JPH11182255A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve scavenging and prevent output performance or exhaust gas performance from deteriorating due to a residue of exhaust gas by setting total flow area per cylinder of exhaust valves provided in a cylinder head of a reciprocation type internal combustion engine to be larger than that of intake valves. SOLUTION: For accelerating the scavenging of combustion gas after combustion stroke of an engine and reducing residual gas, total flow area per cylinder of exhaust valves 91 provided for a cylinder head 3 is formed so as to be larger than that of intake valves 8. In other words, the number of exhaust valves 91 per cylinder is made larger than number of the intake valves 8 to enlarge total flow area per cylinder of the exhaust valves 91. By designing the shape of the top surface 2a of a piston 2 so that intake air sucked from an intake port 5 into the cylinder 1 generates tumbling flow toward an exhaust port 6, scavenging effect is improved. An auxiliary port for discharging the residual gas can be provided for a cylinder head 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine using gaseous fuel, for example, and having means for reducing the residual combustion gas in a cylinder.

[0002]

2. Description of the Related Art In a conventional reciprocating internal combustion engine, in particular, a non-supercharged spark ignition internal combustion engine, it is important to reduce suction resistance to a cylinder in order to increase suction efficiency and improve performance. Therefore, it is common to make the intake valve and the intake port area larger than the exhaust valve and the exhaust port area.

On the other hand, the exhaust gas remaining in the cylinder after the exhaust stroke not only deteriorates the charging efficiency, but also raises the intake air temperature to cause problems such as abnormal combustion and reduced knock resistance. Therefore, conventionally, the overlap period (see FIG. 36) of opening the intake and exhaust valves has been increased to reduce the residual gas amount. However, this method has a problem that the amount of fresh air blown into the exhaust pipe increases.

[0004] The residual combustion gas in the cylinder causes the chemical components of the combustion gas to promote the self-ignition reaction, thereby deteriorating knock resistance, or adversely affecting combustion or generation of exhaust gas. As a result of various studies focusing on the importance of improving the scavenging action and reducing the residual gas, or reducing the residual gas concentration,
The technology described below has been developed.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an internal combustion engine in which the scavenging action is improved and the problem caused by the residual exhaust gas is eliminated.

[0006]

According to the present invention, there is provided a reciprocating internal combustion engine, wherein a total area of a flow passage per cylinder of an exhaust valve provided on a cylinder head is reduced by a flow passage per cylinder of an intake valve. It is configured to be larger than the total area.

[0007] During the overlap period between the exhaust valve and the intake valve, adjustment is made so that the residual gas is well discharged to the exhaust port and that the intake air does not blow through.

The total area of the flow passage per cylinder of the exhaust valve is configured so that the number of exhaust valves per cylinder is larger than the number of intake valves and the total area of the flow passage per cylinder of the intake valve is larger. doing.

It is to be noted that the total area of the flow passage per cylinder of the exhaust valve may be increased in some cylinders of a multi-cylinder engine. This may be adopted when one exhaust manifold is used in a multi-cylinder engine, and the knock resistance of the center cylinder is lower than that of the other cylinders.

As described above, by increasing the total area of the flow passage per cylinder for the exhaust valve compared to the intake valve, the exhaust gas is better discharged, the residual gas is reduced, and the blow-through of fresh air is increased. The scavenging efficiency (the ratio of the total gas amount in the cylinder after scavenging is completed to the fresh air amount remaining in the cylinder) can be improved without the need for scavenging. The total area of the flow passages of the intake / exhaust valves is the total area of the annular gap between each valve (face) and the valve seat.

Further, according to the present invention, the intake flow is configured to generate a tumble flow toward the exhaust port in the cylinder. The tumble flow is a vortex rotating around an axis perpendicular to the cylinder axis, and the swirl flow described later is a vortex rotating around the cylinder axis.

In order to generate the tumble flow, a piston having a shape such that the intake flow generates a tumble flow toward the exhaust port along the top surface is provided. Alternatively, the shape of the intake port is a straight port. Then, it is preferable to adjust the tumble flow and the valve opening timing to an optimum value so that the residual gas is discharged to the exhaust port during the overlap period.

[0013] In this manner, the residual exhaust gas in the cylinder is pushed out toward the exhaust port by the tumble flow generated by the intake fresh air that flows when the intake valve is opened, and the scavenging efficiency is improved.

