JPH06193447A - Air-fuel mixture combustion method for internal combustion engine and perfect premix combustion compression ignition engine - Google Patents

Abstract

PURPOSE:To facilitate the reduction of NOX contained in exhaust gas by interrupting an inflow passage to a sub-combustion chamber by means of a piston during compression stroke while stopping compression of air-fuel mixture, and propagating flame inside a main combustion chamber to the air-fuel mixture inside the sub-combustion chamber during descending of the piston. CONSTITUTION:A main combustion chamber 16 is formed between the lower portion of the head of a cylinder liner 12 and a piston 14. A sub-combustion chamber 50 formed on upper side portion of the main combustion chamber 16 is communicated with the main combustion chamber 16 through a communication port 54 when a piston 14 descends. Following the descending of the piston 14, air-fuel mixture is produced by intake air and fuel from a fuel injection nozzle 38, and allowed to flow into the sub-combustion chamber 50. When the piston 14 is lifted, the communication port 54 is interrupted just before a top dead center, and compressive operation in the sub-combustion chamber 50 is stopped. After ignition inside the main combustion chamber, the piston 14 descends, the communication port 54 is opened, and flame enters the sub-combustion chamber 50. Perfect premix can be made practicable and combustion performance is improved, accordingly. In addition, a catalytic converter rhodium can be used and NOX contained in exhaust gas can be reduced.

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 which supplies a mixture of fuel and air to the inside of a cylinder and burns it.
In particular, the present invention relates to a mixture combustion method for an internal combustion engine that compresses and ignites a mixture generated in an intake stroke, and a complete premixed combustion compression ignition engine.

[0002]

2. Description of the Related Art Internal combustion engines are widely used as power for vehicles, ships, aircraft, generators and the like. Particularly, at present, most automobiles are powered by a gasoline engine (gasoline engine) or a diesel engine (diesel engine).

A gasoline engine is designed to ignite an air-fuel mixture of gasoline, which is a fuel, and air by electric sparks, and has the following advantages. (1) Since a gasoline engine burns a homogeneous air-fuel mixture, it can burn at a stoichiometric air-fuel ratio, and there is no excess oxygen in the exhaust gas. Thus, in the case of a gasoline engine, it is possible to reduce nitrogen oxides (NO _X) by using the three-way catalyst. (2) Since a gasoline engine burns a homogeneous mixture (blue flame combustion), black smoke (smoke) and soot (particulates) are hardly generated. (3) Since a gasoline engine can burn fuel at a stoichiometric air-fuel ratio, air can be used to the maximum extent, and a high-power engine can be obtained.

On the other hand, since the diesel engine is a compression ignition engine in which fuel is injected into compressed air for ignition, the compression ratio can be increased (the direct injection compression ratio is 1).
4-18, the indirect injection type compression ratio with the auxiliary combustion chamber is 20
~ 23). Therefore, the thermal efficiency (fuel consumption rate) is high. Also,
Diesel engines do not adjust the air flow rate by the throttle even in the low load region, make the amount of air supplied to the combustion chamber the same as at full load, and reduce the fuel injection amount only, to achieve the same compression as at full load. Since it is a lean burn based on the ratio, it has an advantage that it does not cause a diaphragm loss and is efficient. Therefore, the diesel engine has the best thermal efficiency among the engines (engines) currently put into practical use.

[0005]

However, the gasoline engine is inferior to the diesel engine in thermal efficiency, while it has the advantages of clean exhaust gas and smoke and high output as described above. That is, the higher the compression ratio, the better the thermal efficiency, but in the case of a gasoline engine, if the compression ratio is too high, knocking occurs, so it is difficult to set the compression ratio to 8 to 10 or more. In addition, in a gasoline engine, when the load is low, both the fuel and air are throttled to create a stoichiometric air-fuel mixture, so the amount of air supplied to the combustion chamber is less than that at full load, and the mixture in the combustion chamber When compressed, the pressure does not rise, the thermal efficiency becomes low, and there is a drawback that the efficiency is poor due to throttling loss. Therefore, the fuel consumption rate is inferior to that of the diesel engine, the CO ₂ emission is large, and it is not preferable from the viewpoint of global warming.

