JPH09326288A - Air vent structure of plug cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air vent structure capable of effectively preventing the entrance of foreign matters into a plug hole in a plug cap such as an in-hole type in which almost all the plug cap is set in the plug hole. SOLUTION: A circular projection part 22 is formed on the lower end side of the outer circumferential surface of a cylindrical part 20 capable of inserting into/removing from a plug hole 60. A boss part 36 is projected on the outer circuhferential surface of the cylindrical part 20 which positions on the upper side than the circular projection part 22 and is hidden in the plug hole 60, a communicating path 40 communicating with the plug hole 60 over the cylindrical part 20 from the boss part 36 is formed, and a ventilation port 38 communicating with the outside air and the communicating path 40 through a space S is formed on the lower surface side of the boss part 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air vent structure for a plug cap applied to a plug hole of an internal combustion engine of an automobile or the like.

[0002]

2. Description of the Related Art Conventionally, as an air vent structure of a plug cap applied to a plug hole of an internal combustion engine in an automobile or the like, for example, there is one as shown in FIG.

The plug cap 100 is provided with a cylindrical portion 102 which is inserted into and removed from the plug hole 120 to close the plug hole 120, and a plug which is exposed from the plug hole 120 above the cylindrical portion 102. An ignition cable introducing portion 116 that closes the hole 120 is provided.

On the lower end side of the cylindrical portion 102, a plug joint 122 is held in a hanging shape, and an ignition cable 124 introduced through an introduction port 128 described later through the plug joint 122 is provided at the bottom of the plug hole 120. It is configured to be connected to the spark plug 130.

Further, an inlet port 128 for introducing the ignition cable 124 into the plug hole 120 is formed on one side of the ignition cable introducing portion 116, and an outwardly projecting shape is formed on the other side. The eaves portion 118 is formed.

Further, a communication portion 104 for communicating the inside of the plug hole 120 and the outside air is formed below the eaves portion 118. The communicating portion 104 has a boss portion 106 projecting from one side of the ignition cable introducing portion 116.
The through hole 108 is formed in the horizontal direction from 06 to the ignition cable introducing portion 116, and the ignition cable introducing portion 116 is formed from the through hole 108 toward the plug hole 102.
By forming the groove 110 on each inner peripheral surface of the tubular portion 102, the groove 110 and the through hole 108 form a communication passage 112 that communicates the inside of the plug hole 120 with the outside air.

With the communication portion 104 thus constructed, when the plug cap 100 is mounted in the plug hole 120 or when the pressure inside the plug hole 120 rises when the internal combustion engine is heated, the inside of the plug hole 120 is Air can be released to the outside through the communication passage 112,
It is possible to prevent the plug cap 100 from rising and coming off due to an increase in the internal pressure of the plug hole 120.

Further, by forming a communication port for communicating with the outside air of the communication passage 112 in the boss portion 106 and extending the eaves portion 110 above the communication portion 104, foreign matters such as water are communicated with each other when washing the vehicle. The plug hole 12 is not directly hit by the part 104.
0 Water etc. are prevented from entering the inside.

[0009]

However, in recent years, with the demand for effective use of the space in the engine room, there is a tendency to use a type in which most of the cylindrical portion is housed in a plug hole (so-called in-hole type). Therefore, there is no room for providing a communication portion on the side surface of the plug cap exposed from the plug hole. Therefore, it is conceivable to form the communication portion on the upper surface of the plug cap, but in this case, there is a problem that foreign matter such as water easily enters the plug hole because the communication portion opens upward.

Therefore, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an air vent structure for a plug cap which can effectively prevent foreign matter from entering the plug hole. To aim.

[0011]

In order to solve the above-mentioned problems, an air vent structure for a plug cap according to the present invention is provided with a tubular portion which can be inserted into and removed from a plug hole and an upper portion of the tubular portion. In the air vent structure of the plug cap, which has an ignition cable introduction part, and in which the communication part that communicates the inside of the plug hole and the outside air is formed in the tubular part, the lower end side of the outer peripheral surface of the tubular part An annular ridge portion is formed along the circumferential direction, and the annular ridge portion is pressed against the inner peripheral surface of the plug hole in an airtight manner, while the communicating portion is located above the annular ridge portion. Further, a boss portion is provided so as to project at an outer peripheral surface position of the tubular portion hidden in the plug hole, a communication passage communicating with the inside of the plug hole is formed from the boss portion to the tubular portion, and the boss portion is formed. On the lower surface side of the communication passage and the Wherein the ventilation opening section for communicating the air is formed.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An air vent structure for a plug cap according to an embodiment of the present invention will be described below.

As shown in FIG. 1, this plug cap 1
0 is a cylindrical portion 20 that can be inserted into and removed from the plug hole 60.
And an ignition cable introducing portion 12 provided on the upper portion of the tubular portion 20.

The ignition cable introducing portion 12 has an inlet 16 on one side thereof for introducing an ignition cable (both not shown) for supplying a high voltage to the ignition plug from the outside into the plug hole 60. At the same time, the eaves portion 18 is extended on the other side.

