JP3036264B2 - Outboard motor intake cooling system - Google Patents

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 system for an outboard motor, and more particularly to an intake air cooling system for an outboard motor which can easily form an intake system cooling water passage and accurately control the intake air temperature. .

[0002]

2. Description of the Related Art In an outboard motor equipped with a fuel injection type four-cycle engine, the cylinder block of the engine becomes hot and the intake air temperature rises. There was no problem. For this reason, in an outboard motor equipped with a fuel injection type four-cycle engine, it is not possible to expect heat of vaporization from the throttle body, so it is necessary to cool the intake air in the intake manifold by radiant heat from the cylinder block. Become.

Therefore, an outboard motor equipped with a four-cycle engine is provided with an intake air cooling device in order to properly control the intake air temperature. This intake air cooling device provides a cooling water passage in an intake manifold, cools intake air supplied to an engine by cooling water flowing through the cooling water passage, and increases the amount of intake air by, for example, cooling the intake air in a high output state. ing.

[0004] Such an intake air cooling device includes:
For example, Japanese Utility Model Laid-Open No. 3-68521, Japanese Patent Laid-Open No. 3-24
No. 9368. Heikai 3-6852
Japanese Patent Application Publication No. JP-A-2005-11064 discloses an intake manifold (intake pipe) having a double structure, a cooling water passage outside the inner pipe through which the intake air flows, and cooling the intake air by cooling water flowing through the cooling water passage. . Japanese Patent Laid-Open No. 3-249368 discloses a cooling water passage provided around an air supply passage of a water-cooled engine, a load state detector for the engine, and a high load of the engine detected by the load state detector. At times, a water supply control circuit is provided for supplying cooling water pumped by a water pump to a cooling water passage around an air supply passage, thereby increasing the amount of air charged into a combustion chamber of the engine to improve output.

[0005]

However, in the conventional intake air cooling system, since the intake system cooling water passage is provided in the intake manifold along the entire intake passage, the cooling water passage for casting the intake manifold is provided. A core is required, the structure of the intake manifold is complicated, and the manufacturing cost is high.

In addition, since the cooling water of the cylinder block cooling water passage as the engine cooling water passage flows through the intake cooling water passage, the cooling water flowing through the intake cooling water passage becomes unnecessarily high in temperature. There is a disadvantage that the intake air temperature cannot be controlled with high accuracy.

[0007]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention provides an outboard motor intake air cooling system for cooling intake air supplied to an engine by cooling water flowing through a cooling water passage provided in an intake manifold. In the cooling device, a spacer is provided between the surge tank portion and the throttle body of the intake manifold, and a tank-side cooling water groove is formed in a tank end surface of the surge tank portion, and the cooling water groove is opposed to the tank-side cooling water groove. A spacer side cooling water groove is formed on the spacer end face of the spacer to form an intake system cooling water passage,
The intake system cooling water passage is provided separately from the engine system cooling water passage.

[0008]

According to the structure of the present invention, the intake-system cooling water passage is formed by the tank-side cooling water groove on the tank end face of the surge tank and the spacer-side cooling water groove on the spacer end face of the spacer. The structure and the like are simplified, and the cooling water of a different system from the cooling water of the engine cooling water passage flows in the cooling water passage of the intake system, so that the intake air temperature can be controlled with high accuracy.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. 1 to 10 show an embodiment of the present invention. 4 to 6, reference numeral 2 denotes a fuel injection type outboard motor. The outboard motor includes a water-cooled four-cycle engine 4, a drive shaft 6 connected to the engine 4, and a propeller 10 connected to the drive shaft 6 via a gear mechanism 8.

The engine 4 is covered with a removable engine cover 12 and an under cover 14 for supporting the engine cover 12 at a lower portion.

The drive shaft 6 is covered by a drive shaft housing 16.

The gear mechanism 8 is covered by a gear case 18.

The engine 4 includes a cylinder block 20
And a cylinder head 22. In the cylinder block 20, a crankshaft 24 is supported, and four cylinders 26 are provided in parallel. In the cylinder block 20, a cylinder block system cooling water passage 28 is formed as an engine system cooling water passage. As shown in FIG. 6, lake water, seawater, etc. from the gear mechanism 8 side are provided in the cylinder head side cooling water passage 30 formed in the cylinder head 22 as the engine system cooling water passage similarly to the cylinder block system cooling water passage 28. Of the first and second cooling water introduction passages 32 in the drive shaft housing 16,
It flows in through 34.

