JP2747988B2 - Method and apparatus for controlling combustion in an internal combustion engine - Google Patents

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 controlling the combustion of an internal combustion engine used in automobiles, ships, aircraft and other civil engineering machines, and more particularly, to the combustion control of an internal combustion engine in which ignition timing can be controlled. The present invention relates to a control method and an apparatus.

[0002]

2. Description of the Related Art As a conventional piston engine among conventional internal combustion engines, as shown in FIG. 5, the intake air in a combustion chamber 3 of a cylinder 1 is compressed by the advance (up) of a piston 2, and ignition is performed. When the electric spark plug 4 is ignited and burned by the function of the system, the piston 2 is retracted (pressed down) by the pressure in the combustion chamber 3 and then the piston 2 is advanced to exhaust (scavenge) the inside of the combustion chamber 3. For this purpose, an intake port 5, an exhaust port 6, and an electric spark plug 4 are provided on the upper surface of the combustion chamber 3 formed on the upper part of the cylinder 1. An intake pipe 7 provided with an air cleaner 8 at the tip is connected, and a fuel mixer 9 is provided in the middle of the intake pipe 7.
Is mixed and introduced into the combustion chamber 3 from the intake port 5, and the exhaust port 6 is connected to an exhaust pipe 11 having a muffler 12 on the way to discharge combustion exhaust gas to the atmosphere. . An intake valve 13 is provided at the intake port 5 so as to be openable and closable, and an exhaust valve 14 is provided at the exhaust port 6 so as to be openable and closable.

Conventionally, when the internal combustion engine having the above configuration is operated, in an engine cycle of four strokes, the intake valve 13 is opened in the intake stroke shown in FIG. A mixture of the atmosphere and the fuel 10 is sucked into the cylinder 1, and in a compression stroke ((b) in FIG. 6), after the intake valve 13 is closed, the piston 2 rises to compress the mixture in the combustion chamber 3. I do. In the explosion process ((c) in FIG. 6), the ignition plug 4 is operated by the operation of the ignition system to ignite and burn the air-fuel mixture. When the pressure in the combustion chamber 3 of the cylinder 1 becomes high due to combustion, the piston 2 is pushed down. Next, in the exhaust stroke ((d) in FIG. 6), the exhaust valve 14 is opened, the piston 2 rises, and the combustion exhaust gas is discharged from the exhaust port 6 through the exhaust pipe 11.

In addition, the cylinder has three ports of an intake port, an exhaust port, and a scavenging port and has no valve. During one revolution of the crankshaft, intake, compression, ignition, explosion, and exhaust are performed. A so-called two-stroke engine that performs one cycle is also used.

In addition to the conventional internal combustion engine, the fuel 10 is mixed in the intake air, compressed in the combustion chamber 3 and ignited by the spark plug 4 as described above. Compression in chamber 3 and self-ignition by injecting fuel into a high-temperature place, one in which the main fuel is ignited based on the partially created fire, etc. is there.

[0006]

However, in any of the conventional types of internal combustion engines, the intake air taken into the combustion chamber 3 of the cylinder 1 always contains oxygen necessary for ignition. Therefore, for example, in the model shown in FIG. 5, when a fuel having a low self-ignition temperature such as light oil is used as the fuel and the intake air is premixed by the mixer 9 and is to be burned in the combustion chamber 3, the compression is performed in the compression stroke. The fuel may self-ignite due to heat. For this reason, there is a problem that it is very difficult to control the ignition timing that should be fired at an appropriate timing at the end of the compression stroke in accordance with the operating state of the engine.

Accordingly, an object of the present invention is to provide a combustion control method and apparatus for an internal combustion engine that can control ignition timing even with fuel having a low self-ignition temperature.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention separates oxygen in an intake stroke and premixes fuel when inhaling oxygen-free intake air into a combustion chamber of an internal combustion engine. Alternatively, oxygen-free intake air and fuel are separately drawn into the combustion chamber and mixed therein, and then
Compressing the oxygen-free intake air and fuel in the compression stroke,
A method of injecting oxygen whose concentration has been adjusted at an arbitrary time during the compression stroke into the combustion chamber, mixing it with the compressed fuel, causing it to react, ignite and burn.