According to the present invention, the cylinder head is provided with an auxiliary port and an auxiliary valve for discharging residual gas. In particular, in an exhaust turbocharged engine, the residual gas in the cylinder can be discharged by opening the auxiliary port to the atmosphere at the end of the exhaust stroke in the exhaust port.

Further, since the gas discharged from the auxiliary port also contains unburned fuel from the intake air, the auxiliary port may be connected to the intake port and returned to the intake side for effective use. At this time, the components of burned gas are also included,
It is desirable to purify through a catalyst.

In an engine having a sub-chamber, since residual gas remains in the sub-chamber, an auxiliary valve is provided in the sub-chamber to discharge and scavenge the residual gas.

Further, according to the present invention, a gas injector for injecting fuel gas after an overlap period of the intake and exhaust valves is provided in the intake port of the cylinder head. It is desirable that the intake gas and the exhaust valve are adjusted so that the residual gas is well discharged to the exhaust port during the overlap opening period.

Therefore, only air is taken in and scavenged,
Since the fuel is injected after the scavenging is sufficiently completed, it is possible to prevent the fuel from flowing through at the time of the overlap.

Further, according to the present invention, an air injector for injecting pressurized air into the cylinder at the end of the exhaust stroke is provided. In an engine having a sub-chamber, the air injector opens into a sub-chamber provided in the cylinder head. Alternatively, an air injector for injecting pressurized air during the overlap period of the intake and exhaust valves may be provided in the intake port of the cylinder head. It is preferable that the residual gas be well adjusted to the exhaust port during the overlap opening period of the intake and exhaust valves and to prevent the intake air from passing through.

As described above, the scavenging efficiency is adjusted by injecting the pressurized air into the cylinder at the end of the exhaust stroke or from the intake port during the overlap period to expel the residual gas and prevent the fresh air from flowing through. improves.

Further, an air injector for injecting pressure air during the overlap period of the intake and exhaust valves and a gas injector for injecting fuel gas after the overlap period are provided in the intake port of the cylinder head. Injecting to expel residual gas and then injecting fuel may improve scavenging and prevent fuel blow-through.

Then, if air is extracted from the downstream of the compressor of the supercharger and piped to the air injector, a dedicated compressor or cylinder may not be required.

According to the present invention, in the internal combustion engine having the exhaust turbocharger, the intake system and / or the exhaust system are provided with the mechanical suction means for improving the scavenging performance.

In an internal combustion engine having an exhaust turbocharger, since an exhaust turbine is provided downstream of the engine, the exhaust pressure in the exhaust port increases, and mechanical suction means for improving the scavenging performance in the intake system. To increase the intake pressure supplied to the intake port, or to interpose mechanical suction means in the exhaust system to extract exhaust and lower exhaust pressure,
Improves the scavenging action in the cylinder.

Further, a passage bypassing the exhaust turbine is provided, and a wastegate valve for improving scavenging performance is provided in the passage.

That is, by providing the waste gate valve bypassing the exhaust turbine, the exhaust pressure can be reduced, and the scavenging is performed in combination with the effect of the mechanical suction means provided in the intake system and / or the exhaust system. Improves action.

Further, as the mechanical suction means, a rotary blower such as a roots blower or a screw compressor is used.

Further, a control device is provided for detecting the knock intensity by providing a knock sensor and controlling the output of the mechanical suction means and the opening of the wastegate valve.

Further, according to the present invention, the intake stroke in which the piston descends and sucks the air-fuel mixture, the compression stroke in which the piston rises and compresses the air-fuel mixture, and the combustion of the air-fuel mixture, the piston descends and the combustion gas is generated 6. An expansion stroke in which the piston expands, an exhaust stroke in which the piston rises and discharges combustion gas, a scavenging suction stroke in which the piston descends and sucks only air, and a scavenging discharge stroke in which the piston rises and discharges gas in the cylinder. One cycle is formed in the process.

That is, two strokes of scavenging suction and scavenging discharge are added between the exhaust stroke and the intake stroke in addition to the conventional four strokes of intake, compression, expansion and exhaust, and the residual gas can be completely discharged.

Further, according to the present invention, the projecting means is provided at a position facing the combustion chamber provided in a concave shape at the top of the piston so as to discharge the residual gas in the combustion chamber.

At the top dead center at the end of the exhaust stroke, the depression in the combustion chamber provided at the top of the piston becomes a dead volume, and the exhaust gas therein is not exhausted. Then, the exhaust gas in the combustion chamber is expelled to improve the scavenging efficiency.

