JP2000345840A - Outboard engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispose a cooling water passage close to a center portion of an engine member from an exhaust gas passage by enhancing an approach surface pressure of the center portion of the engine member. SOLUTION: In this outboard engine, an engine is disposed above an engine holder 2 and an oil pan 5 is disposed below the engine holder 2. A shaft drive housing 8 is disposed below this oil pan 5. An exhaust gas which the engine discharges is discharged into the shaft drive housing 8 through the engine, the engine holder 2 and an exhaust gas passage formed in the oil pan 5. Whereas, cooling water passages 21, 23 and a return water passage are provided around the exhaust gas passage. In this case, a bonding means 35 to the oil pan 5 is provided in the engine holder 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an outboard motor.

[0002]

2. Description of the Related Art Some outboard motor engines have, for example, a cylinder block in which a plurality of cylinders are arranged vertically. Further, an intake port and an exhaust port are formed for each cylinder in the cylinder head joined to the cylinder block. The exhaust gas discharged from each exhaust port is collected in a common exhaust passage and discharged outside the outboard motor.

Since the temperature of the exhaust passage becomes extremely high due to the exhaust gas, a cooling water passage is formed around the exhaust passage to cool the exhaust passage with the cooling water. The cooling water passage is provided in a member through which the exhaust passage passes, such as a cylinder block, an engine holder, and an oil pan.

[0004]

However, since the tightening bolts for connecting the engine holder and the oil pan are arranged only around these members, the contact surface pressure near the center of both members is reduced. Lower than the mating contact pressure. As a result, when the cooling water passage is disposed closer to the center of the engine holder or the oil pan than the exhaust passage, if the cooling water pressure is high, the cooling water leaks from the mating surface between the center portions of the two members.

On the other hand, it is possible to arrange the cooling water passage closer to the periphery of the engine holder and the oil pan than the exhaust passage. In this case, for example, the exhaust gas sampling port is provided in the engine holder, and the cooling water is provided in the oil pan. Can not be formed.

The present invention has been made in view of the above-mentioned circumstances, and the cooling water passage can be arranged closer to the center of the engine member than the exhaust passage by increasing the contact pressure near the center of the engine member. The purpose is to provide an outboard motor.

[0007]

An outboard motor according to the present invention comprises:
In order to solve the above-mentioned problem, an engine is disposed above an engine holder, an oil pan is disposed below the engine holder, and a shaft drive housing is disposed below the oil pan. Exhaust gas discharged by an engine is discharged into the shaft drive housing through an exhaust passage formed in the engine, the engine holder and the oil pan, and a cooling water passage and a return water passage are provided around the exhaust passage. In the external machine, a connecting means for connecting to the oil pan is provided in the engine holder.

According to another aspect of the present invention, the exhaust passage, the cooling water passage, and the return water passage are formed, and a mating surface between the engine holder and the oil pan is formed. The vertical wall to be formed is formed in the engine holder and the oil pan, and the vertical wall is provided with the connecting means.

Further, in order to solve the above-mentioned problems,
As described in claim 3, a vertical wall forming the exhaust passage, the cooling water passage, and the return water passage, and forming a mating surface between the engine holder and the oil pan is formed in the engine holder and the oil pan. The connecting means is provided at the intersection of the vertical walls and the ribs connecting the vertical walls.

According to another aspect of the present invention, the exhaust passage, the cooling water passage, and the return water passage are formed, and a mating surface between the engine holder and the oil pan is provided. And the engine and the outer wall of the oil pan and the engine are connected at a plurality of positions by connecting means.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a left side view of an outboard motor to which the present invention is applied. As shown in FIG. 1, the outboard motor 1 includes an engine holder 2, and an engine 3 is installed above the engine holder 2. The engine 3 is a vertical engine in which a crankshaft 4 is disposed substantially vertically.

An oil pan 5 is arranged below the engine holder 2, and a bracket 6 is attached to the engine holder 2, for example, so that the outboard motor 1 can be mounted on a transom of a hull (not shown) via the bracket 6. Be attached. The periphery of the engine 3, the engine holder 2 and the oil pan 5 of the outboard motor 1 is covered by an engine cover 7.

