JPH094462A - Six-cycle diesel engine having auxiliary chamber - Google Patents

Abstract

PURPOSE: To provide an auxiliary chamber, which can promote the expanding process twice in one compressing stroke with the lapse of time and which can secure the high expansion ration at a low compression ratio so as to improve the theoretical thermal efficiency. CONSTITUTION: A main combustion chamber 1 formed in the cylinder 20 side and an auxiliary chamber 2 formed in a cylinder head 10 are communicated with each other by communication hole 4, and a switching valve 3 is provided in the communication hole 4. A main combustion chamber fuel injection nozzle 5 is provided in the main combustion chamber 1, and an auxiliary chamber fuel injection nozzle 6 is provided in the auxiliary chamber 2. The switching valve 3 is closed near the compression top dead center, and the fuel is injected from the main combustion chamber fuel injection nozzle 5 into the main combustion chamber 1, and the switching valve 3 is opened near the next piston top dead center, and the fuel is injected from the auxiliary chamber fuel injection nozzle 6 into the auxiliary chamber 2, and the fuel is ignited for burning and expansion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 6-cycle diesel engine having a secondary combustion chamber.

[0002]

2. Description of the Related Art Conventionally, a sub-chamber engine having a sub chamber (sub combustion chamber) has been developed for the purpose of improving combustion of the engine. In such a sub-chamber engine, fuel is sprayed into a sub-chamber formed in a cylinder head or a piston head, a communication hole that connects the sub-chamber to a main chamber (main combustion chamber) formed on the cylinder side, and the sub-chamber. It has a fuel injection nozzle, and forms a mixture with the fuel injected into the sub chamber by the intake air flowing into the sub chamber through the communication hole to perform primary combustion, and then the flame from the sub chamber to the main chamber through the communication hole, Gas such as a fuel-air mixture is ejected for secondary combustion.

Japanese Utility Model Laid-Open No. 2-141629 discloses a gasoline engine structure with a sub chamber.
The gasoline engine structure with a sub chamber includes a sub chamber communicating with the combustion chamber, a sub chamber valve provided between the sub chamber and the combustion chamber,
It has a sub-piston that is installed in the sub-chamber so as to be able to move forward and backward, and that can suck and discharge intake air into and from the sub-chamber, and by moving the sub-piston to the suction side and opening the sub-chamber valve at a predetermined point in the suction and compression strokes. The intake air can be sucked from the combustion chamber to the sub chamber, and the intake air can be discharged from the sub chamber to the combustion chamber by moving the sub piston to the discharge side and opening the sub chamber valve near the end of the exhaust stroke.

Further, Japanese Patent Laid-Open No. 5-240049 discloses
A 6-cycle engine is disclosed. In the 6-cycle engine, an air chamber provided in a cylinder head is opened and closed with respect to a combustion chamber by operating an air chamber valve through a communication hole,
The intake stroke, the first compression stroke, the first expansion stroke, the second compression stroke, the second expansion stroke, and the exhaust stroke are sequentially operated in 6 cycles. The air chamber valve is opened in the first compression stroke to introduce compressed air into the air chamber, the fuel is injected from the fuel injection nozzle after the second compression stroke, and the air chamber is opened in the second expansion stroke after the fuel injection. Compressed air is injected into the combustion chamber and disturbed. The intake valve opens in the intake stroke and in the latter half of the first expansion stroke to the first half of the first compression stroke to introduce intake air into the combustion chamber.

Further, the one in which a dividing valve is provided in a communication hole which communicates the main chamber and the sub chamber is disclosed in, for example, Japanese Unexamined Patent Publication No. 3-202668.
No. 6,086,045. A 6-cycle adiabatic engine is disclosed in, for example, Japanese Patent Laid-Open No. 3-115574.