Further, according to the present invention, a fuel injector is provided in an intake port or a cylinder, and a one-way check valve is provided in an exhaust port of a cylinder head in an exhaust discharge direction. The valve is configured to open halfway. The check valve may be any type of check valve as long as the check valve has a small pressure loss, such as a reed valve.

Therefore, the exhaust valve is in the open state also in the intake stroke, but the backflow of exhaust gas from the exhaust pipe is prevented by the check valve in the exhaust port, and further, during the compression stroke, for example, 30 to 60 aBDC ( Until the bottom dead center), the exhaust valve opens and exhaust gas is exhausted completely. And
After the exhaust valve is closed, fuel is supplied from an intake port or a fuel injector provided in a cylinder.

Further, according to the present invention, a single intake valve is provided at the center of the cylinder of the cylinder head, a plurality of exhaust valves are provided around the intake valve, and a plurality of exhaust valves are provided near the exhaust valves. Ignition plug is provided. Alternatively, a single exhaust valve is provided at the center of the cylinder of the cylinder head, a plurality of intake valves are provided around the exhaust valve, and a plurality of spark plugs are provided near the exhaust valve.

Normally, knock is likely to occur in a high temperature portion of a combustion chamber such as an exhaust valve, or in an unburned gas region heated by residual gas and the like, and the residual gas promotes a self-ignition reaction. Therefore,
An intake (exhaust) valve is provided at the center and an exhaust (intake) valve is provided around the center to separate fresh air and burned gas. Further, a plurality of spark plugs are provided around the exhaust valve, and around the exhaust valve. The above problem is avoided by burning the collected residual gas first.

Further, according to the present invention, the intake port of the cylinder head is configured to generate a strong intake swirl flow in the cylinder, and the ignition plug is disposed at the center where the residual gas is collected by the swirl flow. doing.

When the air is suctioned from the intake port that generates a strong swirl flow, the fresh intake air has a low temperature and a high density, so that the outer peripheral portion is rotated by centrifugal force, and the residual gas has a high temperature and a low density. get together. In this way, the residual gas is burned first by the ignition plug provided at the center.

Further, according to the present invention, the intake port of the cylinder head and the top surface of the piston are formed so that the intake flow generates a tumble flow in the cylinder, and the residual exhaust gas is brought into the vicinity of the ignition plug by the tumble flow. It is structured to gather.

In this way, the residual gas is collected near the spark plug by the tumble flow guided to the intake port and the top surface of the piston, and is burned first.

According to the present invention, two intake valves and two exhaust valves are provided in each cylinder in a cylinder head to promote mixing of fresh air and residual gas. Alternatively, two intake valves are provided for each cylinder in the cylinder head, and a tumble flow in which the intake flows rotate in opposite directions to each other is generated in the cylinder. In addition, each of the intake air flows generates a swirl flow rotating in opposite directions to each other.
With this intake valve, the intake air flows into the cylinder so as to generate a swirl flow at one intake valve and a tumble flow at the other intake valve.

As described above, when a plurality of tumble flows or swirl flows are generated to promote the mixing of fresh air and burned gas, the residual gas diffuses uniformly in the cylinder, the concentration thereof becomes thin, and self-ignition occurs. , The temperature deviation is also reduced, and knock resistance is improved.

[0043]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the cylinder head 3
The total area of the flow passage per cylinder of the exhaust valve 9 provided in the intake valve 8 is larger than the total area of the flow passage per cylinder of the intake valve 8. Then, during the overlap period between the exhaust valve 9 and the intake valve 8, the residual gas is adjusted so that the residual gas is well exhausted to the exhaust port and the intake air does not blow through.

2 to 4, the total area of the exhaust valve 9 per cylinder is larger than the number of exhaust valves per cylinder by increasing the number of exhaust valves per cylinder. It is larger than the area. That is, FIG.
3, two exhaust valves 9 and one intake valve 8 are provided, in the example of FIG. 3, three exhaust valves 9 and two intake valves 8 are provided, and in the example of FIG. A valve 9 and one intake valve 8 are provided.

FIG. 5 shows an embodiment in which only a part of the cylinders of the multi-cylinder engine has a larger total flow passage area per cylinder of the exhaust valve. In this embodiment, since one exhaust manifold is used in a multi-cylinder engine and the knock resistance of the center cylinder is worse than that of the other cylinders, the area of the exhaust valve is increased only in the center cylinder.

As described above, by making the total flow path area per cylinder larger for the exhaust valve 9 than for the intake valve 8, the exhaust gas is better discharged and the residual gas is reduced. Is adjusted, scavenging efficiency can be improved without increasing blow-by of fresh air.