Each cylinder 26 is mounted on the crankshaft 24.
One end side of each connecting rod 36 is connected correspondingly. The other end of each connecting rod 36 has a cylinder 2
Each of the pistons 38 slidably provided within 6 is connected. A crank pulley 40 is attached to the upper end of the crankshaft 24 as shown in FIGS.

A camshaft 42 is provided on the cylinder head 22.
Is supported. A cam pulley 44 is attached to the upper end of the cam shaft 42 so as to correspond to the crank pulley 40. The cam pulley 44 and the crank pulley 4
6, a timing belt 46 is wound around as shown in FIGS.

One end of the drive shaft 6 is connected to a lower end of the crankshaft 24.

The gear mechanism 8 is connected to the other end of the drive shaft 6. The propeller 10 is connected to the gear mechanism 8.

As shown in FIG. 1, the cylinder head 22 is formed with an intake port 50 and an exhaust port 52 which open to each combustion chamber 48 corresponding to each cylinder 26. Each intake port 50 communicates with each intake passage 58 formed in each intake branch pipe 56 of an intake manifold 54 attached to the cylinder head 22. An exhaust passage 62 formed by an exhaust passage wall 60 communicates with each exhaust port 52. Each intake branch pipe 56 of the intake manifold 54 is disposed along a side surface of the cylinder block 20, as shown in FIG. Further, each of the exhaust passages 62
Are communicated with the exhaust collecting portion 64.

As shown in FIG. 1, the cylinder head 22 has ignition plugs 66 facing the combustion chambers 48, intake valves 68 for opening and closing the intake ports 50, and exhaust valves for opening and closing the exhaust ports 52. A valve 70 is provided.

Each fuel injection valve 72 is attached to each intake branch pipe 56 of the intake manifold 54 so as to face each of the intake ports 50.

A surge tank 74 for distributing intake air is provided upstream of each intake branch pipe 56.

A throttle body 82 having a throttle valve 80 is attached to the surge tank 74 via an annular spacer 78 having a predetermined thickness and having an intake passage 76 formed therein.

The spacer 78 is provided on the throttle body 8.
The two sides are sealed with a gasket 84, and the throttle body 8 is secured by mounting bolts 88 inserted into bolt holes 86.
2 (see FIGS. 2 and 9).

A throttle guide 90 is mounted upstream of the throttle body 782. Air taken in from the air inlet 92 formed in the engine cover 12 on the rear side of the outboard motor 2 flows into the throttle guide 90 as intake air.

The tank end surface 74 of the surge tank 74
In a, a tank-side cooling water groove 94 is formed in the circumferential direction. A spacer-side cooling water groove 96 is formed on the spacer end face 78 a of the spacer 78 so as to correspond to the tank-side cooling water groove 94. The upstream side intake system cooling water passage 98 is formed by the tank side cooling water groove 94 and the spacer side cooling water groove 96.

A cooling water inlet pipe 100 is connected to one side of the spacer 78, and a cooling water outlet pipe 102 is connected to the other side.

Further, a cooling water passage wall 106 and a cooling water passage cover 108 that covers the inside of the cooling water passage wall 106 are provided in the middle of the intake branch pipe 56 so as to form the downstream-side intake system cooling water passage 104. Mounted.

As shown in FIG. 3, the cooling water from the water pump 110 flows separately from the cooling water in the cylinder block cooling water passage 28, which is the engine cooling water passage, in each of the intake system cooling water passages 98 and 106. (FIGS. 1, 2, and 7)
Arrow AA).

As shown in FIG. 3, an intake system thermostat 112 is provided in the middle of the intake system cooling water passage 98. In the middle of the cylinder block cooling water passage 28, a cylinder block thermostat 114 is provided. In FIG. 10, reference numeral 116 denotes an intake air temperature sensor.

Next, the operation of this embodiment will be described.

The intake air from the throttle guide 90 is distributed by the surge tank 74 and guided to each cylinder 26 via each intake passage 58.