[0006]

To the 0005] Generally, the combustion temperature in the secondary chamber because of the high temperature, as a measure to reduce the production of NO _X, it is effective to combust the fuel-rich.
When the combustion temperature is high, it is effective to use a sub-chamber engine as a type of engine structure in order to burn the fuel rich. In the conventional sub-chamber engine, the expansion ratio with respect to the compression ratio corresponds to 1: 1, and a high compression ratio is required to increase the thermal efficiency. However, when the compression ratio is increased in the sub-chamber engine, the in-cylinder pressure increases, and conversely the mechanical efficiency decreases,
It is also not preferable from the viewpoint of engine strength, and an excellent fuel efficiency cannot be obtained.

An object of the present invention is to solve the above-mentioned problems. Even though it is a sub-chamber combustion system capable of reducing the production of NO _x , one expansion stroke and two expansion strokes are performed. Since the expansion ratio to the compression ratio can be increased by performing the operation, theoretical thermal efficiency can be improved, and even if the compression ratio is set low, a sufficient expansion ratio can be secured to increase the intake pressure. It is to provide a 6-cycle diesel engine having a sub-combustion chamber capable of ensuring an output higher than that of a 4-stroke diesel engine.

[0008]

The present invention is configured as follows to achieve the above object. That is, the present invention is directed to a main combustion chamber formed on the cylinder side, a sub combustion chamber formed in a cylinder head, an on-off valve for opening and closing a communication hole that connects the main combustion chamber and the sub combustion chamber, and the main combustion chamber. A main chamber fuel injection nozzle provided in the sub-combustion chamber and a sub-chamber fuel injection nozzle provided in the sub-combustion chamber. Compress in the open state, close the on-off valve near the compression top dead center, inject fuel into the main combustion chamber with the main chamber fuel injection nozzle, ignite and burn to expand, and exhaust valve near the end of the expansion stroke. Is opened to exhaust combustion gas in the main combustion chamber, the on-off valve is opened near the piston top dead center in the exhaust stroke, and fuel is injected into the auxiliary combustion chamber by the auxiliary chamber fuel injection nozzle for ignition. Burned and expanded, then piston bottom dead In about 6-stroke diesel engine with auxiliary combustion chamber, characterized in that it is driven by repeating the cycle of evacuating the auxiliary combustion chamber of the combustion gas and the cylinder by opening the exhaust valve.

Alternatively, in the present invention, the main combustion chamber formed on the cylinder side, the first auxiliary combustion chamber and the second auxiliary combustion chamber formed on the cylinder head, and the main combustion chamber and the first auxiliary combustion chamber communicate with each other. A first opening / closing valve for opening / closing a communication hole, a second opening / closing valve for opening / closing a communication hole communicating the main combustion chamber and the second auxiliary combustion chamber, and a first fuel injection nozzle provided in the first auxiliary combustion chamber. And a second fuel injection nozzle provided in the second auxiliary combustion chamber, the intake valve being opened in an intake stroke to suck intake air into the cylinder, the first opening valve and the second opening valve. In the open state, the second open / close valve is closed near the compression top dead center to close the first open / close valve to inject fuel from the second fuel injection nozzle into the second auxiliary combustion chamber. It is ignited and burned to expand, and the exhaust valve is opened at the bottom dead center of the piston to form the second auxiliary combustion chamber. The exhaust gas of the main combustion chamber is exhausted, the second opening / closing valve is closed and the first opening / closing valve is opened near the next piston top dead center, and the first auxiliary combustion chamber is opened from the first fuel injection nozzle. It is driven by repeating a cycle of injecting fuel to ignite and burn it to expand it, and then opening the exhaust valve at the piston bottom dead center to exhaust combustion gas in the first auxiliary combustion chamber and the main combustion chamber. The present invention relates to a 6-cycle diesel engine having a secondary combustion chamber characterized by the above.