On the other hand, the diesel engine has higher thermal efficiency than the gasoline engine as described above, but has the following drawbacks. (1) The diesel engine is a diffusion combustion in which fuel is injected into compressed air and burned, and it is necessary to burn in an excess air state. Therefore, diesel engine, the excess oxygen is present in the exhaust gas, the oxygen surplus to consume three-way catalyst can not be used a three-way catalyst, it can not be achieved a reduction of the NO _X by the three-way catalyst . Therefore, there is no catalyst for reducing NO _X in practical level at present, NO _X in the exhaust gas of the diesel engine is large as compared to a gasoline engine. (2) Diesel engine is diffusion combustion, there is locally oxygen-deficient combustion (yellow flame combustion),
Black smoke or soot is generated. (3) Since the diesel engine burns in an excess air state as described above, the utilization rate of air is low, and the output is inferior to that of a gasoline engine.

As described above, the spark ignition type gasoline engine and the compression ignition type diesel engine have advantages and disadvantages that are not present in each other. At present, the deterioration of the environment in urban areas is air pollution mainly caused by NO _X and particulates, and the diesel engine is the main cause. Further, a gasoline engine emits a large amount of CO ₂ , which is not preferable in terms of global warming. Therefore, it is desired to develop an ideal engine having both the advantages of a gasoline engine and the advantages of a diesel engine.

The present invention has been made in view of the above demands, and an object of the present invention is to provide a mixture combustion method for an internal combustion engine having high output, high thermal efficiency, and clean exhaust gas, and a complete premixed combustion compression ignition engine. I am trying.

[0009]

In order to achieve the above object, a method for combustion of a mixture of an internal combustion engine according to the present invention is a mixture of an internal combustion engine which combusts a mixture of air and fuel introduced into a combustion chamber. A gas combustion method, wherein the air-fuel mixture is generated in the air suction step, and when the air-fuel mixture is compressed, a part of the air-fuel mixture is caused to flow into a sub-combustion chamber provided on the inner wall of the cylinder, and the compression step is performed. In the middle of, the piston cuts off the inflow path of the auxiliary combustion chamber to stop the compression of the auxiliary combustion chamber before the ignition temperature of the mixture, while the main combustion formed between the upper part of the piston and the lower surface of the head. In the chamber, the compression process is completed to ignite the air-fuel mixture to start combustion, and when the piston descends to open the inflow passage, the flame in the main combustion chamber is converted into the sub-combustion chamber. Propagate to the mixture and burn It is characterized in that.

Further, the completely premixed combustion compression ignition engine according to the present invention has a main combustion chamber formed inside a cylinder, an intake pipe for guiding air to the main combustion chamber, and the air for the main combustion chamber. At the time of inflow, a fuel supply device for supplying fuel to the main combustion chamber, an auxiliary combustion chamber formed in communication with the main combustion chamber, and the air reciprocating in the cylinder and being supplied to the main combustion chamber. The air-fuel mixture is compressed and ignited while being ignited, and the piston that shuts off the main combustion chamber and the sub-combustion chamber near the top dead center, and the air-fuel mixture is burned at a predetermined operating condition. The exhaust gas recirculation device for supplying a part of the exhaust gas to the main combustion chamber.

The predetermined load condition is medium load or low load of the internal combustion engine. The fuel supply device may be a fuel injection device having a fuel injection nozzle that injects fuel. The fuel injection nozzle may be provided in the head portion of the cylinder or the intake pipe. Further, the fuel supply device may have a fumigation nozzle in which atomized fuel is sucked out by the air passing through the intake pipe.

[0012]

In the present invention configured as described above, when the air is sucked into the combustion chamber, a mixture of air and fuel is created and the mixture is compression ignited. That is, the combustion method of the present invention compresses and ignites the air-fuel mixture generated in advance before entering the compression step. Therefore, the present invention, unlike spray ignition in which fuel is injected into compressed air and ignited, can burn a homogeneous air-fuel mixture having a stoichiometric air-fuel ratio in advance, has high output, high thermal efficiency, and smoke black smoke. Is rarely generated. Further, the present invention burns a homogeneous air-fuel ratio mixture,
Can the purification of exhaust gases to the use of the three-way catalyst, the NO _X in the exhaust gas can be easily reduced.