A holding portion 20 for holding the plug joint 50 in a hanging state is formed in the lower portion of the tubular portion 20, and the ignition cable passes through the inside of the plug joint 50 and the bottom portion of the plug hole 60. Is electrically connected to a spark plug provided in the.

Further, on the lower end side of the outer peripheral surface of the tubular portion 20,
An annular projection 22 having a predetermined height is formed along the circumferential direction.

When the tubular portion 20 is fitted into the plug hole 60, the end of the annular convex portion 22 is brought into pressure-contact with the inner peripheral surface of the plug hole 60 in an airtight manner, and the plug hole 6 is formed.
While 0 is closed to the outside, a space S communicating with the outside air is formed between the outer peripheral surface of the tubular portion 20 and the inner peripheral surface of the plug hole 60 above the annular convex portion 22. .

A communication portion 30 for communicating the inside of the plug hole 60 with the outside air is formed on one side of the tubular portion 20.

As shown in FIGS. 1 to 3, the communicating portion 30 has a boss portion 36 projecting above the annular convex portion 22 and at a position on the outer peripheral surface of the cylindrical portion 20 hidden in the plug hole 60. At the same time, the communication passage 40 that communicates with the inside of the plug hole 60 is formed from the boss portion 36 to the tubular portion 20, and the communication passage 40 and the space S are formed on the lower surface side of the boss portion 36.
A ventilation port portion 38 communicating with is formed.

In this case, the height dimension of the boss portion 36 is
When the cylindrical portion 20 is formed into the plug hole 60 and is formed to have substantially the same height as the annular convex portion 22, the boss portion 36 is inserted.
The end surface of is contacted with the inner peripheral surface of the plug hole 60 by pressure.

Further, the communication passage 40 has a through hole 41 extending horizontally from the boss portion 36 to the tubular portion 20.
And a groove portion 42 formed on the inner peripheral surface of the tubular portion 20 from the through hole 41 to the lower end of the tubular portion 20, and the inside of the plug hole 60 and the outside air have a communication passage configured as described above. , And is communicated with the space S and the ventilation opening 38 formed in the boss portion 36.

The plug cap 1 configured as described above
In the air vent structure of 0, the plug hole 60 is
0, since it is communicated with the outside air through the ventilation port 38 and the space S, when the plug cap 10 is attached to the plug hole 60, or when the internal pressure of the plug hole 60 is increased during the temperature rise of the internal combustion engine, The air inside thereof can be escaped through the above-mentioned ventilation path, and it is possible to prevent the plug cap 10 from rising and coming off due to an increase in the internal pressure in the plug hole 60.

Further, the boss portion 36 is provided so as to project from the outer peripheral surface of the tubular portion 20, the tip thereof is pressed against the inner peripheral surface of the plug hole 60, and the ventilation port portion 38 is formed on the lower surface side of the boss portion 36. Therefore, foreign matters such as water are prevented from directly hitting the ventilation opening 38 during car wash and the like, so that water and the like are prevented from entering the plug hole 60.

[0024]

As described above, according to the air vent structure of the plug cap of the present invention, the annular convex portion is formed along the circumferential direction on the lower end side of the outer peripheral surface of the tubular portion, and the annular convex portion is formed. Is pressed against the inner peripheral surface of the plug hole in an airtight manner, while the communicating portion has a boss portion on the outer peripheral surface position of the cylindrical portion which is above the annular protruding portion and hidden in the plug hole. A communication passage is formed to project from the boss portion to the cylindrical portion and communicates with the inside of the plug hole, and a ventilation port portion that communicates the communication passage and the outside air is formed on the lower surface side of the boss portion. Therefore, the communication between the inside of the plug hole and the outside air can be ensured through the communication passage and the ventilation opening, and foreign matter such as water is prevented from directly hitting the ventilation opening when washing the car. Effective for entry of foreign matter such as water into the plug hole An effect that can be prevented is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing a waterproof structure of a plug cap according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an essential part showing the above waterproof structure.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a sectional view showing a waterproof structure of a conventional plug cap.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Plug cap 12 Ignition cable holding part 20 Cylindrical part 22 Annular convex part 30 Communication part 36 Boss part 38 Ventilation port part 40 Communication path 60 Plug hole

Claims (1)

[Claims] 1. A cylindrical portion that can be inserted into and removed from a plug hole, and an ignition cable introducing portion provided on an upper portion of the cylindrical portion, wherein the cylindrical portion has an inside and outside air. In an air vent structure of a plug cap in which a communicating portion that communicates with the plug cap is formed, an annular ridge portion is formed along the circumferential direction on the lower end side of the outer peripheral surface of the tubular portion, and the annular ridge portion is the plug. While being pressure-contacted to the inner peripheral surface of the hole in an airtight manner, the communicating portion is provided with a boss portion projecting above the annular protruding portion and at a position on the outer peripheral surface of the cylindrical portion hidden in the plug hole. A communication passage communicating with the inside of the plug hole is formed from the boss portion to the tubular portion, and a ventilation port portion communicating the communication passage and the outside air is formed on the lower surface side of the boss portion. The air vent structure of the plug cap characterized by .