JPH0621560B2 - Ship propulsion device - Google Patents

Description

The present invention relates to an exhaust system for a ship propulsion device, and more particularly to an apparatus in a system for reducing exhaust back pressure.

In a conventional ship propulsion device, exhaust gas and cooling water are generally discharged below the surface of the water in order to reduce noise. This measure often results in an undesired back pressure on the engine, because exhaust gases and cooling water have to follow a relatively long path before being discharged.

See the following U.S. Patents which disclose exhaust systems for marine propulsion devices. That is, North US Patent No. 3,759,041 issued September 18, 1973.
Issue, and Herbert, No. 4,01, issued April 26, 1977.
No. 9,456.

The present invention includes a water-cooled internal combustion engine, an exhaust outlet, and an exhaust passage communicating between the engine and the exhaust outlet and guiding exhaust gas and cooling water out of the engine, in which the water flows by centrifugal force. By directing the exhaust gas out of the second portion of the exhaust passage, including a first portion and a second portion laterally adjacent and adjacent to the first portion. A propulsion device for a ship provided with a device for releasing back pressure in the exhaust path.

In one embodiment, the back pressure relief device includes an exhaust gas relief passage in communication between the second portion of the exhaust passage and the atmosphere.

In one embodiment, the exhaust passage also has an upper portion, and the exhaust gas escape passage communicates with the upper portion so that a large amount of water does not enter the escape passage due to the action of gravity and centrifugal force. There is.

The present invention is also a water-cooled internal combustion engine, mounted on the aft beam of a hull, a front end portion, an exhaust opening at the front end portion,
A first exhaust outlet at the front end adjacent to one side of the exhaust opening, a second exhaust outlet at the front end adjacent to the other side of the exhaust opening, an exhaust outlet, the exhaust outlet and the exhaust outlet. An exhaust pipe communicating with the first exhaust escape passage communicating with the first exhaust escape port and the atmosphere; and a second exhaust escape passage communicating with the second exhaust escape port and the atmosphere. Including gimbal
Between the housing and the engine and the first and second exhaust vents for communicating exhaust and cooling water out of the engine between the engine and the exhaust opening and for directing exhaust gas out of the engine. There is provided a ship propulsion device including an exhaust device communicating with the.

In one embodiment, the exhaust device has a conduit portion that communicates with the exhaust opening, the first and second exhaust outlets, and the conduit portion has opposite first and second side surfaces. A bottom part, a first dam part that is adjacent to the first side face and extends upward from the bottom part and that is located on the upstream side of the first exhaust escape port, and is adjacent to the second side face. A second dam portion extending upward from the bottom portion and located upstream of the second exhaust escape port, wherein the bottom portion and the first and second dam portions include a lower center with the conduit portion. The first and second dam sections substantially block water from entering the first and second exhaust vents and further communicate between the engine and the line section.
A pair of exhaust pipes, the exhaust pipes converging in the conduit portion,
Further, it has an arcuate portion immediately upstream of the pipe line portion so that water flows into the central portion below the pipe line portion by the action of centrifugal force and gravity.

In one embodiment, the exhaust pipe line is substantially horizontal and has an upstream end communicating with the exhaust outlet and a downstream end communicating with the exhaust outlet, and the first exhaust escape passage is provided. Has an upstream side portion that extends substantially parallel to the exhaust pipe line and communicates with the first exhaust escape port, and a downstream side portion that extends substantially downward and communicates with the atmosphere. The exhaust escape path has an upstream side portion that extends substantially parallel to the exhaust pipe line and communicates with the second exhaust escape port, and a downstream side portion that extends substantially downward and communicates with the atmosphere.

In one embodiment, the exhaust device includes an end surface that abuts a front end portion of the gimbal housing, a bottom wall surface that extends from the end surface, and a roof portion that extends from the end surface.
A conduit portion extending upwardly from the bottom wall surface and having a pair of side surfaces within the end surface that define an exhaust discharge port that communicates with an exhaust outlet of the gimbal housing, the side surfaces including the roof portion. Defining a port terminating in a spaced relationship with respect to the roof portion, the roof portion including a protruding portion adjacent the end surface and extending outward laterally beyond the side surface, the conduit portion also An outer wall surface extending outwardly from the roof portion in a positional relationship that is separated from the side surface and below the port, and communicates with the first and second exhaust outlets of the gimbal housing, respectively. Defining first and second exhaust relief ports within the end face.

