JPH1134987A - Outboard engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outboard engine capable of preventing cooling water from infiltrating into a manifold-exhaust from an idle exhaust hole to the utmost. SOLUTION: This outboard engine is provided with a guide exhaust mounted with an engine, a tubular manifold exhaust 62 suspended from the lower face of the guide exhaust and guiding the exhaust gas of the engine downward, an idle exhaust hole 62a formed at the upper section of the manifold exhaust 62, an oil pan arranged at an interval with the manifold exhaust 62, ribs 70 connecting the manifold exhaust 62 and the oil pan, and cooling water holes 74 for spraying water on the outer periphery of the manifold exhaust 62. The ribs 70 are arranged between the idle exhaust hole 62a and the cooling water holes 74.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outboard motor that exhausts exhaust gas through an idle exhaust hole of a manifold exhaust at the time of idling.

[0002]

2. Description of the Related Art In a conventional outboard motor, exhaust gas is exhausted through an idle exhaust hole formed in an upper portion of a manifold exhaust at the time of idling. Further, since the manifold exhaust is heated by the exhaust gas, it is cooled by applying cooling water.

[0003]

By the way, the cooling water applied to the manifold exhaust sometimes flows into the manifold exhaust through the idle exhaust hole and flows toward the engine. As a result, the exhaust passage of the engine may be corroded. Further, when seawater reaches the exhaust valve, rust or salting occurs between the valve and the seat, and a gap is generated. Therefore, the output of the engine may be reduced.

An object of the present invention is to provide an outboard motor capable of minimizing the flow of cooling water into a manifold exhaust through an idle exhaust hole. And

[0005]

An outboard motor according to the present invention comprises a guide exhaust (3) on which an engine (16) is mounted.
8), a cylindrical manifold exhaust (62) hanging down from the lower surface of the guide exhaust and guiding the exhaust gas of the engine downward, and an idle exhaust hole (62) formed in the upper part of the manifold exhaust.
a), an oil pan (63) arranged at a distance from the manifold exhaust, a rib (70) connecting the manifold exhaust and the oil pan, and a cooling water hole for supplying water to the outer peripheral surface of the manifold exhaust. (74). The rib is disposed between the idle exhaust hole and the cooling water hole.

In some cases, the rib is formed integrally with the manifold exhaust and the oil pan.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an outboard motor according to the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of an outboard motor according to the present invention as viewed from the side. FIG.
FIG. 3 is a plan sectional view of the upper part of the outboard motor. FIG. 3 is a plan view of the casing and the oil pan unit. FIG. 4 is an enlarged sectional view of a main part of FIG. FIG. 5 is a bottom view of the oil pan unit. Fig. 6 is a sectional view of the lower part of the outboard motor.
It is VI sectional drawing. In FIG. 4, the position of the exhaust hole for idling of the manifold exhaust is shown by a two-dot chain line. This idle exhaust hole is provided on the left wall of the manifold exhaust, and is not provided on the right wall of the manifold exhaust shown in FIG. In FIG. 6, the vicinity of the drainage section is illustrated by a VIa-VIa cross section.

The outboard motor is covered by a housing consisting of an upper cowling 1, a lower cowling 2, an upper casing 3 and a lower casing 4 in this order from the upper side. Upper casing 3 and lower casing 4
In addition, a casing is formed, and an idle exhaust portion 6 is formed at an upper rear end of the upper casing 3, and the idle exhaust portion 6 is provided with an idle exhaust port 7. A drain portion 8 is formed at a lower rear portion of the upper casing 3. Further, a cooling water inlet 11 and a cooling water outlet 12 are formed in the lower casing 4. This cooling water outlet 12
Communicates with the drain portion 8 of the upper casing 3.

