JPH10125441A - Plug cap mounting structure for ignition plug - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plug cap mounting structure for an ignition plug capable of easily mounting a plug cap in an engine head and capable of surely sealing an ignition plug mounting hole. SOLUTION: A plug cap 10 is provided with a rain cover 12 for sealing an ignition plug mounting hole 2 drilled at an engine heat 1, a circular flange part 12 erected on an outside surface of the rain cover 13 and capable of intimate contact with the engine head 1, and a fixing member 30 for fixing the rain cover 13 to the engine head 1. The fixing member 30, when it is threadedly fitted to a protrusion part 20 protruded at the engine head 1, pressure-energizes the flange part 12 to make it intimate contact with a step part 22 of the protrusion 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a plug cap for an ignition plug to be mounted on an engine.
In particular, the present invention relates to an improvement in a mounting structure of a plug cap for a spark plug used in an engine in which a spark plug is mounted deep inside an engine head cover.

[0002]

2. Description of the Related Art An example of a conventional plug plug for an ignition plug in which an ignition plug is mounted deep inside an engine head cover will be described with reference to FIG. A spark plug 3 is attached to the bottom of the. A plug cap 5 is used to connect the ignition cable 4 to the ignition plug 3. The plug cap 5 covers the periphery of a portion connecting the ignition cable 4 to the ignition plug 3,
An insulating pipe 6 is provided to insulate the high-voltage current from leaking. At the upper end of the insulating pipe 6, a rain cover 7 for sealing the spark plug mounting hole 2 in a liquid-tight manner is mounted.

[0003] The rain cover 7 is a member made of insulating rubber, and has a cylindrical main body portion 8 fitted externally to the insulating pipe 6;
A flange portion 9 projecting from an outer peripheral surface of the main body portion 8 and covering an opening portion of the ignition plug mounting hole 2; Accordingly, when the insulating pipe 6 is inserted into the ignition plug mounting hole 2 to connect the ignition cable 4 to the ignition plug 3, the flange 9 covers the opening of the ignition plug mounting hole 2, and dust or water droplets or the like from the outside is formed. In addition to preventing entry into the spark plug mounting hole 2, a ridge 8 a protruding from the outer peripheral surface of the main body portion 8 is fitted to the inner wall surface of the spark plug mounting hole 2,
The spark plug mounting hole 2 is sealed.

[0004]

In order to increase the degree of sealing of the spark plug mounting hole 2 by the conventional rain cover 7, the fitting of the spark plug mounting hole 2 and the ridge 8a of the rain cover 7 is required. It is necessary to strengthen cooperation. However, when the fitting between the spark plug mounting hole 2 and the ridge 8a is strengthened, it becomes difficult to insert the rain cover 7 into the spark plug mounting hole 2, and the ignition cable 4 is connected to the ignition plug 3 by the plug cap 5. Work becomes difficult.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above problems, and a plug cap for an ignition plug which can easily attach a plug cap to an engine head and can securely seal a spark plug mounting hole. An object of the present invention is to provide a mounting structure.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rain cover for sealing a spark plug mounting hole formed in an engine head, and a rain cover which is vertically attached to an outer surface of the rain cover and closely attached to the engine head. A possible annular flange portion, and a fixing member for fixing the rain cover to the engine head, wherein the fixing member presses and urges the flange portion when locked to the engine head, and This is achieved by a structure for mounting a plug cap for an ignition plug, which is characterized in that it is brought into close contact with the plug.

