JP2002195111A - Intake air cooling device for small ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake air cooling device for a small ship capable of suppressing rising of intake air temperature due to engine heat, and as a result, preventing deterioration of engine output due to deterioration of charging efficiency without causing a problem of securing installing space and a problem of an effect by water or the like entering a hull. SOLUTION: In a water vehicle (the small ship), an engine 10 is mounted in an engine compartment 2a inside the hull 2 formed substantially watertight and ducts 11 and 12 introducing external air to the engine 10 are inserted and arranged. In the intake air cooling device for the water vehicle, a cooler 45 comprised by forming a plurality of fins 45c on a cooler body 45a having a cooling water passage 45b is arranged near an upstream side of an inlet 25c of the engine 10, and a branched cooling water pipe 46 branched from a cooling water feed pipe 40 feeding engine cooling water to the cooling water passage 45b is connected to the cooler 45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake air cooling device for cooling the intake air to a small boat having an engine mounted in a substantially watertight hull.

[0002]

2. Description of the Related Art In recent years, a water vehicle (small boat) has been drawing attention in which water sucked from the bottom of a ship is driven by an impeller and jetted rearward of the stern to travel on the water. In this type of water vehicle, it is premised that the vehicle may overturn due to its application, so that the hull is formed substantially watertight to prevent water from entering when overturning, and an engine is mounted in the hull. At the same time, it has a structure in which a duct for introducing outside air is inserted into the hull.

[0003]

However, when the engine is mounted in a hermetically sealed hull, the temperature of the engine compartment tends to rise due to the heat of the engine, and the charging efficiency may deteriorate due to the rise of the intake air temperature. As a result, there is a concern that the engine output is reduced.

From the viewpoint of suppressing such an increase in the intake air temperature, the engine is forcibly cooled by, for example, a cooling fan, a blower, or the like, or the intake air is provided with a cooler similar to an intercooler for a supercharger in an intake system. Or cooling.

[0005] However, when the engine is cooled by the blower or the like, it is necessary to secure an arrangement space in the hull, and it is difficult to adopt it for a small boat. Further, when a cooler similar to an intercooler is provided in the intake system, there is a concern that the intake resistance increases and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and can suppress an increase in intake air temperature due to heat of an engine without causing a problem of securing an arrangement space and a problem of an increase in intake resistance. It is an object of the present invention to provide an intake air cooling device for a small boat that can prevent a decrease in engine output due to a decrease in efficiency.

[0007]

According to a first aspect of the present invention, there is provided a small boat in which an engine is mounted in an engine room in a substantially watertight hull and a duct for supplying external air to the engine is inserted. In the intake air cooling device, a cooler in which a plurality of fins are formed in a cooler body having a cooling water passage is provided in the engine room, and cooling water for supplying cooling water to the engine is provided in the cooling water passage. It is characterized in that a branch cooling water pipe branched from the supply pipe is connected.

Here, the small boat includes a seating tamper having a steering handle while sitting on a saddle-type seat provided on a deck, and an upright type having a steering handle while standing on the deck. , And an open-type so-called jet boat type having an open deck portion.

A second aspect of the present invention is characterized in that, in the first aspect, the cooler is disposed near an upstream side of an intake port of the engine.

A third aspect of the present invention is characterized in that, in the first or second aspect, a plurality of the coolers are arranged on an inner wall of the engine compartment.

[0011]

According to the intake air cooling device of the first aspect of the present invention, a cooler is arranged in the engine room and cooling water to be supplied to the engine is introduced into the cooler. Since the air is cooled, a rise in the intake air temperature can be suppressed, the charging efficiency can be increased, and a decrease in the engine output can be prevented.

Further, since the cooler is disposed separately from the engine in the engine room, the degree of freedom in arranging the cooler can be increased, and the cooler is used for a small boat as compared with a case where a blower or the like is provided. Even in this case, space can be easily secured.

Further, since the above-described cooler has a structure in which fins are formed in a cooler main body having a cooling water passage, the cooler can be more compactly arranged as compared with the case where a cooler similar to the above-described blower or intercooler is employed, and the structure is further reduced. Simple and cost-effective.

According to the second aspect of the present invention, since the cooler is disposed near the upstream side of the intake port of the engine, the air is cooled immediately before the intake port, and the temperature of the air actually taken into the engine is reduced. The filling efficiency can be reliably reduced, and the filling efficiency can be further increased.

According to the third aspect of the present invention, since a plurality of coolers are arranged on the inner side wall of the engine compartment, the air in the entire engine compartment can be cooled.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 6 show a water vehicle (small boat) according to an embodiment (first embodiment) of the present invention.
FIGS. 1 and 2 are views for explaining an intake air cooling device of FIG.
3 is a side view, a plan view of a water vehicle, FIGS. 3 to 5 are side views, a front view, and a plan view of a water-cooled two-cycle engine, and FIG. 6 is a sectional view of a cooler. Note that the terms front, rear, left and right in the present embodiment mean front, rear, left and right as viewed in a state of sitting on a seat.