When the engine (engine) has a medium load or a low load, if the intake pipe is throttled and throttled like a gasoline engine, the required air-fuel mixture is reduced. When compressed, the compression end temperature does not rise and compression ignition becomes difficult. Therefore, in the present invention, when the engine is operated at a medium load or a low load, a part of the exhaust gas burned in addition to the air-fuel mixture is returned to the combustion chamber, and the total amount of gas is made the same as that at the full load to achieve the compression end. The temperature is the same as that at full load and compression ignition is possible.

The complete premixed combustion compression ignition engine of the present invention is provided with a main combustion chamber and a sub combustion chamber, and the sub combustion chamber is isolated from the main combustion chamber near the top dead center of the piston.
In the end of the compression process, the piston closes the inflow path in the end of the compression process, so it stops in the middle of the compression process and does not reach the ignitable temperature, and is stored as a mixture. On the other hand, in the main combustion chamber formed between the upper part of the piston and the lower surface of the head, the compression process is completed and the temperature that can be ignited is reached.
First, combustion is started from the main combustion chamber, then the piston starts descending, and when the inflow path to the sub combustion chamber is opened, high pressure combustion gas flows from the main combustion chamber into the sub combustion chamber, The flame propagates greatly to the air-fuel mixture stored in and starts combustion, so that the combustion gas from the auxiliary combustion chamber re-flows into the main combustion chamber through the inflow passage and completes combustion while being disturbed in the latter period.
For this reason, it becomes possible to perform combustion in a sabate cycle, the impact given to the cylinder and the like can be alleviated, the durability of the engine is improved, and the life can be extended.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a method for combustion of mixture of an internal combustion engine and a complete premixed combustion compression ignition engine according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view of a complete premixed combustion compression ignition engine according to a first embodiment of the present invention.

In FIG. 1, an engine 10 which is a complete premixed combustion compression ignition engine has a piston 14 arranged inside a cylinder liner 12 which constitutes a cylinder.
A main combustion chamber 16 is formed between the lower portion of the head of the cylinder liner 12 and the upper surface of the piston 14. The piston 14 has an ignition recess 17 formed in the upper part for compressing and igniting the air-fuel mixture as described later, and the cylinder liner 1 is formed on the circumferential surface.
Upper top ring 1 for airtightness between the walls of 2
8 and a lower top ring 20 and a second ring 22 are attached. An oil ring 24 is attached to the piston 14 to prevent oil in the crank chamber 26 below the piston 14 from entering the main combustion chamber 16.

The cylinder head is provided with an intake port and an exhaust port, and an intake pipe 28 and an exhaust pipe 30 are connected to these ports. The intake port is the intake valve 32.
It is designed to be opened and closed by
When the intake valve 32 opens and the piston 14 descends, air (fresh air) is sucked into the main combustion chamber 16 from the intake pipe 28 as shown by an arrow 34. The exhaust port is configured to be opened and closed by an exhaust valve 36. As will be described later, when the exhaust valve 36 opens and the piston 14 rises, the combustion gas (exhaust gas) in the main combustion chamber 16 is exhausted. It is discharged to 30. Further, a fuel injection nozzle 38 that constitutes a fuel supply device is attached to the cylinder head. In the fuel injection nozzle 38, the injection hole at the tip faces the main combustion chamber 16, and at the same time fresh air is supplied to the main combustion chamber 16,
Combustion of gasoline, light oil or the like is injected into the main combustion chamber 16 to generate an air-fuel mixture in the main combustion chamber 16.

The intake pipe 28 has a partition 39 at an appropriate position.
Is provided. The partition 39 is provided so as to be biased with respect to the center of the intake pipe 28, and an inside of the intake pipe 28 is divided into an exhaust gas recirculation section 40 having a large flow passage cross-sectional area and a minimum flow rate guarantee passage 42 having a small flow passage cross-sectional area. It is partitioned. And the intake pipe 2
The exhaust gas recirculation section 40 of 8 is connected to one end of an exhaust gas recirculation path 44 which constitutes an exhaust gas recirculation device (EGR device) and has the other end opened to the exhaust pipe 30. is there. In addition, the exhaust gas recirculation unit 40 includes a valve control device 4
A flow rate adjusting valve 48 whose opening and closing is controlled by 6 is provided to adjust the amount of air passing through the exhaust gas recirculation unit 40 and the amount of exhaust gas recirculating from the exhaust gas recirculation passage 44 to the intake pipe 28. I can do it.

