JPS6211471B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to improvements in spark plugs used in internal combustion engines such as automobiles.

``Prior Art'' The basic method of igniting the ignition plug is as shown in Fig.
A suitable plug gap L1 (usually 0.7 mm ) is provided, and when the engine is operating, electricity is supplied from the terminal 5 provided to the center electrode 1 via the ceramic insulator 4 to generate a spark in the plug gap L1, causing the air-fuel mixture in the cylinder to ignite and explode. .

Conventionally, in such a spark plug, Fig. 2 and Fig.
As shown in the figure, the rectangular ground electrode plate 12 bent into an L shape is formed of a continuous flat plate from the welded fixing part 13 to the tip corresponding to the center electrode 11. The inside of the cylinder was divided into a spark generation side 1A and a piston side 1B.

"Problems to be Solved by the Invention" Therefore, the air-fuel mixture around the spark generation side 1A is used as the detonation point to cause a combustion explosion and a flame nucleus is formed, but the piston side 1B of the ground electrode plate 12
Since the spread of fire to the air-fuel mixture was blocked by the ground electrode plate 12 and passed around the plate 12, there was a momentary delay before the fire spread and exploded, so in an internal combustion engine rotating at high speed, some of the air-fuel mixture was completely combusted. The problem is that the next operation is repeated without the engine being fully combusted, resulting in exhaust gas pollution being generated as incompletely combusted gas, and that the combustion efficiency cannot be easily improved.

Therefore, as shown in Utility Model Application Publication No. 51-72634,
There is a technology in which a small-diameter part is formed on the tip side of the ground electrode that forms the spark gap, and the flame kernel formed in the spark gap is grown in the gap between the small-diameter part and the center electrode to obtain a large flame kernel. However, although this conventional technology was able to improve the ignition ability and reliably ignite a lean mixture, it was not possible to easily shorten the combustion time of the mixture in the cylinder, and There are problems in that incompletely combusted gas is likely to be generated during operation, making it difficult to improve engine efficiency and reduce combustion consumption.

``Means for Solving the Problems'' However, the present invention provides a spark plug in which the tip of a ground electrode plate is disposed opposite to the tip of the center electrode, and a plug gap is formed between these tips. An elongated ignition groove is formed with a width smaller than the width, and one end of the ignition groove is opened at the edge of the ground electrode plate closest to the spark generation position, and one end of the ignition groove is narrower than the width of the end surface of the ground electrode plate. The side opening width is formed small, and the other end of the ignition groove is provided in a bag shape on the side surface of the piston of the ground electrode plate so as to be opened in a direction different from the plug gap position.

``Function'' Therefore, when a flame kernel is formed by the spark in the plug gap, the air-fuel mixture in the opening at one end of the ignition groove near the plug gap burns with the flame kernel as a pilot fire, almost simultaneously with the formation, and at the same time The air-fuel mixture in the ignition groove, which has a small volume, can spread quickly and the mixture around the ignition groove on the piston side away from the plug gap can spread during the early stages of combustion. The flame propagation and flame propagation occur almost simultaneously, significantly accelerating the flame propagation speed in the early stage of combustion, and the flame propagation from multiple paths such as the plug gap and ignition groove causes the flow of the air-fuel mixture in the cylinder to be more turbulent than before. The combustion time of the mixture in the cylinder can be easily shortened compared to the conventional structure that only increases the size of the flame kernel, and the generation of incomplete combustion gas can be prevented to reduce exhaust gas. In addition to reducing pollution, it is also possible to improve engine efficiency and reduce fuel consumption more easily than in the past.

"Embodiments" Examples of the present invention will be described in detail below based on the drawings.