[0010]

The present invention is constructed as described above and operates as follows. That is, a 6-cycle diesel engine having this auxiliary combustion chamber has 1 stroke in 6 strokes including an intake stroke, a compression stroke, an expansion stroke, an exhaust stroke, an expansion stroke and an exhaust stroke.
Injecting fuel into the main combustion chamber with the main chamber fuel injection nozzle near the compression top dead center in the closed state of the on-off valve that opens and closes the communication hole that connects the main combustion chamber and the auxiliary combustion chamber. Then, it is ignited, burned and expanded to open the exhaust valve near the piston bottom dead center in the expansion stroke, exhaust the combustion gas in the cylinder including the main combustion chamber, and open and close the piston near the top dead center in the exhaust stroke. The fuel is injected into the sub-combustion chamber by the sub-chamber fuel injection nozzle in the opened state of the valve, ignited and burned, and expanded. Therefore, it is possible to inject fuel into the compressed air existing in the main combustion chamber and the sub combustion chamber and independently ignite and expand the fuel over time to expand the fuel in one compression stroke. The expansion stroke can be performed twice, the expansion ratio can be increased with respect to the compression ratio, and the theoretical thermal efficiency can be significantly improved.

Alternatively, a 6-cycle diesel engine having this auxiliary combustion chamber has 1 stroke in 6 strokes including an intake stroke, a compression stroke, an expansion stroke, an exhaust stroke, an expansion stroke and an exhaust stroke.
And a first sub-combustion chamber and a second sub-combustion chamber are provided in the cylinder head, and the second opening / closing valve of the second sub-combustion chamber is opened near the compression top dead center to open the first sub-combustion chamber. The first opening / closing valve of the auxiliary combustion chamber is closed to make the second auxiliary combustion chamber second.
Fuel is expanded by injecting fuel from a fuel injection nozzle, and the second on-off valve is closed near the next piston top dead center and the first piston is closed.
Since the on-off valve is opened and the fuel is injected into the first auxiliary combustion chamber from the first fuel injection nozzle to expand the fuel, the compressed air existing in the first auxiliary combustion chamber and the second auxiliary combustion chamber changes with time. Independently, it is possible to inject fuel from each of the fuel injection nozzles to expand it, to perform two expansion strokes in one compression stroke, and to increase the expansion ratio with respect to the compression ratio. The theoretical thermal efficiency can be greatly improved.

Further, since this 6-cycle diesel engine can obtain a sufficient expansion ratio with respect to the compression ratio, the intake pressure can be increased, and although it is a 6-cycle type, it is equal to or higher than that of 4 cycles. The output (output / engine volume) can be secured. For example, assuming that the intake air amount per unit rotational speed of 4 cycles is 1, 1 × (4 /
6) = 0.667. If the compression end maximum pressure is the same, P = P ₀ when the compression ratio ε = 10 and the compression ratio ε = 20.
· Ε ^{1. 4} and when a epsilon = 10 In 25.1 × P _0, is epsilon = 20 In 66.3 × P _0. Therefore, 6
6.3 is a × P ₀ /25.1×P ₀ = 2.64. Therefore, 0.667 × 2.64 = 1.76, which means that 6 cycles can increase the output by 1.76 times as compared with 4 cycles.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a 6-cycle diesel engine having a sub combustion chamber according to the present invention will be described below with reference to FIGS. FIG. 1 shows a 6 having a secondary combustion chamber according to the present invention.
4 is a plan view of the lower surface of the cylinder head showing one embodiment of the cycle diesel engine, FIG. 2 is a sectional view taken along line AA of FIG. 1, FIG. 3 is a sectional view taken along line BB of FIG. 1, and FIG.
FIG. 2 is a diagram showing an operation timing of a 6-cycle diesel engine having the auxiliary combustion chamber of FIG.

