JPS603038Y2 - Exhaust and cooling water discharge device for outboard motors - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an exhaust and cooling water discharge device for an outboard motor.

In an outboard motor, the engine is installed at the upper end of the casing, and the cooling water that has been exhausted and circulated by the engine is discharged into the casing.However, when negative pressure is generated in the exhaust pipe due to exhaust pressure pulsations, the cooling water is discharged. This can lead to problems such as deterioration of engine performance or corrosion as a result of the exhaust gas being sucked into the exhaust pipe or into the engine through the exhaust pipe.

In particular, the above-mentioned tendency is remarkable in the case where the exhaust pipe and the cooling water discharge pipe led out from the engine are integrally molded to simplify the structure.

Therefore, the purpose of the present invention is to eliminate the above problems and provide a discharge device that can prevent cooling water from being sucked in. The cooling water discharge pipe is provided with an extension in the casing, and the discharge end of the cooling water discharge pipe protrudes below the discharge end of the exhaust pipe.

To explain the embodiment of the present invention with reference to the drawings, the outboard motor main body A
consists of an engine b installed at the upper end of a casing a, and the engine b is covered by an engine cowling b.

The casing a has a passage 1 extending between its upper end and the rear surface of the lower part of the casing, and the lower end of the passage 1 is opened to form a discharge port 1'.

A unit 2 formed by integrally molding an exhaust pipe 3, a cooling water discharge pipe 4, and a water suction pipe support hole 5 is attached to the passage 1 by being inserted from the upper end.

The exhaust pipe 3 is connected to the exhaust port of the engine b, and its lower portion projects into the passage 1 by an appropriate length.

The cooling water discharge pipe 4 is formed in parallel to the front surface of the exhaust pipe 3,
Its upper end is connected to the terminal end of the cooling water system passage 6 of engine b.

The lower ends of the exhaust pipe 3 and the cooling water discharge pipe 4 are opened downward to form discharge ends 3' and 4', respectively. ′ to protrude downward.

A water suction pipe support hole 5 is formed on the front surface of the cooling water discharge pipe 4, and a cooling water discharge pipe 7 is inserted and supported in this support hole 5. The water suction pipe 7 has its lower end opened at the lower part of the casing, and its upper end It is connected to the starting end of the cooling water system passage 6 of the engine b.

Thus, the exhaust gas from engine b is guided into the exhaust pipe 3.
After being discharged from the discharge end 3' into the passage 1 in the casing a, it passes through the passage 1 and is discharged into the water from the discharge port 1'.

In addition, cooling water such as seawater is sent to the cooling water system line 6 through the water suction pipe 7 to cool the engine b, and is led from the terminal end of the thread line 8 to the cooling water discharge pipe 4 and from the discharge end 4' into the casing. The gas is discharged into the passage 1 and discharged into the water from the discharge port 1' together with the exhaust gas.

In the figure, 8 is a drive shaft that is connected to the engine b and transmits rotation to the propeller 9, 10 is a water storage chamber formed on the outer periphery of the upper part of the unit 2, and 11 is an exhaust passageway for discharging the exhaust gas into the atmosphere. The water reservoir chamber 10 is connected to the cooling water system passage 6 and cooled water is fed into the chamber 10 to cool the base of the exhaust pipe 3, and the water reservoir chamber 10 is connected to the discharge passage through a small hole 12. The cooling water in the chamber 10 is discharged through the discharge passage 11.

In this invention, like earth removal, the exhaust pipe and the cooling water discharge pipe are extended in the casing, and the discharge end of the cooling water discharge pipe is made to protrude downward from the discharge end of the exhaust pipe. Even if negative pressure occurs in the exhaust pipe, the cooling water discharged from the cooling water discharge pipe is far enough away from the discharge end of the exhaust pipe, so it will not be sucked into the exhaust pipe. Therefore, cooling water such as seawater will not be sucked into the exhaust pipe. Alternatively, it is possible to prevent the conventional negative effects that are sucked into the engine through the exhaust pipe.

Therefore, the intended purpose can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of an outboard motor equipped with the device of the present invention, and FIG. 2 is a sectional view taken along line 1--2. In the figure, a...casing, b...engine, 1...passage in the casing, 3...
...exhaust pipe, 3'...discharge end of exhaust pipe, 4.
... Cooling water discharge pipe, 4' ... Its discharge end.

Claims (1)

[Scope of utility model registration request] Exhaust and cooling in an outboard motor in which an exhaust pipe and a cooling water discharge pipe led out from the engine are provided in an extended form within a casing, and the discharge end of the cooling water discharge pipe is made to protrude downward from the discharge end of the exhaust pipe. Water discharge device.