The main feature of the present invention is that a first portion through which water flows by the action of centrifugal force and a second portion separated inward from the first portion.
And a device for venting back pressure in the exhaust path by directing the exhaust gas out of the second part of the exhaust path. Because the exhaust gas is directed out of the second portion of the exhaust path, it is substantially avoided that the exhaust path is depleted of water as water flows to the first portion of the exhaust path.

Another main feature of the present invention is an exhaust path including an upper portion,
There is provided a downwardly extending exhaust relief path communicating between the upper portion of the exhaust path and the atmosphere for guiding the exhaust gas out of the exhaust path.

Since the exhaust gas escape passage communicates with the upper portion of the exhaust passage, the action of gravity holds water from the upper portion to the lower portion of the exhaust passage, so that water is substantially prevented from disappearing from the exhaust passage. .

Another main feature of the present invention is that a front end portion, an exhaust opening of the front end portion, a first exhaust escape opening of the front end portion adjacent to one side of the exhaust opening, and an adjacent side of the exhaust opening are provided. A second escape port at the front end, an exhaust outlet, an exhaust pipe line communicating between the exhaust opening and the exhaust outlet, and a first exhaust escape route communicating between the first exhaust escape port and the atmosphere. And a second exhaust passage communicating with the second exhaust outlet and the atmosphere.

Another main feature of the present invention is to discharge exhaust gas and cooling water from a pair of laterally spaced parts of an internal combustion engine toward a gimbal housing that can be fixed to the aft beam of a ship. A substantially U-shaped exhaust conduit for guiding, comprising two legs extending upward and a connecting portion connecting the legs, the leg having an internal conduit, and the connecting portion comprising: An inner conduit portion communicating with an inner conduit is provided, and the connecting portion has a flat mounting surface that can be mounted to the gimbal housing, the flat mounting surface providing cooling water to the gimbal. A central opening that communicates to the housing and the flat mounting surface includes a pair of spaced ports that can communicate exhaust gases to the gimbal housing So that the central opening In both ends of the section is to provide an exhaust conduit that is spaced relative to the central opening.

Other features and advantages of the present invention will be apparent to one of ordinary skill in the art in light of the following detailed description, appended claims and drawings.

Prior to detailed description of one embodiment of the present invention,
It is to be understood that this invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description and illustrated in the drawings. The invention is capable of other embodiments and of being practiced in various ways. Also, it is to be understood that the phraseology used in the text is for the purpose of description and should not be regarded as limiting.

Shown in the drawings is a marine propulsion device 10 mounted on a hull 12 having a stern beam 14. The ship propulsion system 10 is of the stern propulsion type, that is, inboard / outboard type.

As best shown in FIG. 1, a ship propulsion device.
The 10 includes an engine 16 rigidly mounted on the hull frame by any suitable means such as a rubber support (not shown).
The marine propulsion device 10 also includes a gimbal housing 18 supported on the outer surface of the hull stern beam 14 and fixedly attached to the hull stern beam 14. The gimbal housing 18 can be attached to the aft beam 14 of the hull by any suitable means such as bolts extending through the aft beam 14.

The ship propulsion system 10 also includes a gimbal ring 20 coupled for pivotal movement about a steering axis (not shown) that is generally perpendicular to the gimbal housing 18 and the gimbal howling 20. And a pivot housing 30 that is pivotally coupled about a generally horizontal tilt axis (not shown). Such structures are known in the art and need not be described in further detail.

The ship propulsion device 10 also includes a propulsion unit 34 removably coupled to the pivot housing 30 for pivotal movement of the propulsion unit 34 with the pivot housing 30. In the structure shown, the propulsion unit 34 is releasably connected to the pivot housing 30 by a plurality of bolts (not shown). The propulsion unit 34 includes a propeller 38 mounted on a propeller shaft 40, a substantially horizontal drive shaft having one end removably coupled to the engine 16 and an opposite end having a bevel gear 44 thereon. 42 and. Universal joint mounted to this horizontal drive shaft 42
46 permits pivotal movement of drive shaft 42 with propeller 34.
The bevel gear 44 drives the bevel gear 48 at the upper end of the vertical drive shaft 50. The lower end of this vertical drive shaft 50 has a drive gear 52 thereon. A reversible transmission transmits a pair of driven gears 54 to the propeller shaft 40.
Selectively switch to drive gear 52 to propeller shaft 40
Transmit forward or backward movements against.

