JPH0783145A - Inter-cylinder fuel aerobic injection type internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce a cost, improve evaporating property of fuel while preventing clogging of an eject nozzle, in an inter-cylinder fuel aerobic injection type internal combustion engine formed in such constitution that fuel for each cylinder is injected and-supplied in a cylinder bore in each cylinder while mixing the fuel with air. CONSTITUTION:In a cylinder block 1, an air-fuel mixture supplying port 14 opened in a cylinder bore 3 is provided in a position which is apart by an appropriate size (S) from a bottom dead point toward a top dead point in a piston 2, and an adapter 15 provided with an ejection nozzle 17 is installed on the air-fuel mixture supplying port 14 so that it may stay in the cylinder bore 3, a fuel injection valve 18 is installed on the adapter 15, and also an air supply pipespassage 22 for supplying air into the adapter 15 is connected to the adapter 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an in-cylinder fuel aero-injection type internal combustion engine in which fuel for each cylinder is injected and supplied into a cylinder bore of each cylinder by mixing with air. is there.

[0002]

2. Description of the Related Art In a recent internal combustion engine, in order to achieve low fuel consumption and low pollution by achieving lean burn by stratified intake air, fuel for each cylinder is directly supplied to a cylinder bore in each cylinder. An in-cylinder fuel injection type internal combustion engine for injection and supply has been developed, and for this in-cylinder fuel injection type internal combustion engine, an airless injection type one in which only fuel is injected and supplied into the cylinder bore, There is an aero-injection type in which fuel is mixed with air and injected and supplied into the cylinder bore.

The latter air-fueled type is conventionally known, for example, in SAE Technical Paper 930497.
In FIG. As shown in FIG. 7, an air-fuel mixture supply port is opened on the inner wall surface of the cylinder bore, and an adapter equipped with an ejection nozzle, a fuel injection valve and an electromagnetic air ejection valve is attached to the air-fuel mixture supply port. The ejection nozzle in the adapter is installed so as to look into the cylinder bore in the cylinder block, and in the middle of the intake stroke of the piston in the cylinder bore, the electromagnetic air ejection valve is opened for an appropriate time in accordance with the crank timing, and the adapter is opened. By injecting air into it,
The fuel injected from the fuel injection valve into the adapter is jetted and supplied into the cylinder bore via the jet nozzle while being mixed with the air jetted from the electromagnetic air jet valve. .

In this case, the air-fuel mixture jetted and supplied from the jet nozzle into the cylinder bore is compressed toward the vicinity of the spark plug at the top of the cylinder bore by the ascending movement of the piston, so that it is relatively close to the spark plug. Since a rich air-fuel mixture is formed, lean burn by stratified intake is achieved.

[0005]

However, in the conventional aero-injection type, the fuel injected from the fuel injection valve into the adapter is opened for an appropriate time in accordance with the crank timing of the electromagnetic air injection valve. Which is jetted and supplied into the cylinder bore by jetting of air by. As the electromagnetic air injection valve, as with the fuel injection valve, it is necessary to use a highly accurate and highly responsive valve that reliably opens and closes in accordance with the crank timing, and the electromagnetic air injection valve is used as a piston. Since a control circuit for opening and closing in synchronism with the movement of is also required, the price increases considerably. ． The time that the electromagnetic air jet valve is open, that is,
Since the time during which air is ejected from the ejection nozzle is short, if the fuel injection time from the fuel injection valve becomes long in the high load operation range or the high rotation speed operation range, the mixing property with air will deteriorate. However, the formation of a homogeneous mixture is significantly reduced in the high load operation range. ． Air is ejected from the ejection nozzle by opening the electromagnetic air ejection valve only for a short time during the intake stroke, and the ejection nozzle stops the ejection of air from the ejection nozzle. Due to the presence of being exposed in the cylinder bore under this condition, not only this ejection nozzle is apt to be clogged with carbon or the like in the exhaust gas in the cylinder bore, but also the ejection nozzle, The cooling of the entire adapter with air is insufficient, its failure easily occurs, and its reliability is low. There was a problem such as.

An object of the present invention is to solve the above-mentioned problems of the conventional aero-injection type internal combustion engine.