The auxiliary combustion chamber 5 is provided on the upper side of the main combustion chamber 16.
0 is formed. The sub-combustion chamber 50 communicates with the main combustion chamber 16 through a small communication port (inlet) 54 when the piston 14 descends as shown by an arrow 52, and the main combustion chamber 16
Combustion gas flows in from. Note that FIG.
Reference numeral 56 shown in FIG. 2 is a connecting rod connected to the piston 14 via a piston pin 58.
6 converts the reciprocating motion of the piston 14 into a rotary motion and transmits it to the crankshaft 60.

The operation of the embodiment configured as described above will be described with reference to FIG.
13 to FIG. In the explanation of this operation, the displacement is 1190 cc, the volume of the ignition recess 17 formed in the upper portion of the piston 14 is 20 cc,
Further, an engine in which the volume of the auxiliary combustion chamber 50 is 80 cc is taken as an example.

FIG. 2 shows a state in which the crank angle starting from the top dead center of the piston 14 is 90 degrees. This state is during the suction process, during which the piston 14 is descending as shown by the arrow 62, the exhaust valve 36 is closed and the intake valve 32 is opened, and fresh air is sucked in as the piston 14 descends. While being sucked from the pipe 28 into the main combustion chamber 16 as indicated by an arrow 64, light oil as fuel is gently injected from the fuel injection nozzle 38, and the air-fuel mixture 66 starts to be generated. Further, the piston 14 lowers as shown by the arrow 62 to open the communication port 54 and open the main combustion chamber 16 and the sub combustion chamber 5.
Connect with 0. However, combustion gas (exhaust gas) 68, which has burned the air-fuel mixture 66, remains in the peripheral portion of the main combustion chamber 16 and the inside of the auxiliary combustion chamber 50.

As shown in FIG. 3, when the piston 14 reaches the bottom dead center and the crank angle reaches 180 degrees, the intake process ends, the intake valve 32 is closed together with the exhaust valve 36, and the main combustion chamber 16 is closed. The homogeneous mixture 66 is filled. However, since the main combustion chamber 16 and the sub combustion chamber 50 are only communicated with each other through the small communication port 54, the air-fuel mixture 66 in the main combustion chamber 16 has not yet flowed into the sub combustion chamber 50.

FIG. 4 shows a compression process in which the crank angle is 270 degrees. When the piston 14 starts rising as shown by the arrow 70 and enters the compression process, the homogeneous mixture in the main combustion chamber 16 is shown. 66 also flows into the auxiliary combustion chamber 50. The low temperature oxidation reaction of the homogeneous mixture 66 proceeds during the compression process by the piston 14. Then, when the piston 14 further rises and slightly before top dead center, for example, when the crank angle reaches 345 degrees (15 degrees before top dead center), the upper peripheral surface of the piston 14 closes the opening 54, and the auxiliary combustion chamber 50 Is shut off from the main combustion chamber 16 (see FIG. 5). At this time, in the embodiment, the compression ratio ε of the auxiliary combustion chamber 50 becomes 10.2.

When the piston 14 rises to the top dead center as shown in FIG. 6 and the crank angle reaches 360 degrees, the main combustion chamber 16 has only the ignition recess 17 and the air-fuel mixture 66 is further compressed by the piston 14 to generate the air-fuel mixture. The compression ratio of 66 is 23.8.
To rise. Then, the air-fuel mixture 66 in the ignition recess 17
When the crank angle is 360 degrees and the compression ratio is compressed to 23.8, the ignition is caused due to the temperature rise due to the compression,
Combustion flame 72 is generated, combustion is started, and the explosion process starts (see FIG. 7). However, the auxiliary combustion chamber 50 is
Since it is cut off from the main combustion chamber 16 by 4, the compression ratio is maintained at 10.2 and the air-fuel mixture 66 does not ignite.