The marine vessel propulsion apparatus 10 includes means (not shown) for supplying cooling water to the engine 16. Such means
A pump for pumping water to the engine 16 may be included as is known in the art. The ship propulsion device 10 further includes an exhaust outlet 60, an exhaust passage 62 that communicates between the engine 16 and the exhaust outlet 60, and guides the exhaust gas and the cooling water so as to exit from the engine 16. In the structure shown, the exhaust outlet 60 is arranged at the lower end of the propulsion unit 34 so that the exhaust gas is discharged below the water surface. It is known in the art to exhaust the exhaust gas under water to reduce noise.

In a preferred embodiment, the exhaust path 62 is an engine
16 to gimbal housing 18, from this gimbal housing 18 to propulsion 34, and through propulsion 34 exhaust outlet
62 have been extended. Gimbal housing 18 to propulsion
The portion of the exhaust path 62 extending to 34 is a conventionally known exhaust bellows 64. The portion of the exhaust path 62 that extends through the thruster 34 is also well known and need not be described in further detail.

Exhaust path extending between engine 16 and gimbal housing 18
62 is a conduit portion 68 communicating with the gimbal housing 18.
An exhaust device 66 including (see FIGS. 3 and 4) and a pair of exhaust pipes 70 that communicate with the engine 16 and converge in a pipe line portion 68.

On the upstream side of the point where the exhaust pipe 70 converges, the exhaust pipes have a positional relationship symmetrical to each other. One exhaust pipe 70 communicates with one side of the engine 16, and the other exhaust pipe 70 communicates with the other side of the engine 16. As best shown in FIGS. 1, 3 and 4, the assembly of the two exhaust pipes 70 is generally U-shaped and the upstream or upper end of the exhaust pipes 70 is engine 16
Is in communication with. The tubes 70 curve inwardly and slightly rearward as they extend downwards, and the tubes 70 are bent to extend inwardly and substantially horizontally just upstream of the point where they converge. At the point where these two tubes 70 converge,
As best shown in FIG. 5, the front wall surfaces (tops in FIG. 5) of the two tubes 70 reach a point which is curved rearward. The pipe 70 converges on the pipe portion 68, and the curved front wall surface of the exhaust pipe 70 deflects the exhaust gas and the cooling water in the exhaust pipe to flow into the pipe portion 68. The conduit portion 68 terminates in an end surface 72 that abuts the front end of the gimbal housing 18 when the exhaust system is fully assembled.

The gimbal housing 18 has an exhaust port 74 at the front end (see FIG. 2), a first exhaust escape port 76 at the front end adjacent to one side of the exhaust port 74, and the other side of the exhaust port 74. A second exhaust outlet 78 at the front end adjacent to the exhaust outlet 80 and an exhaust outlet 80
And the exhaust port 74 and an exhaust pipe line 82 communicating with the exhaust outlet 80 pipe. The exhaust pipe line 82 is substantially horizontal. The gimbal housing 18 also has an upstream portion that extends substantially parallel to the exhaust line 82 and that communicates with the first exhaust vent 76 and a downstream portion that extends substantially downwardly and that communicates with the atmosphere. A first exhaust gas escape passage 84 having substantially the same, and an exhaust gas passage 82 extending substantially in parallel with the upstream side portion communicating with the second exhaust gas escape port 78 and extending substantially downward and to the atmosphere. Second exhaust gas escape path 86 having a downstream portion communicating with
Includes and.

In the preferred embodiment, the exhaust port 74 is generally T-shaped, and the exhaust line 82 also has a cross section from the exhaust port 74 to a point slightly rearward of the first and second exhaust escape paths 84, 86. It has a T-shape, and at this point, the exhaust pipe 82 has a circular cross section. The circular portion of this exhaust line 82 communicates with the exhaust outlet 80, which is also circular. The change in cross section of the exhaust line 82 from T-shaped to circular can be seen in FIG.