A 6-cycle diesel engine having this auxiliary combustion chamber includes a cylinder block 15 constituting a cylinder 20, a cylinder head 10 fixed to the cylinder block 15 via a gasket 21, and a piston 9 reciprocating in the cylinder 20. Have This spark ignition type 6
The cycle engine includes a cylinder head 10 and a secondary combustion chamber 2
Are formed. The cylinder block 15 may be provided with holes 19 corresponding to the number of cylinders of the engine, and the cylinder liner 16 having the cylinder 20 may be fitted into the holes 19 or, although not shown, these holes may be formed. The cylinder 19 may be configured by the portion 19. An intake port 11 and an exhaust port 12 are formed in the cylinder head 10, an intake valve 7 is arranged in a valve seat 17 of the intake port 11, and an exhaust valve 8 is arranged in a valve seat 18 of the exhaust port 12. .

In this 6-cycle diesel engine, in particular, a main combustion chamber 1 formed on the cylinder 20 side, a sub combustion chamber 2 formed in the cylinder head 10, and a communication hole connecting the main combustion chamber 1 and the sub combustion chamber 2 with each other. It has an on-off valve 3 for opening and closing 4, a main chamber fuel injection nozzle 5 provided in the main combustion chamber 1, and a sub chamber fuel injection nozzle 6 provided in the sub combustion chamber 2. The main combustion chamber 1 is mainly formed by a recess 22 formed in the piston top of the piston 9 and the lower surface of the cylinder head 10. The on-off valve 3 can be configured to be opened and closed by a valve mechanism including a cam or the like.

In this 6-cycle diesel engine, one cycle is composed of three revolutions of the engine, that is, six strokes including an intake stroke, a compression stroke, an expansion stroke, an exhaust stroke, an expansion stroke and an exhaust stroke. Meanwhile, the piston 9 reciprocates three times in the cylinder 20. This 6
In the cycle diesel engine, fuel is injected from the main chamber fuel injection nozzle 5 into the main combustion chamber 1 near the compression top dead center where the opening / closing valve 3 closes the communication hole 4 to ignite and burn to expand the piston. Work by pushing down. Next, near the top dead center of the exhaust stroke, the opening / closing valve 3 opens the communication hole 4, and at the same time, fuel is injected from the sub-chamber fuel injection nozzle 6 into the sub-combustion chamber 2 to be ignited and burned for expansion, and the piston 9 is pushed down. To work. An example of specific operation of this 6-cycle diesel engine will be described below.

Regarding the operation of this 6-cycle diesel engine, the opening / closing timing of the opening / closing valve 3, the intake valve 7 and the exhaust valve 8 with respect to the displacement of the piston 9 and the injection timing of the main chamber fuel injection nozzle 5 and the sub chamber fuel injection nozzle 6 Are shown in FIG. First, when the intake valve 7 is opened and the piston 9 is displaced from the top dead center to the bottom dead center in the intake stroke, intake air is taken into the cylinder through the intake port 11. At this time, the open / close valve 3 is open and the exhaust valve 8 is closed. The intake valve 7 closes when the piston 9 reaches the bottom dead center. Next, the compression stroke is entered and the piston 9
Is displaced from the bottom dead center to the top dead center, the intake air in the cylinder is compressed, and the intake air is compressed in the main combustion chamber 1 and the auxiliary combustion chamber 2. At the compression top dead center, the on-off valve 3 is closed, and then the main chamber fuel injection nozzle 5 injects fuel into the main combustion chamber 1 to ignite and burn to expand and shift to the expansion stroke, and the piston 9 is expanded by the expansion gas. Work and reach bottom dead center.

Then, the exhaust valve 8 is opened to shift to the exhaust stroke, the piston 9 is displaced from the bottom dead center to the top dead center, and the combustion gas in the cylinder including the main combustion chamber 1 passes through the exhaust port 12 to the cylinder. Exhausted from inside to outside. Piston 9
The exhaust valve 8 is closed and the exhaust stroke ends at the time when reaches the vicinity of the top dead center. Therefore, at the same time as the on-off valve 3 opens,
Fuel is injected from the sub-chamber fuel injection nozzle 6 into the sub-combustion chamber 2, the fuel is ignited and burned to expand and move to an expansion stroke, and the piston 9 works by the expansion gas to reach the bottom dead center. Next, the exhaust valve 8 is opened to shift to the exhaust stroke, the piston 9 is displaced from the bottom dead center to the top dead center, and the combustion gas in the main combustion chamber 1 and the auxiliary combustion chamber 2 is exhausted into the cylinder through the exhaust port 12. Exhausted from the outside. The piston 9 reaches the top dead center, the exhaust valve 8 closes, and the exhaust stroke ends. This 6-cycle diesel engine completes one cycle as described above, and is driven by repeating these cycles.