[0007]

In order to achieve this technical object, "Claim 1" in the present invention is, in a cylinder block having a cylinder bore in which a piston reciprocates, a mixture gas supply port opened in the cylinder bore. Is provided at a position distant from the bottom dead center of the piston by an appropriate dimension toward the top dead center, and an adapter having a jet nozzle is provided in the mixture supply port, and the jet nozzle of the adapter looks into the cylinder bore. Thus, the fuel injection valve into the adapter is attached to the adapter, and the air supply pipe line into the adapter is connected.

According to a second aspect of the present invention, in a cylinder block having a cylinder bore in which a piston reciprocates, a mixture gas supply port opening in the cylinder bore is provided. To the mixture supply port, install an adapter equipped with a jet nozzle so that the jet nozzle of the adapter looks into the cylinder bore. A fuel injection valve to the adapter, and an air supply line to the adapter is connected to the air supply line to reduce the amount of air supplied to the adapter in an idle or extremely low load operating range of the internal combustion engine. The above-mentioned flow rate adjusting means is provided.

[0009]

[Operation] In this configuration, the air supplied from the air supply pipe is discharged from the jet nozzle of the adapter.
Although it constantly ejects toward the inside of the cylinder bore, the mixture supply port to which the adapter with this ejection nozzle is attached is
The piston is reciprocated in the cylinder bore to open and close the cylinder bore.

In this case, the air-fuel mixture supply port is located at an appropriate distance from the bottom dead center of the piston toward the top dead center, and from the bottom dead center to the bottom dead center during the downward movement of the piston. Up to the section from the bottom dead center to the point before the bottom dead center during the upward movement of the piston, that is, when the piston is close to the bottom dead center, the mixture supply port opens by opening into the cylinder bore. Since the air is jetted from the jet nozzle into the cylinder bore inside the cylinder when the air-fuel mixture supply port is open to the inside of the cylinder bore as described above, the fuel injected from the fuel injection valve into the adapter. Can be supplied into the cylinder bore together with the air while being mixed with the air.

Since the air-fuel mixture ejected from the ejection nozzle into the cylinder bore is compressed toward the vicinity of the ignition plug at the top of the cylinder bore by the upward movement of the piston, it is relatively rich in the vicinity of the ignition plug. A mixture can be formed and so-called stratified intake can be achieved.

[0012]

As described above, according to the present invention, the ejection control of the air for supplying the fuel injected from the fuel injection valve into the cylinder bore while vaporizing the fuel is performed by the reciprocating movement of the piston in the cylinder bore. Since the conventional electromagnetic air ejection valve and the control circuit for opening and closing the electromagnetic air ejection valve according to the crank timing can be omitted, it is possible to significantly reduce the price.

Moreover, since the air can be jetted into the cylinder bore for a relatively long time as compared with the conventional case, such as when the piston is in the vicinity of the bottom dead center, it can be operated in a high load operation range or a high rotation operation range. In the above, even when the fuel injection time from the fuel injection valve becomes long, the vaporization property of the fuel can be surely improved as compared with the conventional case, and at the time of starting the internal combustion engine, at the start and end of fuel injection, etc. Also, the fuel can be surely vaporized.

Moreover, the ejection nozzle always ejects air when the piston is in the vicinity of the bottom dead center and the ejection nozzle is exposed in the cylinder bore. On the other hand, when the ejection is not performed, the piston is ejected. Since it is isolated from the inside of the cylinder bore by the above, it is possible to greatly reduce the occurrence of clogging of the ejection nozzle due to the adhesion of carbon or the like in the exhaust gas, and the ejection nozzle, by extension, the adapter and the fuel injection valve It can be effectively cooled by air, and their reliability can be greatly improved.