The upstream side portions of the first and second exhaust escape paths 84 and 86 are separated from the exhaust pipe line 82 by the upper wall surface 87 (see FIG. 8). In another embodiment of the invention, the upper wall surface
87 may be omitted or may include an internal port that communicates with the vent path.

The conduit portion 68 includes a substantially horizontal bottom wall surface 88 (see FIG. 10) extending from the end surface 72, and a substantially horizontal roof portion 90 which is separated upward from the bottom wall surface 88 and extends from the end surface 72. ,
A pair of side surfaces 92 extending upwardly from the bottom wall surface 88 to define an exhaust discharge port 94 within the end surface 72, the side surfaces 92 ending at a distance from the roof 90. Port 96
Is defined.

The roof portion 90 includes a protruding portion 93 adjacent to the end surface 72 and extending outwardly and laterally on the side surface portion 92. The conduit portion 68 also has an outer wall surface 100. The outer wall surface 100 extends downward from the projecting portion 93 of the roof portion 90 and below the port 96 in a positional relationship laterally separated from the side surface portion 92. As a result, first and second exhaust escape ports 102, 104 communicating with the port 96 are formed in the end surface 72.

In a preferred embodiment, the side portion 92 is a conduit portion.
68 extends forward from the end surface 72 of the pipe 68, extends laterally from the front end of the side surface portion 92, and is connected to the end wall surface 106 (see FIG. 5) connected to the outer wall surface 100 of the conduit portion 68. Has been done. The end wall surface 106, like the side surface portion 92, ends in a positional relationship spaced apart from the roof portion 90 (see FIG. 7). First or left side wall 92 and first or left end wall
106 is the outer wall surface 100 on the left side (as shown in FIG. 5).
Dam section extending upward from the bottom 88 of the pipe section adjacent to
108 (see FIG. 10). The second or right side surface portion 92 and the second or right side end surface portion 106 (as shown in FIG. 5) are adjacent the right outer wall surface 100 to the conduit portion 68.
Forming a second dam 110 extending upwardly from the bottom wall surface 88 of the. The bottom wall surface 88 and the first and second dam portions 108,
110 or the left and right sides and side portion 92 define a central portion below the conduit portion 68.

The action of centrifugal force resulting from the inward bending of the exhaust pipe 70
The water in 70 is caused to flow along the bottom or lower portion of the exhaust pipe 70. The force of gravity also causes water to flow along the bottom of the exhaust pipe 70. The centrifugal force resulting from the backward bending of the exhaust pipe 70 causes the water in the pipe 70, which is already flowing along the bottom of the pipe 70, to flow to the central portion of the conduit portion 68. Because of this, the exhaust pipe
The effect of gravity in addition to the combined effect of the two bends in 70, the inner bend and the rear bend, causes the water from the exhaust pipe 70 to flow from the exhaust pipe 70 to the central portion below the conduit section 68. I will let you.

The end surface 72 of the conduit portion 68 is such that the conduit portion 68 communicates with the exhaust port 74 and the first and second exhaust outlets 76, 78 at the front end of the gimbal housing 18.
It abuts the front end of 18. The pipe portion 68 has a bolt 112.
It is detachably fixed to the gimbal housing 18 (see FIG. 8). In particular, exhaust exhaust port 94
Alternatively, the lower central portion and the upper portion of the conduit portion 68 communicate with the exhaust port 74 in the gimbal housing 18,
Exhaust relief port 102 and second exhaust relief port 104
Respectively communicate with the first exhaust escape port 76 and the second exhaust escape port 78 inside the gimbal housing 18. First
The second and second dam portions 108 and 110 are arranged upstream of the first and second exhaust outlets 76 and 78, respectively, and water enters either of the exhaust outlets 76 and 78 in these dam portions. To substantially prevent that.

