JPH059461Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an outboard motor fixed to the rear end of a small boat, which is equipped with an exhaust turbo supercharger.

(Prior Art) Generally, in order to increase the output of the engine, the structure of an internal combustion engine equipped with an exhaust turbocharger is known. Since this exhaust turbo supercharger reaches a high temperature during operation, it is equipped with a cooling mechanism (for example, Japanese Utility Model Publication No. 62-31630).

This cooling mechanism normally uses fresh water to cool internal combustion engines.
A water-cooled cooling structure using fresh water is used.

(Problems to be Solved by the Invention) However, when an exhaust turbo supercharger is provided in a so-called outboard motor, several problems arise.

First, installing an exhaust turbo supercharger inside the cowling that covers the engine not only increases the size of the cowling, but also causes the inside of the cowling to become hot, which causes the engine intake air to become hot, resulting in a reduction in engine output. The problem arises that the amount of energy decreases.

Second, when cooling the exhaust turbo supercharger, the engine cooling mechanism of the outboard motor uses a so-called direct cooling type (a method that cools the boat using the water that floats the boat, such as seawater). The cooling mechanism for the supercharger must also be a direct cooling type.

However, when the turbine casing of an exhaust turbocharger is cooled by direct cooling, if the cooling water is seawater, salt adheres to the inner wall, causing so-called salt damage.

The present invention solves the above problem by devising the arrangement of the exhaust turbo supercharger in an outboard motor equipped with an exhaust turbo supercharger, and by providing a water jacket separate from the turbine casing of the exhaust turbo supercharger. The purpose is to resolve the issue.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a drive case that is swingably supported at the rear end of a small ship, and a direct cooling type that is disposed at the upper end of the drive case. In the outboard motor, the drive case supports a cylinder block of the engine, and the drive case includes a pump that pumps up water from outside the boat and supplies it to a cooling water passage in the engine. The Atsupa case includes an Atsupa case and an intermediate case supporting the Atsupa case, the Atsupa case is provided with a flange portion projecting rearward at an upper end thereof, the flange portion is provided with an exhaust gas outlet of the engine, and the intermediate case includes: The step part extends rearward and faces the flange part, the step part is provided with an exhaust passage for discharging exhaust gas from the engine into water, and an exhaust turbo supercharger is provided on the lower surface of the flange part. The exhaust turbo supercharger is fixed, and the exhaust turbo supercharger includes a turbine casing that introduces exhaust gas into the interior from the exhaust port of the flange portion, and a water jacket with a hollow wall is disposed on the upper surface of the stepped portion, and the water jacket is , a cover part that covers the periphery of the turbine casing together with a separate lid body through a gap; a bend part that constitutes an exhaust communication path of the exhaust turbo supercharger; and the interior of the hollow wall of the cover part and the bend part. a cooling water inlet for introducing cooling water into the hollow wall, and a cooling water outlet for discharging the cooling water inside the hollow wall, the bend portion communicating with the exhaust passage, and the cooling water inlet communicating with the cooling water passage of the engine. , and the cooling water outlet is communicated with the exhaust passage.

(Function) The cover of the water jacket, together with the lid, prevents cold air and water from outside the vessel from directly hitting the turbine casing.

The overboard water pumped up from the pump is supplied to the engine cooling water passage, cools the engine, and then circulates inside the hollow wall of the water jacket from the cooling water inlet of the water jacket to the exhaust turbo supercharger. The heat from the turbine casing is absorbed and discharged from the cooling water outlet to the outside of the ship via the exhaust passage. Also gap L
The air layer also absorbs heat from the turbine casing.

(Embodiment) In FIG. 1 showing an embodiment of the present invention, the left side of the figure is the front.

As shown in FIG. 1, an outboard motor 10 adopting the present invention has a bracket 1 of a drive case 11.
2 is supported at the rear end of the small boat 13 so as to be able to swing horizontally and vertically.

A direct-cooled engine 14 is disposed at the upper end of the drive case 11, and its periphery is covered with a top cowling 15, a top cowling 16, and a lower cowling 17. 18 is an outside air inlet provided in the top cowling 15;
8, air is introduced into the cylinder chamber 20 of the engine 14 from the intake inlet 19 of the engine 14,
After completing the combustion stroke, it is discharged from the exhaust port 21 as exhaust gas.

A crankshaft 22 of the engine 14 extends above and below the outboard motor 10, and a drive shaft 23 inside the drive case 11 is connected to its lower end. A bevel gear 24 is fixed to the lower end of the drive shaft 23, and when this gear 24 meshes with a bevel gear 25a or 25b, power can be transmitted to a propeller 27 underwater via a propeller shaft 26. It's becoming like that.

