
a is provided to extend rearward, and a detachable seat 6 long for two persons is placed rearward on the upper surface of the seat table 4a. By attaching and detaching the seat 6, the inspection opening 4b formed on the upper surface of the seat table 4a can be opened and closed.

Steps 4c are formed on both sides of the seat 4a of the deck member 4 between the deck member 4 and the bulwark 7 projecting upward from both sides of the deck member 4 for the rider to put his / her both feet. ing.

The interior space of the hull 2 is partitioned back and forth by a partition 8, an engine room 9 is formed in a space on the front side of the partition 8, and a pump room 10 is formed in a space on the rear side. A four-cycle type four-cylinder engine 20 is mounted on the hull member 3 at a position below the seat table 4 a in the engine room 9.
1, and a resin fuel tank 22 is fixed to the hull member 3 at a position in front of the engine 20. The engine 20 may be of a two-cycle type.

A propulsion device 30 is disposed in the pump chamber 10. The propulsion device 30 draws water from a water suction port 33 on the bottom of the ship when the impeller 32 is rotated by an engine 20 via an impeller shaft 31. And the water
By jetting backward from the zero nozzle 34, the hull 2 is propelled. The hull 2 is turned by swinging the nozzle 34 left and right by operating the steering handle 5.

At the front of the engine room 9 of the hull 2, a front intake duct 23 is provided which opens to the upper surface of the bow of the deck member 4 and introduces air outside the boat into the engine room 9. At the same time, at the front position of the pump chamber 10 on the rear side of the partition 8, a rear intake duct 24 that opens to the upper surface of the seat table 4 a of the deck member 4 and that introduces air outside the boat into the pump chamber 10 is provided. Is provided.

A downstream end of an intake pipe 40 that is obliquely upward is connected to the port side of the engine 20, and an intake silencer 41 is provided at an upstream end of the intake pipe 40.

An exhaust manifold 42 is connected to the starboard side of the engine 20, and an upstream end of an exhaust pipe 43 is connected to the exhaust manifold 42.
After a U-shaped detour around the front upper part of the engine 20, and further, the muffler 44 connected to the exhaust pipe 43 extends rearward above the port side of the engine 20 and curves downward at the rear side of the engine 20. The downstream end is connected to the inlet of the water lock 45 which extends rearward, penetrates the partition wall 8 and is located on the starboard side in the pump chamber 10. The upstream end of a discharge pipe 46 is connected to the outlet of the water lock 45, and the discharge pipe 46 extends to the port side bypassing the upper part of the pump chamber 10 of the hull member 3, and then extends to the port side. The downstream end is connected to the left side wall of the pump chamber 10 to discharge exhaust gas into the pump chamber 10.

FIG. 3 is a schematic view showing a cooling structure of the jet propulsion boat.

The cooling water flowing through the engine cooling water path 50 is supplied to the positive pressure section 35 of the propulsion unit 30 driven by the engine 20.
The cooling water is supplied to the cooling water jacket of the engine 20 from the cooling water pipe 50a via the Y-nipple 50b and the cooling water pipe 50c. The cooling water whose temperature has risen after flowing through the cooling water jacket of the engine 20 flows to the thermostat 51 via the cooling water pipe 50d, further flows from the thermostat 51 to the thermo junction pipe 59 via the cooling water pipe 50e, and further drains 50f The water is discharged outboard as engine waste water via a throttle 50g. The thermostat 51 maintains the cooling temperature by controlling the cooling temperature of the engine to be substantially constant, for example, 50 ° C.

Further, a branch cooling water pipe 52a is connected to the engine cooling water path 50 before the engine 20 by branching to a cooling water pipe 50c. The branch cooling water pipe 52a forms a branch cooling water path 52. This branch cooling water pipe 52
a has a pressure control valve 53 capable of controlling the flow rate of cooling water.
And the downstream side of the branch cooling water pipe 52a is connected to the oil tank 25. The valve opening pressure of the pressure control valve 53 is set lower than the valve opening pressure of the thermostat 51, and is opened and closed by the pressure of the cooling water in the engine cooling water path 50, and controls the flow rate of the cooling water in the engine cooling water path 50.