Next, another embodiment of the 6-cycle diesel engine having the auxiliary combustion chamber according to the present invention will be described with reference to FIGS. 5 is a plan view showing another embodiment of a 6-cycle diesel engine having a secondary combustion chamber according to the present invention, FIG. 6 is a sectional view taken along line C-C in FIG. 5, and FIG. 7 is taken along line D-D in FIG. FIG. 8 is a cross-sectional view and FIG. 8 is a diagram showing the operation timing of the 6-cycle diesel engine having the auxiliary combustion chamber of FIG. Compared to the above-described embodiment, the 6-cycle diesel engine of this embodiment is provided with two auxiliary combustion chambers in the cylinder head, each auxiliary combustion chamber is provided with a fuel injection nozzle, and the main combustion chamber has an unlimited volume. The difference is that it is designed to be small and there is no fuel injection nozzle in the main combustion chamber, but the operation itself is performed in substantially the same way, and the fuel is Is injected to ignite and burn, and then fuel is injected into the other sub-combustion chamber to ignite and burn, and two expansion strokes are performed in one compression stroke.

The 6-cycle diesel engine of this embodiment has a main combustion chamber 1 formed on the cylinder 20 side, a first auxiliary combustion chamber 2A and a second auxiliary combustion chamber 2B formed on the cylinder head 10, and a main combustion chamber 1 A first opening / closing valve 3A that opens and closes a communication hole 4A that communicates with the first auxiliary combustion chamber 2A, the main combustion chamber 1 and the second
A second opening / closing valve 3B that opens and closes a communication hole 4B that communicates with the auxiliary combustion chamber 2B, a first fuel injection nozzle 6A provided in the first auxiliary combustion chamber 2A, and a second fuel provided in the second auxiliary combustion chamber 2B. It has an injection nozzle 6B. In this 6-cycle diesel engine, the second on-off valve 3B is opened and the first on-off valve 3A is closed to close the second fuel injection nozzle 6 near the compression top dead center.
Fuel is injected into the second auxiliary combustion chamber 2B from B, ignited and combusted to expand, and the piston 9 is pushed down to perform work. Next, the second on-off valve 3B is closed and the first on-off valve 3A is opened near the next piston top dead center to open the first fuel injection nozzle 6
Fuel is injected from A into the first auxiliary combustion chamber 2A, ignited and burned to expand, and the piston 9 is pushed down to perform work. An example of specific operation of this 6-cycle diesel engine will be described below.

Regarding the operation of this 6-cycle diesel engine, the first opening / closing valve 3A for the displacement of the piston 9
FIG. 8 shows the opening / closing timings of the second opening / closing valve 3B, the intake valve 7 and the exhaust valve 8, and the injection timings of the first fuel injection nozzle 6A and the second fuel injection nozzle 6B. First,
When the intake valve 7 is opened and the piston 9 is displaced from the top dead center to the bottom dead center in the intake stroke, intake air is taken into the cylinder through the intake port 11. At this time, the first opening / closing valve 3A and the second opening / closing valve 3B are open, and the exhaust valve 8 is closed. Intake valve 7 near the time when piston 9 reaches bottom dead center
Will be closed. Next, in the compression stroke, the piston 9 is displaced from the bottom dead center to the top dead center, and the main combustion chamber 1, the first
The intake air in the on-off valve 3A and the second on-off valve 3B is compressed. At the compression top dead center, the first opening / closing valve 3A is closed, but the second opening / closing valve 3B is kept open. Therefore, the fuel is supplied from the second fuel injection nozzle 6B to the second auxiliary combustion chamber 2
The fuel is injected into B, the fuel is ignited and burned and expanded, and the piston 9 works by the expanded gas to reach the bottom dead center.