The drive case 11 includes a lower case 29 that rotatably supports the propeller shaft 26 of the propeller 27 via a bearing 28, an intermediate case 30 that is integrally fixed to the upper end of the lower case 29, and an upper end of the intermediate case 30. The upper case 32 is integrally fixed to the upper case 32 and supports the cylinder block 31 of the engine 14. In this embodiment, the lower case 29 and the intermediate case 3
0. Although the upper case 32 is constructed as a separate member, a part or all of these may be integrated.

A rearwardly projecting flange portion 33 is integrally formed at the upper end of the upper case 32, and supports the cylinder block 31 of the engine 14.
The flange portion 33 is provided with an exhaust gas outlet 34 that communicates with the exhaust port 21 of the engine 14 .

The lower case 29 and the intermediate case 30 have a stepped portion 3 that protrudes rearward and faces the flange portion 33.
5 are integrally formed.

An exhaust passage 36 is formed inside the stepped part 35 and extends vertically, and an outlet 37 of the exhaust passage 36 is open underwater.

The middle case 30 is filled with water from the outside of the boat.
Water is pumped up from the inlet 38 of 9, water tube 3
9 to the engine 14 cooling water passage 40 (second
A pump 41 is provided to introduce the gas into the air (see Fig.).

42 is an exhaust turbo supercharger, and the supercharger 42 is arranged between the flange portion 33 and the step portion 35. The turbine casing 43 of the supercharger 42 has an opening communicating with the exhaust port 34 of the flange portion 33, and bolts 44 are installed on the lower surface of the flange portion 33 in a state where exhaust gas from the engine 14 can be introduced inside.
Fixed by

45 is a water jacket, a part of which constitutes a cover part 46 that covers the turbine casing 43, and the other part constitutes a bend part 47 which constitutes an exhaust communication path of the turbine casing 43.

As shown in FIG. 2, the cover part 46 covers the periphery of the turbine casing 43 with a gap L apart, together with an annular lid body 48 made of a steel plate. The lid body 48 is fixed to the side end surface of the cover part 46 with bolts 49. This prevents water from outside the vessel from directly hitting the turbine casing 43.

The internal passage of the bend portion 47 extends downward from the side end of the turbine casing 43 with a required radius of curvature. The bend portion 47 is provided with flanges 50 and 52 at the side and lower ends, respectively. The flange 50 is fixed to the turbine casing 43 with bolts 51. Also, flange 5
2 is connected to the stepped portion 35 of the intermediate case 30 by the bolt 53.
is fixed to the upper end surface of.

54 is a cooling water inlet of the water jacket 45, which communicates with the cooling water passage 40 of the engine 14, and is pumped up by the pump 41 (FIG. 1) to the engine 1.
4 is introduced into the hollow wall 45a of the water jacket 45 from the passage 40 through the cooling water inlet 54.

A cooling water outlet 56 communicates the cooling water inside the hollow wall 45a with the exhaust passage 36 via a pipe 57. Thereby, the cooling water inside the hollow wall 54a is returned to the water via the exhaust passage 36. 58 is a mixing tube for communicating the internal passage of the bend portion 47 and the exhaust passage 36.

In Fig. 2, 59 is the blower and 60 is the blower 5.
9 is an air inlet, and 61 is a pressurized air outlet.

The blower 59 is removably fixed to the case 62 of the supercharger 42 with bolts 62, and before the blower 59 is installed, the lid 4 is removed from the right side of the figure.
8 and secure it.

According to the above structure, as shown in FIG. 1, outside air is taken in from the intake inlet 19 of the engine 14 via the outside air inlet 18 of the top cowling 15, and after the combustion stroke is completed, the outside air is passed from the exhaust port 21 to the flange as exhaust gas. The exhaust gas passes through the exhaust gas outlet 34 of the section 33 and is introduced into the turbine casing 43 of the exhaust turbo supercharger 42 . After driving a turbine (not shown), the gas is discharged into the water from the outlet 37 via the bend portion 47, the mixing tube 58, and the exhaust passage 36.

On the other hand, cooling water (for example, seawater) is pumped up from the intake port 38 of the lower case 29 by the pump 41,
The water is supplied to the inside of the engine 14 through the water tube 39, and after cooling the engine 14, it is circulated inside the hollow wall 45a of the water jacket 45 from the cooling water passage 40 (FIG. 2) through the cooling water inlet 54. , the cooling water passes through the exhaust passage 36 via the piping 57 from the cooling water outlet 56, and is discharged into the water.

While the engine 14 is running, the crankshaft 22
The rotational force is transmitted to the drive shaft 23 and the bevel gear 24, and further to the bevel gear 25a or 25b.
is transmitted to the propeller shaft 26 via the propeller 2
7 rotates, the small boat 11 moves forward or backward.