In the embodiment shown in FIG. 6, the intake flow is generated in the cylinder 1 so as to generate a tumble flow T toward the exhaust port 6. In order to generate the tumble flow T, the piston 2 has such a shape that the intake flow generates a tumble flow T toward the exhaust port 6 along the top surface 2a, or the shape of the intake port 5 is changed. It is a straight port. Then, the tumble flow T and the valve opening timing may be adjusted to an optimum value so that the residual gas is discharged to the exhaust port 6 during the overlap period.

In this manner, the residual exhaust gas in the cylinder 1 is pushed out by the tumble flow T toward the exhaust port 6 generated by the intake fresh air flowing when the intake valve 5 is opened, and the scavenging efficiency is improved.

In the embodiment shown in FIGS.
The cylinder head 3 is provided with an auxiliary port 15 and an auxiliary valve 16 for discharging residual gas. In the engine having the exhaust turbocharger 21 shown in FIG. 7, since the exhaust pressure (the pressure in the exhaust port 6) is high, the cylinder 1 is released from the auxiliary port 15 to the atmosphere at the end of the exhaust stroke.
The residual gas inside can be exhausted.

Since the gas discharged from the auxiliary port 15 also contains unburned fuel from the intake air, FIG.
In the embodiment shown in (1), the auxiliary port 15 is communicated with the intake port 5 and returned to the intake side for effective use. On this occasion,
Since the components of the burned gas are also included, in the embodiment of FIG.
Purification is performed with the catalyst 25 interposed.

As shown in FIG. 10, in an engine having the sub-chamber 18, residual gas remains in the sub-chamber 18. Therefore, the auxiliary valve 16 is provided in the sub-chamber 18 to discharge and scavenge the residual gas. .

In the embodiment shown in FIG. 11, a gas injector 12 is provided in the intake port 5 of the cylinder head 3 for injecting the fuel gas after the overlap period of the intake and exhaust valves (indicated by the symbol A in FIG. 17). . Since only the air is taken in from the intake port 5 and the fuel is injected after sufficiently scavenging, the fuel is prevented from flowing into the exhaust port 6 at the time of overlap.

In the embodiment shown in FIG. 12, an air injector 11 for injecting pressurized air into the cylinder 1 is provided immediately before the end of the exhaust stroke (indicated by reference numeral B in FIG. 17). On the other hand, as shown in FIG. 13, in an engine having the sub chamber 18, the air injector 11 is opened in the sub chamber 18 provided in the cylinder head 3.

In the embodiment shown in FIG. 14, an air injector 11 is provided in the intake port 5 of the cylinder head 3 for injecting compressed air during the overlap period of the intake and exhaust valves (indicated by C in FIG. 17). ing.

As described above, immediately before the end of the exhaust stroke, the cylinder 1
During or during the overlap period, the compressed air is injected from an air injector 11 provided in the intake port 5 to expel the residual gas to the exhaust port 6, thereby improving the scavenging efficiency.

In the embodiment shown in FIG. 15, an air injector 11 for injecting pressurized air into the intake port 5 of the cylinder head 3 during the overlap period of the intake and exhaust valves and a gas injector 12 for injecting the fuel gas after the overlap period. By first injecting compressed air to expel residual gas and then injecting fuel, scavenging action is improved and fuel blow-through is prevented.

As shown in FIG. 16, if air is extracted from the front of the mixer 22 downstream of the supercharger 21 and piped to the air injector 11, a dedicated compressor or cylinder can be eliminated.

Next, in the embodiment shown in FIGS. 18 to 21, an internal combustion engine having an exhaust turbocharger 21 is provided with a mechanical suction for improving a scavenging performance in an intake system and / or an exhaust system. Means 31 are provided.

In the embodiment shown in FIG.
For example, a blower 31 which is a mechanical suction means is interposed in an exhaust pipe from the exhaust gas to the exhaust turbine 21t. A passage 32 that bypasses the exhaust turbine 21t is provided, and a wastegate valve 33 is provided in the passage 32. Reference numeral 23 indicates a throttle valve.

In the embodiment shown in FIG. 19, a blower 31 is provided in front of the supercharger compressor 21c, and two-stage compression is performed by the blower 31 and the compressor 21c to increase the supply pressure.

Further, in the embodiment shown in FIG. 20, blowers 31 are provided both upstream of the supercharger compressor 21c and between the exhaust port 6 and the exhaust turbine 21t.