Next, the exhaust valve 8 is opened to shift to the exhaust stroke, the piston 9 is displaced from the bottom dead center to the top dead center, and the combustion gas in the second auxiliary combustion chamber 2B and the main combustion chamber 1 is exhausted. It is exhausted to the outside through the port 12. When the piston 9 reaches the vicinity of the top dead center, the exhaust valve 8 is closed and the exhaust stroke ends. Therefore, the second on-off valve 3B is closed, but at the same time as the first on-off valve 3A is opened, the fuel is injected from the first fuel injection nozzle 6A into the first auxiliary combustion chamber 2A, and the fuel is ignited and burned to expand. The piston 9 works with the expanded gas to reach the bottom dead center. Then, the exhaust valve 8 is opened to shift to the exhaust stroke, the piston 9 is displaced from the bottom dead center to the top dead center, and the inside of the cylinder including the main combustion chamber 1 and the first
The combustion gas in the auxiliary combustion chamber 2A is exhausted from the inside of the cylinder to the outside through the exhaust port 12. The piston 9 reaches the top dead center, the exhaust valve 8 closes, and the exhaust stroke ends. This 6-cycle diesel engine completes one cycle as described above, and is driven by repeating these cycles.

[0023]

The 6-cycle diesel engine having the auxiliary combustion chamber according to the present invention is constructed as described above and has the following effects. This 6-cycle diesel engine injects fuel from the main chamber fuel injection nozzle to the main combustion chamber near the compression top dead center in the closed state of the on-off valve that opens and closes the communication hole that connects the main combustion chamber and the auxiliary combustion chamber, The fuel ignites and burns and expands, then in the vicinity of the piston top dead center in the exhaust stroke, the fuel is injected from the sub-chamber fuel injection nozzle in the open state of the opening / closing valve into the sub-combustion chamber, and the fuel ignites and burns and expands. . Alternatively, this 6-cycle diesel engine is provided with a first sub-combustion chamber and a second sub-combustion chamber in a cylinder head, and the second opening / closing valve of the second sub-combustion chamber is opened near the compression top dead center to open the first sub-combustion chamber. The first on-off valve of the first sub-combustion chamber is closed, fuel is injected from the second fuel injection nozzle provided with the second sub-combustion chamber, ignited and burned to expand, and then near the piston top dead center in the exhaust stroke. The second on-off valve is closed and the first
The on-off valve is opened to inject fuel from the first fuel injection nozzle of the first auxiliary combustion chamber to ignite and burn to expand. Therefore,
This 6-cycle diesel engine uses compressed air existing in the main combustion chamber or the auxiliary combustion chamber, or the first air
The compressed air existing in the auxiliary combustion chamber or the second auxiliary combustion chamber and the main combustion chamber may be injected with fuel independently from each of the fuel injection nozzles over time to ignite, burn, and expand. Therefore, the expansion stroke can be performed twice in one compression stroke, the expansion ratio can be increased with respect to the compression ratio, and the theoretical thermal efficiency can be significantly improved.

In this 6-cycle diesel engine,
Since the expansion ratio is at most twice the compression ratio, a predetermined expansion ratio can be secured even if the compression ratio is set low, and the intake pressure can be increased. It is possible to obtain an output (output / engine volume) for a volume equal to or higher than the operation of four cycles. That is,
The 6-cycle operation reduces the number of suctions per rotation as compared with the 4-cycle operation, but can increase the intake pressure. Further, this 6-cycle diesel engine can obtain the same thermal efficiency as that of the direct injection type regardless of the premixed combustion. Especially, since it is the premixed combustion, soot generation is small, and NO _x and HC are generated. Can be suppressed.