As described above, most of the water in the exhaust pipe 70 flows into the central portion below the conduit portion 68 by the action of centrifugal force and gravity. Therefore, most of the water flows from the conduit portion 68 into the exhaust exhaust port 94 and the exhaust port 74 and into the exhaust conduit 82 of the gimbal housing 18 to the exhaust outlet 60 inside the propulsion machine 34. The flow from the pipe portion 68 through the exhaust escape ports 102 and 104 to the exhaust escape ports 76 and 78 in the gimbal housing 18 is mainly exhaust gas. Therefore, the exhaust gas is discharged into the atmosphere through the exhaust escape paths 84 and 86. The exhaust of this exhaust gas through the exhaust escape paths 84 and 86 reduces the back pressure in the engine 16.

Looking at the exhaust path formed by one exhaust pipe 70 and half of the conduit portion 68, that is, by separating FIG. 5 from the bottom to the bottom, the exhaust path has water flowing inside due to centrifugal force. The first portion (the central portion of the conduit portion 68, that is, the outside of the bend) and the second portion laterally separated from the first portion (the outer wall surface 100 on the right side of the conduit portion 68). And a portion adjacent to, that is, the inside of the bend). The marine propulsion device 10 will thus include means for venting back pressure in the exhaust path by directing the exhaust gas out of the second portion of the exhaust path (inside the bend). Although various suitable means can be used, in the preferred embodiment, this means includes a first exhaust relief path 84 in communication between the second portion of the exhaust path and the atmosphere. Although this preferred embodiment includes two such exhaust paths that are plane-symmetric with respect to each other and converge into one exhaust path, the present invention also includes a first portion within which the centrifugal force causes water to flow. And a second inwardly spaced from this first part
It is to be understood that it is also possible to carry out in an exhaust path consisting of only one exhaust pipe including

As best seen by referring to FIG. 10, the exhaust path 62 also includes an upper portion 95 (dams 108, 1).
(Above 10)) is included. The first exhaust escape passage 84 communicates with one of the upper portions 95 so that a large amount of water does not enter the escape passage 84 due to the action of gravity and centrifugal force. On the other hand, the dam part 10
Reference numeral 8 blocks the state of communication with the lower portion of the exhaust path 62. This prevents water from entering the first exhaust escape passage 84 from the lower portion of the exhaust passage 62.
Further, the dam portion 110 also prevents water from entering the second exhaust gas escape path 86 in the same manner.

As described above, according to the present invention, most of the exhaust gas is discharged to the atmosphere through the communication means of the second passage portion, so that the back pressure in the exhaust passage can be reduced.

Various features and advantages of the invention are set forth in the appended claims.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a ship propulsion apparatus embodying the present invention, FIG. 2 is an elevation view showing a front end portion of a gimbal housing, and FIG. 3 is an exhaust pipe and a rear end portion of a pipeline portion. FIG. 4 is an elevational view showing the same, FIG. 4 is a side view showing the exhaust pipe and the conduit portion shown in FIG. 3, and FIG.
6 is a partial bottom view showing an exhaust pipe and a pipe line portion taken along line 6-6 in FIG. 3, FIG. 7 is a partial sectional view showing an exhaust pipe and a pipe passage line taken along line 7-7 in FIG. 8 is a sectional view taken along line 8-8 in FIG. 2 further including an exhaust pipe and a conduit portion, and FIG. 9 is a sectional view taken along line 9-9 in FIG. 2 further including an exhaust pipe and a conduit portion; And FIG. 10 is an enlarged view showing the end face of the conduit portion. 10 …… Ship propulsion device, 12 …… Hull, 14 …… Stern beam material, 16
...... Engine, 18 ...... Gimbal housing, 20 ...... Gimbal ring, 30 ...... Pivot housing, 34 ...... Propulsion machine, 38
...... Propeller, 40 …… Propeller shaft, 42 …… Drive shaft, 44,
48 …… Bevel gear, 46 …… Universal joint, 50 …… Drive shaft, 52… Drive gear, 54 …… Driven gear,
60 ... Exhaust outlet, 62 ... Exhaust path, 64 ... Exhaust bellows,
66 ... Exhaust device, 68 ... Pipe part, 70 ... Exhaust pipe, 72 ...
… End, 74… Exhaust port, 76 …… First exhaust port, 78…
… Second exhaust escape port, 80 …… Exhaust outlet, 82 …… Exhaust pipe line, 84 …… First exhaust escape route, 86 …… Second exhaust escape route, 87 …… Upper wall surface, 88 …… Bottom wall, 90 ... Roof, 92 ... Side, 94 ... Exhaust exhaust port, 96 ... Port, 100 ... Outer wall, 102 ... First exhaust escape port,
104 …… Second exhaust escape port, 106 …… End wall, 108
…… The first dam part, 110 …… The second dam part.