4 to 7 show a first embodiment of the present invention, in which a ground electrode plate 32 bent into an L-shape has one end corresponding to the center electrode 31 via a suitable plug gap, and the other end. is welded to the fixing part 33. This ground electrode plate 32 is located on the back side of the spark generation side 3A near the plug gap, that is, on the piston side 3B.
A bag-shaped gas mixture reservoir 37 is formed on the surface of the air conditioner. Furthermore, both side edges 3 of the ground electrode plate 32 are removed from the reservoir 37.
6, 36 and an ignition groove 38 communicating with the tip edge 35,
38, 38 are formed. Therefore, the center electrode 3
A spark is generated between the plug gap between the ground electrode plate 32 and the spark generating side 3A, and a flame nucleus is formed with the spark generation side 3A as the detonation point, and a combustion explosion is caused around it. The spread of fire to a certain air-fuel mixture is once blocked by the ground electrode plate 32, and when passing around the plate 32, an ignition groove 38 that communicates from the bag-shaped reservoir 37 to the side edges 36, 36 and the tip edge 35 of the plate 32 is formed. , 38, 38 quickly spreads, and then these fires further spread to the mixture inside the bag-shaped reservoir 37. Therefore, this reservoir 3
During the early fire spread and explosion of the air-fuel mixture in the reservoirs 37..., the gas expansion force in the reservoirs 37 rebounds against the walls within the bag-like reservoirs, and each reservoir 37 is formed with physical velocity. is released into the cylinder from the position where it is located. Then, the unburned air-fuel mixture remaining in the cylinder can be caused to spread substantially simultaneously with the explosion at the spark generation position. The ignition grooves 38, 38, 38 not only assist in the spread of the air-fuel mixture in the reservoir 37, but also
Similarly to 7, when the air-fuel mixture in the ignition grooves 38, 38, 38 spreads and explodes, the expansion force of the gas in the ignition grooves 38, 38, 38 is repelled within the grooves and physically accelerated to flow into the cylinder. Let it be released.

FIG. 8 shows a modification of the first embodiment, in which a bag-shaped and long reservoir 47 is formed in the longitudinal direction of the ground electrode plate 42, and from this reservoir 47 both side edges 46, 4
6 may be formed. Further, the ignition grooves 48 and the reservoir portions 47 can also be formed in a grid pattern.

9 to 12 show a second embodiment of the present invention, in which two ground electrode plates 52, 5 are bent into an L shape.
2 has one end corresponding to the tip of the center electrode 51 via a suitable plug gap, and the other end to the fixing part 5.
3 are welded to each other. This kind of type having a plurality of ground electrode plates 52 is mainly used in rotary engines, and the ground electrodes 52, 5
2 is a bag-shaped mixture reservoir 5 similar to the first embodiment.
7, 57 and the ignition groove 5 communicating with the tip edge 55, 55
The distal edges 55, 55 of the ground electrode plates 52, 52 are curved to correspond to the circumferential surface of the distal end of the center electrode 51.
Therefore, the bag-shaped reservoirs 57, 57 are located close to the center electrodes on the piston side 5B of the ground electrode plates 52, 52.
The ignition groove 58, which is formed in the surface and communicates with the reservoir portions 57, 57, is located at the tip edges 55, 55 of the curved ground electrode plates 52, 52, which are closest to the circumferential surface of the center electrode 51.
The electrodes are formed so as to communicate with each other and correspond to the positions closest to the center electrode 51, respectively.

Thus, the center electrode 51 and the ground electrode plates 52, 52
At the same time, a spark is generated between the plug gap and a combustion explosion is generated around the spark generation position (plug gap position) as the detonation point.
Immediately the tip edges 55, 55 of the ground electrode plates 52, 52
ignition grooves 58 communicating with the bag-shaped reservoirs 57, 57;
58, and then the mixture in the bag-shaped reservoirs 57, 57. Even if the combustion capacity of the combustible bodies is the same, the amount of combustion will be different. Smaller parts burn faster, so for example, if a square-shaped cross section ignites, the fire will spread as quickly as the corners, and the ignition grooves that act as fuses will burn as quickly as the corners of the rod. , the air-fuel mixture in the reservoir 57 is combusted and exploded with almost no time difference.

Therefore, when the air-fuel mixture in the reservoirs 57, 57 spreads and explodes, the gas expansion force in the reservoirs 57, 57 is repelled by the walls within the reservoirs, and this has a physical velocity, causing each reservoir to explode. The unburned air-fuel mixture that is discharged from the position where the portions 57, 57 are formed and remains in the cylinder can be caused to spread substantially simultaneously with the explosion at the spark generation position. flash groove 58,
It goes without saying that 58 functions as a reservoir in the same manner as described above.

The ignition grooves 38 and 48 are shown in FIGS. 7 and 11.
Ground electrode plate 3 on the center electrode side as shown by the imaginary line in the figure.
The groove 3 is inclined toward the edges 35, 36, 46 of 2, 42.
8 and 48 closer to the spark generation position, the air-fuel mixture in the ignition grooves 38 and 48 can be spread quickly and reliably.