In the embodiment shown in FIGS. 18 to 21, the internal combustion engine having the exhaust turbocharger 21 is:
Since the exhaust pressure in the exhaust port 6 is high with the exhaust turbine 21t in the wake, the blower 31 is provided in the intake system to increase the intake pressure supplied to the intake port 5, or the blower 31 is provided in the exhaust system. The scavenging action in the cylinder 1 is improved by sucking out the exhaust gas and reducing the exhaust pressure. The exhaust pressure is further improved by providing the waste gate valve 33 bypassing the exhaust turbine 21t through the passage 32.

In the embodiment shown in FIG. 21, a knock sensor 36 is provided on the cylinder side to control the output of the blower 31 and the opening of the wastegate valve 33.
5 are provided.

As shown in the flowchart of FIG. 22, the knock is detected by the knock sensor 36 (step S22).
1) The controller 35 calculates the knocking intensity from the detected value (step S2), and outputs the opening of the wastegate valve 33 and the output of the blower 31 corresponding to the knocking intensity (step S3). S1
Has returned to.

Next, the operation cycle of the present invention will be described with reference to FIGS. First, (a) in the intake stroke,
from a to b, the fuel is injected from the fuel injector provided in the intake port or the cylinder, and intake air-fuel mixture of boost pressure p _A, compressing the mixture from b to c in (b) the compression stroke.
Then, combustion occurs between c and d, (c) the combustion gas expands from d to e in the expansion stroke, and (d) the back pressure p _{E in the} exhaust stroke.
Emit combustion gas. Then, in (e) scavenging intake stroke to intake air only at feeding pressure p _A, to discharge air containing residual gas (f) scavenging exhaust stroke. One cycle is constituted by the above six strokes.

That is, two strokes of scavenging suction and scavenging discharge are added between the exhaust stroke and the intake stroke in addition to the conventional four strokes of intake, compression, expansion and exhaust, and the residual gas can be completely discharged.

Further, in the embodiment shown in FIGS. 25 and 26, a projecting means is provided at a position facing the combustion chamber 2b provided on the top of the piston 2 in a concave shape so as to discharge the residual gas in the combustion chamber 2b. doing.

In the embodiment shown in FIG. 25, the cylinder head 3
An electromagnet 38 which can move in the vertical direction is provided as a protruding means. The upper coil 38a is repelled during the exhaust stroke, and the lower coil 38b is sucked to protrude into the cylinder 1 so that the piston 2 is moved to the top dead center. When it comes, it enters the combustion chamber 2b to remove residual gas.

In the embodiment shown in FIG. 26, the projecting means is constituted by a piston 38A and is operated by a cam 39.

In the embodiment shown in FIG. 27, a reed valve 41, which is a one-way check valve, is provided in the exhaust port 6 of the cylinder head 3 in the exhaust direction, and the exhaust valve 9 is moved halfway through the compression stroke. The valve is configured to open.

Therefore, even during the intake stroke, the exhaust valve 9
Is open, and the reed valve 4 in the exhaust port 6
1 prevents the backflow of exhaust gas from the exhaust pipe, and further opens the exhaust valve 9 during the compression stroke, for example, to 30 to 60 aBDC, and exhaust gas is completely exhausted. In addition,
Since fresh air blows through, in-cylinder injection is performed by the gas injector 12.

In the embodiment shown in FIG. 28, a single intake valve 8 is provided in the center of the cylinder of the cylinder head 3, and a plurality of, in the illustrated example, four exhaust valves 9 surround the intake valve 8.
And a plurality of, in the example shown, four ignition plugs 27 are provided near the exhaust valves 9. In the embodiment shown in FIG. 29, a single exhaust valve 9 is provided in the center of the cylinder of the cylinder head 3, a plurality of intake valves 8 are provided around the exhaust valve 9, and a plurality of ignition valves are provided near the exhaust valve. A stopper 27 is provided.

Normally, knock tends to occur in an unburned gas region heated by residual gas and the like, and the residual gas promotes a self-ignition reaction. Therefore, in the center, the intake (exhaust) valve 8 (9)
An exhaust (intake) valve 9 (8) is provided around the exhaust gas, the fresh air and the burned gas are separated, and a plurality of spark plugs 27 are provided around the exhaust valve 9. The residual gas that accumulates in the fuel is burned first to avoid problems.

In the embodiment shown in FIG. 30, the intake ports 5, 5 of the cylinder head 3 are configured to generate a strong intake swirl flow S in the cylinder 1, and the residual gas is collected by the swirl flow S. A spark plug 27 is provided at a central portion X of the fuel cell.