When the air-fuel mixture 66 in the main combustion chamber 16 begins to burn, it becomes a high-temperature combustion gas and expands rapidly, pushing down the piston 14 that has passed the top dead center as shown by the arrow 74 in FIG. However, the crank angle of the auxiliary combustion chamber 50 is 375
Main combustion chamber 1 by piston 14 until the temperature exceeds
6 is cut off, and the air-fuel mixture 66 in the auxiliary combustion chamber 50 has not yet started to burn. When the piston 14 further descends and the crank angle reaches about 405 degrees, the communication port 5
4 is opened and the main combustion chamber 16 and the sub-combustion chamber 50 communicate with each other (see FIG. 9), and the combustion flame 72 enters the sub-combustion chamber 50 from the main combustion chamber 16 and the air-fuel mixture 66 in the sub-combustion chamber 50. Combustion is started.

The combustion flame 72 in the auxiliary combustion chamber 50 is shown in FIG.
As shown in FIG. 5, the piston 14 is further pushed down by being blown out into the main combustion chamber 16 through the communication hole 54 and expanding.
Then, when the crank angle reaches about 450 degrees, high temperature exhaust gas 68 after combustion of the air-fuel mixture 66 is generated in the peripheral portion of the main combustion chamber 16. Further, when the piston 14 reaches the bottom dead center as shown in FIG. 11 and the crank angle reaches 540 degrees, the combustion of the air-fuel mixture 66 is completed and the explosion process is completed, so that the main combustion chamber 16 and the auxiliary combustion chamber 50 are separated. The exhaust process similar to the conventional engine in which the exhaust gas 68 that has been filled is discharged from the combustion chamber is entered.

That is, when the piston 14 reaches the bottom dead center, the exhaust valve 36 is opened as shown in FIG. And
The piston 14 rises as shown by the arrow 76 in FIG. 12 due to the inertia of the crankshaft 60, and exhausts the exhaust gas 68 in the main combustion chamber 16 to the outside through the exhaust pipe 30 as shown by the arrow 78. Note that FIG. 12 shows a state where the crank angle is 630 degrees. After that, the piston 14 reaches the top dead center, the crank angle becomes 720 degrees (= 0 degree), and only the lean exhaust gas 68 exists in the main combustion chamber 16 (ignition recess 17) and the sub combustion chamber 50. Then, the next inhalation process is started.

As described above, in the embodiment, since the homogeneous air-fuel mixture 66 in which fuel and air are premixed is compressed and ignited, complete premixing of fuel and air is possible. Therefore, it becomes possible to burn the fuel at the stoichiometric air-fuel ratio, and it is possible to obtain a high-power engine that maximizes the use of air as in the conventional gasoline engine. Further, in this embodiment, since the homogeneous air-fuel mixture 66 of the stoichiometric air-fuel ratio is burned, the three-way catalyst can be used, and the three-way catalyst can reduce CO and HC in the exhaust gas 68 as well as NO _X. Not only can the exhaust gas 68 be purified, but black smoke and soot can be eliminated. Moreover, because it is ignited by compression ignition, it can be burned with a compression as high as a diesel engine,
It is possible to obtain an engine with excellent thermal efficiency.

In the embodiment, the piston 14 blocks the main combustion chamber 16 and the auxiliary combustion chamber 50 before the top dead center so that the air-fuel mixture 66 in the auxiliary combustion chamber 50 is not compressed and ignited. When 14 descends and the main combustion chamber 16 and the auxiliary combustion chamber 50 communicate with each other, the combustion flame 72 of the main combustion chamber 16 starts the combustion of the air-fuel mixture 66 in the auxiliary combustion chamber 50. It is possible to realize a sabate cycle-like combustion, which is a smooth composite combustion that avoids explosive combustion. Therefore, the impact acting on the cylinder liner 12 and the piston 14 can be weakened, and the engine 10
The durability and reliability of can be improved. Further, in the embodiment, since the auxiliary combustion chamber 50 is provided above the cylinder block, it is possible to disperse the heat load of the cylinder head, which is advantageous in ensuring durability and reliability.

The valve control device 46 receives a control signal from an electronic control unit (not shown).
When the engine 10 is operating at full load,
The flow rate adjusting valve 48 closes the exhaust gas recirculation path 44. Then, when the engine 10 has a medium load or a low load, the valve control device 46 opens the flow rate adjusting valve 48 that closes the exhaust gas recirculation path 44 based on the control signal output from the electronic control unit to open the exhaust pipe. A part of the exhaust gas 68 flowing through the exhaust gas 30 is guided to the exhaust gas recirculation section 40 to guide the main combustion chamber 16
While reducing the amount of fresh air flowing through the exhaust gas recirculation unit 40. This is for the following reason.