The cooling water flowing through the branch cooling water pipe 52a flows through the cooling water passage of the oil tank 25 to cool the oil.
The cooling water whose temperature has risen after flowing through the passage of the oil tank 25 is joined at the thermo junction pipe 52 via the branch cooling water pipe 52b, and discharged from the drain pipe 50f as engine waste water to the outside of the boat.

The connecting pipe 6 is connected to the Y-shaped nipple 50b.
0a, a Y-shaped nipple 60b is connected, and an exhaust system cooling water pipe 60c is connected to the Y-shaped nipple 60b.
An exhaust system cooling water path 60 that supplies cooling water to the exhaust system is provided separately from the engine 20.

The exhaust system cooling water pipe 60c is connected to the exhaust pipe 43, and the cooling water flows from the cooling water passage of the exhaust pipe 43 through the cooling water passage of the exhaust manifold 42 and the cooling water passage of the muffler 44 to be cooled. Mixed with exhaust gas from the cooling water passage and discharged as exhaust water. Further, pilot water is discarded from a throttle 60d of the exhaust pipe 43 through a throttle 60f provided on a side surface of the hull 2 through a drain pipe 60e. In addition, the muffler waste water is discharged from the drainage pipe 60h through the restriction 60i through the restriction 60i from the restriction 60g of the muffler 44.

A lubrication system cooling water pipe 70a is connected to the Y-shaped nipple 60b, and a lubrication system cooling water path 70 for supplying cooling water to the lubrication system separately from the engine 20 is provided. The oil tank 2 is located downstream of the lubrication system cooling water pipe 70a.
5, the cooling water flows through the cooling water passage of the oil tank 25 to cool the oil, and the cooling water whose temperature has increased through the passage of the oil tank 25 flows through the branch cooling water pipe 52 b to the thermo junction pipe 52. And discharged from the drain pipe 50f as engine waste water outboard.

As described above, the valve opening pressure of the thermostat 51 is set higher than the valve opening pressure of the pressure control valve 53, and the cooling water flows from the engine cooling water path 50 by the control of the pressure control valve 53 before the engine 20. To control the supply flow rate of the cooling water to the engine 20.

When the engine 20 is started, the cooling water flowing through the engine cooling water passage 50 is supplied to the engine 20, but the cooling water does not flow because the temperature of the cooling water is low and the thermostat 51 is closed. Engine cooling water path 50
When the pressure of the cooling water increases, the pressure control valve 53 opens, and the flow rate of the cooling water supplied to the engine 20 can be reduced to improve the startability.

After starting, the engine cooling water path 50
When the pressure of the cooling water increases, the pressure control valve 53 opens to control the flow rate of the cooling water supplied to the engine cooling water path 50, thereby suppressing the fluctuation of the pressure of the cooling water supplied to the engine 20 that occurs depending on the operating state. In addition, the cooling temperature can be sufficiently maintained constant in accordance with the operation state of the engine 20, a predetermined engine performance can be obtained, and the exhaust gas value can be stabilized.

An exhaust system cooling water path 60 for supplying cooling water to the exhaust system separately from the engine 20 is provided to cool the exhaust system. In addition, a lubrication system cooling water path 70 for supplying cooling water to the lubrication system is provided separately from the engine 20, so that the lubrication system can be cooled.

Next, the cooling structure of the engine will be described with reference to FIGS. 4 is a perspective view of the engine, FIG. 5 is a side view of the engine, FIG. 6 is a plan view of the engine, and FIG.
8 is a front view of the engine, FIG. 8 is a cross-sectional view of the engine, FIG. 9 is a view of the exhaust manifold seen from the engine connection side, and FIG.
FIG. 11 is a view from the exhaust pipe connection side of the exhaust manifold, and FIG.
Is a sectional view showing a water backflow prevention structure of an exhaust pipe, FIG. 12 is a plan view showing a pressure control valve, FIG. 13 is a sectional view showing a pressure control valve, and FIG. 14 is a sectional view showing a thermostat.

The engine 20 according to this embodiment includes a crankcase 20a, a cylinder block 20b, and a cylinder head 20c. As shown in FIGS. 8, 12, and 13, a cooling water pipe 50c of an engine cooling water path 50 is connected to a side wall of the cylinder block 20b through a joint 90, and the cooling water is supplied to a cooling water jacket of the cylinder block 20b. 20b1.