Particularly, in the case of the construction as in "Claim 2", the jet speed of the air from the jet nozzle into the cylinder bore becomes slow in the idling or extremely low load operation region of the internal combustion engine, so that the cylinder bore The air-fuel mixture in the engine can be made uniform, in other words, the intake air in the idle or extremely low load operation range can be brought closer to the uniform intake from the stratified intake air, so combustion by performing the stratified intake air in the idle or extremely low load operation range Has the effect of avoiding instability, increase in combustion noise, and occurrence of misfire during deceleration.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment. This first embodiment is applied to a four-cycle internal combustion engine, and in the figure, reference numeral 1 indicates a cylinder block provided with a cylinder bore 3 in which a piston 2 reciprocates, and an upper surface of the cylinder block 1 has a lower surface. A cylinder head 4 having a recessed combustion chamber 5 opening in the cylinder bore 3 is attached to the cylinder head 4, and an intake port 7 with an intake valve 6, an exhaust port 9 with an exhaust valve 8 and an ignition plug 10 are provided in the cylinder head 4. An intake passage 13 with a throttle valve 12 from an air cleaner 11 is connected to the intake port 6.

The cylinder block 1 is provided with an air-fuel mixture supply port 14 which opens into the cylinder bore 3.
Is provided in a portion of the piston 2 which is appropriately separated from the bottom dead center (B.D.C.) toward the top dead center (T.D.C.) by a dimension S, and the mixture supply port 14 is provided with Adapter 1 mounted so as to close the air-fuel mixture supply port 14
5 has a mixing chamber 16 formed therein and an ejection nozzle 17 extending from the mixing chamber 16 toward the inside of the cylinder bore 3. Further, the fuel injection valve 1 in which the adapter 15 is controlled by the control circuit 24 to inject the fuel into the mixing chamber 16 in an amount suitable for the operating state of the internal combustion engine at the crank timing.
Install 8. The adapter 15 may be formed integrally with the cylinder block 1.

On the other hand, the air on the clean side in the air cleaner 11 is introduced into the air pump 20 via the air introducing pipe 19 and compressed, and then introduced into the accumulator 21 to compress the compressed air in the accumulator 21 into the air. It is supplied into the mixing chamber 16 of the adapter 15 through the supply pipe 22. Incidentally, the accumulator 2
1 is provided with a relief valve 23 for maintaining the air pressure in the accumulator 21 appropriately below the pressure.

In this structure, as the piston 3 reciprocates in the cylinder bore 3, as shown in FIG.
It is well known in the art that the intake stroke, the compression stroke, the explosion stroke and the exhaust stroke are repeated in this order. Jet nozzle 17 in the adapter 15
From the above, the air supplied from the air supply pipe line 22 is constantly ejected toward the inside of the cylinder bore 3. However, the mixture supply port 14 to which the adapter 15 with the ejection nozzle 17 is attached is a piston in the cylinder bore 3. The reciprocating motion of 2 opens and closes the inside of the cylinder bore 3.

In this case, the air-fuel mixture supply port 14 is
The piston 2 is located at a position appropriately separated by a dimension S from the bottom dead center (BDC) to the top dead center (TDC), and the bottom dead occurs during the downward movement of the piston 2. The section of S from the point before to the bottom dead center, and the section of S from the bottom dead center to the bottom dead center during the upward movement of the piston 2, that is,
The air is jetted from the jet nozzle 17 in the air-fuel mixture supply port 14 into the cylinder bore 3 by opening the piston in the cylinder bore 3 only for a section of 2S when the piston is near the bottom dead center. Since it is performed when the air supply port 14 is opened to the inside of the cylinder bore 3 as described above, the adapter 15
While mixing the fuel injected from the fuel injection valve 18 into the mixing chamber 16 with the air in the mixing chamber 16,
It can be supplied into the cylinder bore 3 together with the air.

The air-fuel mixture jetted from the jet nozzle 17 into the cylinder bore 3 is ignited by the ascending movement of the piston 2 in the combustion chamber 5 at the top of the cylinder bore 3.
Since it is compressed toward the vicinity of 0, a relatively rich air-fuel mixture can be formed near the spark plug 10 and so-called stratified intake can be achieved. on the other hand,
The jet nozzle 17 always jets air when the piston 2 is near the bottom dead center and the jet nozzle 17 is exposed in the cylinder bore, while when the jet 2 is not jetted, the air is jetted by the piston 2. Since it is isolated from the inside of the cylinder bore 3,
It is possible to significantly reduce the occurrence of clogging due to the adhesion of carbon or the like in the exhaust gas, and, in the case of a four-cycle internal combustion engine, the ejection of air from the ejection nozzle 17 causes the piston 2 to move during the exhaust stroke. By being performed even in the vicinity of the bottom dead center, the jet of air causes the jet nozzle 17 and the adapter 1
5 and the fuel injection valve 18 can be cooled more effectively.