In FIG. 1, reference numeral 1 denotes a water vehicle, and a hull 2 of the water vehicle is formed by connecting a lid-like deck 4 to a bathtub-like hull 3 in a watertight manner with a gunnel 5. An openable / closable hatch cover 6 is provided at the front end of the deck 4, and a steering handle 7 is provided behind the hatch cover 6, and a saddle saddle type on which a plurality of occupants can sit is provided behind the steering handle 7. A seat 8 is provided. A foot deck 4a extending in the front-rear direction of the hull is formed in a stepped manner on the left and right sides below the seat 8 of the deck 4, and the left and right foot decks 4a are opened toward the rear of the hull.

A fuel tank 9 is provided below the steering wheel 7 in the hull 2, and an engine 10 is provided in an engine room 2a below the seat 8 behind the fuel tank 9. Further, a maintenance opening (not shown) is formed below the seat 8 of the deck 4, and the maintenance opening is opened and closed by removing the seat 8, so that maintenance work around the engine can be performed.

At the rear end of the hull 3 is formed a tunnel-shaped recess 14 constituting a propulsion chamber 13.
A propulsion duct 15 having a suction port 15a opening at the bottom of the vessel and an injection port 15b opening at the stern 2b is provided in the inside of the vessel 4. An impeller shaft 16 extending in the longitudinal direction of the hull is inserted into the propulsion duct 15, and a front end of the impeller shaft 16 is connected to the engine 1 via a coupling 17.
0 crankshaft 18.

The water vehicle 1 generates a propulsion force by pressurizing the water sucked from the suction port 15a by the rotation of the impeller shaft 16 and jetting the water from the jet port 15b, whereby the water vehicle 1 slides on the water. In addition, the injection port 15
A nozzle deflector 19, which swings up and down and left and right by the operation of the steering handle 7, is attached to b, thereby turning the hull 2 and changing the trim angle.

The engine 10 is a water-cooled two-cycle parallel three-cylinder engine, and is mounted with the crankshaft 18 oriented substantially horizontally in the longitudinal direction of the hull and with the cylinder axes oriented substantially vertically. The engine 10 has a structure in which a cylinder block 10b and a cylinder head 10c are stacked and connected to an upper portion of a crankcase 10a, and is fixed to a ship bottom via a mount member 20.

The exhaust system of the engine 10 has an exhaust manifold 30 at each exhaust port (not shown) of the engine 10.
, The exhaust manifold 30 is connected to first and second exhaust expansion tubes 31 and 32, and the second exhaust expansion tube 32 is connected to a water lock 33. The water lock 33 is for preventing water outside the boat from flowing back to the engine side, and is disposed on the left side of the propulsion duct 15. Further, a rear exhaust pipe 34 is connected to the water lock 33, and the rear exhaust pipe 34 is connected to the inside of the propulsion chamber 13 so that exhaust gas is discharged into water outside the boat.

The exhaust manifold 30 is formed by integrally forming a branch pipe 30a connected to each exhaust port and a junction 30b formed by merging the respective branch pipes 30a into one. Has an exhaust port opening upward. The first exhaust expansion pipe 31 extends forward from the junction 30b to the front of the engine 10, makes a U-turn backward so as to surround the front of the engine, and extends rearward on the right side of the engine. Has made. The second
The exhaust expansion pipe 32 is separated from the first exhaust expansion pipe 31 by the engine 10.
And extends obliquely downward to the left from the rear of the engine, extends rearward therefrom, and is connected to the front wall of the water lock 33. A catalyst 37 for purifying the exhaust gas is disposed upstream of the second exhaust expansion pipe 32. The upper part of the second exhaust expansion pipe 32 is covered with a heat insulator 35.

The cooling system of the engine 10 supplies cooling water to the exhaust manifold 30, and then supplies the cooling water to the cylinder head 10c from the cylinder block 10b. 31,3
2 are sequentially supplied, and thereafter discharged from the propulsion chamber 13 together with the exhaust gas to the outside of the ship. The cooling water is supplied to the exhaust manifold 30 and the first and second exhaust expansion pipes 3.
The cooling water jackets (not shown) having a double wall structure formed on the outer peripheral portions of the first and second cylinders 32 and the cooling water jackets (not shown) formed in the cylinder head 10c and the cylinder block 10b come to flow. ing.

