JP2589903Y2 - Seal structure of ignition device for internal combustion engine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure for an ignition device of an internal combustion engine.

[0002]

2. Description of the Related Art A spark plug is mounted on a cylinder head of an internal combustion engine.
Water, debris, etc. from the opening formed in the lid or rocker cover
As shown in FIG. 7 , in order to prevent
A rubber cover 3 is fitted on the side of the terminal 2 connected to the plug 2 to seal the plug insertion port 4.

[0003] A rubber cover 3 is provided at a locking portion of the ignition coil 5.
Fits to protect terminal 2 and protrudes downward cylindrically
The formed skirt portion 6 is fitted into the plug insertion port 4 and inserted.
Intrusion of dust and the like into the entrance 4 is prevented.
-75358).

[0004]

However, in the case of a rubber cover having such a shape, the skirt portion 6 is undercut, so that the molding die of the rubber cover is complicated, and since there are many irregularities, the rubber cover is formed. There is a disadvantage that the life of the mold is short.

[0005] Further, the sealing surface substantially corresponds to the skirt portion 6.
Since only the contact portion with the plug insertion port 4 is provided,
If water accumulates above the opening level, check the seal surface.
Water may intrude .

As a countermeasure, for example, the outside of the rubber cover 3
It is possible to increase the diameter, but if you do so,
A large space is required around the rubber cover 3
The cylinder head and rocker cover become large.

The purpose of the present invention is to solve such a problem.

[0008]

The present invention provides a seal structure of an ignition device for an internal combustion engine in which a plug insertion port surrounded by an annular wall is sealed by an elastic cover fitted to a high-voltage line connected to an ignition plug. in the the first sealing portion in contact with the inner peripheral surface of the plug insertion port into the elastic cover, provided <br/> a second seal portion flange-shaped contacting the open end face of the plug insertion port Rutotomoni, Provide a boss outside the plug insertion slot,
At the boss part, the second sealing part is the opening end face of the plug insertion port.
The ignition coil is fixed so as to be pressed .

[0009]

Therefore, the seal has a simple shape and can be sealed by the first and second plural seal portions, so that it is waterproof or dustproof.
Is improved. The brim-shaped 20th seal is a simple shape
It is plugged by an ignition coil that presses this
It is in close contact with the opening end face of the insertion port and exhibits sealing properties.
The area and outer diameter of the device need only be small, and the distance from the surroundings can be reduced accordingly.

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

As shown in FIGS. 1 and 2, a cylinder head
A plug insertion opening 21 provided in a main body 20 such as a cover or a rocker cover is surrounded by an annular wall 22 around the opening.
A spark plug 25 is attached to the bottom of the hole 24 following the wall surface 3.

An elastic cover 26 for sealing the plug insertion opening 21 is fitted to a hooking portion 28 on the lower surface of the ignition coil 27, and a shield pipe 30 for a high-voltage wire 29 from the ignition coil 27 is press-fitted and supported at a lower portion. .

When the shield pipe 30 is inserted into the plug insertion port 21, the elastic cover 26
1, the shield pipe 30 is fitted to the spark plug 25,
The high-voltage wire 29 comes into contact with the plug terminal 31. The elastic cover 26, the you contact with the first seal portion 32 cylindrical in contact with the inner peripheral surface 23 of the plug insertion opening 21, the open end of the plug insertion opening 21 to 33 (upper surface of the annular wall 22) Two seal portions 34 are provided, and sealing is performed on a plurality of surfaces. Second
The seal portion 34 is formed in a brim-like shape and is in contact with the open end portion 33.
The surface to be touched is a substantially flat and simple shape .

In this case, a plurality of annular projections 35 formed on the first seal portion 32
It is designed to be adhered to.

The ignition coil 27 has its own fixed
And press the second seal portion 34
The second seal portion 34 is fixed to a mounting boss portion 36 formed on the body 20 by a bolt 37, and in this set state, the second seal portion 34 comes into contact with the opening end surface 33 of the plug insertion port 21 at a predetermined surface pressure. .

Reference numeral 38 denotes an air hole communicating with the inside of the hole 24.

As described above, the inner peripheral surface 2 of the plug insertion port 21
3, the first seal portion 32 contacts the opening end surface 33 of the plug insertion port 21 and the second seal portion 34 seals, so that even if water accumulates on the annular wall 22 at the open end or more, the water is plugged. It does not enter the inner peripheral surface 23 side of the insertion port 21,
Can be sealed securely.