In the present invention, one of the main points is to always burn a homogeneous air-fuel mixture having a stoichiometric air-fuel ratio and use a three-way catalyst for purification of exhaust gas. I want to make it happen. However, in the case of a low load such as a gasoline engine with the same aim, if both the fuel and air are throttled to compress the stoichiometric air-fuel mixture, the amount of air supplied to the combustion chamber will be less than at full load. However, when the mixture in the combustion chamber is compressed, the pressure does not rise, the thermal efficiency becomes low, and throttling loss occurs, resulting in poor efficiency. Therefore, the gasoline engine is inferior in fuel consumption rate to the diesel engine, emits a large amount of CO ₂ , and is not preferable in terms of global warming. In order to solve this problem, in the present invention, when the engine is operated under medium or low load, a part of the exhaust gas burned in addition to the air-fuel mixture is returned to the combustion chamber to enable compression ignition. This enables combustion with high thermal efficiency.

That is, in the embodiment, an exhaust gas recirculation device is provided as shown in FIG. 1, and a part of the exhaust gas 68 flowing through the exhaust pipe 30 is returned to the intake pipe 28 at the time of medium load or low load of the engine. Supply to combustion chamber 16 and combustion chamber 1
The total amount of gas in 6 and 50 is secured, and the compression end temperature is adjusted during full load operation to enable compression ignition of the air-fuel mixture 66.

In FIG. 14, an example of the ratio of the exhaust gas recirculation amount to the total intake amount described above is shown as a map on the graph of the engine speed and the shaft average effective pressure.

The minimum flow rate guarantee passage 42 is necessary to generate the air-fuel mixture 66 when the engine 10 is operated at a low load and the flow rate adjusting valve 48 shuts off the fresh air flowing through the exhaust gas recirculation section 40. This is to secure freshness.

FIG. 15 is a sectional view of the complete premixed combustion compression ignition engine according to the second embodiment. This embodiment is the same as the first embodiment except that the mounting position of the fuel injection nozzle that constitutes the fuel supply device is different from that of the first embodiment. That is, the fuel injection nozzle 38 of the second embodiment.
Is an in-intake-pipe injection type provided on the downstream side of the exhaust gas recirculation part 40 of the intake pipe 28. Also in this embodiment, the same effect as that of the above embodiment can be obtained. In the case of the second embodiment, instead of the fuel injection nozzle 38, a fumigation nozzle may be used in which mist-like fuel is sucked out by the air (including the exhaust gas 68) flowing through the intake pipe 28.

In the above embodiments, the case where the fuel is light oil has been described, but the fuel is gasoline or natural gas,
Other liquid or gaseous fuels such as hydrogen may be used.
Further, in the above-described embodiment, the engine in which the volume of the ignition recess 17 is 20 cc and the volume of the auxiliary combustion chamber 50 is 80 cc has been described, but the size of the ignition recess 17 and the auxiliary combustion chamber 50, the ratio to the displacement, the compression, The ratio and the like can be appropriately changed depending on the type of fuel, the required output, and the like.
Also, the size of the communication port 54 may be appropriately determined by experiments or the like.

[0037]

As described above, according to the present invention, when the air is sucked into the combustion chamber, a mixture of air and fuel is produced and the mixture is compressed and ignited. Unlike injecting fuel inside and igniting, a homogeneous air-fuel mixture that has been adjusted to the theoretical air-fuel ratio in advance can be burned, high output and high thermal efficiency can be achieved, and the generation of black smoke and soot can be almost eliminated. it can. Further, to burn homogeneous mixture of the stoichiometric air-fuel ratio, can make use of the three-way catalyst for purification of exhaust gas can be reduced NO _X in the exhaust gas.

When the engine has a medium load or a low load, if a part of the exhaust gas is recirculated to the combustion chamber, the total intake amount can be the same as that at the full load even at the medium load or the low load. The compression end temperature becomes the same as at full load, and compression ignition is possible.

[Brief description of drawings]

FIG. 1 is a sectional view of a complete premixed combustion compression ignition engine according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram during a suction process with a crank angle of 90 degrees.

FIG. 3 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram at the end of suction work with a crank angle of 180 °.

