JP3064590B2 - Spark plug device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a spark plug about easily spark plug device of the detachable small.

[0002]

2. Description of the Related Art In recent years, automobiles have come to have various functions. Along with this, a large number of in-vehicle components are mounted in an engine room of an automobile, and miniaturization of each in-vehicle component is desired. Spark plugs also play an important role as ignition devices for gasoline internal combustion engines. Conventionally, as a spark plug, for example, as shown in FIG. 2, a main body 11 of the spark plug, a mounting screw portion 12 provided on one side of the main body 11, and an insulator 16 provided on the other side.
Consists of

The mounting screw 12 has a bottom 122
Has a center electrode 13 and a ground electrode 14. The mounting screw portion 12 is a mounting portion for screwing into a combustion chamber of an internal combustion engine. The insulator 16 has a metal head terminal 5 protruding at the tip thereof. The head terminal 5 has a screw 5 for connection to a high tension cord as shown in the figure.
1 (M4 screw type head terminal). And
The head terminal 5 is designed so that it can be used for both a plug terminal and an M4 terminal (Japanese Patent Application Laid-Open No. 3-47575).

On the other hand, the high tension code 33 is
It has a metal cord 331 inside, and a concave high voltage terminal 34 at the tip. Inside the high voltage terminal 34, a coil spring 2 as a metal elastic body is disposed. In the coil spring 2, the upper end 2
1 is fixed to the high voltage terminal 34, and the lower end portion 22 is brought into contact with the head terminal 5 of the spark plug 10. Further, the lower end portion 22 is formed by forming a flat spiral. The insulator 16 of the spark plug 10 has a holding cap 31.
Is fitted. In addition, the opening 3 above the holding cap 31
The connection portion 335 of the high tension cord 33 is fitted into 11. The mainstream of the above-mentioned spark plugs has a head terminal length K of 10 mm and an insulator length N of 23 mm.

[0005]

However, since the conventional spark plug 10 is long as described above, it is used in a narrow engine head portion with no space. In recent years, plug overhead type coils have been adopted, and the space around the plug has been regulated. Also, the attachment and detachment of the spark plug is very difficult because it is obstructed by a large number of in-vehicle components in a small engine room. In view of the above problems, a spark
An object of the present invention is to provide a spark plug device in which a plug is small and can be easily attached and detached.

[0006]

A solution means of the present invention, the present <br/> body center electrode is enclosed, with one outer diameter provided on the side is taken of 14mm or less <br/> threaded portion of the body, said body insulator and, on the exposed to the other side
Electrically conductive with the center electrode, and
Exposed to a thickness of 1.0 to 1.5 mm on the side opposite to the side of the main body
Made of a metal plate provided so as to be
A lug, a metal elastic body capable of contacting the metal plate,
The spark plug is held and fixed while holding the metal elastic body.
And a retaining cap fitted to the insulator
A high-tension cord that, in the spark plug device characterized by comprising a. Most notably in the present invention, the centered electrodes and the electrically metal plate connected is exposed from the distal end of the insulator, it is abutted against the elastic metal body to the metal plate, also outside of the mounting screw portion Diameter 1
4 mm or less.

In the present invention, the metal plate has a plate shape, and is made of conductive Fe or Cr.
-Mo alloy and the like. The thickness of the metal plate is 1.
It is preferable to set it to 0 to 1.5 mm. The metal plate is electrically connected to the center electrode via a conductive layer provided inside the insulator of the spark plug. The bottom of the mounting screw has a center electrode and a ground electrode.
A spark discharge is formed between the center electrode and the ground electrode due to the high voltage difference. The length T (see FIG. 1) of the mounting screw is preferably 14 mm or less. If it is larger than this, it becomes difficult to attach and detach the plug in the narrow plug hole.

On the other hand, the high tension cord has a cord and a concave high voltage terminal therein as in the prior art. A metal elastic body is provided inside the high voltage terminal. Examples of the metal elastic body include a coil spring and a disc spring. These are in contact with the metal plate at the lower end. Also, on the outer periphery of the spark plug insulator,
Fit the holding cap as before. The holding cap is brought into close contact with the insulator . In addition, in the holding cap and the insulator, it is preferable that corrugations are provided on the surfaces facing each other so that the irregularities of both are engaged with each other. Corrugation prevents flashover. Also, the high tension cord can be securely fixed to the spark plug.