[Brief description of drawings]

FIG. 1 is a plan view of a lower surface of a cylinder head showing an embodiment of a 6-cycle diesel engine having a secondary combustion chamber according to the present invention.

FIG. 2 is a cross-sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB in FIG. 1;

FIG. 4 is a diagram showing an operation timing of a 6-cycle diesel engine having the auxiliary combustion chamber of FIG.

FIG. 5 is a plan view of the lower surface of the cylinder head showing another embodiment of the 6-cycle diesel engine having the auxiliary combustion chamber according to the present invention.

6 is a cross-sectional view taken along the line CC of FIG.

7 is a cross-sectional view taken along the line DD of FIG.

8 is a diagram showing an operation timing of a 6-cycle diesel engine having the auxiliary combustion chamber of FIG.

[Explanation of symbols]

 1 Main Combustion Chamber 2 Sub Combustion Chamber 2A First Sub Combustion Chamber 2B Second Sub Combustion Chamber 3 Open / close valve 3A First Open / close valve 3B Second Open / close valve 4 Communication hole 4A First communication hole 4B Second communication hole 5 Main chamber fuel Injection nozzle 6 Sub-chamber fuel injection nozzle 6A First fuel injection nozzle 6B Second fuel injection nozzle 7 Intake valve 8 Exhaust valve 9 Piston 10 Cylinder head 20 Cylinder

Claims (2)

[Claims] 1. A main combustion chamber formed on the cylinder side, a sub combustion chamber formed in a cylinder head, an opening / closing valve for opening and closing a communication hole that connects the main combustion chamber and the sub combustion chamber, and the main combustion chamber. It has a main chamber fuel injection nozzle provided and a sub chamber fuel injection nozzle provided in the auxiliary combustion chamber, the intake valve is opened during the intake stroke, and intake air sucked into the cylinder is opened by the opening / closing valve. In this state, the on-off valve is closed near the compression top dead center, fuel is injected into the main combustion chamber by the main chamber fuel injection nozzle, ignited and burned to expand, and the exhaust valve is opened near the end of the expansion stroke. Combustion gas in the main combustion chamber is exhausted by opening it, the on-off valve is opened near the piston top dead center in the exhaust stroke, and fuel is injected into the auxiliary combustion chamber by the auxiliary chamber fuel injection nozzle for ignition combustion. To inflate, then in front of piston bottom dead center A six-cycle diesel engine having a sub-combustion chamber, which is driven by repeating a cycle of opening the exhaust valve and exhausting combustion gas in the cylinder and the sub-combustion chamber. 2. A main combustion chamber formed on the cylinder side, a first auxiliary combustion chamber and a second auxiliary combustion chamber formed on the cylinder head,
A first on-off valve that opens and closes a communication hole that communicates the main combustion chamber and the first auxiliary combustion chamber, a second on-off valve that opens and closes a communication hole that communicates the main combustion chamber and the second auxiliary combustion chamber, and A first fuel injection nozzle provided in the first sub-combustion chamber and a second fuel injection nozzle provided in the second sub-combustion chamber, and the intake valve is opened in the intake stroke and sucked into the cylinder. The air is compressed in the open state of the first open / close valve and the second open / close valve, and the first open / close valve is closed in the open state of the second open / close valve near the compression top dead center to close the second fuel injection nozzle. Fuel is injected into the second auxiliary combustion chamber to ignite, burn, and expand, and the exhaust valve is opened at the piston bottom dead center to exhaust combustion gas in the second auxiliary combustion chamber and the main combustion chamber. The second on-off valve is closed and the first on-off valve is opened near the top dead center of the piston of By injecting fuel is expanded by ignition and combustion in the first sub-combustion chamber from the first fuel injection nozzle,
Next, the exhaust valve is opened at the bottom dead center of the piston to open the first valve.
A 6-cycle diesel engine having a sub-combustion chamber and a sub-combustion chamber, which is driven by repeating a cycle of exhausting combustion gas in the main combustion chamber.