JP2002299004A - Plug cap for spark plug - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide plug cap for a spark plug to be easily set in a plug hole, capable of securely preventing penetration of water drops into the plug hole. SOLUTION: An engaging part is formed in a rain cover, closely attached to the surface of the outer wall of a projecting part of the plug hole projecting from an engine head cover, when the plug cap is inserted into the plug hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug cap for an ignition plug for connecting an ignition cable or an ignition coil to an ignition plug of, for example, an automobile engine. The present invention relates to a spark plug plug cap that can reliably prevent water droplets from entering.

[0002]

2. Description of the Related Art A plug cap for an ignition plug is used to connect an ignition cable or an ignition coil to an ignition plug of an engine and to hermetically seal a plug hole. An example of the structure of such a spark plug plug cap will be described with reference to FIGS. A spark plug 3 is attached to the bottom of the plug hole 2.
An ignition plug plug cap 5 is used to connect an ignition cable (not shown) or an ignition coil 4 for supplying a high voltage to the ignition plug 3.

At the lower end of the plug cap 5, there is provided a tip cap portion 8 formed of an insulating rubber material so as to be fitted to the insulator portion 3a of the ignition plug 3 and to prevent leakage of high voltage current. . Further, at the upper end, a rain cover portion 10 for preventing water droplets from entering the plug hole 2 is formed.

[0004] The rain cover section 10 includes a main body section 11.
On the outer peripheral surface of the main body portion 11, a fitting portion 12 that fits into the inner wall surface of the plug hole 2 and a flange portion 13 that is in close contact with the surface of the engine head cover 1 are provided in a protruding manner. I have.

When the plug cap 5 is inserted into the plug hole 2, the connection terminal 7 is fitted into the terminal portion 3b at the upper end of the ignition plug 3, and an ignition cable or ignition coil 4 (not shown) is connected to the ignition plug 3. You. At the same time, the fitting portion 12 of the rain cover portion 10 is fitted in the plug hole 2 to seal the plug hole 2 in a liquid-tight manner, and the flange portion 13 is in close contact with the engine head cover 1 so that the opening portion of the plug hole 2 is formed. To prevent water droplets from entering the plug hole 2.

[0006]

However, in the conventional spark plug plug cap 5 described above, the fitting portion 12 of the rain cover portion 10 fits inside the plug hole 2 and the flange portion 13 as described above. Are tightly attached to the engine head cover 1 to seal the plug hole 2 in a liquid-tight manner, and a closed space exists. For this reason, the temperature of the space rises when the engine is started and falls when the engine is stopped. When the temperature falls, the space becomes negative pressure, sucks water droplets around the flange portion 13, and further passes through the fitting portion 12. A phenomenon in which water drops enter the plug hole 2 occurs.

Therefore, in order to increase the degree of sealing the plug hole 2 in a liquid-tight manner, the degree of fitting between the plug hole 2 and the fitting portion 12 of the rain cover portion 10 must be increased. Then, when the spark plug plug cap 5 is attached to the plug hole 2, the fitting portion 12 of the rain cover portion 10 comes into strong sliding contact with the inner wall surface of the plug hole 2, and the spark plug plug cap 5 Is difficult to attach to the plug hole 2.

The present invention has been made in view of the above problems, and has as its object to provide a plug cap for an ignition plug that can be easily mounted in a plug hole and that can reliably prevent water droplets from entering the plug hole. And

[0009]

According to the present invention, there is provided a tip cap for sealing a spark plug to insulate the spark plug and a rain cover for covering an opening of a plug hole. In a plug cap for an ignition plug for connecting an ignition cable or an ignition coil to an ignition plug in a plug hole integrated with a cover portion, a portion of the plug hole protruding from an engine head cover is defined as a plug hole protrusion, A plug cap for an ignition plug, characterized in that a fitting portion that is in close contact with the outer wall surface of the hole projecting portion is provided in the rain cover portion.

[0010]

According to the above construction, when the plug cap for an ignition plug is inserted into the plug hole, the fitting portion of the rain cover does not protrude into the plug hole and is inserted without sliding contact. When the plug hole is further inserted, the fitting portion comes into close contact with the outer wall surface of the plug hole, so that the plug hole is liquid-tightly sealed. Even if the degree of fitting between the fitting portion and the outer wall surface of the portion 2a of the plug hole protruding from the engine head cover is increased, the deformation of the fitting portion is not restricted, and the plug of the plug plug for the spark plug is used. The installation work in the hall can be performed well.