Claims (10)

[Claims] 1. A marine propulsion device comprising a water-cooled internal combustion engine (16) and a tiltable and steerable propulsion device (34), wherein the water-cooled internal combustion engine is arranged in front of a stern beam (14). Yes, the propulsion unit can be placed behind the poop beam (14) and is usually located below the surface of the exhaust outlet (60).
Further comprising an exhaust passage (62) communicating between the water-cooled internal combustion engine (16) and the exhaust outlet (60), the exhaust passage (62) supplying exhaust gas and cooling water to the water-cooled It can be guided from an internal combustion engine and discharged through the exhaust outlet (60), and the exhaust path (62) is a structure that can be fixed to the stern beam (14). The structure (18) that allows exhaust gas and cooling water to easily pass from the front to the rear of the stern beam (14), and the first passage portion (68, 70) that extends in a curved manner. ), And a second passage portion (102, 104) that extends curvedly and extends into the structure,
Communication means (76, 84) communicating with the second passage portion
(78, 86), the first passage portion extends forward from the structure, water is flowing by centrifugal force, and the second passage portion (102, 104) is Extending forward from the structure (18), laterally adjacent to and spaced apart from the first passage portion, substantially free from water, the communication means (76, 84) (78, 86) communicates with the atmosphere independently of the exhaust outlet (60) so that the exhaust gas can be discharged to the atmosphere, and the second passage portion (102) of the exhaust path (62). ，
The back pressure in the exhaust path is reduced by guiding the exhaust gas from the exhaust port (104), thereby reducing the flow rate of the exhaust gas passing through the exhaust outlet (60). 2. The communication means of the structure (18) comprises a second passage portion (102, 10) of the exhaust path (62).
4) and the atmosphere, the exhaust gas escape path (84,
86) The marine propulsion device according to claim 1, characterized in that 3. The exhaust path (62) also includes an upper portion (9).
5), and the exhaust gas escape route (84, 8)
6) is characterized in that, due to the action of gravity and centrifugal force, most of the cooling water is in communication with the upper portion (95) so as not to enter the exhaust gas escape passages (84, 86). The marine vessel propulsion apparatus according to claim 2. 4. A water-cooled internal combustion engine (16) and a stern beam (1)
Gimbal housing (18) attachable to 4)
And an exhaust device (66), wherein the gimbal housing (18) has a front end (18).
a), an exhaust port (74) provided at the front end, and a first exhaust escape port (76) provided at the front end adjacent to one end side of the exhaust port (74), A second exhaust escape port (78) provided adjacent to the other end of the exhaust port (74) at the front end, an exhaust outlet (80), the exhaust port (74) and the exhaust. An exhaust pipe line (82) communicating with the outlet (80) and the first exhaust escape port (76)
First exhaust escape path (84) for communicating between the air and the atmosphere
And a second exhaust escape path (86) communicating between the second exhaust escape port (78) and the atmosphere, wherein the exhaust device (66) cools exhaust gas and cooling water to the water cooling system. The water-cooled internal combustion engine (16) communicates with the exhaust port (74) so that it can be guided from the internal combustion engine (16), and the exhaust device (66) connects the exhaust gas to the water-cooled internal combustion engine. The water-cooled internal combustion engine (16) and the first and second exhaust vents (7) so that they can be guided from the engine (16).
6, 78) is in communication with the propulsion device for ships. 5. The exhaust device (66) includes the exhaust port (7).
4) and the first and second exhaust escape ports (76, 78) are connected to each other by a pipe line portion (68), and the pipe line portion (68) has first and second pipes at both ends. The second dam part (92), the bottom wall surface (88), the first dam part (108), and the second dam part (110) are provided, and the first dam part (108). Is positioned upstream of the first exhaust vent (76) and extends upwardly from the bottom wall surface (88) adjacent to the first side surface portion (92), and the second dam is provided. The part (110) is positioned upstream of the second exhaust vent (78) and extends upward from the bottom wall surface (88) adjacent to the second side surface part (92), The bottom wall surface (88) and the first and second dam portions (10
