JPH10339252A - Ignition plug mounting structure of outboard engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make water hardly collect in a plug hole, and easily discharge the collected water by forming a water drain hole in the plug hole. SOLUTION: An ignition plug is connected horizontally to a combustion chamber of an outboard engine from the outside. The ignition plug is mounted in a plug hole 24 for mounting the ignition plug formed in a cylinder head cover 8, and a plug cap 25 is inserted in the ignition plug. A flange 28 is formed in an opening part 26 of the plug hole 24, and a part of a lower part of the flange 28 is notched to form a notched part 29. A flange 30 to be fitted to the inner side of the flange 28 of the opening part 26 is formed on the inner side of a cap cover 27. A recessed part 31 is formed in an edge part of the opening part 26 located in the notched part 29 to function a part between the recessed part 31 and the flange 30 as a water drain hole 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a spark plug mounting structure for an outboard motor.

[0002]

2. Description of the Related Art A DOHC engine having two camshafts for opening and closing intake and exhaust valves can have an ignition plug attached to the center of a cylinder. The spark plug is
Usually, a plug hole for mounting a spark plug formed in a cylinder head cover is mounted.

[0003]

However, DOH
Since the plug hole of the C engine is extremely deep, water easily accumulates. Since the spark plug is an electrical component, it is not preferable that water accumulates in the plug hole, and it is desirable that the spark plug be discharged quickly.

The present invention has been made in view of the above circumstances, and provides an outboard motor spark plug mounting structure that makes it difficult for water to accumulate in a plug hole and that can easily discharge accumulated water. Aim.

[0005]

According to the present invention, there is provided a spark plug mounting structure for an outboard motor according to the present invention.
As set forth in claim 1, an outboard motor in which an ignition plug is horizontally connected to a combustion chamber aligned with a cylinder formed horizontally in a cylinder block from a plug hole for mounting an ignition plug formed in a cylinder head cover. In the spark plug mounting structure, a drain hole is formed in the plug hole.

In order to solve the above-mentioned problem, a plug cap is inserted into an ignition plug in the plug hole and an end of the plug hole is inserted into an end of the plug cap. A cap cover for closing the opening is attached, and a flange is formed along an opening edge of the opening of the plug hole, and a notch is formed at a lower portion of the flange, while the plug is formed inside the cap cover. A flange that can be fitted to the flange of the hole opening is formed, and a recessed portion that is recessed toward the back of the plug hole is formed at an edge of the plug hole opening located at the notch of the flange of the plug hole opening. A drain hole is formed between the recess and the flange B of the cap cover.

Further, in order to solve the above-mentioned problems,
As described in claim 3, a plug cap is inserted into the ignition plug in the plug hole, and a cap cover for closing an opening of the plug hole is attached to an end of the plug cap, A flange is formed along an opening edge of the opening, and a notch is formed at a lower portion of the flange, and a flange that can be fitted to the flange of the plug hole opening is formed inside the cap cover. A notch is formed in the flange of the cap cover facing the notch of the flange of the plug hole opening, and a drain hole is formed in both notches.

[0008]

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

FIG. 1 is a left longitudinal sectional view of an outboard motor to which the present invention is applied, and FIG. 2 is a rear view thereof. As shown in FIGS. 1 and 2, the outboard motor 1 includes an engine holder 2, and an engine 3 is installed above the engine holder 2. The engine 3 is, for example, a water-cooled 4-cycle DO
An HC three-cylinder engine is configured by combining a cylinder head 4, a cylinder block 5, a crankcase 6, and the like, and is mounted on the engine holder 2 via a cam chain case 7.

The cylinder block 5 is arranged behind the crankcase 6, that is, on the right side in FIG. The cylinder head 4 is arranged behind the cylinder block 5. Further, the rear part of the cylinder head 4 is covered by a cylinder head cover 8. The cam chain case 7 is arranged below the crankcase 6, the cylinder block 5, the cylinder head 4 and the cylinder head cover 8.

A crankshaft 9 is disposed vertically in the crankcase 6, while an oil pan 10 is disposed below the engine holder 2. In addition, the periphery from the engine 3 to the oil pan 10 is covered with an engine cover 11.

