JP2604410Y2 - Outboard exhaust 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 exhaust system for a diesel outboard motor.

[0002]

2. Description of the Related Art It has been known that a diesel outboard motor mixes exhaust gas from an engine with cooling water and discharges the water into the water in order to reduce noise and increase cooling efficiency. That is, FIG. 6 is an overall side view of the conventional diesel outboard motor, FIG. 7 is an enlarged side sectional view of the mixing section, and FIG. 8 is an XX sectional view in FIG. The drive unit is housed in the drive unit case 3 in the center, and the drive unit case 3 is stored in the upper case 3a.
A diesel engine 2 is fixedly mounted on an upper case 3a via an engine mount 5, and a propulsion device 4 is arranged below the drive unit.

[0003] An exhaust pipe 6 is connected to an exhaust manifold 2 a extending below the diesel engine 2.
A lower end of the exhaust pipe 6 projects into a drain passage 7 formed in the upper case 3a, and an upper portion of the drain passage 7 communicates with a cooling water passage 5a formed in an engine mount 5 from which cooling water of the engine 2 is discharged. The lower part communicates with a drainage passage formed in the lower case 3b for discharging to the sea, and an idle port 9 is formed in the rear part of the drive unit case 3 to discharge exhaust and cooling water mixed during berthing or cruising. I am trying to do it.

[0004] The cooling water discharged from the engine through the cooling water passage 5 a is discharged toward the outer periphery of the exhaust pipe 6, is disposed so as to cool the exhaust pipe 6, and is generated on the outer periphery of the exhaust pipe 6. The sulfide is constantly washed away to prevent corrosion, and the exhaust pipe 6, which is heated by the exhaust gas, is cooled to extend the life and reduce noise.

[0005]

As described above, conventionally, the exhaust pipe is cooled by projecting the exhaust pipe into the drain passage.
The sulfide on the outer peripheral surface of the exhaust pipe is washed away by flowing cooling water to the outer circumference of the exhaust pipe.However, the exhaust mixing part is in a severe corrosive environment with seawater and sulfur in exhaust gas. Corrosion may cause the outboard motor to fail prematurely. In particular, this tendency is strong in a diesel outboard motor using a diesel engine, and in a structure in which an oil pan is installed in contact with an exhaust passage, holes may be opened in the oil pan due to corrosion, and oil There was a risk of serious accidents such as spills and seizure of the engine.

[0006]

Means for Solving the Problems The present invention is configured as follows in order to solve the above problems. De
Mixes cooling water and exhaust gas from diesel engine 2
Outboard diesel engine
Placed on the diesel engine 2 to the top of the down Jin mount 5
And the exhaust manifold 2a of the diesel engine 2
The exhaust pipe 6 communicates with the engine mount.
5 and the lower part of the exhaust pipe 6 is
It is disposed inside the engine pipe on the side of the mounting portion of the exhaust pipe 6.
A cooling water passage 5a is formed in the und 5, and the cooling water is
The exhaust pipe 6 and the engine
Between the cooling water and exhaust gas formed between the
A sacrificial anode 13 is provided in the kissing portion, and the sacrificial anode 13 is fixed.
The sacrificial anode mount 12 to be fixed together with the exhaust pipe 6
It is fixed to the mount 5 .

[0007]

By using such means, in the mixing section, the exhaust gas and the cooling water from the diesel engine 2 are mixed and discharged into the discharge passage 7, and at this time, the sulfur content in the exhaust gas is cooled. It dissolves in water and reacts with the sacrificial anode 13 to form sulfide, and this sulfur is removed from the drive unit case 3 and the engine mount 5.
To prevent corrosion.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The problems to be solved by the present invention and the means for solving them are as described above, and the configuration of the embodiments will be described with reference to the attached drawings. FIG. 1 is a front sectional view of a mixing unit according to a first embodiment of the present invention, FIG. 2 is a side sectional view of a mixing unit according to a second embodiment of the present invention, and FIG. 3 is a third embodiment of the present invention. 4 is a cross-sectional view of a mounting portion of a sacrificial anode in the first and second embodiments, and FIG. 5 is a cross-sectional view of a mounting portion of a sacrificial anode in the third embodiment.

Referring to FIG. 1, a first embodiment of the present invention will be described. The overall configuration is the same as that of the related art. An upper case 3a of the drive unit case 3 is fixed below the engine mount 5, and the diesel engine 2 is mounted on the upper portion of the engine mount 5, and the exhaust manifold 2a
The exhaust pipe 6 is communicated with the
At 11, the cooling water passage 5 is fixed to the upper part of the engine mount 5, and
a is formed so that the cooling water flows down toward the exhaust pipe 6.

An upper portion of the sacrificial anode mount 12 is fixed to a lower portion of the bolt 11.
Is extended downward, and the sacrificial anode 13 of the present invention is attached to the lower portion of the sacrificial anode mounting base 12. The sacrificial anode 13 is made of zinc in the present embodiment, but may be made of a metal having a higher ionization tendency than the material of the drive unit case 3 and the engine mount 5, and is formed in a bolt shape. Is not limited. As shown in FIG. 4, the sacrificial anode 13 has a threaded portion of the sacrificial anode 13 inserted into the sacrificial anode mount 12 and is fixed with a nut 14. Reference numeral 15 denotes a seal.

