JPH11182399A - Igniting method for internal combustion engine and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of knocking by successively performing ignition from a portion which is high in temperature within a combustion chamber, that is, a portion where self-ignition is easy to be generated. SOLUTION: An ignition plug 5a is mounted in the vicinity of an exhaust valve 4, an ignition plug 5b is mounted in the vicinity of the center of a cylinder 1 and an ignition plug 5c is mounted on the side of a cylinder wall of a suction valve 3. The ignition plug 5a is connected with an ignition control unit 15 via an ignition coil 11a, the ignition plug 5b is connected with the ignition control unit 15 via an ignition coil 11b and a delay circuit 14 and the ignition plug 5c is connected with the ignition control unit 15 via the ignition coil 11c and a delay circuit 14. In this constitution, the ignition plug 5a in the vicinity of the exhaust valve 4 which becomes the highest temperature within a combustion chamber ignites air-fuel mixture at first. Next, the ignition plugs 5b, 5c ignite unburned gas, being slightly made later than the ignition plug 5a by the delay circuit 14. Thus, flame is smoothly propagated to the whole of the combustion chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for igniting a mixture of fuel and air supplied to a combustion chamber provided in the combustion chamber of the internal combustion engine.

[0002]

2. Description of the Related Art There is known an internal combustion engine which ignites a mixture of fuel and air by a spark from a spark plug, which is one ignition means provided in a cylinder head.

However, in the above-described technique, for example, as shown in FIGS. 2 to 5, combustion starts from a combustion B1 ignited by a spark plug 5, which is a fixed ignition point at one point in a combustion chamber 1a. 2), the flame propagates into the combustion chamber 1a. In this case, the unburned gas G around the combustion portion B2
May be compressed, become self-ignited under high temperature and high pressure, and abnormal combustion (knocking) may occur. The self-ignition which causes this knocking is likely to occur from a high temperature portion even in the combustion chamber, and a general representative thereof is that the vicinity of the exhaust valve H
(See FIGS. 4 and 5).

[0004] If the engine is continuously operated in a state where knocking occurs, not only is the output generally reduced, the fuel consumption is deteriorated, etc., but also the durability is not desirable. It can be destroyed.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned problems of the prior art, and provides an ignition method and apparatus for an internal combustion engine which suppresses the occurrence of knocking. It is an object.

[0006]

According to the present invention, there is provided an ignition method for an internal combustion engine which is provided in a combustion chamber of the internal combustion engine and ignites a mixture of fuel and air supplied to the combustion chamber. The ignition means is provided at a plurality of places in the combustion chamber, and the ignition means is configured to sequentially ignite from the ignition means provided at a place where knocking easily occurs.

Further, an ignition device for an internal combustion engine according to the present invention is provided in a combustion chamber of the internal combustion engine, and ignites a mixture of fuel and air supplied to the combustion chamber. Ignition means are provided at a plurality of locations in the combustion chamber, and the second, third, etc. ignition means are connected to the first ignition means via a delay circuit. It is provided at each location.

In implementing the ignition device for an internal combustion engine according to the present invention, it is preferable that the ignition means comprises a spark plug and a spark generation means.

In the ignition device for an internal combustion engine according to the present invention, it is preferable that the high-temperature portion in the combustion chamber is near an exhaust valve of a cylinder head.

According to the present invention having the above-described structure, ignition is performed from a position where self-ignition which causes knocking is most likely to occur, so that combustion by ignition is reliably performed before self-ignition occurs. In other words, before self-ignition occurs,
Since the air-fuel mixture is burned by the spark, there is no room for self-ignition. As a result, abnormal combustion due to self-ignition is reliably suppressed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, members having the same functions as those of the related art are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 1, a cylinder head 2 attached to a cylinder 1 has two intake valves 3, 3 and 2
And a plurality of (three in the illustrated example) ignition means, a first ignition plug 5a, which is the first ignition means of the plurality of (three in the example shown) is attached near the exhaust valve 4. Near the center of the cylinder 1, a second spark plug 5b,
A third spark plug 5c is provided on the cylinder wall side of the intake valves 3, 3.
Are attached.

An ignition control unit 15 is connected to the first ignition plug 5a by an electric circuit via an ignition coil 11a, and the second ignition plug 5b is connected to the ignition control unit via an ignition coil 11b and a delay circuit 14. The third ignition plug 5c is similarly connected to the ignition control unit 15 via the ignition coil 11c and the delay circuit 14 by an electric circuit.