At this time, the intake air is supplied to the throttle body 82
In the vicinity, the cooling water is cooled by the cooling water flowing through the upstream-side intake system cooling water passage 98. As shown in FIGS. 1, 2, and 7, this cooling water flows out of the cooling water outlet pipe 102 through the cooling water inlet pipe 100 through the upstream intake air cooling water passage 98, and controls the temperature of the intake air flowing near the throttle body 82. I do.

As a result, the upstream-side intake system cooling water passage 98 is formed by the tank-side cooling water groove 94 on the tank end surface 74a of the surge tank portion 74 and the spacer-side cooling water groove 96 on the spacer end surface 478a of the spacer 78. further,
Since the downstream side intake system cooling water passage 104 is also configured separately,
The core for the cooling water passage is not required at the time of manufacturing, and the upstream-side intake system cooling water passage 98 can be easily provided.
The mold structure of the intake manifold 54 can be simplified, the manufacturing cost can be reduced, and the cost can be reduced.

Since there is no need to form a cooling water passage in the throttle body 82 itself, the throttle body 78
2 can be simplified.

Further, since the periphery of the throttle body 82 is effectively cooled by the cooling water in the upstream side intake system cooling water passage 98, even if sensors such as the intake air temperature sensor 116 are provided as shown in FIG. Does not adversely affect

Furthermore, since the cooling water in the cylinder block system cooling water passage 28 does not flow in the upstream side intake system cooling water passage 98, the intake air temperature can be adjusted to a target, and the intake air temperature is controlled accurately. be able to.

The upstream side intake system cooling water passage 98 can be formed to be long in the direction of intake air flow as shown in FIG. According to this configuration, the cooling surface area of the intake air is increased,
The intake air can be cooled more effectively.

[0038]

As apparent from the above detailed description, according to the present invention, a spacer is interposed between the surge tank of the intake manifold and the throttle body, and the tank-side cooling water groove is formed on the tank end face of the surge tank. The cooling water passage is formed opposite to the cooling water groove on the tank side, and the cooling water groove on the spacer side is formed on the spacer end face to form the intake cooling water passage.The intake cooling water passage is separate from the engine cooling water passage. , The mold structure of the intake manifold can be simplified, and the intake air temperature can be controlled accurately.

[Brief description of the drawings]

FIG. 1 is a sectional view of the outboard motor taken along line II-II of FIG.

FIG. 2 is a sectional view of a spacer.

FIG. 3 is an explanatory diagram of a flow of cooling water.

FIG. 4 is a side view of the outboard motor.

FIG. 5 is a rear view of the outboard motor indicated by an arrow 〓 in FIG.

FIG. 6 is a sectional view of the outboard motor taken along line II-II of FIG.

FIG. 7 is a schematic side view of an engine of the outboard motor.

FIG. 8 is a partially cutaway plan view of the outboard motor.

FIG. 9 is a partially cutaway side view of the engine.

FIG. 10 is a front view of the engine indicated by an arrow X in FIG. 6;

[Explanation of symbols]

 2 Outboard motor 4 Engine 6 Drive shaft 8 Gear mechanism 10 Propeller 28 Cylinder block system cooling water passage 74 Surge tank part 78 Spacer 82 Throttle body 94 Tank side cooling water groove 96 Spacer side cooling water groove 98 Upstream side intake system cooling water passage 104 Downstream intake system cooling water passage

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuyuki Shomura 300, Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd. (72) Inventor Hidehiko Yoshioka 300, Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd. (72 ) Inventor Jiro Saiga 300, Takatsuka-cho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd. (56) References JP-A-2-45648 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01P 3/12 F01P 3/20 F02B 29/04

Claims (1)

(57) [Claims] 1. An outboard motor intake cooling system for cooling intake air supplied to an engine by cooling water flowing through a cooling water passage provided in an intake manifold, wherein a spacer is provided between a surge tank portion of the intake manifold and a throttle body. A cooling water groove is formed on the tank end face of the surge tank section, and a cooling water groove is formed on the spacer end face of the spacer so as to face the cooling water groove. An intake air cooling device for an outboard motor, comprising a passage, wherein the intake system cooling water passage is provided separately from the engine system cooling water passage.