Each branch pipe 30 of the exhaust manifold 30
A cooling water inlet 30c is formed in the cooling water jacket facing a, and a common distribution joint 39 is connected to each cooling water inlet 30c. The downstream end 40a of the cooling water supply pipe 40 is connected to the distribution joint 39, and the upstream end 40b is connected to the downstream side of the impeller 16a of the propulsion duct 15 (see FIGS. 2 and 3). . A part of the water pressurized by the impeller 16a is supplied as cooling water to the exhaust manifold 30 via the cooling water supply pipe 40, and from here, is supplied to the above-described cooling system. In this way, by cooling in ascending order of temperature, the temperature rise in the engine room 2a due to engine heat is suppressed.

In the intake system of the engine 10, an independent carburetor 22 is connected to the crankcase 10a via an intake pipe 21 communicating with an independent crank chamber of each cylinder. Connect the intake chamber 23 of
An intake box 25 is connected to an upstream side of the intake chamber 23 via an intake hose 24.

The intake chamber 23 is disposed below the second exhaust expansion pipe 32 on the right side of the engine, and the intake box 25 is disposed below the first exhaust expansion pipe 31 in front of the engine. Thus, the large-diameter first and second exhaust expansion tubes 31,
The capacity of the suction chamber 23 and the suction box 25 is increased by effectively utilizing the empty space below the space 32.

A silencing resonator 26 is connected to the intake hose 24, and also functions as a storage section for storing water that has entered from the intake box 25 at the time of overturning. The water accumulated in the resonator 26 flows out of the intake box 25 to the outside when the hull 2 is restored. The lower edge of the intake outlet 24a of the intake hose 24 is formed higher than the upper edge of the intake inlet 24b (see FIG. 4). This prevents water that has entered the intake box 25 and the storage section 26 from flowing into the intake chamber 23 when the hull 2 is restored by overturning.

A check valve 27 for discharging water accumulated in the suction box 25 to the outside is provided on the bottom wall 25a of the suction box 25. An intake port 25c is opened in the left side wall 25b of the intake box 25, and the hull 2 is connected to the intake port 25c.
It is designed to inhale the air inside.

In the engine room 2a, an intake air cooling device which is a feature of the present embodiment is provided. This intake air cooling device includes intake ducts 11 and 12 for introducing outboard air into the engine room 2a, and a cooler 45 provided in the engine room 2a.

The intake ducts 11 and 12 are respectively inserted and arranged in front of the fuel tank 9 in the hull 2 and behind the engine 10. The air intake port 11a of the front intake duct 11 is covered with a hatch cover 6, and the air intake port 12a of the rear intake duct 12 is covered with a seat 8, which prevents water from entering the hull 2. are doing. The air outlets 11b and 12b of the intake ducts 11 and 12 are open in the hull 2 (see FIG. 1).

The cooler 45 is made of die-cast aluminum and has a hollow cooling water passage 45b formed in a rectangular box-shaped cooler body 45a, and a plurality of fins 45c formed in the cooler body 45a. Are integrally formed. A cooling water inlet 45d is formed at the lower end of the cooler body 45a, and a cooling water outlet 45e is formed at the upper end thereof.

The branch cooling water pipe 4 is connected to the cooling water inlet 45d.
6, a downstream port 46a is connected, and an upstream port 46b is connected to a branch pipe 47 provided on the cooling water supply pipe 40 on the upstream side of the distribution joint 39. A drain pipe 48 is connected to the cooling water outlet 45e, and a drain port of the drain pipe 48 is led out of the boat. The drain pipe 48 may be joined to the above-described cooling water of the exhaust system.

The cooler 45 is disposed vertically in the vicinity of the upstream side of the intake port 25c, and the fins 45c extend substantially horizontally, that is, along the flow direction of the air flowing into the intake port 25c. Are located. Thereby, the air immediately before flowing into the intake port 25c is cooled.

Next, the operation and effect of this embodiment will be described.

According to the intake air cooling device of the present embodiment, the cooler 45 is arranged near the intake port 25c of the engine 10 mounted in the hull 2 and the engine cooling water is circulated through the cooler 45. The heat of the air in the engine room 2a is
The air that has been absorbed by the fins 45c and whose temperature has been reduced flows into the intake box 25. As a result, the charging efficiency of the engine 10 can be increased, and the engine output can be improved.

Further, since the cooler 45 is arranged near the upstream side of the intake port 25c, the air can be cooled immediately before the intake port 25c. To improve the charging efficiency of the engine. Further, since the cooling water having a low temperature before being supplied to the engine 10 is introduced into the cooler 45, the cooling efficiency can be improved, and from this point, the charging efficiency can be further improved.

Since the cooler 45 is arranged separately from the engine 10, the degree of freedom in arranging the cooler can be increased, and the cooler 45 is arranged in a narrow space like the hull 2 of the water vehicle 1. Even in this case, space can be easily secured.