The pressure control valve 53 is connected to the joint 90.
Are mounted by mounting bolts 91. A connection portion 53a1 is formed in the valve housing 53a of the pressure control valve 53, and the branch cooling water pipe 52a of the branch cooling water path 52 is connected to the connection portion 53a1. Inside the valve housing 53a, a valve body 53b has an opening 90b formed by a grommet 90a of the joint 90.
Is provided so that it can be opened and closed. The valve body 53b is urged by a spring 53c in a direction to close the opening 90b, and when the pressure of the cooling water pipe 50c of the engine cooling water path 50 exceeds a predetermined value, the valve body 53b moves against the spring 53c to open. 90b is opened, and the cooling water flows to the oil tank 25 side through the branch cooling water pipe 52a. The oil tank 25 is arranged on the rear side of the engine 20, and the lower side of the oil tank 25 is connected to the downstream side of the branch cooling water pipe 52 a.

The cooling water supplied to the cooling water jacket 20b1 of the cylinder block 20b is
cooling a cooling water jacket (not shown) formed in
The gas flows from the cylinder head 20c to the thermostat 51 via the cooling water pipe 50d, and the thermostat 51 controls the temperature.

The engine-side connecting portion 42c of the exhaust manifold 42 is formed such that four exhaust passages 42a are arranged in a horizontal direction, and the engine-side connecting portion 42c communicates with an exhaust passage (not shown) of the cylinder block 20b. Connected. Exhaust pipe side connection part 42 of exhaust manifold 42
d is formed such that four exhaust passages 42a are vertically overlapped and two are arranged in the horizontal direction. The exhaust pipe side connection part 42d is connected to the upstream pipe part 43a of the exhaust pipe 43, and the downstream pipe part 43b is connected to the muffler 44. Four exhaust passages 43c are formed in the upstream piping portion 43a and the downstream piping portion 43b so as to communicate with the four exhaust passages 42a of the exhaust manifold 42, and cooling is provided around the four exhaust passages 43c. A water passage 43d is formed,
The exhaust pipe 43 is cooled by the cooling water flowing through the cooling water passage 43d.

The cooling water flowing through the cooling water passage 43d is:
It flows into a cooling water passage 44b formed around the exhaust passage 44a of the muffler 44. The cooling water flowing through the cooling water passage 44 b is supplied to a rubber hose 4 connected to the water lock 45.
8 is discharged. The rubber hose 48 absorbs bending and vibration between the muffler 44 and the water lock 45,
The rubber hose 48 is cooled by cooling water to prevent the temperature from rising due to exhaust.

At the downstream end of the muffler 44, a pipe tail 49 is attached by a bolt 49a, a space 49b is formed between the pipe tail 49 and the rubber hose 48, and the cooling water flowing from the cooling water passage 44b receives the pipe tail 49. This prevents backflow into the exhaust passage 44a of the muffler 44. Further, a water-stop rib 44c is formed inside the downstream end of the muffler 44, and the water-stop rib 44c prevents the cooling water from flowing back to the exhaust passage 44a.

If the exhaust gas of the engine 20 is directly discharged to the outside of the hull through the exhaust pipe, noise increases. Therefore, a water lock 45 composed of a sealed tank is provided. The amount is reduced and discharged outside the hull.

The exhaust system cooling water pipe 60c is connected to a connection 43b1 of the downstream pipe section 43b of the exhaust pipe 43, and the cooling water flows from the cooling water path 43d of the exhaust pipe 43 to the cooling water path 42b of the exhaust manifold 42 and the muffler 44. Cooling water passage 4
The cooling water flows through the cooling water passage 44b of the muffler 44.
Mixed with exhaust gas and discharged as exhaust water. Further, the downstream side pipe portion 43b of the exhaust pipe 43 has a throttle 60d at a high position.
A pilot water is provided from the throttle 60d through a drainage line 60e to a throttle 60f provided on a side surface of the boat body 2.
And can be vented. Also,
The muffler waste water is discharged from the drainage pipe 60h to the outside of the boat from the throttle 60g of the muffler 44.