An engine 16 is provided in a cowling composed of an upper cowling 1 and a lower cowling 2, and a crankshaft 17 of the engine 16 is connected to a drive shaft 19. The drive shaft 19 vertically penetrates the inside of the upper casing 3, the lower end of which reaches the lower part of the lower casing 4, and the propeller 22 is attached to the rear end through a transmission mechanism 21 such as a bevel gear. The rotating propeller shaft 24 is rotationally driven. The drive shaft 19, the transmission mechanism 21, and the propeller shaft 24 form a drive system of the propulsion device. A cooling water pump 27 is provided at an intermediate portion of the drive shaft 19,
A lubricating oil pump 28 is provided at a lower end of the drive shaft 19 and is driven by rotation of the drive shaft 19 and the crankshaft 17. Further, the lower end of the shift rod 29 switches the transmission mechanism 21 forward, neutral, or reverse.

A mounting bracket 33 for mounting the outboard motor on a small boat is fixedly mounted on a transom 36 of the small boat. The outboard motor main body is rotatably attached to the rear of the mounting bracket 33 via a pivot shaft or the like.

The engine 16 is mounted and fixed on a guide exhaust 38 made of an aluminum alloy, is an L-type four-cycle four-cylinder, and is provided with four substantially horizontal cylinders 41 in a vertical direction. 41 has piston 4
2 are slidably arranged. One end of a connecting rod 43 is connected to the piston 42,
Is connected to the crankshaft 17. The engine case 46 of the engine 16 is made of an aluminum alloy, and a cooling water passage 48 is formed around the cylinder 41. The cooling water in the cooling water passage 48 cools the cylinder 41 and the like.

The combustion gas burned in the combustion chamber 49 of the engine 16 passes through the exhaust passage 51 of the engine case 46, flows through the exhaust passage 52 of the guide exhaust 38, and flows into the manifold exhaust 62 of the oil pan unit 61. I have. The oil pan unit 61 includes a cylindrical manifold exhaust 62 located at a substantially central portion, and oil pans 63 arranged at intervals along the front, rear and right sides of the manifold exhaust 62.
An exhaust chamber 64 disposed on the left side of the manifold exhaust 62; a cooling water passage 66 formed adjacent to the right side of the oil pan 63; and an overflow section formed on the lower left side of the exhaust chamber 64. 67, a manifold exhaust 62 and an oil pan 63
A space 68 is formed between the two. This space 68
Communicates with the exhaust chamber 64. An idle exhaust hole 62 is provided on the upper left side of the manifold exhaust 62.
a is formed, and idle flow holes 64 a are formed in the outer wall of the exhaust chamber 64. This idle circulation hole 64
a is disposed so as to be substantially opposed to the idle exhaust hole 62a, and the exhaust flowing out from the idle exhaust hole 62a of the manifold exhaust 62 is indicated by a two-dot chain line in FIGS. 3, 5, and 6. , Flows toward the idle circulation hole 64 a of the exhaust chamber 64.

On the outer peripheral surface of the upper part of the manifold exhaust 62, substantially triangular plate-like ribs 69 are provided on both sides of the idle exhaust hole 62a, that is, on the front and rear sides, respectively.
Are formed so as to extend in the vertical direction and protrude. The manifold exhaust 62 and the oil pan 63 are integrally connected at two places (in this embodiment, at the front side and the rear side) by plate-like ribs 70. The rib 70 is formed continuously from a substantially upper end of the manifold exhaust 62 to an intermediate portion, and extends substantially vertically. The lower end of the manifold exhaust 62 is formed so as to project below the lower surface of the oil pan 63. Further, the upper end of the manifold exhaust 62 and the upper end of the oil pan 63 are connected to the connecting portion 7.
1, and a cooling water groove 73 as a cooling water passage is formed on the upper surface of the connecting portion 71. In the cooling water groove 73, two cooling water holes 74 are formed. The aforementioned ribs 69 and 70 are provided with cooling water holes 74.
And the idle exhaust hole 62 a, and the upper end is continuous with the lower surface of the connection portion 71. The lower end of the cooling water passage 66 is connected to the cooling water pump 27 by a pipe 80. As shown in FIG. 5, the lower end of the overflow portion 67 extends along the lower side of the rear portion of the oil pan 63, and a drain passage 75 having an open lower surface is formed.

