JP2001065444A - Ignition decice for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent water from entering a plug hole to which an ignition plug is attached by arranging an air delivery hole for connecting the inside of the plug hole and an outside to each other, and mounting a water vapor permitting and water proofing raw material having a water vapor permeability and for preventing the passage of water such as rain water from allowing on an outlet of the air delivery hole. SOLUTION: A rain cover part 21 is disposed between a high pressure tower 14 formed by a case 13 and a protector part 22, and an air delivery hole 24 for ventilating air in a plug hole 32 is arranged in the rain cover part 21. The air delivery hole 24 is formed so as to directly circulate between the plug hole 32 and outside air, a water vapor permitting and water proofing raw material 27 is arranged on a part of the air delivery hole 24 so as to prevent water drops and soot from invading from an outside into the plug hole 32. A water vapor preventing material 28 is mounted on a delivery hole outlet of the air delivery hole 25 is mounted so as to prevent water drop and soot which exist in the vicinity of the air delivery hole 25 from staying in the air delivery hole 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an internal combustion engine, and more particularly to an air discharge structure for an ignition device directly attached to a spark plug.

[0002]

2. Description of the Related Art FIG. 3 is a partial side view of a conventional ignition device for an internal combustion engine mounted on an engine block. In FIG. 3, as is well known, an engine block 30 of an internal combustion engine has a plug hole 3 that is a mounting hole for a spark plug 31.
A terminal portion serving as a high-voltage input portion of the ignition plug 31 is arranged at the bottom of the plug hole 32.

An ignition device for supplying a high voltage to the ignition plug will be described. The ignition device 1 includes a primary voltage input unit 11
A protector portion 22 having a resin-molded exterior member is inserted below the case 13 having an upper portion, and an ignition plug 31 integrated therewith with an adhesive or the like below the protector portion 22. Is provided. Further, the protector unit 2
On the upper part 2, a droplet intrusion prevention member (hereinafter referred to as "rain cover part") 21 formed of a material such as rubber in a circular shape is similarly provided integrally by an adhesive.

[0004] The protector portion 22 and the plug cap 24 connected to the case 13 are inserted into a plug hole 32, and the plug cap 24 is pushed into the ignition plug 31. Further, the case 13 has a bolt 41
Is fixed to the engine block 30 by a fixing member such as
By covering and sealing the outlet of the plug hole 32 with the rain cover portion 21, it is possible to prevent the intrusion of droplets and the like into the plug hole 32 and to prevent the occurrence of poor electrical connection of the ignition plug 31. I have.

When the internal combustion engine is operated and the internal air is exposed to corona discharge caused by a high voltage of several tens of kV, it is ozonized. Therefore, the metal near the plug hole 32 including the ignition plug 31, the rain cover portion 21 and the plug The cap portion 23 is oxidized, and the deterioration and corrosion of this portion may rapidly progress, leading to high voltage leakage. Plug hole 3
When the temperature inside the plug 2 becomes extremely high and the engine vibrates, the sealing portion sealing the plug hole 32 may rise from the inner wall of the plug hole 32 and impair the sealing with the inner wall of the plug hole 32 in some cases. .

For this reason, in the rain cover part 21, the air discharge hole 25 is formed so that air flows outside the plug hole 32 through the air discharge hole 25, and the plug hole 32 is formed.
A hollow air discharge pipe 29 connected to the air discharge hole 25 is attached to the case 13 so that droplets of water or the like do not easily enter the inside, and air expanded by heat generated and ozone generated by corona discharge are released.

The air discharge pipe 29 circulates air inside and outside the plug hole 32, and prevents the intrusion of droplets from the air discharge hole by setting the air discharge hole outlet independently high.

[0008]

However, in the conventional ignition device for an internal combustion engine as described above, the case 13 must be provided with an air discharge pipe 29 having a complicated shape in order to improve waterproofness. Is formed, the number of assembling steps increases, the mold becomes complicated, and the mold life is shortened.

