JPH0674744B2 - 5 cycle internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a 5-cycle internal combustion engine used as an automobile gasoline engine, an automobile diesel engine, or the like.

(Prior Art) As a conventional internal combustion engine, for example, “Automotive Engineering Complete Book 4
As described in "Rolled Gasoline Engine" (published by Sankaido Co., Ltd. in July, 1980) is known.

Among the conventional internal combustion engines, the most common and currently frequently used 4-cycle gasoline engine is an engine that performs four strokes of an intake stroke, a compression stroke, an explosion stroke, and an exhaust stroke while the engine makes two revolutions. Is.

In the exhaust stroke, the exhaust valve is opened at the same time as the piston moves to the upward stroke, and the expanded combustion gas is discharged.

(Problems to be Solved by the Invention) However, in such a conventional four-cycle gasoline engine, when the piston reaches the top dead center, the exhaust action is almost finished, and the combustion gas remains in the cylinder space at the top dead center. However, due to this residual combustion gas, the intake air-fuel mixture is reduced by the amount of the residual combustion gas even when the process proceeds to the next intake stroke, and the engine output decreases accordingly.

As shown in FIG. 5, the cylinder space volume at the top dead center
V _U (also called the combustion chamber volume) is V _T is the cylinder total volume when the piston reaches the bottom dead center ε is the compression ratio, and the effective intake volume V _{A of the} air-fuel mixture (also called the stroke volume) is V _A = V _T −V _U.

Especially, in an engine in which equipment such as a converter or a muffler having a high gas passage resistance (exhaust resistance) is installed in the exhaust system, the residual combustion gas is not sufficiently discharged due to the influence of the exhaust resistance, and therefore the density thereof is also reduced. As a result, a large amount of combustion gas will remain. Therefore, the exhaust system muffler and converter are designed to have as low resistance as possible,
However, there is a limit to lowering the resistance value, and therefore, for example, loss of engine output due to residual combustion gas in an automobile engine reaches several to several tens of percent of the engine output.

In other words, the exhaust resistance directly affects the loss of the engine output, which causes the following problems.

(B) The exhaust system muffler is designed to combine various muffling principles to reduce the exhaust noise. However, in any muffler, there is a strong correlation between the noise reduction degree and the exhaust resistance. A muffler with high resistance has low exhaust noise. Moreover, in recent years, due to noise pollution, a vehicle with even quieter exhaust noise is required, so exhaust resistance tends to increase,
The loss of the engine output due to the above-mentioned residual combustion gas increased as the exhaust resistance increased.

(B) In the heat balance of an internal combustion engine, 30
About% is discarded in the exhaust. Therefore, it is very meaningful to collect and effectively use this exhaust energy from the viewpoint of energy saving. Therefore, it is conceivable to provide an exhaust gas turbine or the like in the exhaust system in order to recover the heat, but any method will increase exhaust resistance and lead to loss of engine output. In addition, the engine output is lost more than the recovered energy, and it is practically difficult to recover the exhaust energy.

Further, as a conventional internal combustion engine, for example, pages 156 to 1 of "Automotive Engineering Complete Book 4 Vol.
There is known a turbocharged gasoline engine equipped with a turbocharger as described in page 63, Japanese Utility Model Publication No. 60-178329, etc.

This turbocharged gasoline engine uses exhaust gas to rotate a turbine, and a compressor mounted coaxially to the turbine increases the intake pressure to increase the engine output, especially in a high-speed rotation range. .

However, this turbocharged gasoline engine aims to increase the engine output by paying attention to the intake side, but the loss of the engine output due to the residual combustion gas as described above is exactly the same, and this loss is The exhaust resistance is increased by providing the turbine in the exhaust system, and in this respect, the loss of the engine output due to the residual combustion gas is larger than that of the engine without the turbocharger.

(Means for Solving Problems) The present invention solves the problems described above, that is, eliminates the loss of engine output due to residual combustion gas and eliminates the influence of exhaust resistance on output. In order to achieve this object, the present invention is directed to an internal combustion engine having an intake hole, an intake valve and an exhaust hole, and an exhaust valve, and an exhaust gas is provided separately from the intake / exhaust hole and intake / exhaust valve systems. Scavenging means for injecting into the cylinder pressurized air sufficient to discharge residual combustion gas when the valve is opened is connected to a compressor driven by a turbine provided in the exhaust system of the engine, and the scavenging means is connected to the compressor. In addition to the forced scavenging stroke by the scavenging means, five strokes are performed in the order of the intake stroke, the compression stroke, the explosion stroke, the exhaust stroke, and the forced scavenging stroke while the engine rotates twice.