A shaft drive housing 8 is provided below the oil pan 5. A drive shaft 9 is disposed substantially vertically in the engine holder 2, the oil pan 5 and the shaft drive housing 8, and an upper end thereof is connected to a lower end of the crankshaft 4. The drive shaft 9 extends downward in the shaft drive housing 8 and is configured to drive a propeller 13 through a bevel gear 11 and a propeller shaft 12 in a gear case 10 provided at a lower portion of the shaft drive housing 8.

The engine 3 mounted on the outboard motor 1 includes:
For example, it is a four-cycle three-cylinder engine configured by combining a cylinder head 14, a cylinder block 15, a crankcase 16, and the like. The engine 3 is a water-cooled engine that takes in seawater, lake water, and river water from an intake 17 provided in the gear case 10 and uses it as cooling water.

A cylinder block 15 is disposed at the forefront of the engine 3, that is, behind (right side) a crankcase 16 disposed at the leftmost side in FIG. The cylinder head 14 is disposed behind the cylinder block 15.

FIG. 2 is an enlarged longitudinal sectional view of a central portion of the outboard motor 1. FIG. 3 is a top view of the oil pan 5, and FIG. 4 is a bottom view of the oil pan 5. And FIG.
Is a top view of the engine holder 2 and FIG. 6 is a bottom view of the engine holder 2.

As shown in FIGS. 2 to 6, a water pump 18 connected to the water intake 17 is provided at the bottom of the shaft drive housing 8. Water pump 18
Is driven by a drive shaft 9, and a water supply pipe 19 is arranged upward from the water pump 18.

A horizontal cooling water passage 20 extending in the horizontal direction is formed at the bottom of the oil pan 5, and the cooling water inlet 20 a provided at the upstream end of the horizontal cooling water passage 20 is connected to the water supply pipe 19.
Are connected at the downstream end. Further, from the middle of the horizontal cooling water passage 20, a vertical cooling water passage 21 which is surrounded by the outer wall 5a and the vertical wall 5b extends upward. A cooling water outlet 22 for water detection is formed on the outer wall 5a of the oil pan 5.

A cooling water passage 23 is formed in the engine holder 2 so as to penetrate the engine holder 2 in the vertical direction and is surrounded by an outer wall 2a and a vertical wall 2b. Connect. The downstream end of the cooling water passage 23 is connected to a cooling water jacket (not shown) formed in the engine 3.

Further, the cooling water that has cooled the various parts of the engine 3 becomes return water and becomes the engine holder 2 and the oil pan 5.
Is guided to return water passages 24 and 25 formed by being surrounded by the outer walls 2a and 5a and the vertical walls 2b and 5b.
A return water outlet 26 is formed on the bottom surface of the oil pan 5 and drains the return water to a space formed in the shaft drive housing 8.

On the other hand, exhaust gas discharged from each cylinder (not shown) of the engine 3 is formed in the shaft drive housing 8 through exhaust passages 27 and 28 formed in the engine holder 2 and the oil pan 5. Exhausted into space. The exhaust passages 27 and 28 penetrate in the vertical direction of the engine holder 2 and the oil pan 5, and surround the outer wall 2.
a, 5a, cooling water passages 21, 23 and return water passage 2
4, 25 are formed so as to be surrounded by the vertical walls 2b, 5b, and are offset to one side from a center line (not shown) connecting the front and rear of the outboard motor 1 and, in the present embodiment, to the left side. . An exhaust gas sampling port 29 connected to the exhaust passage 27 is formed on the outer wall 2a of the engine holder 2.

The above-described vertical cooling water passage 2 of the oil pan 5
1, a cooling water passage 23 of the engine holder 2, a return water passage 24 formed in the engine holder 2 and the oil pan 5,
25 are arranged around the exhaust passages 27 and 28, respectively.
The exhaust gas is cooled by cooling water and return water.

For example, as shown in FIG. 6, the cooling water passage 23 formed in the engine holder 2 extends substantially from the front side of the exhaust passage 27 to the center of the engine holder 2 on the side opposite to the exhaust gas sampling port 29. It is formed and arranged in the shape of a letter. The return water passage 24 formed in the engine holder 2 is formed and arranged on the rear side of the exhaust passage 27.

