JPH01262288A - Power unit for inboard outer machine - Google Patents

Abstract

PURPOSE:To make an engine compact in size as a whole as well as to abate the propagation of an exhaust noise to a living room by using a horizontal opposed type 2-cycle engine as the engine of an inboard outer machine, and installing an exhaust pipeline in an interval between an engine body and a ship's bottom. CONSTITUTION:In a power unit for an inboard outer machine, setting up an engine in the hull and driving a propulsion unit installed at the outside of the hull, a horizontal opposed type 2-cycle engine 12 is adopted as the engine. An exhaust manifold 37 is connected to an exhaust port 36 installed in the lower side of symmetrical cylinder blocks 26, and an exhaust pipe 38 and an exhaust silencer box 39 are set up between the engine 12 and a ship's bottom 11B. An exhaust passage is not installed in the upper part and side parts of the engine so that an external form of the whole engine is made compact in size. In addition, an exhaust noise emitted upward from the exhaust pipeline is intercepted by an engine body, so that its propagation to a living quarter is thus abatable.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a power unit for an inboard/outboard motor.

[Prior Art] Inboard-outboard motors use a power unit in which an engine is disposed inside the hull, and the engine drives a propulsion device provided outside the hull.

Conventionally, the engines constituting the above power unit are
The exhaust passage leading to the engine runs around the side of the engine body.

[Problems to be Solved by the Invention] However, the above conventional inboard/outboard motor has the following problems.

■Exhaust passages and exhaust silencing boxes are arranged around the engine body, which increases the overall appearance of the engine and makes engine maintenance difficult.

■Exhaust noise radiated from the exhaust passage easily passes through the engine room cover etc. and reaches the living space inside the hull.
The noise level in the living space is high.

An object of the present invention is to make the entire engine more compact by improving the power unit, improve the maintenance workability of the engine, and reduce exhaust noise.

[Means for Solving the Problems] The present invention provides a power unit for an inboard/outboard motor in which an engine is disposed inside the hull and a propulsion device provided outside the hull is driven by the engine, in which a horizontally opposed engine is used as the engine. The exhaust pipe line connected to the engine is arranged in an area surrounded by the engine body and the bottom of the ship.

[Effect] According to the present invention, there are the following effects.

■Since a horizontally opposed engine is used, the engine exhaust port can be easily installed on the bottom side of the engine body.
The exhaust passage can be easily arranged in the area surrounded by the engine body and the bottom of the ship.

(2) Therefore, the exhaust passage is not installed above or to the side of the engine, and as a result, the overall appearance of the engine is made more compact and the maintenance workability of the engine is improved.

■Exhaust noise radiated upward from the exhaust passage is reliably insulated by the engine body and does not reach the living space inside the hull.In addition, exhaust noise radiated downward reaches the water even if it passes through the bottom of the ship. There is no adverse effect on the interior of the ship.

[Example] Fig. 1 is a side view showing one embodiment of the present invention, and Fig. 2 is a side view showing one embodiment of the present invention.
A sectional view taken along line II-II in the figure, Figure 3 is a plan view showing the engine, Figure 4 is a front view showing how auxiliary equipment is attached to the engine, and Figure 5 shows how the engine is installed in the hull. It is a schematic diagram.

As shown in FIG. 1, the inboard/outboard motor 10 has an engine 12 disposed inside a hull 11, and the engine 12 drives a propulsion unit (propulsion device) 13 provided outside the hull 11.

In the propulsion unit 13, a gimbal ring 15 is rotatably connected to a gimbal housing 14 attached to the stern plate 11A of the hull 11, and the propulsion unit 13 is rotatably connected to the gimbal ring 15. 16 is a tilting cylinder device provided between the gimbal ring 15 and the propulsion unit 13.

The engine 12 is fixed to a mount (not shown) provided on the bottom 11B of the hull 11. A base shaft 20 of a propulsion unit 13 is connected to the output shaft 17 of the engine 12 via a joint 18 and a universal joint 19, and an upper gear train 2
1. Intermediate shaft 20A.

A propeller shaft 23 is connected via a lower gear train 22. The upper gear train 21 or the lower gear train 22 constitutes a forward/reverse switching mechanism, and a propeller shaft 23 is provided with a propeller 24 .

As shown in FIGS. 1 to 3, the engine 12 consists of a horizontally opposed two-stroke engine, and includes a crankcase 25, left and right cylinder blocks 26 provided on both sides of the crankcase 25, and each cylinder block 26. With the provided cylinder head 27, the engine body 1
It constitutes 2A. 100 is a flywheel.