The scavenging means is a means for injecting pressurized air into the cylinder, such as a scavenging valve or a scavenging nozzle.

(Operation) Therefore, in the five-cycle internal combustion engine of the present invention, by adopting the above-mentioned means, the exhaust system opens in the exhaust system of the engine following the exhaust stroke in which the exhaust gas is opened and the piston rises. The scavenging means that injects the compressed air from the compressor driven by the installed turbine into the cylinder performs the forced scavenging stroke to forcibly discharge the residual combustion gas to the outside, and creates the cylinder space at the piston top dead center. The compressed air remains in place of the residual combustion gas, and in the subsequent intake stroke, almost the total cylinder volume becomes the effective intake volume of the air-fuel mixture, and the loss of engine output due to the residual combustion gas can be eliminated.

Further, as described above, since the residual combustion gas is exhausted to the outside by the forced scavenging action, the direct influence on the engine output due to the exhaust resistance can be eliminated, so that the turbine installed in the exhaust system of the engine can be eliminated. Even if a compressor driven by is added, there is almost no reduction in engine output,
The engine effectively utilizes exhaust gas energy.

(Examples) Hereinafter, examples of the present invention will be described in detail with reference to the drawings. In describing this embodiment, a 5-cycle gasoline engine used as an automobile engine will be taken as an example.

First, the configuration of the embodiment will be described.

The 5-cycle gasoline engine A of the embodiment has a cylinder 1, a piston 2, an intake pipe 3, an intake valve 4, an exhaust pipe 5, an exhaust valve 6, a scavenging pipe 7, and a scavenging valve, as shown in FIGS. 1 to 4. (Scavenging means) 8, an exhaust gas turbine (turbine) 9, and an air compressor (compressor) 10 are main components.

The cylinder 1 is a cylindrical cylinder formed in a cylinder block, and the cylinder arrangement in the case of having a plurality of cylinders includes L type (series type), V type, opposed piston type and the like.

The piston 2 is provided in the cylinder 1 so as to be able to reciprocate, and the piston 2 is connected to a crankshaft 12 via a connecting rod 11a and a crank arm 11b, as shown in FIG.

The intake pipe 3 is a pipe into which a mixture of air and fuel is sucked. An intake hole 13 of the intake pipe 3 is opened in the cylinder head portion 1a of the cylinder 1, and a cam is provided at the position of the intake hole 13. An intake valve 4 is provided which opens and closes in response to rotation of the shaft.

The intake pipe 3 is provided with a carburetor 23, a fuel injection nozzle 33, and an intake air amount sensor pipe 43 that senses an increase in the intake air amount due to the engine output. The valve actuator 53
Is installed.

The exhaust pipe 5 is a pipe for discharging combustion gas after explosive combustion to the outside, and an exhaust hole 15 of the exhaust pipe 5 is opened in the cylinder head portion 1a of the cylinder 1, and the exhaust hole 15 is located at a position of the exhaust hole 15. An exhaust valve 6 that opens and closes according to the rotation of the camshaft and the like is provided.

The exhaust pipe 5 is provided with a bypass exhaust pipe 25 which is a bypass pipe for an excessive amount of exhaust gas, a converter 35, and a muffler 45, and an exhaust gas turbine 9 is provided in the middle of the exhaust pipe 5. The bypass exhaust pipe 25 includes a normally closed bypass valve connected to the valve actuator 53.
55 is provided.

The exhaust gas turbine 9 is an exhaust energy extraction unit that receives the exhaust gas energy from the exhaust pipe 5 and rotates.
A tip end portion of a turbine shaft 20 of the exhaust gas turbine 9 is projected and extended to the scavenging pipe 7, and an air compressor (turbo blower) 10 is attached to the tip end portion.

In the figure, 20a is a bearing housing and 20b is a bearing.

The scavenging pipe 7 is a main component of a scavenging system that is separate from the intake system and the exhaust system, and is a pipe that injects pressurized air from the air compressor 10 into the cylinder 1 when the exhaust valve 6 is open. A scavenging hole 17 of the scavenging pipe 7 is opened in the cylinder head portion 1a of the cylinder 1, and a scavenging valve 8 that opens and closes according to the rotation of a camshaft etc. is provided at the position of the scavenging hole 17. .