As shown in FIGS. 4 and 14, a thermostat 51 is provided on a side wall of the oil tank 25. In the thermostat 51, a thermo element 51b that expands and contracts according to temperature inside the housing 51a can open and close the opening 51c.
0d, the thermostat 51 controls the flow rate of the cooling water flowing to the cooling water pipe 50e according to the temperature. The thermostat 51b opens and closes the opening 51c according to the temperature. To maintain the cooling temperature.

As shown in FIG. 4, a lubrication system cooling water pipe 70a of a lubrication system cooling water path 70 for supplying cooling water to the lubrication system separately from the engine 20 is connected to the oil tank 25. Cooling oil.

Although this embodiment has been applied to a small boat equipped with a propulsion unit, it can be similarly applied to a small boat equipped with an outboard motor.

[0048]

As described above, according to the first aspect of the present invention, the pressure control valve opens and closes in accordance with the pressure of the cooling water in the engine cooling water path at the preceding stage of the engine, and the supply flow rate of the cooling water to the engine By controlling the pressure, the pressure of the cooling water supplied to the engine can be suppressed from fluctuating, the cooling temperature can be sufficiently maintained constant according to the operating state of the engine, the predetermined engine performance can be obtained, and the exhaust gas value can be further improved. Can be stabilized.

According to the second aspect of the present invention, there is provided a thermostat for opening and closing the engine cooling water path, and by setting the valve opening pressure of the thermostat higher than the valve opening pressure of the pressure control valve, excessive cooling water is supplied to the thermostat. Pressure is not applied, and the temperature of the cooling water can be controlled with high accuracy.

According to the third aspect of the present invention, since the thermostat is provided on the cooling water outlet side of the engine, the cooling temperature of the engine can be maintained substantially constant by the thermostat.

According to the fourth aspect of the present invention, an exhaust system cooling water path for supplying cooling water to the exhaust system separately from the engine is provided, and the exhaust system can be cooled.

According to the fifth aspect of the present invention, a lubrication system cooling water path for supplying cooling water to the lubrication system separately from the engine is provided, and the lubrication system can be cooled.

[Brief description of the drawings]

FIG. 1 is a side view of a jet propulsion boat.

FIG. 2 is a plan view of the jet propulsion boat.

FIG. 3 is a schematic view showing a cooling structure of the jet propulsion boat.

FIG. 4 is a perspective view of an engine.

FIG. 5 is a side view of the engine.

FIG. 6 is a plan view of the engine.

FIG. 7 is a front view of the engine.

FIG. 8 is a sectional view of the engine.

FIG. 9 is a view of the exhaust manifold as viewed from the engine connection side.

FIG. 10 is a diagram viewed from the exhaust pipe connection side of the exhaust manifold.

FIG. 11 is a sectional view showing a water backflow prevention structure of an exhaust pipe.

FIG. 12 is a plan view showing a pressure control valve.

FIG. 13 is a sectional view showing a pressure control valve.

FIG. 14 is a sectional view showing a thermostat.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Small boat 20 Engine 30 Propeller 50 Engine cooling water path 52 Branch cooling water path 53 Pressure control valve

Claims (5)

[Claims] 1. A small boat that includes a propulsion device driven by an engine and guides cooling water supplied from the propulsion device to the engine to cool the engine, comprising: an engine cooling water path for supplying cooling water to the engine; A branch cooling water path having a pressure control valve that opens and closes in accordance with the pressure of the cooling water in the engine cooling water path at a stage preceding the engine and that can control the flow rate of the cooling water in the engine cooling water path. Small boats. 2. The small boat according to claim 1, further comprising a thermostat for opening and closing the engine cooling water passage, wherein a valve opening pressure of the thermostat is higher than a valve opening pressure of the pressure control valve. 3. The small boat according to claim 2, wherein the thermostat is provided on a cooling water outlet side of the engine. 4. The small boat according to claim 1, further comprising an exhaust system cooling water path for supplying cooling water to an exhaust system separately from the engine. 5. The small boat according to claim 1, further comprising a lubrication system cooling water path for supplying cooling water to the lubrication system separately from the engine.