JPH08144897A - Two fluid injector of internal combustion engine - Google Patents

Abstract

PURPOSE: To reduce power necessary for compression of injected air while improving combustion and restraining the formation of NOx by providing a mechanism for taking out a portion of combustion gas from a cylinder after the completion of combustion and a mechanism for supplying the combustion gas to an injection valve. CONSTITUTION: There are provided a mechanism for taking out a portion of combustion gas from a self-cylinder or other cylinder after the completion of combustion and a mechanism for boosting a portion of combustion gas taken out of that mechanism by a compressor to supply it to an injection valve. Namely, in predetermined timing of the expansion stroke of an internal combustion engine a high pressure cut valve 18 is controlled by a controller 9 to take a portion of high pressure combustion gas out of the self- or other cylinder and boost it for obtaining combustion gas to be jetted. Thus, the power loss of the engine consumed by the compression work is substantially reduced. Also, since the injected combustion gas includes much CO2 , the mixture of gas in the cylinder is promoted to restrain the formation of NO2 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-fluid injection device for an internal combustion engine.

[0002]

2. Description of the Related Art The construction of a conventional two-fluid injection device for a diesel engine will be described with reference to FIG. 0 in the figure
1 is a two-fluid injection valve, 02 is a check valve, 03 is an air injection pipe,
Reference numeral 04 is a compressed air reservoir, 05 is a compressor, 06 is an air cleaner, 07 is a fuel injection pipe, 08 is a fuel injection pump,
09 is a controller, 010 is a cylinder head, 011
Indicates a piston, and 012 indicates a combustion chamber.

Next, the operation of the conventional example will be described.
In the compression stroke, the piston 01 rises and the combustion chamber 012
When the air inside is compressed to a high temperature and high pressure, the fuel pressurized by the injection pump 08 is injected at an appropriate timing from the injection valve 01 into the combustion chamber 012 through the fuel injection pipe 07, and the fuel burns by self-ignition. To start. At the same time, the air filtered by the air cleaner 06 is compressed by the compressor 05 to a pressure higher than the maximum pressure in the combustion chamber and stored in the air reservoir 04. The high-pressure air in the air reservoir is simultaneously injected into the combustion chamber 012 from the fuel injection valve 01 at an appropriate timing with respect to the injected fuel.

As described above, the controller 09 is provided in order to inject fuel and high pressure air at appropriate timing. (However, depending on the engine, the controller 09 may not be provided, and although the fuel and air are injected by the same injection valve 01 in this conventional example, they may be injected by different injection valves.) As described above, by injecting air directly into the combustion chamber 012, the mixture of fuel spray and air can be promoted, the combustion period is short, and the complete combustion diesel with little unburned components such as black smoke and HC. Institution can be realized. Further, the promotion of mixing suppresses the temperature of the combustion gas from rising and suppresses the generation of NO _x .

[0005]

However, the above-mentioned conventional example has the following drawbacks. That is, since air is a compressible fluid, a large amount of power is required to compress it to high pressure. Particularly in a diesel engine, the compression ratio is high and the maximum pressure in the combustion chamber during combustion is also high. Therefore, the supercharged engine may exceed 15 MPa, and the air for injection needs to be compressed to a high pressure of 20 MPa or more.

Therefore, the power required for air compression becomes very large, resulting in a reduction in the thermal efficiency of the engine. Further, since high-pressure air is used as a fluid for promoting mixing, the combustion itself is improved, but there is a drawback that the combustion gas temperature rises and conversely increases NO _x depending on the conditions.

An object of the present invention is to solve the problems of the conventional device, utilize exhaust gas in order to reduce the power required to compress the injection air, and produce a favorable air-fuel mixture, thereby improving combustion and reducing NO. ₍ EN) Provided is a two-fluid injection device for an internal combustion engine, which aims to suppress the generation of _x .

[0008]

DISCLOSURE OF THE INVENTION The present invention is a two-fluid injection device for injecting fuel and gas for promoting mixing directly into the cylinder of an internal combustion engine. It is characterized by having a mechanism for taking out a part and a mechanism for boosting a part of the combustion gas taken out from the mechanism by a compressor and supplying it to the injection valve.

[0009]

The present invention is configured as described above, and a part of the high pressure combustion gas in the cylinder is taken out during the expansion stroke, and the combustion gas is further compressed by the compressor for use in the engine. The power loss of the engine consumed for the compression work is greatly reduced.