In the embodiment, the scavenging valve 8 is provided with the scavenging guide plate 81, and as shown by the arrows in FIGS. 3 and 4, the injection path of the pressurized air is rotated in the space of the cylinder 1 along the inner peripheral surface. However, the scavenging efficiency of combustion gas is improved.

The air compressor 10 is a compressor that uses the exhaust gas energy collected by the exhaust gas turbine 9 to generate pressurized air for forcibly scavenging the combustion gas in the cylinder 1, and projects into the scavenging pipe 7. It is provided at the tip of the extended turbine shaft 20.

Next, the operation of the embodiment will be described for each stroke.

(A) Intake stroke When the intake valve 4 is opened, the piston 2 descends from the top dead center, and the air-fuel mixture mixed with the fuel injected from the fuel injection nozzle 33 is sucked into the cylinder 1 or the carburetor 23. The mixture created by is inhaled.

(B) Compression stroke Next, the piston 2 rises from the bottom dead center. At this time, the intake valve 4, the scavenging valve 8 and the exhaust valve 6 are all closed, and the air-fuel mixture is compressed and its temperature and pressure rise.

(C) Explosion stroke Just before the top dead center at the end of the compression stroke, the mixture is ignited by the spark plug. Then, the high-pressure gas generated by the combustion pushes the piston 2 downward to work.

(D) Exhaust stroke In the next rising stroke of the piston 2, the exhaust valve 6 is opened, and the expanded high-temperature and high-pressure combustion gas is discharged to the exhaust pipe 5.

The combustion gas that has been discharged into exhaust gas is
The exhaust gas turbine 9 is rotated by a part of the heat energy and pressure energy of the exhaust gas during the passage of, and then passes through the converter 35 and the muffler 45 and is discharged to the atmosphere.

In the operation of recovering the exhaust gas energy by the exhaust gas turbine 9, the intake air amount sensor pipe 43 is used as a sensing unit, and
Bypass valve driven by valve actuator 53
By controlling the valve opening degree of 55, the excess amount of exhaust gas is diverted to the bypass exhaust pipe 25, so that the pressure of the exhaust gas sent to the exhaust gas turbine 9 is maintained so as not to exceed the set pressure.

(E) Forced scavenging stroke When the piston 2 is near the top dead center or reaches the top dead center in the exhaust stroke of the piston 2, the scavenging valve 8 is opened and added by the air compressor 10 which is coaxially rotated with the exhaust gas turbine 9. In the process in which compressed air is injected into the space of the cylinder 1 to forcibly discharge the residual combustion gas to the outside, the exhaust valve 6 closes and the forced scavenging process ends. Since the amount of the pressurized air in the forced scavenging stroke increases in accordance with the number of revolutions of the exhaust gas turbine 9, both the pressure and the flow rate of the pressurized air become higher as the engine becomes higher and the scavenging time becomes shorter. As a result, a stable scavenging action can be obtained without controlling the pressurized air.

Since the effective intake capacity of the air-fuel mixture becomes the total volume of the cylinder due to the forced scavenging stroke, and compressed air remains instead of the residual combustion gas in the intake stroke, the air-fuel mixture has a higher concentration than the bearing. It is necessary to adjust the fuel supply system so that the air-fuel mixture has the same concentration as the conventional one when the air is taken into the cylinder 1. Becomes

As described above, in the 5-cycle gasoline engine A of the embodiment, the scavenging pipe 7 and the scavenging valve 8 are provided, and the compressed air from the air compressor 10 driven by the exhaust gas turbine 9 when the exhaust valve 6 is opened is used. Since the residual combustion gas is forcibly discharged to the outside, that is, the forced scavenging is performed, the loss of the engine output due to the residual combustion gas is eliminated, and as a result, the engine output can be increased.

In addition, most residual combustion gas is exhausted to the outside by the forced scavenging action, which can eliminate the direct influence of exhaust resistance on the engine output, which greatly increases the design freedom of the exhaust system. The air compressor 10 which is increased and driven by the exhaust gas turbine 9 in the exhaust system of this engine
Even if the engine is added, the engine output is hardly reduced, and the engine can be made by effectively utilizing the exhaust gas energy.

Further, as described above, the degree of freedom in designing the exhaust system is greatly increased, so that in addition to the exhaust gas turbine 9, an exhaust noise reducing device, an exhaust gas energy recovery device for other purposes, etc. are positively added. You can do it.

Further, in the embodiment, a high scavenging effect can be achieved by the arrangement of the scavenging holes 17 and the scavenging guide plate 81 provided on the scavenging valve 8.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and the present invention can be applied even if there is a design change or the like within a range not departing from the gist of the present invention. included.