When the intake air is sucked from the intake ports 5 and 5 that generate a strong swirl flow S, the intake fresh air has a low temperature and a high density, so that the outer peripheral portion rotates by centrifugal force, and the residual gas has a high temperature and a low density. So gather in the center X. Thus, the residual gas is burned first by the ignition plug 27 disposed at the central portion X.

In the embodiment shown in FIG. 31, the intake port 5 of the cylinder head 3 and the piston top surface 2a are formed such that the intake flow generates a tumble flow T in the cylinder 1.
The structure is such that residual exhaust gas is collected near the ignition plug 27 by the tumble flow T.

Therefore, the residual gas is collected near the ignition plug 27 by the tumble flow T guided to the intake port 5 and the piston top surface 2a, and can be burned first.

In the embodiment shown in FIG. 32, two intake valves 8 and two exhaust valves 9 are provided axially symmetrically for each cylinder in the cylinder head 3 in order to promote mixing of fresh air and residual gas. doing. Alternatively, in the embodiment shown in FIG. 33, two intake ports 5t and 5t are provided for each cylinder in the cylinder head to generate tumble flows T1 and T2 in which the intake air flows in the cylinder 1 in opposite directions. To
Alternatively, in the embodiment shown in FIG. 34, the two intake ports 5s and 5s generate swirl flows S1 and S2 in which the intake flows rotate in opposite directions to each other in the cylinder 1.
Furthermore, in the embodiment shown in FIG. 35, the two intake ports 5s and 5t allow the intake air flow into the cylinder 1 to be swirled by the one intake port 5s and the other intake port 5t.
To generate the tumble flows T respectively.

In this way, a plurality of tumble flows T or swirl flows S are generated to promote the mixing of fresh air and burned gas, and the residual gas is uniformly diffused into the cylinder 1 to reduce its concentration. The effect on self-ignition is reduced, the temperature deviation is also reduced, and knock resistance is improved.

[0080]

The present invention is constructed as described above. The scavenging action is improved and the residual gas is reduced or its concentration is reduced, so that not only the output performance or the exhaust gas performance is improved but also the residual gas is improved. The effect on self-ignition due to the above is reduced, and the knocking resistance is improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment in which a valve area of an exhaust valve is larger than that of an intake valve.

FIG. 2 is a diagram showing an embodiment in which the number of exhaust valves is larger than that of intake valves.

FIG. 3 is a diagram showing another embodiment in which the number of exhaust valves is larger than that of intake valves.

FIG. 4 is a diagram showing still another embodiment in which the number of exhaust valves is larger than that of intake valves.

FIG. 5 is a diagram showing an embodiment in which the number of valves in some cylinders is larger for exhaust valves than for intake valves.

FIG. 6 is a cross-sectional view illustrating an embodiment configured to generate a tumble flow.

FIG. 7 is a sectional view showing an embodiment provided with an auxiliary port.

FIG. 8 is a sectional view showing another embodiment provided with an auxiliary port.

FIG. 9 is a sectional view showing still another embodiment provided with an auxiliary port.

FIG. 10 is a sectional view showing an embodiment in which an auxiliary port is provided in a sub chamber.

FIG. 11 is a cross-sectional view showing an embodiment in which a gas injector is provided in an intake port.

FIG. 12 is a sectional view showing an embodiment provided with an air injector.

FIG. 13 is a sectional view showing an embodiment in which an air injector is provided in a sub chamber.

FIG. 14 is a sectional view showing an embodiment in which an air injector is provided in an intake port.

FIG. 15 is a sectional view showing an embodiment in which a gas injector and an air injector are provided.

FIG. 16 is a cross-sectional view showing an embodiment in which air is extracted from the downstream of the compressor and piped to the air injector.

FIG. 17 is a timing chart for explaining the injection timing of gas and air injectors.

FIG. 18 is a configuration diagram showing an embodiment in which a blower is interposed in an exhaust system.

FIG. 19 is a configuration diagram showing an embodiment in which a blower is interposed in an intake system.

FIG. 20 is a configuration diagram showing an embodiment in which a blower is interposed in each of the intake and exhaust systems.

FIG. 21 is a configuration diagram showing an embodiment in which a knock sensor is provided with a blower interposed in an exhaust system.

FIG. 22 is a flowchart of the control device in FIG. 20;

FIG. 23 is an explanatory diagram of an operation in a six-stroke cycle.