Further, since the seal portions 32 and 34 have a simple shape, the production of the mold of the elastic cover 26 is facilitated.
Since the mold has few irregularities, the life of the mold is significantly prolonged.

The seal 34 on the open end face 33 of the plug insertion port 21 is connected to the ignition coil 2 fixed to the boss 36.
7 and the brim-shaped portion is
It is designed to be close to the outside diameter and area.
Mounting of the surrounding ignition coil 27
The distance between the boss 36 and the ignition coil
27 can also be reduced in size, and
0 can also be made compact.

Since the brim-shaped seal portion 34 is used, even if there are variations in the dimensions of each portion, it is possible to cope with the variations and to reliably perform the sealing.

FIGS. 3 to 6 show other embodiments.

FIG. 3 shows the outer diameter of the brim-shaped second seal portion 41 of the elastic cover 40 by changing the outer diameter of the plug end 21 to the opening end surface 33.
That is, it is larger than the maximum outer diameter of the annular wall 22.

According to this, water does not accumulate on the opening end face 33 of the plug insertion port 21 and sealing can be performed more reliably.

FIG. 4 shows that the thickness of the collar-shaped second seal portion 51 of the elastic cover 50 is gradually reduced toward the outer periphery. FIG. 5 shows the plug insertion opening of the collar-shaped second seal portion 61 of the elastic cover 60. The entire portion of the opening 21 that comes into contact with the opening end face 33 is thinned.

By doing so, the sealing portion 5 can be set at the time of setting.
Even if 1 and 61 are distorted, the air holes 38 are not deformed by this, so that the air holes 38 can be prevented from being closed.

[0026] FIG. 6 is obtained by forming a long oval cross-section the cross-section of the air hole 71 of the elastic cover 70 in the radial direction of the elastic cover 70.

By doing so, the sealing portion 7 can be set at the time of setting.
Even if the air hole 71 is deformed due to distortion of the air hole 71, the air hole 71 is closed.
I won't lose .

[0028]

As described above, the present invention provides a seal structure of an ignition device for an internal combustion engine in which a plug insertion port surrounded by an annular wall is sealed by an elastic cover fitted to a high-voltage line connected to an ignition plug. in a first seal portion that contacts the inner peripheral surface of the plug insertion port into the elastic cover, set <br/> only a second seal portion flange-shaped contacting the open end face of the plug insertion port Rutotomoni A boss is provided outside the plug insertion port,
At the boss part, the second seal part at the opening end face of the plug insertion port
Since the ignition coil is fixed so as to be pressed, it can be reliably sealed, the elastic cover can be easily manufactured, and the space around the plug insertion opening can be reduced, so that the ignition coil and the like can be made compact.

[Brief description of the drawings]

FIG. 1 is a sectional view.

FIG. 2 is a perspective view in which a part of an elastic cover is cut away.

FIG. 3 is a sectional view of a main part of another embodiment.

FIG. 4 is a sectional view of a main part of another embodiment.

FIG. 5 is a sectional view of a main part of another embodiment.

FIG. 6 is a sectional view of a main part of another embodiment.

FIG. 7 is a sectional view of a conventional example.

[Explanation of symbols]

21 Plug insertion port 22 Annular wall 23 Inner peripheral wall 25 Ignition plug 26 Elastic cover 27 Ignition coil 29 High voltage wire 30 Shield pipe 32 First seal part 33 Open end face 34 Second seal part 36 Boss part 38 Air hole 41 Second Seal part 51 Second seal part 61 Second seal part 71 Air hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F02P 13/00

Claims (1)

(57) [Scope of request for utility model registration] 1. A seal structure for an ignition device for an internal combustion engine, wherein a plug insertion port surrounded by an annular wall is sealed by an elastic cover fitted to a high-voltage line connected to an ignition plug. Rutotomoni provided a first seal portion that contacts the inner peripheral surface of the mouth, and a second seal portion flange-shaped contacting the open end face of the plug insertion opening, the plug insertion
A boss is provided outside the mouth, and a second seal is provided on the boss.
Part of the ignition coil so that the
A seal structure for an ignition device for an internal combustion engine, wherein the seal structure is fixed .