The engine 12 has left and right cylinder banks 28A and 28B.
form three cylinders each, and both cylinders are punctured 28A, 2
An intake port 30 is provided at the upper part of the crank chamber 29 sandwiched between the crank chambers 8B and 8B. A reed valve 3 is provided at the intake port 30 of the engine 12.
An intake manifold 32 is connected via 1. The intake manifold 32 is bent by 90 degrees, and a carburetor 33 and an intake silencer box 34 are connected to a connection port 32A that opens laterally. As a result, one cylinder bank 28A
A carburetor 33 and an intake silencer box 34 are installed above the engine.

The engine 12 is provided with a scavenging passage 35 that communicates each cylinder with the crank chamber 29 at, for example, three positions above and on the side of the left and right cylinder blow blocks 26, and
An exhaust port 36 for each cylinder is provided on the lower side of the cylinder 6.

Exhaust ports 36 provided on the lower side of the left and right cylinder blocks 26
Left and right exhaust manifolds 37 are connected to the left and right exhaust manifolds 37, left and right exhaust pipes 38 having a U-shape are connected to the flywheel side of each exhaust manifold 37, and both exhaust pipes 38 are connected to an exhaust silencer box 39. The exhaust silencer box 39 is disposed below the crankcase 25 in a space sandwiched between the left and right exhaust manifolds 37. That is, the exhaust pipe line connected to the exhaust port 36 of the engine 12 is arranged in the area surrounded by the engine body 12A and the bottom 11B, as described above.

The exhaust silencer box 39 communicates with an exhaust passage provided inside the propulsion unit 13 via a rising exhaust pipe 40 or the like, and discharges the exhaust gas of the engine 12 from the boss portion of the propeller 24 into the water. .

The engine 12 also includes an alternator 41, a starter motor 42, and a water pump 43 in four parts of the engine body 12A.
Auxiliary equipment such as The alternator 41 is installed at the top of the cylinder block 26 that constitutes the cylinder bank 28B opposite to the cylinder bank 28A in which the intake system is installed, and the starter motor 42 is connected to the crankcase 2.
A water pump 43 is installed next to the intake manifold 32 at the top of the crankcase 25 , and a water pump 43 is installed at the front of the intake manifold 32 at the top of the crankcase 25 .

Note that the hull 11 in which the engine 12 is disposed has a fifth
As shown in the figure, a benched rear seat 44 can be provided above the engine 12.

Next, the operation of the above embodiment will be explained.

■Since the horizontally opposed engine 12 is used, the engine 12
The exhaust port 36 of the engine body 12A can be easily connected to the bottom 11B of the engine body 12A.
The exhaust passage (exhaust manifold 37, exhaust pipe 38, exhaust muffling box 39) can be installed on the side of the engine body 1.
It can be easily arranged in the area surrounded by 2A and the bottom 11B.

(2) Therefore, the exhaust passage is not routed above or to the side of the engine 12, and as a result, the overall appearance of the engine is made more compact and the maintenance workability of the engine 12 is improved.

■Exhaust noise radiated upward from the exhaust passage is reliably insulated by the engine body 12A and does not reach the living space inside the hull. Furthermore, exhaust noise radiated downward is
Even if it passes through the ship's bottom 11B, it only reaches the water and does not have any adverse effect on the inside of the ship.

In the implementation of the present invention, the engine may be a 4-cycle engine as long as it is of a horizontally opposed type.

[Effects of the Invention] As described above, according to the present invention, by improving the power unit, it is possible to downsize the entire engine, improve engine maintenance workability, and reduce exhaust noise.

[Brief explanation of the drawing]

FIG. 1 is a side view showing one embodiment of the present invention, and FIG. 2 is a side view showing one embodiment of the present invention.
Figure 3 is a plan view showing the engine, Figure 4 is a front view showing how accessories are attached to the engine, and Figure 5 is a diagram showing how the engine is installed on the hull. It is a schematic diagram. 10... Inboard/outboard motor, 11... Hull. 11B...Bottom, 12...Engine, 12A...Engine body, 36...Exhaust port, 37...Exhaust manifold (exhaust pipe), 38...
Exhaust pipe (exhaust pipe line), 39...Exhaust silence box (exhaust pipe line).

Claims (1)

[Claims] (1) In an inboard/outboard motor power unit in which an engine is disposed inside the hull and the engine drives a propulsion device provided outside the hull, a horizontally opposed engine is used as the engine, and an exhaust pipe line connected to the engine is used. A power unit for an inboard/outboard engine characterized by being disposed in an area surrounded by the engine body and the bottom of the ship.