Further, in the case of a four-cycle internal combustion engine, the fuel injection from the fuel injection valve 18 is, as shown in FIG. 3, from the end of the air ejection during the exhaust stroke to the end of the air ejection during the intake stroke. It suffices to do this within the section L (crank angle is about 360 degrees) up to the point of. However, in the case of a supercharged internal combustion engine, if it is not possible to inject a quantity of fuel corresponding to the high rotation and high load operating range in the section L, the intake passage 13 from the air cleaner 11 to the intake port 7 Of the throttle valve 12 or the intake port 7
In addition, it is sufficient to provide the auxiliary fuel injection valve 25 which is controlled by the control circuit 24 to inject additional fuel in the high rotation and high load operation range.

FIG. 4 shows a second embodiment. In the second embodiment, in addition to the first embodiment, the adapter 1 is connected to the air supply line 22 to the adapter 15.
The flow rate adjusting means 26 is provided so as to reduce the amount of air supplied to No. 5 in the idling or extremely low load operation range of the internal combustion engine.

That is, as shown in FIG. 4, a flow rate control valve 26 is provided in the middle of the air supply line 22, and the flow rate control valve 26 is controlled by the control circuit 24 so as to operate in an idle or internal combustion engine. It is configured so as to close in the extremely low load operating range, whereby the ejection speed of the air from the ejection nozzle 17 into the cylinder bore 3 becomes slow in the idling or extremely low load operating range of the internal combustion engine. The air-fuel mixture in the inside can be made uniform, in other words, the intake air in the idle or extremely low load operation range can be made closer to the uniform intake air from the stratified intake air.

In the second embodiment, instead of the flow control valve 26, the accumulator 21 is made to gradually reduce the air pressure in the accumulator 21 in relation to the opening degree of the throttle valve 12 and the like. By providing such a pressure adjusting valve, the amount of air supplied to the adapter 15 may be reduced in the idling or extremely low load operation range of the internal combustion engine.

Further, although the above-described embodiment has been applied to a four-cycle internal combustion engine, the present invention is not limited to this four-cycle internal combustion engine and is also applicable to a two-cycle internal combustion engine. It goes without saying that it can be applied to.

[Brief description of drawings]

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

FIG. 2 is an enlarged view of a main part in FIG.

FIG. 3 is a diagram showing a process.

FIG. 4 is a diagram showing a second embodiment of the present invention.

[Explanation of symbols]

 1 Cylinder Block 2 Piston 3 Cylinder Bore 4 Cylinder Head 5 Combustion Chamber 7 Intake Port 9 Exhaust Port 10 Spark Plug 14 Mixture Supply Port 15 Adapter 16 Mixing Chamber 17 Jet Nozzle 18 Fuel Injection Valve 20 Air Pump 22 Air Supply Pipeline

Claims (2)

[Claims] 1. A cylinder block having a cylinder bore in which a piston reciprocates, and a mixture supply port opening in the cylinder bore is provided at a position distant from the bottom dead center of the piston toward a top dead center by an appropriate dimension. An adapter provided with a jet nozzle is attached to the mixture supply port so that the jet nozzle of the adapter looks into the cylinder bore, and a fuel injection valve into the adapter is attached to the adapter. An in-cylinder fuel aero-injection type internal combustion engine, characterized in that an air supply pipeline to the adapter is connected. 2. A cylinder block having a cylinder bore in which a piston reciprocates, and a mixture gas supply port opening in the cylinder bore is provided at a position distant from the bottom dead center of the piston toward a top dead center by an appropriate dimension. An adapter provided with a jet nozzle is attached to the mixture supply port so that the jet nozzle of the adapter looks into the cylinder bore, and a fuel injection valve into the adapter is attached to the adapter. An air supply pipeline to the adapter is connected, and the air supply pipeline is provided with flow rate adjusting means for reducing the amount of air supplied to the adapter in an idle or extremely low load operation range of the internal combustion engine. Characteristic is a cylinder fuel aero-injection internal combustion engine.