Further, as a second embodiment, as shown in FIG. 2, the mounting structure of the sacrificial anode 13 is such that the sacrificial anode 13 is mounted on the upper case 3a of the drive unit case 3 where the lower part of the exhaust pipe 6 is located by the bolt 16. A base 12 'is fixedly mounted, and the sacrificial anode 1 is mounted on the other side of the sacrificial anode mounting base 12'.
3 is fixed by a nut 14 as shown in FIG.

Further, as a third embodiment of the mounting structure of the sacrificial anode 13, as shown in FIG. 3, the sacrificial anode mounting base 12 is eliminated and the sacrificial anode 13 is directly mounted below the exhaust pipe 6. That is, as shown in FIG. 5, a bolt 17 is fixedly erected on the side surface of the exhaust pipe 6 by welding (19), and a nut-shaped sacrificial anode 13 'is fixed to the bolt 17 by tightening.

In such a configuration, the drive unit case 3 and the engine mount 5 are made of an aluminum alloy that is easy to mold, and aluminum is easily ionized and thus easily corroded. The cooling water is discharged to the mixing portion of the drain passage 7 through the pipe 6, while the cooling water is discharged from the cooling water passage 5 a of the engine mount 5 to the exhaust pipe 6 so as to hit the exhaust pipe 6 and wash out the outer periphery. At this time, the sulfur content in the exhaust gas is dissolved in the cooling water to form negative divalent ions, which easily reacts with the positive divalent metal, and reacts with the sacrificial anode 13 to form sulfide. In the present embodiment, since the sacrificial anode 13 is made of positive divalent metal zinc, it becomes zinc sulfide,
The sacrificial anode 13 is corroded, and aluminum, which is a positive trivalent metal, is easily ionized, but hardly reacts with sulfur, and does not react with the drive unit case 3 or the engine mount 5 to avoid corrosion. Further, seawater enters from the discharge passage at the lower end, and its salt becomes a factor of corrosion, but does not react with the drive unit case 3 or the engine mount 5 and does not reach the corrosion.

[0014]

[Effects of the Invention] The present invention is constructed as described above, and has the following effects. First, the exhaust pipe 6 and
Cooling water and exhaust gas formed between the engine mount 5
The sacrificial anode 13 is provided in the mixing part of
As in the technology, when the sacrificial anode 13 is submerged in water,
Cooling water is mixed in the air even if it is not
Under the conditions under which water is applied,
The effect of the sacrificial anode can be exhibited if it is charged
It is. Therefore, under environmental conditions that are not constantly submerged in water
Thus, the effect of the sacrificial anode 13 can be exhibited.
When the outboard motor is not driven in rotation, the sacrificial anode
13 is no longer energized, so the sacrificial anode 13
It can last longer and delay the replacement period.
Will come. Second, the sacrificial anode for fixing the sacrificial anode 13
The pole mount 12 is attached to the engine mount 5 together with the exhaust pipe 6.
Fixed, simplifies the configuration of the mounting part for the sacrificial anode 13
You can do it. Third, by providing the sacrificial anode in the mixing portion, corrosion due to sulfides and the like generated by exhaust gas discharged through the exhaust pipe concentrates on the sacrificial anode and extends to corrosion of the exhaust pipe and the drive unit case. Therefore, corrosion is prevented, and no serious accidents can be prevented without perforation.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a mixing unit according to a first embodiment of the present invention.

FIG. 2 is a side sectional view of a mixing unit according to a second embodiment of the present invention;

FIG. 3 is a side sectional view of a mixing unit according to a third embodiment of the present invention;

FIG. 4 is a sectional view of a mounting portion of a sacrificial anode in the first and second embodiments.

FIG. 5 is a sectional view of a mounting portion of a sacrificial anode in a third embodiment.

FIG. 6 is an overall side view, partly in section, of a conventional outboard motor.

FIG. 7 is a side sectional view of a conventional mixing unit.

8 is a sectional view taken along line XX in FIG. 7;

[Explanation of symbols]

 2 Diesel engine 3 Drive unit case 5 Engine mount 6 Exhaust pipe 7 Drain passage 13 Sacrificial anode

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yukito Sato 1-32 Chaya-cho, Kita-ku, Osaka-shi, Osaka Yanmar Diesel Co., Ltd. (56) References JP-A-3-3916 (JP, A) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) F01P 11/06 C23F 13/06 F01N 3/02 F01P 3/12

Claims (1)

(57) [Scope of request for utility model registration] A cooling water and a drainage from a diesel engine.
Diesel ship that mixes gas and gas and discharges it into the water
Diesel on top of engine mount 5
The engine 2 is mounted, and the exhaust
An exhaust pipe 6 communicates with the manifold 2a, and an upper portion of the exhaust pipe 6
Is fixed to the engine mount 5 and the lower part of the exhaust pipe 6 is
The exhaust pipe 6 is disposed inside the gin mount 5.
Forming a cooling water passage 5a in the side engine mount 5;
The cooling water is drilled so as to flow down to the exhaust pipe 6.
Cooling water formed between the exhaust pipe 6 and the engine mount 5
A sacrificial anode 13 is provided in a mixing portion between
The sacrifice anode mount 12 for fixing the sacrifice anode 13 is connected to an exhaust pipe.
An exhaust device for an outboard motor, wherein the exhaust device is fixed to an engine mount 5 together with the engine mount 6 .