FIG. 24 is a pV diagram of FIG. 23.

FIG. 25 is a sectional view showing an embodiment provided with a projecting means.

FIG. 26 is a sectional view showing another embodiment of the projecting means.

FIG. 27 is a sectional view showing an embodiment in which a reed valve is provided in an exhaust port.

FIG. 28 is a front view showing an embodiment in which a plurality of exhaust valves are provided around a single intake valve and an ignition plug is provided in the vicinity thereof.

FIG. 29 is a front view showing an embodiment in which a plurality of intake valves are provided around a single exhaust valve and a plurality of spark plugs are provided.

FIG. 30 is a front view showing an embodiment configured to collect residual gas in a swirl flow.

FIG. 31 is a cross-sectional view showing an embodiment configured to collect residual gas in the vicinity of an ignition plug by a tumble flow.

FIG. 32 is a front view showing an embodiment in which intake and exhaust valves are arranged axially symmetrically.

FIG. 33 is a perspective view showing an embodiment configured to generate tumble flows that rotate in opposite directions.

FIG. 34 is a top view showing an embodiment configured to generate swirl flows that rotate in opposite directions.

FIG. 35 is a perspective view showing an embodiment configured to generate a swirl flow and a tumble flow.

FIG. 36 is a valve timing chart illustrating an overlap period.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylinder 2 ... Piston 3 ... Cylinder head 5 ... Intake port 6 ... Exhaust port 8 ... Intake valve 9 ... Exhaust valve 11 ... Air injector 12 ... Gas injector 15 Auxiliary port 16 Auxiliary valve 18 Sub chamber 21 Exhaust turbocharger 21c Compressor 21t Turbine 22 Mixer 23 Throttle 25 ... Catalyst 27 ... Ignition plug 31 ... Blower 32 ... Bypass 33 ... Waste gate valve 35 ... Control device 36 ... Knock sensor 38 ... Protruding means 41 ... Lead valve

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI F02B 29/02 F02B 29/02 D 29/06 29/06 D 29/08 29/08 E 31/00 31/00 Z 31 / 02 31/02 C 33/38 33/38 37/00 302 37/00 302A 37/18 43/00 A 43/00 43/06 43/06 75/02 A 75/02 75/18 L 75/18 F02D 13/02 K F02D 13/02 F02F 3/26 A F02F 3/26 3/28 B 3/28 F02M 21/02 301R F02M 21/02 301 301P F02B 37/12 301A (72) Inventor Shiki Sajio Tokyo Tokyo 2-13-7-1006 Midori, Sumida-ku (72) Inventor Kazuhisa Okamoto 4-13-21-A210, Nakameguro, Meguro-ku, Tokyo (72) Inventor Kenji Nakagawa 15-10 Miyamatsucho, Hiratsuka-shi, Kanagawa −715 (72) Inventor Satoshi Shimogata 2-1-14-102, Kasuga-cho, Nerima-ku, Tokyo (72) Inventor Yasuharu Kawabata Yokohama, Kanagawa 3-3-3308 −304, Shiomidai, Isogo-ku, Yokohama-shi

Claims (33)