"Effects of the Invention" As is clear from the above embodiments, the present invention has the tips of the ground electrode plates 2, 12, 32, 42, 52 arranged opposite to the tips of the center electrodes 1, 11, 31, 41, 51,
In the spark plug in which a plug gap L1 is formed between these tips, the ground electrode plates 2, 12, 32,
Forming ignition grooves 38, 48, 58 on the piston sides 3B, 5B of 42, 52, which are narrower than this width and elongated,
Edges 35, 36, 4 of the ground electrode plates 2, 12, 32, 42, 52 closest to the spark generation position
6, 55 are opened at one end side of the ignition grooves 38, 48, 58, and the ground electrode plates 2, 12, 32, 4
The ignition groove 38, 4 is smaller than the width of the end face of
The opening width of one end of the ignition groove 38, 48, 58 is made small, and the ground electrode plate 2, 12, 32 is shaped like a bag so that the other end of the ignition groove 38, 48, 58 is opened in a direction different from the plug gap L1 position. , 42, 52 on the piston side 3B, 5B surface, and when a flame kernel is formed by the spark of the plug gap L1, the ignition groove 3 close to the plug gap L1 is provided.
The air-fuel mixture in the opening at one end of 8, 48, 58 burns using its flame kernel as a pilot fire almost simultaneously with this formation, and the air-fuel mixture in the ignition grooves 38, 48, 58, which have a smaller volume than the others, spreads quickly. Then, plug gap L1
The ignition groove 38 on the piston side 3B, 5B away from the
The air-fuel mixture around 48, 58 can be spread in the early stage of combustion, and the flame propagation around the plug gap L1 and the flame propagation around the ignition grooves 38, 48, 58 are carried out almost simultaneously, so that the flame can spread in the early stage of combustion. In addition to being able to significantly accelerate the propagation speed, the early fire spreading effect of the ignition grooves 38, 48, and 58 serves as a pilot flame that runs almost simultaneously with the ignition by the spark, making it possible to quickly spread the fire over a wider area than before. , it is possible to immediately increase the power of the internal combustion engine by early combustion of the air-fuel mixture in the cylinder.
The flame propagation from multiple paths such as 58 can disturb the flow of the air-fuel mixture in the cylinder more than before, further accelerating the spread of air-fuel mixture. The combustion time of the air-fuel mixture can be significantly shortened, the generation of incomplete combustion gas can be prevented and exhaust gas pollution can be reduced, and engine efficiency can be improved and fuel consumption reduced more easily than before. It has the following effects.

[Brief explanation of the drawing]

Figures 1 to 3 show conventional examples.
2 is an enlarged sectional explanatory view of the main part, FIG. 3 is a bottom view of the previous figure, and FIGS. 4 to 7 show a first embodiment of the present invention. , Figure 4 is an enlarged sectional view of the main parts, Figure 5 is a bottom view of the previous figure,
FIG. 6 is an enlarged explanatory view taken along the line CC of the previous figure, FIG. 7 is an enlarged cross-sectional view taken along the line D-D of the previous figure, FIG. 8 is an explanatory view of a modified example, and FIGS. The drawings show a second embodiment of the present invention, in which Fig. 9 is an enlarged sectional view of the main part, Fig. 10 is a bottom view of the previous figure, Fig. 11 is an enlarged sectional explanatory view of part E, and Fig. It is an enlarged explanatory view of part F. 1, 11, 31, 41, 51... center electrode,
2, 12, 32, 42, 52...Ground electrode plate, 3
7, 47, 57...Tamebe, 38, 48, 58...
Flaming ditch.

Claims (1)

[Claims] 1. In a spark plug in which the tips of the ground electrode plates 2, 12, 32, 42, 52 are arranged opposite to the tips of the center electrodes 1, 11, 31, 41, 51, and a plug gap L1 is formed between these tips, the ground electrode plates 2 ,1
2, 32, 42, 52 piston side 3B, 5B has a narrower and narrower ignition groove 38, 48, 58 than this width.
and the ground electrode plates 2, 12, 32, 4
Edge 3 closest to the spark generation position of 2,52
5, 36, 46, 55, the ignition grooves 38, 48,
One end side of 58 is opened, and the ground electrode plates 2, 1
The opening width on one end side of the ignition grooves 38, 48, 58 is formed smaller than the end face width of the ignition grooves 38, 48, 52, and the other end side of the ignition grooves 38, 48, 58 is different from the position of the plug gap L1. Ground electrode plates 2, 12, 32, 4 are arranged in a bag shape to open toward the direction.
An ignition plug characterized in that it is provided on the piston side 3B and 5B surfaces of the pistons 2 and 52.