A drive shaft housing 12 is provided below the oil pan 10. The upper end of the drive shaft 13 is spline-fitted to the lower end of the crankshaft 9, for example. The drive shaft 13 extends downward in a shaft pipe 14 formed in the drive shaft housing 12, and the gear case 1 provided in a lower portion of the drive shaft housing 12.
5 is configured to drive the propeller 16 via a bevel gear and a propeller shaft (not shown).

In the cylinder block 5 of the engine 3, three cylinders 17 arranged vertically are formed horizontally. Further, the combustion chambers 1 matched with these cylinders 17
8 is formed on the cylinder head 4. A piston 19 is slidably inserted in the cylinder 17 in the horizontal direction, and the piston 19 and the crankshaft 9 are connected by a connecting rod 20. Then, the reciprocating stroke of the piston 19 is converted into the rotational movement of the crankshaft 9.

A valve mechanism 22 such as two camshafts 21 is disposed in the cylinder head 4. A cam chain (not shown) is arranged in the cam chain case 7, and the cam chain 21 operatively connects the cam shaft 21 and the crank shaft 9.

The ignition plug 2 is inserted into the combustion chamber 18 from the outside.
3 are joined horizontally. The spark plug 23 is mounted through a plug hole 24 formed in the cylinder head cover 8 for mounting a spark plug. A plug cap 25 is inserted into the ignition plug 23.

FIG. 3 shows an enlarged sectional view of the vicinity of the plug hole opening 26 in a first embodiment, and FIG. 4 shows a second embodiment in an enlarged sectional view. 5 is an arrow view along the line VV of FIG. 3, FIG. 6 is an arrow view along the line VI-VI of FIG. 3, FIG. 7 is an arrow view along the line VII-VII of FIG. FIG. 8 shows VIII- of FIG.
It is an arrow view along VIII line. The same components are denoted by the same reference numerals.

As shown in FIGS. 3 and 4, a cap cover 27 for closing the opening 26 of the plug hole 24 is integrally attached to the end of the plug cap 25 exposed outside the cylinder head cover 8.

As shown in FIG. 3 to FIG.
A flange 28 is formed along the opening edge of the opening 26 of FIG. 4, and a part of the lower portion of the flange 28 is cut out to form a cutout 29. Further, inside the cap cover 27, a flange 30 which can be fitted inside the flange 28 of the plug hole opening 26 is formed in an annular shape.

In the first embodiment, FIG. 3 and FIG.
As shown in FIG. 5, a recess 31 is formed at the edge of the plug hole opening 26 located in the cutout 29 of the flange 28 formed in the opening 26 of the plug hole 24 so as to be recessed toward the inside of the plug hole 24. Then, a drain hole 32 is formed between the recess 31 and the flange 30 of the cap cover 27.

In the second embodiment, as shown in FIGS. 4 and 8, the flange 30 of the cap cover 27 facing the cutout 29 of the flange 28 formed in the opening 26 of the plug hole 24 is also provided. A similar notch 33 is formed, and a drain hole 34 is formed by both notches 29 and 33. Next, the operation of the present embodiment will be described.

Since the plug hole 24 of the DOHC engine 3 is extremely deep, water easily accumulates. However, by closing the plug hole 24 with the cap cover 27, the intrusion of water is minimized. Even if water enters, the drain hole 3 is formed in the opening 26 of the plug hole 24.
The formation of 2, 34 allows the accumulated water to be easily discharged.

Further, since the drain holes 32 and 34 can be formed by simple processing, no cost is required.

[0023]

As described above, according to the spark plug mounting structure for an outboard motor according to the present invention, the cylinder head cover is formed in the combustion chamber that is aligned with the cylinder formed horizontally in the cylinder block. In a spark plug mounting structure for an outboard motor in which a spark plug is horizontally connected to a plug hole for mounting a spark plug, a drain hole is formed in the plug hole, so that water collected in the plug hole can be easily discharged.