An intake port provided in a combustion chamber of an internal combustion engine includes:
The downstream end of an intake pipe having an oxygen separator which is designed to separate and recover oxygen in the middle is connected, and oxygen is separated by the oxygen separator and oxygen-free intake air is burned from the intake port. While inhaling into the room, supplying fuel to the middle of the intake pipe on the downstream side of the oxygen separator, premixing the fuel with the oxygen-free intake air and entering the combustion chamber, or In addition to the oxygen-free intake air, fuel is directly supplied to the combustion chamber to mix the oxygen-free intake air with the fuel in the combustion chamber, and the combustion chamber is further provided with an exhaust port and oxygen injection. A nozzle is installed, an exhaust pipe is connected to the exhaust port, and the upstream end of the intake pipe is opened to the atmosphere or connected to the middle of the exhaust pipe so that combustion exhaust gas can be taken in. The oxygen injection nozzle has To connect the oxygen supply pipe having an oxygen concentration regulator, a structure in which the oxygen separated and collected in the oxygen separator to allow the injection into the concentration adjusting burns from oxygen injection nozzle chamber.

Further, an exhaust port is provided in a combustion chamber of the internal combustion engine, and a fuel injection nozzle and an oxygen injection nozzle are provided. A predetermined pressure after the explosion in the combustion chamber is provided in an exhaust pipe connected to the exhaust port. A flow regulating valve is provided for discharging the exhaust gas having the above-mentioned characteristics while remaining in the combustion chamber, and the exhaust gas remaining in the combustion chamber is injected into the combustion chamber from the fuel injection nozzle as an inhaled gas. And the oxygen whose concentration has been supplied through the oxygen concentration regulator can be injected from the oxygen injection nozzle into the combustion chamber.

[0011]

The fuel is premixed with the oxygen-free intake air and is then sucked into the combustion chamber, or the fuel is separately supplied to the combustion chamber and then mixed with the oxygen-free intake air in the combustion chamber. When compressed, even if the temperature rises above the self-ignition temperature of the fuel, the fuel does not self-ignite because the intake air contains no oxygen. At any time during the compression stroke, oxygen whose concentration has been adjusted is injected into the combustion chamber from the oxygen injection nozzle, whereby the oxygen mixes with and reacts with the compressed fuel whose temperature has been raised to the self-ignition temperature or higher. Burn. Therefore, the ignition can be performed at an arbitrary timing by selecting the timing of injecting oxygen, that is, the timing of combustion can be controlled by adjusting the timing of injecting oxygen.

Further, if the combustion exhaust gas is used for the intake air, it becomes easy to configure an underwater power system of an engine that is used underwater, for example, underwater.

Furthermore, if the combustion exhaust gas is left in the combustion chamber and is compressed assuming that it is the intake gas in the next cycle, the intake stroke and the exhaust stroke become unnecessary even in the case of a four-stroke engine. It can be.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. Similar to the embodiment shown in FIG.
At the upper part of the intake port 5 having an intake valve 13 and an exhaust valve 14
And the piston 2 is moved up and down to rotate the crankshaft 15. Further, the intake port 5 is supplied with the air taken in from an air cleaner 8 installed at the tip. In the configuration in which an intake pipe 7 is connected to the exhaust port 6 and an exhaust pipe 11 having a muffler 12 in the middle thereof is connected to the upper part of the combustion chamber 3 in FIG.
An oxygen injection nozzle 16 is installed in place of the electric spark plug 4 in the above, and an oxygen separator 17 for separating and recovering oxygen in the air is installed at an intermediate position of the intake pipe 7. The oxygen separated and recovered in the above-mentioned oxygen injection nozzle 1
A supply pipe 18 for supplying to 6 is provided between the oxygen separator 17 and the oxygen injection nozzle 16.