Incidentally, an outer wall 2a around the engine holder 2 and a cooling water passage 23 and a return water passage 24 inside the outer wall 2a.
And the lower surface of the vertical wall 2b forming the exhaust passage 27, the outer wall 5a around the oil pan 5, and the vertical wall 5b forming the vertical cooling water passage 21 and the exhaust passage 28 therein.
Form a mating surface 30 that aligns and adheres to each other (see FIGS. 3 and 6).

The engine holder 2 and the oil pan 5 are fastened and fixed to the engine 3 composed of the cylinder head 14, the cylinder block 15 and the crankcase 16 by a plurality of through bolts 31 as connecting means. The holder 2 and the oil pan 5 are joined to each other by a plurality of other bolts 32 serving as coupling means.
Are fixed to the engine 3 after being connected in advance. A gasket (not shown) is interposed on a mating surface (not shown) between the engine 3 and the engine holder 2 and a mating surface 30 between the engine holder 2 and the oil pan 5.

As shown in FIG. 4, a total of eight through-bolts 31, for example, four on each side of the outer wall 5a around the oil pan 5, are arranged as shown in FIG. The oil pan 5 is inserted from below the oil pan 5 toward the upper engine holder 2. Further, three bolts 32 for connecting the engine holder 2 and the oil pan 5 in advance are arranged, for example, one at the front side of the oil pan 5 and two at the rear side.
Is inserted from below to the upper engine holder 2.

Then, the cooling water passages 21 and 23, the return water passage 24,
25 and vertical walls 2b, 5 forming exhaust passages 27, 28
b and a rib 33 connecting these vertical walls 2b and 5b, a bolt hole 34 is formed.
A bolt 35 as a connecting means is inserted from the upper surface of the engine holder 2 toward the oil pan 5 below and tightened (see FIGS. 2 and 5), whereby the engine holder 2 and the oil pan 5 are substantially omitted in plan view. The central parts are joined.

Next, the operation of the present embodiment will be described.

When the drive shaft 9 rotates with the operation of the engine 3, cooling water is pumped up by the water pump 18, passes through the water supply pipe 19, and passes through the cooling water inlet 20 a through the horizontal cooling water passage 20 formed in the oil pan 5. Cooling water is guided to the vertical cooling water passage 21. This cooling water is guided to each part of the engine 3 through a cooling water passage 23 formed in the engine holder 2, and the cooling water that has cooled each part of the engine 3 becomes return water and returns to the shaft drive housing via return water passages 24 and 25. The water is drained into the space formed in 8.

On the other hand, the exhaust gas discharged from each cylinder (not shown) with the operation of the engine 3 is discharged into the shaft drive housing 8 through the exhaust passage 27 in the engine holder 2 and the exhaust passage 28 in the oil pan 5. You.

In the present invention, the cooling water passages 21 and 23 and the return water passages 24 and 25 formed in the engine holder 2 and the oil pan 5 are connected to the exhaust passages 27 and 28, respectively.
, And the exhaust gas is cooled by the cooling water and the return water, whereby the temperature rise in the shaft drive housing 8 is regulated and the adhesion of calcium to the outer wall of the shaft drive housing 8 is prevented. .

Cooling water passages 21 and 23 and return water passage 2
Outer walls 2a, 5a and vertical walls 2b, 5 forming
b, the through holes 31 arranged on both sides of the outer wall 5a around the oil pan 5 fasten the engine holder 2 and the oil pan 5 to the engine 3 together. Surface pressure is applied to the mating surface 30 around the pan 5, and sufficient sealing performance is ensured.

The outer walls 2a, 5a and the vertical walls 2 forming the cooling water passages 21, 23 and the return water passages 24, 25
Of the b and 5b, the vertical walls 2b and 5b are connected to the engine holder 2 and the oil pan 5 by bolts 35 provided at intersections of the vertical walls 2b and 5b and the ribs 33 connecting these vertical walls 2b and 5b. As a result, surface pressure is applied to the mating surface 30 of the engine holder 2 and the central portion of the oil pan 5,
Sufficient sealing properties are ensured.

As a result, even if the cooling water pressure is increased, the cooling water does not leak from the mating surface 30 at the center of the engine holder 2 and the oil pan 5, so that the cooling efficiency of the engine 3 and the exhaust gas is improved.