FIG. 4 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram during a compression process with a crank angle of 270 degrees.

FIG. 5 is a view for explaining the operation of the embodiment, and is an explanatory view of a state where the crank angle becomes 345 degrees and the sub combustion chamber is cut off from the main combustion chamber by the piston.

FIG. 6 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram at the end of the compression process when the crank angle is 360 degrees.

FIG. 7 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram for the compression ignition of the air-fuel mixture when the crank angle is 360 degrees.

FIG. 8 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram during the explosion process with a crank angle of 375 degrees.

FIG. 9 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram of a state in which the crank angle is 405 degrees and the main combustion chamber and the auxiliary combustion chamber are in communication.

FIG. 10 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram of combustion of the air-fuel mixture in the auxiliary combustion chamber during the explosion process with a crank angle of 450 degrees.

FIG. 11 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram at the end of the explosion process with a crank angle of 540 degrees.

FIG. 12 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram during an exhaust process with a crank angle of 730 degrees.

FIG. 13 is a diagram for explaining the operation of the embodiment, and is an explanatory diagram at the end of the exhaust process with a crank angle of 720 degrees.

FIG. 14 is a diagram showing an example of the ratio of the exhaust gas recirculation amount to the total intake air amount in the embodiment in relation to the engine rotation speed and the shaft average effective pressure.

FIG. 15 is a sectional view of a complete premixed combustion compression ignition engine according to a second embodiment of the present invention.

[Explanation of symbols]

10 engine (engine) 12 cylinder (cylinder liner) 14 piston 16 main combustion chamber 17 ignition recess 28 intake pipe 30 exhaust pipe 38 fuel supply device (fuel injection nozzle) 44, 48 exhaust gas recirculation device (exhaust gas recirculation passage, flow rate adjustment) Valve) 50 auxiliary combustion chamber

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area F02M 69/00

Claims (7)

[Claims] 1. An air-fuel mixture combustion method for an internal combustion engine, which combusts an air-fuel mixture introduced into a combustion chamber, wherein the air-fuel mixture is generated in a step of sucking the air and the air-fuel mixture is compressed. At this time, a part of the air-fuel mixture is caused to flow into the auxiliary combustion chamber provided on the inner wall of the cylinder, and the inflow passage of the auxiliary combustion chamber is blocked by the piston in the middle of the compression process, so that the ignition temperature of the air-fuel mixture is set before the ignition temperature. Stop the compression of the secondary combustion chamber, while
In the main combustion chamber formed between the upper portion of the piston and the lower surface of the head, when the compression process is completed, the mixture is ignited to start combustion, and the piston descends to open the inflow passage. A combustion method for an air-fuel mixture in an internal combustion engine, wherein the flame in the main combustion chamber is propagated and burned in the air-fuel mixture in the auxiliary combustion chamber. 2. A main combustion chamber formed inside a cylinder,
An intake pipe that guides air to the main combustion chamber, a fuel supply device that supplies fuel to the main combustion chamber when the air flows into the main combustion chamber, and a sub combustion chamber that is formed in communication with the main combustion chamber. And reciprocates in the cylinder to compress and ignite the air-fuel mixture supplied to the main combustion chamber and to ignite the fuel, and the main combustion chamber and the auxiliary combustion chamber near the top dead center. And a piston for shutting off the exhaust gas, and an exhaust gas recirculation device for supplying a part of the exhaust gas that combusts the air-fuel mixture to the main combustion chamber under a predetermined operating condition. Mixed combustion compression ignition engine. 3. The complete premixed combustion compression ignition engine according to claim 2, wherein the predetermined load condition is medium load or low load of the internal combustion engine. 4. The complete premixed combustion compression ignition engine according to claim 2 or 3, wherein the fuel supply device has a fuel injection nozzle for injecting the fuel. 5. The complete premixed combustion compression ignition engine according to claim 4, wherein the fuel injection nozzle is provided in a head portion of the cylinder. 6. The complete premixed combustion compression ignition engine according to claim 4, wherein the fuel injection nozzle is provided in the intake pipe. 7. The fuel supply device includes a fumigation nozzle which is provided in the intake pipe and discharges the atomized fuel into the air by being sucked by the air flowing through the intake pipe. The complete premixed combustion compression ignition engine according to claim 3, wherein