The present invention has been made in order to solve such a problem, and it is possible to prevent water from entering the inside of a plug hole 32 in which a spark plug 31 is mounted by using a simple structure with a small number of steps. It is an object of the present invention to provide an ignition device for an internal combustion engine that can prevent the occurrence of a poor electrical connection of the ignition plug 31 and allow air expanded by heat generated from the internal combustion engine to escape to extend the life of the ignition device.

[0010]

According to the present invention, there is provided an ignition device for an internal combustion engine according to the present invention, wherein a member for supplying a high voltage generated by the ignition device to an ignition plug includes a protector portion, a rain cover portion, and a plug cap. In the rain cover part, an air discharge hole is provided to connect the inside and outside of the plug hole, and the air discharge hole outlet has good moisture permeability and does not allow liquid water such as rainwater to pass through An ignition device for an internal combustion engine equipped with a waterproof material.

Further, the member for supplying the high voltage generated from the ignition device to the ignition plug may be formed integrally with an elastic protector.

[0012]

In the ignition device for an internal combustion engine according to the present invention, the air inside the plug hole 32 can flow with the outside air through the moisture-permeable waterproof material 28 provided at the outlet of the air discharge hole 25. The air expanded by the heat generated by the operation and ozone generated by the corona discharge can be discharged to the outside of the plug hole 31. Further, with a simple structure, the intrusion of droplets such as water is prevented, so that the intrusion of droplets and the like into the plug hole 32 is prevented, and the occurrence of electrical connection failure of the ignition plug 31 is prevented.

[0013]

FIG. 1 is a partial sectional view showing an ignition block for an internal combustion engine according to a first embodiment of the present invention mounted on an engine block.
FIG. 2 is a partially enlarged view of FIG.
1 and 2, the ignition device 1 is composed of components in a case 13, a rain cover 21, a protector 22, and a plug cap 24.

The case 13 includes a primary coil and a secondary coil (not shown), an igniter such as a power transistor in some cases, and a primary voltage input unit 11 and a core, which serve as a low voltage input unit from a battery or the like. After placement, it is molded with resin.

On the lower surface of the case 13, a secondary voltage output section 12 serving as a high voltage output section of the ignition device 1 is arranged.
It is distributed in. A high-voltage tower 14 is formed in a part of the case 13 where the secondary voltage output unit 12 is arranged.

The ignition plug 31 is disposed at the bottom of a plug hole 32 in which the engine block 30 is formed into a concave shape. The electrode is connected to the combustion chamber, and the terminal for receiving the secondary voltage from the ignition device 1 is connected to the plug hole 32. It is located in. The engine block is provided with a hole for mounting and fixing the ignition device 1, and the bolt 41 is screwed into the hole to fix the ignition device 1 to the engine.

Next, the protector unit 22 will be described. The protector section 22 realizes electrical connection between the secondary voltage output section 12 and the terminal of the spark plug 31 and is formed by rubber or resin molding. A secondary voltage transmission member 26 made of a metal material is embedded. Springs 27-27 are provided at both ends of the secondary voltage transmitting member, so that the secondary voltage output section 12 and the terminal of the ignition plug 31 are reliably connected.

A plug cap 24 is disposed between the protector 22 and the spark plug 31 for physical connection between the two. The plug cap 24
Is made of a deformable rubber material, and the protector 22
Are integrated with one end using an adhesive or the like. Then, the plug cap 24 is joined to the ignition plug 31 by the deformation action.

The case 13 which is the other end of the protector section 22 has the following configuration. That is, the rain cover 21 is disposed between the high-pressure tower 14 formed by the case 13 and the protector 22. The rain cover part 21 connects the case 13 and the protector part 22 and has a plug hole 32.
It also prevents water droplets and dust from entering the inside. Therefore, one circumference of the outer wall of the rain cover portion 21 is formed longer than the inner circumferential length of the plug hole 32, and the space in the plug hole 32 is sealed by press-fitting this portion into the plug hole 32.