The oxygen supply pipe 18 is provided with an oxygen concentration controller 19, a temperature controller 20, and an injection pump 21 in this order from the upstream side. The oxygen concentration controller 19 includes the oxygen separator 17 is connected to a branch pipe 22 branched from the downstream side to remove a part of the oxygen-free gas from the oxygen concentration controller 1.
9 to reduce the oxygen concentration, or provide an oxygen supply / discharge line 24 between the oxygen supply unit 23 and oxygen supply / discharge to adjust the oxygen concentration to a level suitable for combustion. Further, the temperature can be adjusted and supplied by the temperature adjuster 20.

Numeral 9 denotes the same fuel mixer as the conventional system shown in FIG. 5, which mixes fuel 10 with intake air. Reference numeral 25 denotes a valve in the supply pipe 18.

When the intake air is sucked into the combustion chamber 3, the intake valve 13 is opened, the exhaust valve 14 is closed, and when the piston 2 moves backward (down), clean air is sucked through the air cleaner 8. In the process, the atmosphere is introduced into the oxygen separator 17, oxygen O ₂ in the atmosphere is separated and taken out, and gas containing no oxygen is premixed with the fuel 10 as intake air, and is supplied to the combustion chamber 3 through the intake port 5. Inhaled from.

When the intake air obtained by premixing the fuel 10 with the gas containing no oxygen enters the combustion chamber 3, after the intake valve 13 is closed,
The piston 2 is compressed by moving forward (ascending).
The compression ratio is set to be equal to or higher than that of a conventional engine even when the fuel 10 is light oil or gasoline.

Although the temperature of the compressed intake air rises above the self-ignition temperature of the fuel 10, the self-ignition does not occur because the intake air contains no oxygen.

At any point during the compression stroke, the valve 25 in the oxygen supply pipe 18 is opened, and a gas containing oxygen whose concentration is adjusted and whose temperature is adjusted (only oxygen, oxygen and nitrogen gas, carbon dioxide gas, inert gas, When the mixed gas such as gas) is pressurized by the injection pump 21 and injected into the combustion chamber 3 from the oxygen injection nozzle 16, it is mixed with the fuel 10 which has been compressed in the compression stroke and has been heated to the self-ignition temperature or higher. Reaction and combustion will occur. Therefore, the timing of combustion can be controlled by adjusting the timing of injecting the gas containing oxygen from the oxygen injection nozzle 16 into the combustion chamber 3. At this time, even if the fuel 10 is light oil or other fuel that has a low self-ignition temperature and cannot be used by being premixed with intake air (normal air), the present invention uses the oxygen-free intake air and fuel. Since it becomes possible to perform premixing and perform combustion with good timing,
Since the air utilization rate of the engine is greatly improved, it is possible to use an engine that uses light oil as fuel and that is not inferior to the power of a gasoline engine. In addition,
The pressure of the gas containing oxygen injected from the oxygen injection nozzle 16 into the combustion chamber 3 needs to be higher than the pressure in the compressed combustion chamber 3.

In the above description, the timing of injecting the gas containing oxygen from the injection nozzle 16 into the combustion chamber 3 can be arbitrarily controlled. For example, the control unit 26 is provided as shown by a two-dot chain line in FIG. Thus, an opening command may be given to the valve 25 in accordance with an arbitrary set time of the timer, or mechanical control may be performed so that the fuel is injected at the end of the compression stroke. Also, the oxygen injection nozzle 16
The amount of oxygen injected from the nozzle can be changed at intervals of opening and closing the valve by providing a valve in the oxygen injection nozzle 16 or by adjusting the pressure by the oxygen injection pump 21 to a high or low level. However, the increase and decrease can be controlled according to the engine speed. Further, the composition of the gas containing oxygen injected from the oxygen injection nozzle 16 may be, as described above, only oxygen or a mixture of oxygen and another gas (nitrogen, carbon dioxide, inert gas, or the like). is there. The reason for adjusting the concentration by supplying and discharging oxygen or mixing other gas with oxygen is that if the concentration of oxygen is too high, combustion explosively occurs, which is not preferable in terms of the structural strength of the engine. This is also to suppress harmful substances such as NOx generated at the time of combustion, and further, it is not preferable in terms of safety management to place high-concentration oxygen near an engine generating high heat.