8, 110) form a central portion (68a) below the conduit portion (68), and the first and second dam portions (108, 110) are filled with water in the first and second portions. Of the exhaust system (66), and the exhaust device (66) communicates between the water-cooled internal combustion engine (16) and the pipe portion (68). An exhaust pipe (70) is provided, the exhaust pipe (70) converges on the pipe line portion (68), and the exhaust pipe (70) causes water to be subjected to centrifugal force and gravity. And an arcuate portion (70a) immediately upstream of the conduit portion (68) so as to flow into a central portion (68a) below the conduit portion (68). The marine vessel propulsion apparatus according to claim 4. 6. The exhaust pipe line (82) is substantially horizontal and has an upstream end (82) communicating with the exhaust port (74).
a) and a downstream end portion (82b) communicating with the exhaust outlet (80), the first exhaust escape path (84) includes the exhaust conduit (8).
2) extends substantially parallel to the first exhaust escape port (7
6) having an upstream side portion (84a) communicating with the downstream side portion (84b) extending substantially downward and communicating with the atmosphere, and the second exhaust gas escape passageway (86) includes the exhaust gas passageway. (8
2) extending substantially parallel to the second exhaust escape port (7
8. The marine propulsion device according to claim 4, characterized in that it has an upstream portion (86a) communicating with 8) and a downstream portion (86b) extending substantially downward and communicating with the atmosphere. . 7. The exhaust device (66) includes a conduit portion (6).
8), wherein the conduit portion (68) abuts the front end (18a) of the gimbal housing (18) at an end surface (7).
2) and a bottom wall surface (88) extending from the end surface (72)
And a roof portion (90) extending from the end surface (72) and an upper portion extending from the bottom wall surface (88), thereby communicating with the exhaust port (74) of the gimbal housing (18). A pair of side surface portions (92) forming an exhaust port (94) on the end surface (72), the pair of side surface portions (92) being located apart from the roof portion (90). Ending in a relationship to form a port (96), the roof portion (90) extending outwardly and laterally adjacent the end face (72) on the pair of side surface portions (92). A portion (93), and the conduit portion (68) has an outer wall surface (100), the outer wall surface (100) with respect to the pair of side surface portions (92). From the roof (90), the posi- Preparative (96) extends downwardly direction to below, whereby the first and second waste gate port of the gimbal housing (18) (76,7
8. The marine propulsion device according to claim 4, wherein first and second exhaust escape ports (102, 104) respectively communicating with 8) are formed on the end surface (72). 8. Exhaust from a pair of laterally spaced portions of an internal combustion engine (16) toward a gimbal housing (18) fixable to the aft beam (14) of the ship. A substantially U-shaped exhaust conduit (66) for guiding gas and cooling water, comprising two upwardly extending leg portions (70, 70) and a connecting portion (68) connecting the leg portions, The part (70) has an internal conduit (70b), the connecting part (68) has an internal conduit part (68b) communicating with the internal conduit (70b), and the connecting part. (68) is a flat mounting surface (7) that can be mounted on the gimbal housing (18).
2), wherein the flat mounting surface (72) comprises a central opening (94) for conducting cooling water to the gimbal housing (18), the flat mounting surface (72) being , A pair of spaced ports (102, 104), the pair of ports (102, 104) being adapted to communicate the exhaust gas to the gimbal housing (18). Exhaust conduit, characterized in that it is arranged at both ends of the opening (94) at a distance from the central opening. 9. A central opening (94) is provided in the inner conduit portion (68) so that water can be conducted from the inner conduit portion (68b) toward the central opening (94).
Exhaust conduit according to claim 8, characterized in that it further comprises means (92, 108, 110) for connection to b). 10. The pair of ports (102, 102) spaced laterally from the internal conduit portion (68b).
Means (92, 108, 11) for connecting said pair of ports (102, 104) to said internal conduit portion (68b) so that exhaust gas can be conducted towards said (104).
0) is further provided, and Claim 8 is characterized by the above-mentioned.
Exhaust conduit according to paragraph.