The oil pan unit 61 configured as described above is integrally formed of metal such as aluminum or iron, fixed to the lower surface of the guide exhaust 38 with bolts or the like, and is inserted from the guide exhaust 38 into the upper casing 3. Hanging.

Below the oil pan unit 61,
A cylindrical muffler 76 is attached via a metal gasket 77, and a space between the oil pan unit 61 and the upper casing 3 and a space between the muffler 76 and the upper casing 3 form a water reservoir 81. A drain groove 79 is formed at the center left and rear of the upper end of the muffler 76. The drain groove 79 communicates with the lower end of the overflow section 67 of the oil pan unit 61 and the drain passage 75, and also has an upper part. It is also in communication with the drain section 8 of the casing 3. The exhaust chamber 6
4, the lower opening of the space 68 between the manifold exhaust 62 and the oil pan 63, and the lower opening of the manifold exhaust 62 are gaskets 77.
, And is in communication with the muffler 76.

When the engine 16 of the outboard motor configured as described above operates, the combustion gas, that is, the exhaust gas of the engine 16 passes through the exhaust passage 51 of the engine case 46,
The gas flows into the manifold exhaust 62 via the exhaust path 52 of the guide exhaust 38 and the like. When the propeller 22 is rotating at a relatively high speed, the exhaust gas flows downward from the lower surface opening of the manifold exhaust 62 and is discharged from the boss of the propeller 22 to the outside of the outboard motor via the muffler 76 and the like. Have been. On the other hand, at the time of idling, the water that has entered the lower casing 4 prevents exhaust from the boss of the propeller 22, and the exhaust gas in the manifold exhaust 62 passes through the idle exhaust hole 62 a of the manifold exhaust 62. Then, it flows into the exhaust chamber 64, and then flows into the upper part of the water reservoir 81 from the idle circulation hole 64 a. Then, the air flows into the idle exhaust portion 6 through a flow path (not shown) of the guide exhaust 38, and is exhausted from the outboard motor through the idle exhaust port 7.

The water outside the outboard motor, that is, the cooling water, sucked from the cooling water inlet 11 is pumped up by the cooling water pump 27, and is supplied to the pipe 80, the cooling water passage 66 of the oil pan unit 61 and the guide exhaust 38. The coolant flows into the cooling water passage 48 of the engine 16 through the flow path, and cools the engine 16. Then, the water that has cooled the engine 16 flows into the water sump 81 through a flow path (not shown) of the guide exhaust 38. When the water level in the sump 81 rises above the upper end of the overflow section 67 of the oil pan unit 61, the water in the sump 81
Through the drain passage 75 of the oil pan unit 61 and the drain groove 79 of the muffler 76, through the drain portion 8 of the upper casing 3, and discharged from the cooling water discharge port 12 of the lower casing 4 to the outside of the outboard motor. ing.

Further, a part of the cooling water flowing through the cooling water passage 66 of the oil pan unit 61 flows into the cooling water groove 73 of the oil pan unit 61 through the flow path of the guide exhaust 38 and the like, and the cooling water flows. From the hole 74, the space 6 between the manifold exhaust 62 and the oil pan 63
8, falls on the outer surface of the manifold exhaust 62, and while cooling the manifold exhaust 62,
It is flowing down. Then, it is discharged from the boss of the propeller 22 to the outside of the outboard motor via the muffler 76 and the like.

The rotation of the crankshaft 17 causes the lubricating oil pump 28 to operate, thereby supplying the lubricating oil in the oil pan 63 to the engine 16.
And the sliding surface of the cylinder 41 are lubricated.

As described above, in this embodiment, since the cooling water passage 66 is formed integrally with the oil pan 63, the cooling water from the cooling water pump 27 passes through the cooling water passage 66, and The lubricating oil in the pan 63 can be efficiently cooled, and the length of the pipe 80 can be shortened by the length of the cooling water passage 66. And,
It is easy to secure the volume of the oil pan 63.