In the present embodiment, the cooler 45 has a structure in which the cooling water passage 45b is formed in the cooling water main body 45a and a large number of fins 45c are formed. Therefore, compared to the case where the above-described blower or intercooler is employed. Cooling structure can be simplified and the cost can be reduced.

In the above embodiment, the case where the cooler 45 is vertically disposed near the upstream side of the intake port 25c has been described. However, the arrangement structure of the cooler of the present invention is not limited to this. For example, a cooler may be arranged so as to surround the outside of the intake port. Further, as shown in FIG. 4, a plurality of coolers 45 'may be attached to the inner walls of the deck 4 and the hull 3 constituting the engine room 2a, thereby cooling the entire engine room 2a. This is the invention of claim 3.

FIG. 7 is a view for explaining an intake air cooling device according to a second embodiment of the present invention. In this embodiment,
A case where the invention is applied to a water vehicle equipped with a four-cycle engine 50 will be described.

The hull 2 of this embodiment comprises a hull 3 and a deck 4
Are connected in a watertight manner, which is substantially the same as in the first embodiment.

The engine 50 is a water-cooled four-cycle parallel four-cylinder engine in which the crankshaft 50a is arranged horizontally in the longitudinal direction of the hull, and the cylinder axis is inclined to the right in the ship width direction. . The engine 50
Is a cylinder block 52 in which a piston 51 is inserted and arranged.
And a cylinder head 53 having exhaust and intake ports 53a and 53b formed therein.
3, a head cover 54 is mounted, and the cylinder head 53 is further provided with exhaust and intake cam shafts 57 and 58 for driving the exhaust and intake valves 55 and 56 to open and close.

Above the head cover 54, an intake box 60 is provided. The intake box 60 is a middle case in which an upper case 62 is airtightly assembled to a lower case 61 with a seal member 63 interposed therebetween. The lower case 61 is connected to a head cover 54 via a stay 64.
It is fixed by bolting it.

A throttle body 65 and an air cleaner 66 are accommodated in the intake box 60. The throttle body 65 is connected to the intake port 53b of the cylinder head 53 through the lower case 61,
The intake port 65 a of the throttle body 65 is open upward in the intake box 60. The air cleaner 66 is fixed to the lower case 61, and an air suction port 66a of the air cleaner 66 is inserted through the lower case 61 and opens outside the intake box.

A cooler 70 is disposed outside the intake box 60 near the air inlet 66a on the upstream side. The cooler 70 is formed by integrally forming a large number of fins with a cooler body through which engine cooling water flows, and has the same structure as the cooler of the first embodiment.

According to the intake air cooling device of the present embodiment, since the cooler 70 is disposed near the air inlet 66a of the air cleaner 66, the air cooled by the cooler 70 flows into the air cleaner 66, and Efficiency can be improved, and the same effects as in the first embodiment can be obtained.

In the above-described embodiment, the case where the cooler 70 is arranged near the air inlet 66a of the air cleaner 66 has been described. However, the present invention is arranged such that the cooler 70 'is arranged near the intake inlet 65a of the throttle body 65. In this case, the same effect as above can be obtained.

[Brief description of the drawings]

FIG. 1 is a side view of a water vehicle for explaining an intake air cooling device according to a first embodiment of the present invention.

FIG. 2 is a plan view of the water vehicle.

FIG. 3 is a side view of a water-cooled two-stroke engine provided with the intake cooling device.

FIG. 4 is a front view of the engine.

FIG. 5 is a plan view of the engine.

FIG. 6 is a sectional view of a cooler of the intake air cooling device.

FIG. 7 is a rear view of a water-cooled four-stroke engine for explaining an intake air cooling device according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 water vehicle (small boat) 2 hull 2a engine room 10,50 engine 11,12 duct 25c intake port 40 cooling water supply pipe 45,70 cooler 45a cooler body 45b cooling water passage 45c fin 46 branch cooling water pipe 65a intake flow Inlet (inlet) 66a Air inlet (inlet)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F01P 3/12 F01P 3/12 3/20 3/20 S F02M 35/10 311 F02M 35/10 311C 35 / 16 35/16 Z

Claims (3)

[Claims] 1. An intake cooling system for a small boat in which an engine is mounted in an engine room in a substantially watertight hull and a duct for supplying external air to the engine is inserted and arranged. A cooler formed by forming a large number of fins in a cooler body having a water passage is provided, and a branch cooling water pipe branched from a cooling water supply pipe for supplying cooling water to the engine is connected to the cooling water passage. An air intake cooling device for a small boat. 2. The intake cooling system for a small boat according to claim 1, wherein the cooler is disposed near an upstream side of an intake port of the engine. 3. The air intake cooling device for a small boat according to claim 1, wherein a plurality of the coolers are arranged on an inner side wall of the engine room.