Incidentally, the rain cover portion 21 is provided with an air discharge hole 24 for bleeding air from the plug hole 32. The air discharge hole 24 is formed so as to directly flow between the plug hole 32 and the outside air, and a part of the air discharge hole 24 is provided with a moisture permeation preventing material 27 so that water droplets and dust can be removed from the outside through the plug hole. 32 so as not to enter.

Further, when a moisture permeable waterproof material 28 is attached to the outlet of the front air discharge hole 25, water droplets and dirt existing near the air discharge hole 25 are prevented from staying in the air discharge hole 25, and clogging is prevented. Can be prevented beforehand, and good air discharge can be performed.

In the above configuration, the configuration of the air discharge hole 25 is not particularly limited as long as it allows the air to flow between the plug hole 32 and the outside air.
There is also no particular limitation on the shape and the arrangement position, and any shape can be specified as long as it is a path from the outside air to the plug hole 32. Further, in the above-described embodiment, the ignition device using the protector has been described as an example. However, an ignition device using a distributor or an ignition coil embedded in a plug hole may be used.
2 can be applied to anything that needs to be sealed from the outside air.

Next, FIG. 3 is a partial cross-sectional view in which an ignition device for an internal combustion engine according to a second embodiment of the present invention is attached to an engine block, and FIG. 4 is a partially enlarged view of FIG. 3 and 4, the ignition device 2 includes a case 13
And a protector unit 23.

Like the ignition device 1 according to the first embodiment, the primary coil and the secondary coil are housed in the same case 13 of the ignition device 2 and, if necessary, an igniter such as a power transistor. After the primary voltage input unit 11 as a low voltage input unit from a battery or the like and an iron core are arranged, the core is molded with resin.

On the lower surface of the case 13, the high voltage output from the ignition device 2 is output from a secondary voltage output unit (not shown), and is output via a protector unit 23.
1 is distributed. A high voltage tower 14 is formed in a portion where the secondary voltage output unit 12 is disposed.

The ignition plug 31 is disposed at the bottom of a plug hole 32 formed by processing the engine block 30 into a concave shape. The electrode is connected to the combustion chamber, and the terminal for receiving the secondary voltage from the ignition device 1 is connected to the plug hole 32. It is located in. The engine block is provided with a hole for mounting and fixing the ignition device 1, and the bolt 41 is screwed into the hole to fix the ignition device 1 to the engine.

Next, the protector section 23 will be described. The protector section 23 realizes electrical connection between the secondary voltage output section and the terminal of the spark plug 31 and is formed of an elastic body such as rubber. A secondary voltage output section on the lower surface of the case 13 is provided with a spring 27.
Is electrically connected to the protector unit 23 and the spring 2
When the ignition coil is mounted, the spring 27 and the terminal of the ignition plug 31 are configured to be reliably connected to each other when fitted to the high-pressure tower 14 that houses the ignition coil 7.

The outer circumference of a part of the outer wall of the protector portion 23 is formed longer than the inner peripheral length of the plug hole 32, and this portion is press-fitted into the plug hole 32 so that the space in the plug hole 32 is sealed. ing. This also prevents water droplets and dust from entering the plug hole 32.

Incidentally, the protector section 23 is provided with an air discharge hole 24 for releasing air from the plug hole 32. The air discharge hole 24 is formed so as to directly flow between the plug hole 32 and the outside air, and a part of the air discharge hole 24 is provided with a moisture permeation preventing material 27 so that water droplets and dust can be removed from the outside through the plug hole. 32 so as not to enter.

When a moisture permeable waterproof material 28 is attached to the outlet of the front air discharge hole 25, water droplets and dirt near the air discharge hole 25 are prevented from remaining in the air discharge hole 25, and clogging is prevented. Can be prevented beforehand, and good air discharge can be performed.