[0011]

1 to 3 show a plug cap for an ignition plug according to a first embodiment of the present invention.
This will be described in detail with reference to FIG. Here, FIG. 1 is an overall longitudinal sectional view showing a state in which a spark plug plug cap according to the present invention is mounted in a plug hole, FIG. 2 is an enlarged sectional view of a main part of the spark plug plug cap shown in FIG. 1 is an overall longitudinal sectional view showing a state before a plug cap for an ignition plug according to the present invention is attached to a plug hole.

The spark plug plug cap 100 of the first embodiment shown in FIGS. 1 to 3 connects an ignition cable (not shown) or an ignition coil 4 (not shown) to an ignition plug 3 mounted in a plug hole 2. Hall 2
For liquid-tight sealing. The plug cap 100 houses a tip portion 4 a of the ignition coil 4 for supplying a high voltage to the ignition plug 3 and a connection terminal 7 for connecting the tip portion 4 a to the ignition plug 3. Thus, when the plug cap 100 is inserted into the plug hole 2, the connection terminal 7 is fitted into the terminal portion 3a at the upper end of the ignition plug 3, and the ignition coil 4 is connected to the ignition plug 3. Further, a tip cap portion 8 made of an insulating rubber material, which is fitted to the insulator portion 3a of the ignition plug 3 to prevent leakage of high-voltage current, is fitted to the lower end of the plug cap 100.

The upper end portion 21 of the plug cap 100
Is mounted with a rain cover 30 formed of an insulating rubber material. This rain cover part 30
Is for preventing water droplets from penetrating into the plug hole 2, and has a cylindrical main body portion 3 fitted to the upper end portion 21 thereof.
1 and a substantially disk-shaped flange portion 32 erected on the outer peripheral surface of the main body portion 31. When the flange 32 comes into close contact with the surface of the engine head cover 1, the opening of the plug hole 2 is covered, so that water drops such as rainwater and car wash water do not easily enter the plug hole 2. However, unlike the conventional rain cover part 10 shown in FIG. 6, the rain cover part 30 does not include the fitting part 12 that is inserted into the plug hole 2 and fits inside the plug hole 2.

In the present embodiment, a fitting portion 33 is provided on a part of the flange portion 32, and the fitting portion 33 is shaped so that a part of the inner wall of the flange portion 32 projects. A portion of the plug hole 2 protruding from the engine cover 1 is provided as a plug hole protruding portion 2a, and the fitting portion 33 is in close contact with the outer wall of the plug hole 2a.

Next, the operation of the spark plug plug cap 100 of the first embodiment having the above-described structure will be described with reference to FIGS. When the connection terminal 7 in the plug cap 100 is fitted with the terminal portion 3b of the ignition plug 3, the flange 32 of the rain cover 30 is in close contact with the surface of the engine head cover 1 to cover the opening of the plug hole 2 and Since the fitting portion 33 of the rain cover seals the plug hole 2 in a liquid-tight manner, water droplets such as rainwater and car wash water do not easily enter the opening of the plug hole 2.

That is, after the plug cap 100 for the ignition plug of the present embodiment is inserted into the plug hole 2, the fitting portion 3 of the rain cover
3 is configured to be in close contact with the outer wall surface of the plug hole 2. Therefore, when the spark plug plug cap 100 of this embodiment is attached to the plug hole 2,
Even if the fitting force of the fitting part 33 is increased, there is no restriction on the shape change of the fitting part 33, and the fitting part 33 of the rain cover part 30 does not rub against the outer wall surface of the plug hole 2 due to strong sliding contact. The attachment of the spark plug plug cap 100 to the plug hole 2 can be performed extremely easily.