[0009]

Oite to the operation and effect of the present invention, the tip of <br/> insulator of the spark plug is exposed to a thickness 1.0~1.5mm
In this manner, a flat metal plate is provided, and a metal elastic body is brought into contact with the metal plate. That is, in the conventional spark plug, the protruding head terminal provided at the upper end is eliminated, and a flat metal plate is provided there. Therefore, in the present invention, the overall length of the spark plug can be reduced. The outer diameter D of the mounting screw is
It is 14 mm or less. Therefore, the spark plug can be downsized also in this respect. Since the overall length of the spark plug is reduced as described above, the size of the spark plug is reduced, so that the space around the spark plug has a margin. Therefore, in the engine room, the mounting space for other in-vehicle components is increased. Further, since there is sufficient space, it is easy to attach and detach the spark plug.
As described above, according to the present invention, it is possible to provide a spark plug device in which the spark plug is small and easy to attach and detach.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A spark plug device according to an embodiment of the present invention will be described with reference to FIG. The spark plug 1 of this embodiment includes a main body 11 of the spark plug, a mounting screw portion 12 provided on one side of the main body 11, and an insulator 16 provided on the other side.
And a flat metal plate 18 provided at the distal end of the insulator 16 for making contact with the coil spring 2 as a metal elastic body of the high tension cord 33. The outer diameter D of the mounting screw portion 12 is 12 mm.
The metal plate 18 is electrically connected to the center electrode 13 via a conductive layer provided inside the insulator 16.

In this embodiment, the insulator 16 is made of alumina.
A flat metal plate 18 made of iron is mounted and fixed to the tip of the metal plate 18 by a central shaft. An uneven corrugation 161 is formed on the outer peripheral surface of the insulator 16. The length N of the insulator 16 is 15 mm .
The thickness of the metal plate 18 is Ri 1.0mm der insulator 1
6 is exposed on the side opposite to the side of the main body 11 by the thickness.
So that not. Further, the mounting screw portion 12 is provided below the main body 11. The bottom portion 122 of the mounting screw portion 12 is provided with a center electrode 13 at the center and a ground electrode 14 near the center electrode 13. A spark discharge is formed between the center electrode 13 and the ground electrode 14 due to the high voltage difference.

For the spark plug 1 constructed as described above, a holding cap 31 made of rubber is fitted to the insulator 16 in the same manner as in the prior art, and the holding cap 31 is further fitted with the rubber of the high tension cord 33. The connection part 335 made of a metal is fitted. As a result, the bottom portion 22 of the coil spring 2 provided on the high tension cord 33 is brought into contact with the metal plate 18 of the spark plug to achieve electrical conduction. The length of the coil spring 2 in the free state is 20 mm.

The spark plug 1 of this embodiment has a structure in which a flat metal plate 18 is provided at the tip of the insulator 16 and the coil spring 2 is brought into contact with the metal plate 18. That is, in the conventional spark plug, the protruding head terminal provided at the upper end thereof is eliminated, and a flat metal plate 18 is provided there. for that reason,
The overall length of the spark plug 1 is reduced. The outer diameter D of the mounting screw portion 12 is 12 mm. Therefore, the spark plug 1 can be downsized also in this respect. As described above, since the overall length of the spark plug is reduced, the size of the spark plug is reduced, and the space around the spark plug can be afforded. Therefore, in a narrow engine head plug hole, a mounting space for other in-vehicle components, for example, an overhead coil is increased. Furthermore, since there is ample space, the attachment and detachment of the spark plug is easy.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a connection state between a spark plug and a high tension cord in an embodiment.

FIG. 2 is a cross-sectional view showing a state of connection with a spark plug and a high tension cord in a conventional example.

[Explanation of symbols]

 1,10. . . Spark plug, 11. . . Body, 12. . . 12. mounting screw part, . . Center electrode, 14. . . Ground electrode, 16. . . Insulator, 18. . . Metal plate, 2. . . Coil spring, 31. . . Holding cap, 33. . . 4. High tension code, . . Head terminal,

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Claims (1)

(57) [Claims] 1. A main body of the center electrode is enclosed, and a mounting threaded portion outer diameter less 14mm provided at one side of the body, above
An insulator is exposed on the other side of the serial body, the center electrode and the collector
Electrically conductive, opposite to the body side of the insulator
On the side so as to be exposed with a thickness of 1.0 to 1.5 mm
A spark plug composed of a metal plate, a metal elastic body capable of contacting the metal plate, and a metal bullet.
Hold the body and fix the spark plug
A high-speed cable consisting of a holding cap fitted to an insulator
Spark plugs and wherein the emissions activation code, in that it consists of.