Moreover, since the injected combustion gas is a combustion gas containing a large amount of CO ₂ having a low oxygen concentration, mixing of the gases in the cylinder is promoted, but the NO _x production reaction is suppressed, and CO 2 is suppressed. It has the effect of reducing black smoke by the effect of the water-gas reaction due to _2, which enables the development of a diesel engine with low fuel consumption and low pollution.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 illustrates a case of two-fluid injection of a diesel engine as in the conventional example. In the figure, 1
Is a two-fluid injection valve, 2 is a check valve, 3 is an air injection pipe, 4 is a compressed air reservoir, 5 is a compressor, 7 is a fuel injection pipe, 8 is a fuel injection pump, 9 is a controller, 10 is a cylinder head, 11 Is a piston, 12 is a combustion chamber, 13 is a source gas reservoir, 14 is a check valve, 15 is a relief valve, 16 is a gas pipe,
Reference numeral 17 is an extraction hole, 18 is a high pressure cut valve, 19 is a signal for injection control, and 20 is a signal for gas extraction control.

Next, the operation of the first embodiment will be described. When the engine controls the high-pressure cut valve 18 by the controller 9 at a predetermined timing of the expansion stroke to take out a part of the high-pressure combustion gas from itself or another cylinder and pressurizes it by the compressor 5, combustion gas for injection is obtained. .

The high-pressure cut valve 18 is an automatic valve that closes at a pressure higher than the compression pressure in the cylinder (in the case of a supercharged engine, the compression pressure at maximum rotation and maximum load), and the expansion stroke of the engine. Only in this case, the electronically controlled valve is combined so that the high pressure cut valve 18 operates. At the time when the combustion reaction is completed, only the combustion gas is extracted, and thereafter the pressure is increased and stored in the original gas reservoir 13.

The amount of gas taken out from the cylinder is adjusted by the passage area of the extraction hole for taking out the gas. With such a configuration, the combustion gas once flowing out of the cylinder when the engine expands is returned to the inside of the cylinder when the gas is injected, so that the compression work loss of the piston 11 does not occur. Therefore, compression of gas is only required to increase the pressure from the pressure at the time of extraction to the injection pressure from the injection valve.Compared to the conventional case of compression from atmospheric pressure, only the power required to increase the pressure from the atmosphere to the extraction pressure is used. You can save money.

Further, in the case of conventional mixing promotion by air injection, the combustion temperature may increase and NO _x may increase depending on the conditions, but in the case of the present invention, the extracted combustion gas is used as the injection gas. Therefore, the O ₂ concentration is low and CO
_The high concentration of ₂ promotes mixing, but lowers the combustion temperature and suppresses the production of NO _x . Further, the production of black smoke can be suppressed by the water gas reaction effect of CO ₂ . In this example, the case where the fuel and the air are injected by one injection valve is shown, but it is needless to say that basically the same result can be obtained by using different injection valves.

[0016]

According to the present invention, the same effect as the conventional mixing promotion and combustion improvement by the two-fluid injection can be maintained, and the power loss necessary for gas compression can be greatly reduced, and the thermal efficiency of the engine can be improved. Is improved. Furthermore, since exhaust gas is used, there is little black smoke and unburned components such as HC, and NO _x
It is possible to realize a clean internal combustion engine with a low fuel consumption rate and low pollution, which produces less fuel.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a two-fluid ejection device according to a first embodiment of the present invention.

FIG. 2 is a corresponding diagram of FIG. 1 of a conventional example.

[Explanation of symbols]

1 ... Two fluid injection valve, 2 ... Check valve, 3 ... Gas injection pipe, 4 ...
Compressed gas reservoir, 5 ... Compressor, 7 ... Fuel injection pipe, 8
... Fuel injection pump, 9 ... Controller, 10 ... Cylinder head, 11 ... Piston, 12 ... Combustion chamber, 13 ... Original gas reservoir, 14 ... Check valve, 15 ... Relief valve, 16 ... Extraction gas passage, 17 ... Extraction hole , 18 ... High pressure cut valve, 19 ... Injection control signal, 20 ... Gas extraction control signal.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F02M 63/00 N 67/04

Claims (1)

[Claims] 1. A two-fluid injection device for injecting a fuel and a gas for promoting mixing directly into a cylinder of an internal combustion engine,
Internal combustion engine having a mechanism for taking out a part of the combustion gas after completion of combustion from itself or another cylinder, and a mechanism for boosting a part of the combustion gas taken out from the mechanism by a compressor and supplying the same to an injection valve Two-fluid ejector.