[Claims] 1. A reciprocating internal combustion engine, wherein the total flow passage area per cylinder of an exhaust valve provided in a cylinder head is larger than the total flow passage area per cylinder of an intake valve. An internal combustion engine characterized in that: 2. The total flow path area per cylinder of the exhaust valve is set such that the number of exhaust valves per cylinder is greater than the number of intake valves and larger than the total flow path area of the intake valve per cylinder. The internal combustion engine of claim 1, wherein the internal combustion engine is configured. 3. The internal combustion engine according to claim 1, wherein the total area of the flow path of the exhaust valve is larger than the total area of the flow path of the intake valve for some of the cylinders of the multi-cylinder engine. 4. An internal combustion engine characterized in that an intake flow is generated in a cylinder to generate a tumble flow toward an exhaust port. 5. The internal combustion engine of claim 4, including a piston shaped to generate a tumble flow along the top surface of the intake flow toward the exhaust port. 6. The internal combustion engine according to claim 4, wherein the shape of the intake port is a straight port. 7. An internal combustion engine having an auxiliary port and an auxiliary valve for discharging residual gas to a cylinder head. 8. The internal combustion engine according to claim 7, wherein said auxiliary port communicates with an intake port. 9. The internal combustion engine according to claim 8, wherein a catalyst is interposed between said auxiliary port and said auxiliary port and communicates with an intake port. 10. The internal combustion engine according to claim 7, wherein said auxiliary port opens into a sub-chamber provided in a cylinder head. 11. An internal combustion engine having a gas injector for injecting fuel gas after an overlap period of intake and exhaust valves in an intake port of a cylinder head. 12. An internal combustion engine having an air injector for injecting compressed air into a cylinder at the end of an exhaust stroke. 13. The internal combustion engine according to claim 12, wherein said air injector opens into a sub-chamber provided in a cylinder head. 14. An internal combustion engine having an air injector for injecting pressurized air during an overlap period between intake and exhaust valves in an intake port of a cylinder head. 15. An air injector for injecting pressurized air during an overlap period of an intake / exhaust valve and a gas injector for injecting fuel gas after an overlap period are provided in an intake port of a cylinder head. Features internal combustion engine. 16. The air injector according to claim 12, wherein air is extracted from the downstream side of the compressor of the supercharger and connected to the air injector.
5. The internal combustion engine of any one of 5. 17. An internal combustion engine having an exhaust turbocharger, wherein a mechanical suction means for improving a scavenging performance is interposed in an intake system. 18. An internal combustion engine having an exhaust turbocharger, wherein an exhaust system is provided with mechanical suction means for improving scavenging performance. 19. An internal combustion engine having an exhaust turbocharger, wherein a mechanical suction means for improving scavenging performance is interposed in each of an intake system and an exhaust system. 20. The internal combustion engine according to claim 17, wherein a passage bypassing the exhaust turbine is provided, and a wastegate valve is provided in the passage. 21. A control device for providing a knock sensor to detect a knock intensity and controlling an output of the mechanical suction means and a waste gate valve opening.
0 internal combustion engine. 22. The mechanical suction means is a roots blower or a screw compressor.
The internal combustion engine according to any one of 1. 23. An intake stroke in which a piston descends and sucks an air-fuel mixture, a compression stroke in which a piston rises and compresses an air-fuel mixture, and an expansion stroke in which an air-fuel mixture burns to lower a piston and expand combustion gas. One cycle is formed by six strokes: an exhaust stroke in which the piston rises and discharges combustion gas, a scavenging suction stroke in which the piston descends and sucks only air, and a scavenging discharge stroke in which the piston rises and discharges gas in the cylinder. An internal combustion engine characterized by: 24. An internal combustion engine characterized in that projecting means is provided at a position facing a combustion chamber provided in a concave shape on the top of a piston to discharge residual gas in the combustion chamber. 25. A fuel injector is provided in an intake port or a cylinder, and a one-way check valve is provided in an exhaust port of a cylinder head in an exhaust discharge direction to open the exhaust valve halfway through a compression stroke. An internal combustion engine characterized in that: 26. A fuel injector is provided in an intake port or a cylinder, a single intake valve is provided in a central portion of a cylinder of a cylinder head, and a plurality of exhaust valves are provided so as to surround the intake valve. An internal combustion engine comprising a plurality of spark plugs provided near a valve. 27. A method in which a single exhaust valve is provided at the center of a cylinder of a cylinder head, a plurality of intake valves are provided around the exhaust valve, and a plurality of spark plugs are provided near the exhaust valve. Features internal combustion engine. 28. The intake port of a cylinder head is configured to generate a strong intake swirl flow in a cylinder, and an ignition plug is disposed at a central portion where residual gas is collected by the swirl flow. Internal combustion engine. 29. An intake port and a piston top surface of a cylinder head are formed such that an intake flow generates a tumble flow in a cylinder, and the exhaust gas is collected near an ignition plug by the tumble flow. An internal combustion engine characterized by: 30. An internal combustion engine in which two intake valves and two exhaust valves are disposed in each cylinder in an axially symmetric manner to promote mixing of fresh air and residual gas in a cylinder head. 31. Each cylinder head has two cylinders per cylinder.
An internal combustion engine provided with a plurality of intake valves and configured to generate a tumble flow in which intake air flows in opposite directions in a cylinder. 32. Each cylinder head has two cylinders per cylinder.
An internal combustion engine comprising: a plurality of intake valves, wherein the internal combustion engine is configured to generate a swirl flow in which intake air flows in opposite directions in a cylinder. 33. Each cylinder head has two cylinders per cylinder.
An internal combustion engine comprising: a plurality of intake valves; wherein an intake flow is generated in a cylinder so that a swirl flow is generated by one intake valve and a tumble flow is generated by the other intake valve.