For example, although a 5-cycle gasoline engine is illustrated in the embodiment, it can be applied to a diesel engine. However, in general, a diesel engine has a compression ratio that is more than twice that of a gasoline engine, so the output increasing effect of a gasoline engine cannot be expected.

Further, in the conventional internal combustion engine, for example, page 284 and page 285 of the above-mentioned “Automotive Engineering Complete Book 4 Volume Gasoline Engine” are described.
There is known an automobile engine using the exhaust gas recirculation device (referred to as EGR) described on the page.

The exhaust gas recirculation device, the principle of occurrence of N _OX combustion temperature by increasing the amount of gas per unit calorific value if more inactive ingredients in mixture air-fuel ratio even at the same lowers decreases , A device for returning a part of the exhaust gas as the inactive component to the intake system and adding it to the air-fuel mixture, and the effective intake volume V _A of the air-fuel mixture is further increased by the circulating gas volume V _{EGR as} shown in FIG. Get smaller.

However, even if EGR is required as an exhaust measure, at least the loss of engine output due to the combustion gas remaining in the cylinder space volume V _U at the piston top dead center can be eliminated,
You can expect an increase in output, and if you do not apply extra EGR by the amount of residual combustion gas discharged by scavenging, it will not be possible to expect a large output increase if it interferes with exhaust measures,
At least the direct effect of exhaust resistance can be eliminated.

Further, in the embodiment, the scavenging pipe and the scavenging valve are used as the scavenging device, but an air injection nozzle or the like may be used.

Further, in the embodiment, the end of the scavenging timing is set to the timing when the exhaust valve is closed, but it is possible to expect a supercharging effect by continuing the scavenging even when the exhaust valve is closed and the intake valve is opened.

Further, when the knock (abnormal combustion) phenomenon increases due to the application of the present invention, it is effective to provide a cooler for cooling the pressurized air after the air compressor.

(Advantages of the Invention) In addition to the intake / exhaust holes and intake / exhaust valves, scavenging means for injecting into the cylinder pressurized air sufficient to exhaust the residual combustion gas when the exhaust valve is opened is provided, and the scavenging means exhausts the engine Connect the compressor driven by the turbine installed in the system,
In addition to the forced scavenging stroke by the compressor and the scavenging means, while the engine makes two revolutions, the intake combustion stroke, the compression stroke, the explosion stroke, the exhaust stroke, and the forced scavenging stroke are performed in the order of five strokes. Is forcibly scavenged, the loss of the engine output due to the residual combustion gas is eliminated, and the effect that the engine output can be increased can be obtained.

In addition, since the residual combustion gas is almost exhausted to the outside by the forced scavenging action, it is possible to eliminate the direct influence of the exhaust resistance on the engine output, which greatly increases the design freedom of the exhaust system. However, even if a compressor driven by a turbine is added to the exhaust system of this engine, there is almost no reduction in engine output, and the engine can effectively utilize exhaust gas energy. Is obtained.

[Brief description of drawings]

FIG. 1 is an overall view showing an intake / exhaust gas scavenging path of a 5-cycle gasoline engine of an embodiment of the present invention, FIG. 2 is a schematic view of an embodiment engine, FIG. 3 is a plan view of the embodiment engine, and FIG. FIG. 5 is a partial cross-sectional view taken along the line I-I, FIG. 5 is an explanatory view of the cylinder volume of the engine, and FIG. 6 is an explanatory view of the cylinder volume of the engine with EGR. A: 5-cycle gasoline engine (5-cycle internal combustion engine) 1 ... Cylinder 4 ... Intake valve 6 ... Exhaust valve 8 ... Scavenging valve (scavenging means) 9 ... Exhaust gas turbine (turbine) 10 ... Air compressor (Compressor) 13 …… Intake hole 15 …… Exhaust hole

Claims (1)

[Claims] 1. An internal combustion engine having an intake hole, an intake valve, an exhaust hole, and an exhaust valve, which is separate from the intake / exhaust hole and intake / exhaust valve system and is sufficient to exhaust residual combustion gas when the exhaust valve is opened. A scavenging means for injecting pressurized air into the cylinder is provided, and a compressor driven by a turbine provided in the exhaust system of the engine is connected to the scavenging means, and a forced scavenging stroke is added by the compressor and the scavenging means so that the engine is A five-cycle internal combustion engine characterized by performing five strokes in the order of an intake stroke, a compression stroke, an explosion stroke, an exhaust stroke, and a forced scavenging stroke during two revolutions.