By injecting oxygen in the above-described compression stroke and reacting with fuel premixed with intake air to cause combustion,
The pressure in the combustion chamber 3 becomes high and the piston 2 is pushed down,
By opening the exhaust valve 14 and raising the piston 2 in the next exhaust stroke, the combustion exhaust gas is discharged from the exhaust port 6 through the exhaust pipe 11 to the atmosphere through the silencer 12.

Next, FIG. 2 shows another embodiment of the present invention. In place of the exhaust pipe 11 in the embodiment shown in FIG.
The intake pipe 7 is connected to a surplus gas discharge valve 28 in the middle of the pipe 27 so that the combustion exhaust gas 29 taken out from the surplus gas discharge valve 28 is used as intake air. The oxygen concentration adjuster / oxygen mixer that enables the oxygen from the oxygen cylinder 30 and the inert gas from the inert gas cylinder 31 to be supplied to the separated and recovered oxygen by the oxygen separator 17. 32, the oxygen separated from the combustion exhaust gas 29 is mixed with oxygen from the oxygen cylinder 30 to increase the oxygen concentration, or the separated and recovered oxygen is mixed with an inert gas to reduce the oxygen concentration. The oxygen concentration can be adjusted as described above.

The other components are the same as those shown in FIG. 1, and the same components are denoted by the same reference numerals.

In this embodiment, an oxygen cylinder 30 and an inert gas cylinder 31 are provided so that the oxygen concentration can be adjusted, and the combustion exhaust gas 29 from the combustion chamber 3 other than the atmosphere is used as intake air. Therefore, the present invention can be applied to an engine used in a place where there is no air, that is, underwater. In this case, since it is not necessary to make the intake air the same composition as the atmosphere, there is an advantage that it is easy to configure an underwater power system in an engine used as a power source in water.

FIG. 3 shows still another embodiment of the present invention. After the explosion stroke in the combustion chamber 3 of the cylinder 1 is completed,
In the configuration as shown in the embodiment of FIG. 1 in which the piston 2 rises and discharges the combustion exhaust gas through the exhaust port 6 and the exhaust pipe 11, after the explosion, the combustion exhaust gas having a predetermined pressure is discharged into the combustion chamber 3. The exhaust pipe 11 is provided with a flow control valve 33 so that the exhaust gas is discharged while the combustion exhaust gas remains while the piston 2 rises to discharge the combustion exhaust gas when the piston 2 rises.
By discharging the combustion exhaust gas while remaining in the combustion chamber 3 by the flow control valve 33, a part of the combustion exhaust gas is left in the combustion chamber 3.
It is assumed that the gas is taken in the next cycle and compressed, so that the fuel 10 is pumped by the injection pump 34 and injected from the fuel injection nozzle 35 on the upper surface of the combustion chamber without sucking into the combustion chamber 3. At the same time, the temperature of the oxygen gas whose concentration was adjusted by the oxygen concentration controller 19 in which the oxygen 36 and the gas 37 containing no oxygen were mixed to adjust the oxygen concentration was adjusted by the temperature controller 20. rear,
The fuel is pressurized by an injection pump 21 and injected into the combustion chamber 3 from one or a plurality of oxygen injection nozzles 16 installed on the side of the combustion chamber.

The fuel injection nozzle 35 may be provided on the side of the combustion chamber, and the oxygen injection nozzle 16 may be provided on the upper surface of the combustion chamber.

According to this embodiment, if a part of the combustion exhaust gas is left in the combustion chamber 3 and is regarded as the intake gas in the next cycle, and the compression is performed, a so-called compression as shown in FIG.
The intake stroke ((a) in FIG. 6) and the exhaust stroke ((d) in FIG. 6) of the four-stroke engine cycle become unnecessary, and
Although the engine is a stroke engine, unlike the two-stroke engine cycle that is often used at present, fuel consumption does not deteriorate due to the two-stroke operation. As a result, there is an advantage that the engine can be made compact, have a high output, and have a fuel consumption rate as low as a four-stroke engine.