Preferably, a cylindrical protrusion coaxial with the spark plug mounting hole is provided on the engine head.
The fixing member is engaged with a male screw formed on the outer peripheral surface of the protruding portion, so that the fixing member is locked to the engine head. Preferably, a circlip in which a cylindrical protrusion coaxial with the spark plug mounting hole protrudes from the engine head, and wherein the fixing member is mounted in a concave groove formed in an outer peripheral surface of the protrusion. , The fixing member is locked to the engine head. According to the above configuration, the fixing member fixed to the engine head presses and urges the flange portion of the rain cover to bring the flange portion into close contact with the engine head, thereby sealing the spark plug mounting hole. There is no need to strengthen the fitting with the rain cover.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a spark plug mounting structure according to an embodiment of the present invention. Here, FIG. 1 shows a first embodiment of the present invention.
FIG. 2 is an enlarged vertical cross-sectional view of a main part of the rain cover shown in FIG. 1, and FIG. 3 is a vertical cross-sectional view of a main part of the rain cover shown in FIG. FIG. 2 is an enlarged vertical sectional view of a main part showing a mounting structure of a plug cap for an ignition plug.

First, referring to FIGS. 1 and 2, a description will be given of a structure for mounting a plug cap for a spark plug according to a first embodiment of the present invention. As shown in FIG. 1, an ignition plug 3 is attached to the bottom of an ignition plug attachment hole 2 formed in the engine head 1. A plug cap 10 is used to connect the ignition cable 4 to the ignition plug 3. The plug cap 10 includes:
An insulating pipe 6 is provided to cover the periphery of the portion where the ignition cable 4 is connected to the ignition plug 3 and to insulate the high-voltage current from leaking. A rain cover 13 for sealing the spark plug mounting hole 2 is provided at the upper end of the insulating pipe 6.
Is attached.

The rain cover 13 is a member formed of an insulating rubber material, and has a cylindrical main body portion 11 fitted to the insulating pipe 6 and an annular flange portion vertically provided on an outer peripheral surface of the main body portion 11. 12 are provided. Further, on the outer peripheral surface of the main body portion 11, a convex ridge 11a is provided so as to protrude. However, when the ridge 11a is inserted into the ignition plug mounting hole 2, the rain cover 13
For centering and guiding, and does not fit tightly with the inner wall surface of the spark plug mounting hole 2.

On the other hand, the engine head 1 has a cylindrical projection 20 projecting therefrom. The projection 20 is coaxial with the spark plug mounting hole 2, and has an inner diameter of the inner diameter of the spark plug mounting hole 2. Is the same as Further, the protrusion 2
A male screw 21 is formed on the outer peripheral surface of the zero. Also, the rain cover 13 is provided inside the tip of the protrusion 20.
A step portion 22 capable of storing the flange portion 12 is formed.

A fixing member 30 is detachably attached to the projection 20. The fixing member 30 made of hard plastic has a cylindrical main body portion 31 that is screwed into a male screw 21 formed on the outer peripheral surface of the protruding portion 20, and an inner protruding portion provided on an upper inner peripheral surface of the main body portion 31. And a flange 32. The inner flange 32 is connected to the protrusion 20.
, And the flange portion 12 of the rain cover 13 can be sandwiched. Further, the inner flange 32 through which the rain cover 13 is inserted has a flange portion 1.
A through-hole 33 smaller than 2 is formed.

Next, attachment of the plug cap 10 according to the first embodiment configured as described above will be described. First, the fixing member 30 is attached to the rain cover 13 of the plug cap 10 in advance. When the insulating pipe 6 of the plug cap 10 is inserted into the spark plug mounting hole 2 and the ignition cable 4 is connected to the spark plug 3,
The flange portion 12 of the rain cover 13 is housed in the step portion 22 of the protrusion 20.

In this state, when the female screw 34 of the fixing member 30 is screwed into the male screw 21 of the projecting portion 20, the fixing member 30
Is displaced downward in the axial direction of the spark plug mounting hole 2, and the lower surface of the inner flange 32 comes into contact with the upper surface of the flange portion 12 of the rain cover 13. When the fixing member 30 is further rotated, the flange portion 12 of the rain cover 13 is rotated.
Is compressed in the axial direction of the spark plug mounting hole 2 by the step portion 22 of the protruding portion 20 and the inner flange 32 of the fixing member 30, and is fixed to the engine head 1 in a state of being in close contact with both members.