A plug cap is inserted into the ignition plug in the plug hole, and a cap cover for closing the opening of the plug hole is attached to an end of the plug cap. A flange is formed along the opening edge thereof, and a notch is formed at a lower portion of the flange, and a flange that can be fitted to the flange of the plug hole opening is formed inside the cap cover, and the plug hole is formed. At the edge of the plug hole opening located at the notch of the opening flange, a recess is formed which is recessed toward the inside of the plug hole, and water is drained between the recess and the flange B of the cap cover. Since the hole is formed, the intrusion of water into the plug hole can be prevented with a simple structure, and the drainage of water that has accumulated in the plug hole can be prevented. It is also facilitated.

Further, a plug cap is inserted into the ignition plug in the plug hole, and a cap cover for closing the opening of the plug hole is attached to an end of the plug cap. A flange is formed along the opening edge thereof, and a notch is formed at a lower portion of the flange, and a flange that can be fitted to the flange of the plug hole opening is formed inside the cap cover, and the plug hole is formed. Because a notch was formed in the flange of the cap cover opposite to the notch of the opening flange, and a drain hole was formed in both notches,
Simple structure prevents water from entering the plug hole,
In addition, it is easy to discharge water that has entered and accumulated in the plug hole.

[Brief description of the drawings]

FIG. 1 is a left vertical sectional view of an outboard motor showing an embodiment of a spark plug mounting structure for an outboard motor according to the present invention.

FIG. 2 is a rear view of the outboard motor shown in FIG.

FIG. 3 is an enlarged sectional view showing the first embodiment in the vicinity of a plug hole opening;

FIG. 4 is an enlarged sectional view showing a second embodiment in the vicinity of a plug hole opening;

FIG. 5 is an arrow view along the line VV in FIG. 3;

FIG. 6 is an arrow view along the line VI-VI in FIG. 3;

FIG. 7 is an arrow view along the line VII-VII in FIG. 4;

FIG. 8 is an arrow view along the line VIII-VIII in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outboard motor 3 Engine 4 Cylinder head 5 Cylinder block 8 Cylinder head cover 17 Cylinder 18 Combustion chamber 23 Ignition plug 24 Plug hole 25 Plug cap 26 Plug hole opening 27 Cap cover 28, 30 Flange 29, 33 Notch 31 Depression 32, 34 drain holes

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Katsuhiro Fukuda 300 Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd. (72) Inventor Jun Ito 300 Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd. (72) Inventor Akira Takahashi 300, Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd. (72) Inventor Shuichi Hagino 300, Takatsukacho, Hamamatsu-shi, Shizuoka Suzuki Co., Ltd.

Claims (3)

[Claims] 1. A spark plug mounting structure for an outboard motor in which a spark plug is horizontally connected to a combustion chamber aligned with a cylinder formed horizontally in a cylinder block from a plug hole for mounting a spark plug formed in a cylinder head cover. 3. A spark plug mounting structure for an outboard motor according to claim 1, wherein drain holes 32, 34 are formed in said plug hole 24. 2. The ignition plug 2 in the plug hole 24.
A plug cap 25 is inserted into the plug cap 3, and a cap cover 27 for closing the opening 26 of the plug hole 24 is attached to an end of the plug cap 25. The opening 26 of the plug hole 24 has an opening edge. A notch 29 is formed below the flange 28, and a flange 30 is formed inside the cap cover 27 so as to be fittable with the flange 28 of the plug hole opening 26. At the edge of the plug hole opening 26 located at the notch 29 of the flange 28 of the plug hole opening 26, a recess 31 is formed which is recessed toward the inside of the plug hole 24, and the recess 31 and the cap are formed. 2. A spark plug mounting structure for an outboard motor according to claim 1, wherein a drain hole is formed between the cover and the flange. 3. The ignition plug 2 in the plug hole 24.
A plug cap 25 is inserted into the plug cap 3, and a cap cover 27 for closing the opening 26 of the plug hole 24 is attached to an end of the plug cap 25. The opening 26 of the plug hole 24 has an opening edge. A notch 29 is formed below the flange 28, and a flange 30 is formed inside the cap cover 27 so as to be fittable with the flange 28 of the plug hole opening 26. The notch (33) is formed in the flange (30) of the cap cover (27) facing the notch (29) of the flange (28) of the plug hole opening (26), and the drain holes (34) are formed in both notches (29) and (33). Outboard motor spark plug mounting structure.