[0031]

According to the ignition device 1 or 2 for an internal combustion engine of the present invention described above, the moisture permeable waterproof material 27 is provided at the outlet of the air exhaust hole 24 provided in the rain cover portion 21 of the protector portion 22 and the protector portion 23. By mounting with a simple structure, even if droplets of water or the like are likely to enter the plug holes 32 formed in the engine block 30, they do not enter through the air discharge holes 24, so that the ignition plug 31
Can prevent poor electrical contact due to intrusion of droplets of water or the like, and can maintain good combustion of the internal combustion engine.
At the same time, the air expanded by the heat generated by the operation of the internal combustion engine and the ozone generated by the corona discharge can be discharged to the outside, so that the life of the ignition device for the internal combustion engine can be extended. Further, since it is not necessary to form a complicated shape in order to prevent the intrusion of the droplet, the molding die is simplified and the life of the die can be extended.

[Brief description of the drawings]

FIG. 1 is a sectional view of an ignition device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 shows an enlarged cross-sectional view of the rain cover part of FIG.

FIG. 3 shows a sectional view of an internal combustion engine ignition device according to a second embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of a plug cap part shown in FIG. 3;

FIG. 5 shows a sectional view of a conventional ignition device for an internal combustion engine.

[Explanation of symbols]

 In the drawings, the same reference numerals indicate the same or corresponding parts. DESCRIPTION OF SYMBOLS 1 Ignition device 2 Ignition device 11 Primary voltage input part 12 Secondary voltage output part 13 Case 14 High voltage tower 21 Rain cover part 22 Protector part of Example 1 23 Protector part of Example 2 24 Plug cap 25 Air exhaust hole 26 2 Next voltage transmission member 27 Spring 28 Moisture permeable waterproof material 29 Air discharge pipe 30 Engine block 31 Spark plug 32 Plug hole 41 Volt

Claims (7)

[Claims] An ignition device for an internal combustion engine having an air discharge hole for flowing between a plug hole formed in an engine block and outside air outside the plug hole, wherein a part of the air discharge hole prevents moisture permeation. An ignition device for an internal combustion engine, comprising a material. 2. An ignition device for an internal combustion engine for generating a high voltage applied to a spark plug of the internal combustion engine, wherein a member for supplying the high voltage generated by the ignition device to the ignition plug includes a rain cover portion, a protector portion, and a plug. In the rain cover part composed of a cap part and connected to the protector part, an air discharge hole communicating between the inside and the outside of the plug hole is provided, and a moisture-permeable waterproof material is attached to a part of the air discharge hole. An ignition device for an internal combustion engine, comprising: 3. An ignition device for an internal combustion engine that generates a high voltage applied to a spark plug of the internal combustion engine, wherein the ignition coil is housed in a plug hole. An ignition device for an internal combustion engine, comprising: an air discharge hole for communicating outside air; and a moisture-permeable and waterproof material mounted on a part of the air discharge hole. 4. An internal combustion engine igniter for generating a high voltage applied to a spark plug of an internal combustion engine, comprising a protector section for supplying a high voltage to an ignition coil, wherein the protector section is made of an elastic material. An internal combustion engine igniter having a secondary voltage transmission member in the protector section, the air conditioner having an air discharge hole for communicating the air inside the plug hole and the outside air, An ignition device for an internal combustion engine, wherein a moisture permeable waterproof material is attached to a part. 5. An internal combustion engine igniter for generating a high voltage applied to an ignition plug of an internal combustion engine, comprising a protector section for supplying a high voltage to an ignition coil, wherein the protector section is made of an elastic material. An internal combustion engine igniter having a secondary voltage transmission member in the protector section, the air conditioner having an air discharge hole for communicating the air inside the plug hole and the outside air, An ignition device for an internal combustion engine, wherein a moisture permeable waterproof material is attached to a part. 6. The ignition device for an internal combustion engine according to claim 1, wherein a position where the moisture-permeable and waterproof material is mounted is provided at an outlet of the air discharge hole. 7. The ignition device for an internal combustion engine according to claim 1, wherein the air discharge hole has a straight shape that is easy to form.