JPS592764B2 - internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal combustion engine, in particular to a diesel engine having a vortex chamber sub-combustion chamber.

An object of the present invention is to provide an internal combustion engine that uses a low-cetane fuel such as low temperature and alcohol, which has poor self-ignition properties, as the main fuel for output control, stabilizes the ignitability of the fuel, and significantly reduces smoke density. That's true.

Using low-cetane fuel such as alcohol as fuel for diesel engines can significantly reduce the smoke concentration, which can be used as a countermeasure for exhaust gases and to conserve resources by saving diesel oil, etc. However, low-cetane fuel such as alcohol The fuel had poor self-ignition properties and had problems with engine performance.

The present invention solves the above problems and provides a diesel engine with good engine performance and exhaust performance using low cetane fuel such as alcohol as the main fuel. An ignition injection nozzle that injects a fuel with good self-ignition properties such as light oil into the combustion chamber, and a main fuel injection nozzle that injects a low cetane fuel such as alcohol as the main fuel, which uses this as a spark to ignite. The internal combustion engine is equipped with a two-fuel, two-injection system that enables efficient combustion of low-cetane fuels such as alcohol depending on specific spray formation and timing.

Embodiments of the present invention will be described below based on the drawings.

1 is the cylinder, 2 is the piston, 3 is the cylinder head, 4
5 is a main combustion chamber, and 5 is an auxiliary combustion chamber provided in the cylinder head 3.

During the compression stroke, air flows into the auxiliary combustion chamber 5 in a tangential direction into the spherical auxiliary combustion chamber 5 through a communication passage 6 with the main combustion chamber 4, generating a violent vortex and flowing into the flow. It is a vortex chamber type that injects fuel to aid in mixing.

In the present invention, such a vortex chamber type sub-combustion chamber 5 is provided with a high fuel injection nozzle 7 and a main fuel injection nozzle 8 for injecting a low cetane fuel such as alcohol.

Both injection nozzles are arranged in the following specific injection directions.

That is, the ignition fuel injection nozzle 7 has an angle such that the ignition fuel spray injected therefrom is formed along the peripheral wall surface of the sub-combustion chamber 5, and the main fuel injection nozzle 8 has an angle such that the ignition fuel spray injected therefrom is formed along the peripheral wall surface of the sub-combustion chamber 5. The angle is such that the main fuel spray E is directed approximately toward the center of the sub-combustion chamber 5.

Furthermore, the injection timing of both injection nozzles is such that light oil is first injected from the ignition fuel injection nozzle 7 as a spark, and then alcohol, which is the main fuel, is injected from the main fuel injection nozzle 8 after a slight delay time. Controlled by a pump (circuit).

Note that the reference numeral 9 in the figure indicates a glow plug for starting assistance in cold weather.

The present invention configured as described above has the following functions and effects.

Prior to main fuel injection, the light oil ignition fuel injected from the ignition injection nozzle 7 is sprayed along the peripheral wall of the auxiliary combustion chamber 50 due to the influence of the air vortex A generated in the auxiliary combustion chamber 5. is formed, and then a main fuel spray E of alcohol injected from the main fuel injection nozzle 8 is formed.

That is, the main fuel spray E, which is a low cetane number alcohol with poor self-ignition properties, is surrounded by the high-performance fuel spray with good self-ignition properties, forming a spray of two types of fuel.

Before ignition, the sprays of these two types of fuel hardly mix, so the light oil that is the ignition fuel is not cooled by the latent heat of vaporization of the main fuel, alcohol, so the ignition stability remains extremely high.

When the ignited fuel self-ignites due to compression, the high-temperature, low-density combustion gas is drawn toward the center of the auxiliary combustion chamber 5 by the air vortex A, enveloping the main fuel and mixing well, resulting in efficient combustion. be.

Therefore, according to the present invention, a low cetane number fuel such as alcohol, which has poor self-ignition properties but low smoke concentration, is used as the main fuel,
Only the ignition is achieved by burning the main fuel, such as alcohol with a high self-ignition property, such as alcohol with a high self-ignition property, so it is possible to obtain almost the same engine performance as a conventional engine that uses diesel oil as the main fuel. , a diesel engine with greatly improved smoke emission can be obtained.

[Brief explanation of the drawing]

The drawing is a sectional view of the main part of the present invention. 1...Cylinder, 2...Piston, 3
... Cylinder head, 4 ... Main combustion chamber, 5 ... Sub-combustion chamber, 6 ... Value circuit, 7
...Fuel injection nozzle for ignition, 8...Main fuel injection nozzle, L...Fuel spray for ignition, E.
...Main fuel spray, A... Air vortex.

Claims (1)

[Scope of Claims] 1. In an internal combustion engine having a vortex chamber type auxiliary combustion chamber, a fuel injection nozzle for ignition of light oil or the like as an ignition fuel is provided in the side combustion chamber, and a fuel injection nozzle for ignition as a main fuel for output control is provided. An internal combustion engine comprising: a main fuel injection nozzle that injects a spray of low cetane fuel such as alcohol into the vicinity of the center of the combustion chamber with a slight delay from the ignition fuel injection.