The cooling water passages 21 and 23 and the return water passages 24 and 25 are separated from the exhaust passages 27 and 28 by the engine holder 2.
The oil pan 5 can be disposed near the center of the oil pan 5, and the engine holder 2 can have an exhaust gas sampling port 29 and the oil pan 5 can have a cooling water outlet 22 for detecting cooling water.

[0037]

As described above, according to the outboard motor of the present invention, the engine is disposed above the engine holder, the oil pan is disposed below the engine holder, and the shaft drive housing is disposed below the oil pan. And exhausting the exhaust gas discharged by the engine into the shaft drive housing through an exhaust passage formed in the engine, the engine holder and the oil pan,
In the outboard motor provided with the cooling water passage and the return water passage around the exhaust passage, the connecting means for coupling with the oil pan is provided in the engine holder. The performance is improved.

A vertical wall forming the exhaust passage, the cooling water passage and the return water passage, and forming a mating surface between the engine holder and the oil pan is formed in the engine holder and the oil pan. Since the connecting means is provided on the vertical wall, the contact surface pressure between the engine holder and the central portion of the oil pan is increased, and the sealing performance is improved.

Further, a vertical wall forming the exhaust passage, the cooling water passage and the return water passage, and forming a mating surface between the engine holder and the oil pan is formed in the engine holder and the oil pan. Since the connecting means is provided at the intersection of the vertical walls and the ribs connecting these vertical walls, the contact pressure between the engine holder and the central portion of the oil pan is further increased, and the sealing performance is further improved.

Further, means for connecting the outer wall of the engine holder and the oil pan, which form the exhaust passage, the cooling water passage and the return water passage, and the mating surface of the engine holder and the oil pan, with the engine. At a plurality of locations, the mating surface pressure around the engine holder and the oil pan is increased, and the sealing performance is improved.

[Brief description of the drawings]

FIG. 1 is a left side view showing an embodiment of an outboard motor according to the present invention.

FIG. 2 is an enlarged longitudinal sectional view of a central portion of the outboard motor.

FIG. 3 is a top view of the oil pan.

FIG. 4 is a bottom view of the oil pan.

FIG. 5 is a top view of the engine holder.

FIG. 6 is a bottom view of the engine holder.

[Explanation of symbols]

 Reference Signs List 1 outboard motor 2 engine holder 2a, 5a outer wall 2b, 5b vertical wall 3 engine 5 oil pan 8 shaft drive housing 20, 21, 23 cooling water passage 24, 25 return water passage 27, 28 exhaust passage 31, 32, 35 volt (Coupling means) 33 Rib connecting vertical walls

Claims (4)

[Claims] An engine is disposed above an engine holder, an oil pan is disposed below the engine holder, a shaft drive housing is disposed below the oil pan, and exhaust gas discharged by the engine is discharged from the engine, the engine holder, and the engine holder. In an outboard motor provided with a cooling water passage and a return water passage around the exhaust passage while discharging the oil pan through the exhaust passage formed in the oil pan into the shaft drive housing, the oil pan is disposed in the engine holder 2. An outboard motor, comprising: means for coupling to an outboard motor (5). 2. The exhaust passages 27 and 28, the cooling water passage 2
Vertical walls 2b, 5b are formed in the engine holder 2 and the oil pan 5 to form the mating surfaces 30 between the engine holder 2 and the oil pan 5, respectively. The outboard motor according to claim 1, wherein said connecting means (35) is provided on said vertical walls (2b, 5b). 3. The exhaust passages 27 and 28, the cooling water passage 2
Vertical walls 2b, 5b are formed in the engine holder 2 and the oil pan 5 to form the mating surfaces 30 between the engine holder 2 and the oil pan 5, respectively. 2. An outboard motor according to claim 1, wherein said connecting means is provided at an intersection between said vertical walls 2b, 5b and a rib 33 connecting said vertical walls 2b, 5b. 4. The exhaust passages 27 and 28, the cooling water passage 2
1 and 23 and return water passages 24 and 25, and the engine 3 with the outer walls 2a and 5a of the engine holder 2 and the oil pan 5 forming the mating surface 30 between the engine holder 2 and the oil pan 5. The outboard motor according to claim 2, wherein the outboard motor is connected at a plurality of positions by connecting means.