The present invention is not limited to the above embodiment. For example, FIGS. 1 and 2 show a single oxygen injection nozzle 16 for injecting into the combustion chamber 3. 4 and 4 may be installed on the upper surface as shown in FIGS. 1 and 2 and also installed on the side surface as shown in FIG. 3 to inject oxygen from above and from the side.
As shown in (a), one or a plurality of flow paths 39 are formed between the upper and lower seal rings 38 of the piston 2 and the upper surface of the piston 2, and the flow path 39 is formed during the compression stroke when the piston 2 rises. An injection nozzle 16 may be provided so as to communicate therewith, and oxygen may be injected from the bottom surface of the combustion chamber 3. As shown in FIG. 4 (b), oxygen is directed upward using a gap between the piston 2 and the cylinder 1. The oxygen injection nozzle 16 may be provided on the side wall of the cylinder 1 so as to inject the oxygen.

Further, in the embodiment shown in FIGS. 1 and 2, the case where the fuel is premixed with the gas containing no oxygen is shown. However, when the fuel is supplied without the premixing, the gas containing no oxygen is used. After being sucked into the combustion chamber 3 as intake air, fuel may be injected from a fuel injection nozzle and mixed in the combustion chamber to prepare for oxygen injection. This makes it possible to apply to an engine that injects fuel into the combustion chamber 3 without premixing.

Further, while the embodiment shown in FIGS. 1 and 2 has been described for a four-stroke engine, it is also applicable to a two-stroke engine, and FIG. 1 shows a piston engine. Can be similarly applied, and it is needless to say that various changes can be made without departing from the gist of the present invention.

[0032]

As described above, according to the method and apparatus for controlling combustion of an internal combustion engine of the present invention, oxygen is separated during the intake stroke so that fuel containing no oxygen is taken into the combustion chamber of the internal combustion engine. Or the oxygen-free intake air and fuel are separately sucked into the combustion chamber and mixed in the combustion chamber, and then the oxygen-free intake air and fuel are compressed in a compression stroke, and the compression stroke is performed. At any time, oxygen whose concentration has been adjusted is injected into the combustion chamber, mixed with the compressed fuel, reacted, ignited and burned, so that in the compression stroke, oxygen is contained in the intake air. Even if the temperature is raised above the self-ignition temperature of the fuel, the fuel does not self-ignite, and oxygen whose concentration is adjusted is injected at any time during this compression stroke, and the temperature is raised above the self-ignition temperature. Raised The fuel can be mixed and burned, and the self-ignition timing of the fuel can be controlled by the timing of oxygen injection instead of the conventional spark plug and fuel injection timing. This makes it possible to self-ignite the fuel at an arbitrary timing, and accordingly, even for fuels, such as light oil fuel, whose self-ignition temperature is low and the fuel cannot be premixed with the atmosphere, oxygen It is possible to mix with intake air that does not contain gas and to make combustion to be performed in a timely manner, significantly improving the air utilization rate as an engine, and as a result, it is an engine that uses light oil as fuel but is not inferior to the power of a gasoline engine In addition, combustion can be stably performed because the oxygen concentration is appropriately adjusted.

In addition, since oxygen is separated and recovered by the oxygen separator, it is possible to use air other than air as the intake air, and the gas from which the oxygen in the combustion exhaust gas from the combustion chamber is removed is used as the intake air. Further, by preparing an oxygen cylinder, an underwater power system can be easily configured in an engine used as a power source in water without air.

Further, an exhaust port is provided in the combustion chamber of the internal combustion engine, and a fuel injection nozzle and an oxygen injection nozzle are provided. A predetermined pressure after the explosion in the combustion chamber is provided in the exhaust pipe connected to the exhaust port. A flow regulating valve is provided for discharging the exhaust gas having the above-mentioned characteristics while remaining in the combustion chamber, and the exhaust gas remaining in the combustion chamber is injected into the combustion chamber from the fuel injection nozzle as an inhaled gas. The fuel from the combustion chamber can be injected from the oxygen injection nozzle into the combustion chamber through the oxygen-adjusted oxygen supplied through the oxygen concentration controller. The gas is discharged from the exhaust pipe while remaining in the combustion chamber, and the residual gas is compressed assuming that the gas is taken in the next cycle. Of these, the intake stroke and the exhaust stroke become unnecessary, and the engine becomes a two-stroke engine. In addition, unlike the case of a normal two-stroke engine cycle, the engine can have a high output and a fuel consumption rate as low as a four-stroke engine. ,
The engine can be made compact by two strokes.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one embodiment of the present invention.