A cooling water hole 74 for spraying water to the manifold exhaust 62 and a manifold exhaust 6
Ribs 69, 70 between the idle exhaust holes 62a.
And the ribs 69 and 70 have an upper end located above the upper end of the idling exhaust hole 62a and a lower end located below the lower end of the idling exhaust hole 62a. The water that has fallen from the water hole 74 flows through the manifold exhaust 6 through the idle exhaust hole 62a.
2 can be reduced.

The embodiment of the present invention has been described above in detail.
The present invention is not limited to the above embodiment,
Within the gist of the present invention described in the claims,
Various changes can be made. Modification examples of the present invention are exemplified below. (1) In the embodiment, the engine 16 is a four-cycle, four-cylinder engine. For example, it is also possible to use two cycles or two cylinders.

(2) The structure, quantity, arrangement and the like of the cooling water passages and drain holes can be appropriately changed unless otherwise specified in the claims. (3) If the ribs 69 and 70 are arranged between the cooling water hole 74 and the idling exhaust hole 62a,
The shape and arrangement can be changed as appropriate. Also, instead of being formed integrally with the oil pan unit 61, they are formed separately,
It is also possible to attach. However, when integrally formed, the manufacturing cost can be reduced gradually, the oil around the manifold exhaust 62 can be efficiently circulated when the oil pan unit 61 is cast, and the metal such as molten aluminum can be used as the manifold exhaust. It can flow evenly to the tip of 62. Furthermore, rib 7
0, the lower end is located in the middle of the manifold exhaust 62, but it is also possible to extend the lower end to the lower end of the oil pan 63 or the lower end of the manifold exhaust 62.

(4) The shape and structure of the oil pan unit 61 can be changed as appropriate. For example, the shapes of the manifold exhaust 62 and the oil pan 63 can be changed, and the overflow section 67 and the cooling water passage 66 can be omitted. (5) In the embodiment, the idling exhaust hole 62a
Is formed on the left side wall of the manifold exhaust 62, but its arrangement can be changed as appropriate.

[0025]

According to the present invention, the rib for connecting the manifold exhaust and the oil pan is provided with an idle exhaust hole formed on the upper portion of the manifold exhaust and a cooling water hole for supplying water to the outer peripheral surface of the manifold exhaust. And is located between. Therefore, the rib can prevent the cooling water from the cooling water hole from entering the manifold exhaust from the idle exhaust hole as much as possible.

Further, when the rib is formed integrally with the manifold exhaust and the oil pan, the oil around the manifold exhaust at the time of casting can be efficiently performed by the rib, and the occurrence of defective products at the time of casting can be reduced. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an outboard motor according to the present invention as viewed from the side.

FIG. 2 is a plan sectional view of an upper portion of the outboard motor.

FIG. 3 is a plan view of a casing and an oil pan unit.

FIG. 4 is an enlarged sectional view of a main part of FIG. 1;

FIG. 5 is a bottom view of the oil pan unit.

6 is a sectional view of a lower part of the outboard motor, and is a sectional view taken along line VI-VI of FIG. 5;

[Explanation of symbols]

 16 Engine 38 Guide exhaust 62 Manifold exhaust 62a Exhaust hole for idle 63 Oil pan 70 Rib 74 Cooling water hole

Claims (2)

[Claims] A guide exhaust on which an engine is mounted, a guide exhaust hanging from a lower surface of the guide exhaust,
A cylindrical manifold exhaust that guides exhaust gas of the engine downward; an idle exhaust hole formed at an upper portion of the manifold exhaust; an oil pan disposed at a distance from the manifold exhaust; and a manifold exhaust. A rib for connecting the oil pan with the cooling water hole for spraying water on the outer peripheral surface of the manifold exhaust, wherein the rib is disposed between the exhaust hole for idle and the cooling water hole. Outboard motor. 2. The outboard motor according to claim 1, wherein said rib is formed integrally with a manifold exhaust and an oil pan.