The operation will be described below. For example, gas and air are supplied into the cylinder 1 from the intake valves 3 and 3 as an air-fuel mixture through a mixer (not shown). When the air-fuel mixture is compressed by a piston (not shown), the air-fuel mixture is compressed to a high temperature in the combustion chamber. High pressure. Then, a first spark plug 5a is attached near the exhaust valve 4, which has the highest temperature in the combustion chamber, and ignites the air-fuel mixture by blowing a spark to the plug 5a as in the conventional technology.

If there is only one ignition plug near the center, the flame propagates from the center of the cylinder (combustion chamber) to the periphery, but the flame ignited from the vicinity of the exhaust valve passes through the second ignition plug 5b and the second ignition plug. The sparks of the third spark plug 5c are slightly delayed (for example, 1 millisecond) from the first spark plug in the delay circuit, so that the unburned gas is ignited one after another and the flame is smoothly propagated to the entire combustion chamber. .

The first spark plug 5a is installed in the vicinity of the exhaust valve 4 at a location where the temperature of the combustion chamber is high. Combustion starts from the location where the temperature is high and is cooled by fresh air near the intake valve. The flame spreads toward, and is sequentially ignited by the second and third spark plugs, so that self-ignition is prevented and knocking does not occur.

If knocking occurs, the ignition control unit 15 is adjusted to delay the ignition timing of the first spark plug (the second and third spark plugs are automatically further delayed), or Alternatively, the ignition timing of the second and third spark plugs may be adjusted by adjusting the delay device 14.

Further, the ignition means is not limited to the combination of the ignition plug and the ignition coil which is the spark generation means, but may use a conventionally known technique such as a sub-chamber type combustion chamber or light oil injection.

FIG. 6 shows a second embodiment of the present invention. In FIG. 6, the present invention is applied to an engine having two cylinders 1-1 and 1-2, and ignition plugs 5a-1, 5b-1, and 5c-1 are provided on the cylinder 1-1 side. On the 1-2 side, spark plugs 5a-2, 5b-
2, 5c-2 are provided. And the spark plug 5
a-1, 5a-2 via a distributor 10-a, spark plugs 5b-1, 5b-2 via a distributor 10-b, and spark plugs 5c-1, 5c-2 via a distributor 10-c. Each of them is electrically connected to an ignition control unit (not shown in FIG. 6).

Other configurations and operations are the same as the embodiment of FIG. 1 in the embodiment of FIG.

[0021]

The present invention is configured as described above,
Since the combustion chamber is configured to ignite sequentially (in the air-fuel mixture) from a location where the temperature is high, that is, a location where self-ignition is likely to occur, knocking can be prevented, and output and fuel efficiency can be improved. Since no impact force is applied, it also contributes to durability.

[Brief description of the drawings]

FIG. 1 is an overall configuration block diagram showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an ignition process according to the related art.

FIG. 3 is a schematic view showing a process of flame propagation according to the related art.

FIG. 4 is a schematic diagram showing a state in a combustion chamber when knocking occurs in a conventional technique.

FIG. 5 is a plan view showing a conventional combustion chamber.

FIG. 6 is a block diagram showing a main part of a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylinder 2 ... Piston 3 ... Intake valve 4 ... Exhaust valve 5 ... Ignition plug 5a, 5a-1, 5b-2 ... 1st ignition plug 5b, 5b-1 5b-2 ... second spark plug 5c, 5c-1, 5c-2 ... third spark plug 10, 10-a, 10-b ... distributor 11 ... ignition coil 14. ..Delay devices 15 ... Ignition control devices

Claims (4)

[Claims] 1. An ignition method for an internal combustion engine which is provided in a combustion chamber of an internal combustion engine and ignites a mixture of fuel and air supplied to the combustion chamber, wherein ignition means is provided at a plurality of positions in the combustion chamber. A method for igniting an internal combustion engine, wherein the ignition means is configured to sequentially ignite from ignition means provided at a location where knocking is likely to occur. 2. An ignition device for an internal combustion engine, which is provided in a combustion chamber of the internal combustion engine and ignites a mixture of fuel and air supplied to the combustion chamber, wherein ignition means are provided at a plurality of positions in the combustion chamber of the internal combustion engine. And the second and the third with respect to the first ignition means.
Are connected via a delay circuit.
Wherein the ignition means is provided at a high temperature location in the combustion chamber. 3. The ignition device for an internal combustion engine according to claim 2, wherein said ignition means comprises a spark plug and a spark generation means. 4. The ignition device for an internal combustion engine according to claim 2, wherein the high temperature portion in the combustion chamber is near an exhaust valve of a cylinder head.