Next, a plug cap for an ignition plug according to a second embodiment of the present invention will be described with reference to FIG. Here, FIG. 4 is an overall vertical sectional view showing a state where the plug cap 200 for an ignition plug according to the present invention is attached to a plug hole. A tip cap 50 for sealing to insulate the spark plug; an insulating pipe 51 attached to the tip cap 50 and inserted into the plug hole 2; and an insulating pipe 51 for covering the opening of the plug hole 2.
And a rain cover 40 attached to the spark plug plug cap 200. That is, in the first embodiment, the spark plug plug cap 100 is integral, but in the second embodiment, the plug cap body is composed of three parts: the rain cover 40, the tip cap 50, and the insulating pipe 51. ing.

As in the first embodiment, a fitting portion 43 is provided on a part of the flange portion 42, and the fitting portion 43 is shaped so that a part of the inner wall of the flange portion 42 projects. . A portion of the plug hole 2 protruding from the engine head cover 1 is provided as a plug hole protrusion 2a.
The fitting portion 43 is in close contact with the outer wall of the plug hole protrusion 2a.

Therefore, when the plug cap 200 for an ignition plug of the present embodiment is attached to the plug hole 2, even if the fitting force of the fitting portion 43 is increased,
There is no restriction on the shape change of the
Since the plug 3 is not strongly rubbed against the outer wall surface of the plug hole 2, the plug cap 200 for the ignition plug can be attached to the plug hole 2 very easily.

In the above embodiment, the connection method between the ignition plug 3 and the ignition cable or the ignition coil 4 not shown
However, in the case where the ignition coil 4 is fixed with screws or the like and the plug plug for the ignition plug is sandwiched between the ignition coil 4 and the ignition coil 4, the same method can be used even if a spring and a connection terminal are used for the connection method of the ignition cable or the ignition coil 4. The effect is obtained.

[0021]

As described above, by applying the technique of the present invention, when the plug cap for the spark plug is inserted into the plug hole, the outer wall surface of the plug hole protruding portion protruding from the engine head cover in the plug hole. The plug hole is liquid-tightly sealed by the close contact of the fitting portion of the rain cover. Therefore,
When attaching the plug cap for the spark plug to the plug hole, the sealing portion of the rain cover does not strongly contact the inner wall surface of the plug hole. It is possible to provide a good spark plug plug cap that can surely prevent water droplets from entering.

[Brief description of the drawings]

FIG. 1 is an overall longitudinal section showing a state in which a plug cap for an ignition plug according to a first embodiment of the present invention is attached to a plug hole.

FIG. 2 is an enlarged sectional view of a main part of the spark plug plug cap shown in FIG. 1;

FIG. 3 is an overall longitudinal sectional view showing a state before the plug cap for the ignition plug according to the first embodiment of the present invention is attached to the plug hole.

FIG. 4 is an overall longitudinal sectional view showing a state in which a plug cap for an ignition plug according to a second embodiment of the present invention is attached to a plug hole.

FIG. 5 is an overall longitudinal sectional view showing a state where a conventional plug plug for an ignition plug is attached to a plug hole.

FIG. 6 is an enlarged sectional view of a main part of the plug cap for the ignition plug shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine head cover 2 Plug hole 3 Ignition plug 4 Ignition coil 7 Connection terminal 8 Tip cap part 21 Upper end part 30 Rain cover part 31 Body part 32 Flange part 33 Fitting part 100 Plug cap for ignition plug

Claims (2)

[Claims] An ignition plug in a plug hole in which a tip cap portion and a rain cover portion covering an opening of a plug hole are provided, the tip plug portion sealing the spark plug to insulate the spark plug, and the rain cover portion being integrated with the rain cover portion. In the plug cap for an ignition plug that connects an ignition cable or an ignition coil to the plug hole, a portion of the plug hole protruding from the engine head cover is defined as a plug hole projection, and a fitting portion that is in close contact with the outer wall surface of the plug hole projection is rained. A plug cap for an ignition plug, which is provided on a cover portion. 2. A tip cap for sealing a spark plug to insulate it, an insulating pipe attached to the tip cap and inserted into a plug hole, and attached to the insulating pipe to cover an opening of the plug hole. In a plug cap for an ignition plug for connecting an ignition cable or an ignition coil to an ignition plug in a plug hole provided with a rain cover, a portion of the plug hole protruding from the engine head cover is defined as a plug hole protrusion, and the plug hole protrusion is provided. A plug cap for an ignition plug, characterized in that a rain cover is provided with a fitting portion that is in close contact with an outer wall surface of the plug.