FIG. 2 is a schematic diagram showing another embodiment of the present invention.

FIG. 3 is a schematic diagram showing still another embodiment of the present invention.

FIG. 4 shows a configuration example of an oxygen injection nozzle.
FIG. 3 is a schematic view of a structure in which fuel is injected from the bottom of a combustion chamber through a piston, and FIG. 4B is a schematic view of a structure in which fuel is injected through a space between a piston and a cylinder.

FIG. 5 is a schematic view showing an example of a conventional internal combustion engine.

FIG. 6 is a schematic view showing a four-stroke engine cycle, in which (a) shows an intake stroke, (b) shows a compression stroke, (c) shows an explosion stroke, and (d) shows an exhaust stroke.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston 3 Combustion chamber 5 Inlet 6 Exhaust port 7 Intake pipe 9 Fuel mixer 10 Fuel 11 Exhaust pipe 16 Oxygen injection nozzle 17 Oxygen separator 18 Oxygen supply pipe 19 Oxygen concentration regulator 20 Temperature regulator 21 Oxygen injection pump Reference Signs List 25 Valve 27 Out-system discharge pipe 28 Excess gas discharge valve 29 Combustion exhaust gas 30 Oxygen cylinder 31 Inert gas cylinder 32 Oxygen concentration adjuster / oxygen mixer 33 Flow control valve 35 Fuel injection nozzle

Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 21/04 F02D 21/04 F02M 25/07 F02M 25/07 A 25/12 25/12 A 33/00 33/00 C

Claims (3)

(57) [Claims] 1. A method according to claim 1, wherein oxygen is separated in an intake stroke and oxygen-free intake air is sucked into a combustion chamber of an internal combustion engine. The fuel is premixed or oxygen-free intake air and fuel are separately supplied to the combustion chamber. Inhaled and mixed in the combustion chamber, then
Compressing the oxygen-free intake air and fuel in the compression stroke,
Combustion of an internal combustion engine characterized by injecting oxygen whose concentration has been adjusted at an arbitrary time during the compression stroke into the combustion chamber, mixing with the compressed fuel, causing it to react, ignite and burn. Control method. 2. The oxygen separator according to claim 1, further comprising: an intake port provided in a combustion chamber of the internal combustion engine connected to a downstream end of an intake pipe having an oxygen separator for separating and recovering oxygen. The oxygen-free intake air is separated from the oxygen-free intake air into the combustion chamber through the intake port, and the fuel is supplied to the middle of an intake pipe downstream of the oxygen separator to supply the oxygen-free intake air. The fuel is pre-mixed into the combustion chamber, or the fuel is directly supplied to the combustion chamber separately from the oxygen-free intake air to mix the fuel with the oxygen-free intake air in the combustion chamber. So as to provide an exhaust port and an oxygen injection nozzle in the combustion chamber,
An exhaust pipe is connected to the exhaust port, and the upstream end of the intake pipe is opened to the atmosphere or connected to the middle of the exhaust pipe so that combustion exhaust gas can be taken in. An oxygen supply pipe having an oxygen concentration adjuster is connected in the middle, so that the oxygen separated and recovered by the oxygen separator is adjusted in concentration and injected into the combustion chamber from the oxygen injection nozzle. A combustion control device for an internal combustion engine. 3. An exhaust port is provided in a combustion chamber of an internal combustion engine, and a fuel injection nozzle and an oxygen injection nozzle are provided. A predetermined pressure after an explosion in the combustion chamber is provided in an exhaust pipe connected to the exhaust port. A flow regulating valve is provided for discharging the exhaust gas having the above-mentioned characteristics while remaining in the combustion chamber, and the exhaust gas remaining in the combustion chamber is injected into the combustion chamber from the fuel injection nozzle as an inhaled gas. Wherein the oxygen-adjusted oxygen supplied through the oxygen-concentration regulator is injected into the combustion chamber from the oxygen injection nozzle. Combustion control device.