That is, the mounting structure of the spark plug plug cap of the first embodiment does not seal the spark plug mounting hole 2 by strongly fitting the rain cover 13 into the spark plug mounting hole 2. The rain cover 13 can be easily fixed to the engine head 1. Further, the flange 12 formed on the rain cover 13 is brought into close contact with the step 22 of the projection 20 by the fixing member 30 which is engaged with the projection 20 protruding from the engine head 1. The hole 2 can be reliably sealed.

Further, a portion where the outer peripheral portion of the flange portion 12 comes into contact with the step portion 22 is a cap-shaped fixing member 30.
As a result, the spark plug mounting hole 2 can be more securely sealed without high-pressure car wash water or the like directly falling. And the plug cap 10
Is removed from the spark plug mounting hole 2, the fixing member 30
If the plug is rotated in the opposite direction to the time of attachment, the screw engagement with the protrusion 20 is released, and then the rain cover 13 is pulled out, the plug cap 10 can be easily removed.

Next, with reference to FIG. 3, a description will be given of a mounting structure of a spark plug plug cap according to a second embodiment of the present invention. As shown in FIG. 3, the mounting structure of the spark plug plug cap according to the second embodiment includes a fixing member 50 for fixing the flange 12 of the rain cover 13, wherein the fixing member 50 protrudes from the engine head 1. It differs from the mounting structure of the above-described first embodiment in that the mounting structure is locked to a circlip 42 via a circlip 42.

That is, the cylindrical protrusion 40 protruding from the engine head 1 is coaxial with the spark plug mounting hole 2 and has the same inner diameter as the inner diameter of the spark plug mounting hole 2. Further, a concave groove 41 extending in the circumferential direction is formed in the outer peripheral surface of the protruding portion 40, and the concave groove 41 is formed.
A circlip 42 is mounted inside. Further, a rain cover 13 is provided inside the tip of the protrusion 40.
A step portion 43 capable of storing the flange portion 12 is formed.

On the other hand, the rigid member 50 made of hard plastic has a cylindrical main body portion 51 fitted on the outer peripheral surface of the projecting portion 40, and an inner flange protruding from the inner peripheral surface of the upper end of the main body portion 51. 52. The inner flange 5
Numeral 2 is opposed to the step portion 43 of the protruding portion 40 so that the flange portion 12 of the rain cover 13 can be sandwiched. Also, the inner flange 52 through which the rain cover 13 is inserted.
Is formed with a through hole 53 smaller in diameter than the flange portion 12. Further, an engagement groove 54 is formed in the inner peripheral surface of the main body 51.

Next, the mounting of the plug cap 10 according to the second embodiment configured as described above will be described. First, the fixing member 50 is attached to the rain cover 13 of the plug cap 10 in advance. When the insulating pipe 6 of the plug cap is inserted into the ignition plug mounting hole 2 and the ignition cable 4 is connected to the ignition plug 3,
The flange 12 of the rain cover 13 is housed in the step 43 of the projection 40.

In this state, the main body 51 of the fixing member 50
Is externally fitted to the protruding portion 40 and displaced toward the engine head 1, the circlip 42 mounted on the protruding portion 40 is pressed and urged radially inward by the main body portion 51 of the fixing member 50, and the diameter thereof is reduced. It enters the concave groove 41. Also,
The lower surface of the inner flange 52 of the fixing member 50 is the rain cover 1
After coming into contact with the upper surface of the flange portion 12 of the third
Is further displaced, the flange portion 12 of the rain cover 13 is sandwiched and compressed by the step portion 43 of the projecting portion 40 and the inner flange 52 of the fixing member 50, and is fixed to the engine head 1 in a state of being in close contact with both members. . At the moment when the engaging groove 54 of the fixing member 50 faces the circlip 42 mounted on the protrusion 40, the circlip 42 expands in diameter and enters the engaging groove 54, and the fixing member 50
Locked to zero.