Further, as shown in FIG. 2, the exhaust turbo supercharger 42 pressurizes clean air introduced from an air inlet 60 with a blower 59, and passes the clean air from the pressurized air outlet 61 to the intake inlet of the engine 14 via a pipe (not shown). 19 (1st
) to supercharge the engine 14.

During the above operation, the turbine casing 43 absorbs the heat of the exhaust gas and reaches a high temperature (100°C to 600°C).
Since it is disposed between the external flange portion 33 and the stepped portion 35 of the cooling device 1, a sufficient cooling effect can be obtained by dissipating heat to the outside air. Moreover, since the turbine casing 43 is covered with the cover part 46 of the water jacket 45 together with the lid body 48, outside air and water from outside the vessel are directly directed to the turbine casing 4.
3, and cracking due to thermal strain can be prevented. Furthermore, since the air layer in the gap L and the cooling water in the water jacket 45 also absorb the heat of the turbine casing 43, they promote the cooling action of the turbine casing 43 and act as a heat insulating material, thereby preventing other components in the drive case 11 from being heated. Prevent heat conduction.

(Effects of the invention) As explained above, according to the invention, the exhaust turbo supercharger 42 is fixed to the lower surface of the flange part 33 where the step part 35 faces, so that the supercharger 42 which is in a high temperature state is , will be placed outside. Therefore, the supercharger 42 is sufficiently cooled by radiating heat to the outside.

Moreover, according to the present invention, the turbine casing 43 of the supercharger 42 is connected to the cover part 46 and the lid body 48 of the water jacket 45 disposed on the upper surface of the step part 35.
The gap L is separated and covered by the water jacket 45, and the exhaust turbo supercharger 4
Since the second exhaust communication path is configured, cold water or air does not directly hit the turbine casing 43 which is in a high temperature state, and cracking due to thermal distortion can be prevented. In addition, the air layer in the gap L and the cooling water in the water jacket 45 also absorb the heat of the turbine casing 43, so they promote the cooling effect of the turbine casing 43 and also act as a heat insulator.
This prevents heat from being conducted to other members within the drive case 11. Furthermore, since a gap L is provided between the cover part 46 and the turbine casing 43, the heat of the turbine casing 43 is buffered by the air layer in the gap L, so even if the cooling water is seawater, So-called salt damage is less likely to occur.

Further, according to the present invention, a cooling water inlet 54 for introducing cooling water into the air wall 45a of the cover part 46 and the bend part 47 and a cooling water outlet 56 for discharging the cooling water inside the hollow wall 45a are provided, and the bend part 47
communicates with the exhaust passage 36 , the cooling water inlet 54 communicates with the cooling water passage 40 of the engine 14 , and the cooling water outlet 56 communicates with the exhaust passage 36 , so the supercharger 42 is connected to the lower surface of the flange portion 33 . Coupled with the fact that it is fixed, the structure is simplified and piping is streamlined.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the present invention, and FIG. 2 is an enlarged view of FIG. 1 with a portion cut away. 10... Outboard motor, 11... Drive case, 1
3...Small ship, 14...Direct cooling engine, 29
...Lower case, 30...Middle case, 31...
Cylinder block, 32...Atsupa case, 33
...Flange part, 34 ...Exhaust gas discharge port, 35
...Stepped portion, 36...Exhaust passage, 40...Cooling water passage, 41...Pump, 42...Exhaust turbo supercharger, 43...Turbine casing, 45...Water jacket, 45a...Hollow wall, 46...Cover part, 47...Bend part, 48...Lid body, 54...
Cooling water inlet, 56...Cooling water outlet, L...Gap.

Claims (1)

[Scope of utility model registration request] It is equipped with a drive case that is swingably supported at the rear end of a small boat, and a direct-cooled engine that is placed at the upper end of the drive case. For outboard motors equipped with a pump that supplies cooling water passages inside the
The drive case includes a top case that supports the cylinder block of the engine, and an intermediate case that supports the top case. The intermediate case includes a stepped portion extending rearward and facing the flange portion, and the stepped portion includes an exhaust passage inside thereof for discharging exhaust gas from the engine into water. , an exhaust turbo supercharger is fixed to the lower surface of the flange portion, and the exhaust turbo supercharger includes a turbine casing that introduces exhaust gas into the interior from the exhaust port of the flange portion; A water jacket with a hollow wall is disposed, and the water jacket includes a cover portion that covers the periphery of the turbine casing together with a separate lid body across a gap, and a bend that constitutes an exhaust communication path of the exhaust turbo supercharger. a cooling water inlet for introducing cooling water into the hollow wall of the cover part and the bend part, and a cooling water outlet for discharging the cooling water inside the hollow wall, and communicating the bend part with the exhaust passage. An outboard motor with an exhaust turbo supercharger, characterized in that the cooling water inlet communicates with the cooling water passage of the engine, and the cooling water outlet communicates with the exhaust passage.