That is, the mounting structure of the plug cap for the spark plug of the second embodiment is similar to that of the first embodiment described above, in that the rain cover 13 is firmly fitted into the spark plug mounting hole 2 to thereby mount the spark plug. Since the hole 2 is not sealed, the rain cover 13 can be easily fixed to the engine head 1. Also, a fixing member 50 that is locked to the protruding portion 40 protruding from the engine head 1.
The flange portion 1 formed on the rain cover 13
2 is brought into close contact with the step portion 43 of the projecting portion 20,
The spark plug mounting hole 2 can be securely sealed.

In addition, in the mounting structure of the second embodiment, a concave groove 41 is formed on the outer peripheral surface of the projecting portion 40,
Moreover, since it is only necessary to attach the circlip 42, the processing of the protruding portion 40 can be easily performed as compared with the case where the male screw is formed on the protruding portion as in the first embodiment described above. When the plug cap 10 is to be removed from the spark plug mounting hole 2, the fixing member 50 is pulled up in advance, the engagement of the circlip 42 with the projection 40 is released, and then the rain cover 13 is pulled out. 10 can be easily removed. The mounting structure of the plug plug for an ignition plug according to the present invention is not limited to the configurations of the rain cover, the flange portion, the fixing member, and the like in each of the above embodiments, and it goes without saying that various configurations can be adopted. .

[0024]

As is apparent from the above description, in the mounting structure of the plug cap for an ignition plug according to the present invention, the fixing member locked to the engine head presses and biases the flange portion of the rain cover so that the engine is pressed. By contacting the head closely, the spark plug mounting hole is sealed. Therefore, the spark plug mounting hole can be securely sealed with the flange portion of the rain cover, and it is not necessary to strengthen the fitting between the spark plug mounting hole and the rain cover, so that the rain cover is inserted into the spark plug mounting hole. It won't be difficult. Therefore, it is possible to provide a structure for mounting a plug cap for a spark plug, which can easily mount the plug cap on the engine head and can reliably seal the spark plug mounting hole.

[Brief description of the drawings]

FIG. 1 is an overall vertical sectional view showing a mounting structure of a plug cap for an ignition plug according to a first embodiment of the present invention.

FIG. 2 is an enlarged longitudinal sectional view of a main part of the rain cover shown in FIG.

FIG. 3 is an enlarged vertical sectional view of a main part showing a mounting structure of a plug cap for an ignition plug according to a second embodiment of the present invention.

FIG. 4 is an overall vertical sectional view showing a conventional mounting structure of a plug cap for an ignition plug.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine head 2 Ignition plug mounting hole 3 Ignition plug 4 Ignition cable 6 Insulation pipe 10 Plug cap 13 Rain cover 11 Main part 12 Flange part 20 Projection part 21 Male screw 22 Step part 30 Fixing member 31 Main part 32 Inner flange 33 Through hole 34 Female screw

Claims (3)

[Claims] 1. A rain cover for sealing a spark plug mounting hole formed in an engine head, an annular flange vertically suspended from an outer surface of the rain cover and capable of closely adhering to the engine head, and the rain cover. A fixing member for fixing the fixing member to an engine head, wherein the fixing member presses and urges the flange portion when the locking member is locked to the engine head to bring the flange portion into close contact with the engine head. Plug cap mounting structure. 2. A cylindrical projection coaxial with the ignition plug mounting hole is projected from the engine head, and the fixing member is screwed into a male screw formed on an outer peripheral surface of the projection. The mounting structure for a spark plug plug cap according to claim 1, wherein the fixing member is locked to the engine head. 3. A circuit wherein a cylindrical protrusion coaxial with the spark plug mounting hole protrudes from the engine head, and the fixing member is mounted in a concave groove formed in an outer peripheral surface of the protrusion. The mounting structure for a plug cap for an ignition plug according to claim 1, wherein the fixing member is locked to the engine head by engaging with a clip.