JP2002266644A - Engine and auxiliary combustion chamber mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the technique capable of providing a high compression ratio and high efficiency by injecting the fuel to a main combustion chamber 1 with high pressure without using a complex and expensive fuel injection device, in an engine 100 provided with the main combustion chamber 1 and the auxiliary combustion chamber 10 communicated through a communication passage 23, and a fuel supply means 30 and an ignition means 32 mounted in the auxiliary combustion chamber 10. SOLUTION: A main combustion chamber hole 21 on the main combustion chamber 1 side of the communicating passage 23 is made on position projected from a cylinder head 9 to the main combustion chamber 1, the shaft center direction of the main combustion chamber hole 21 is intersected to the shaft center direction of a cylinder 3, and an air supply means 31 is mounted for supplying the air A to the auxiliary combustion chamber 10 to which the fuel is supplied by the fuel supply means 30, to form a combustible zone X on the ignition means 32 side of the auxiliary chamber 10, and an over-concentration zone Y on the communicating passage 23 side of the auxiliary chamber 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a main chamber defined by a cylinder and a top surface of a piston, a sub-chamber provided in a cylinder head and communicating with the main chamber through a communication passage, and a fuel chamber in the sub-chamber. The present invention relates to an engine including a fuel supply means for supplying the fuel and an ignition means for igniting the fuel in the sub chamber, and a sub chamber mechanism constituted by the sub chamber.

[0002]

2. Description of the Related Art In general, engines can be broadly classified into spark ignition engines (hereinafter referred to as SI engines) and diesel engines.

[0003] In an SI engine, a mixture of air and fuel, which is an example of an oxygen-containing gas, is sucked into a combustion chamber and compressed, and then ignited by a spark plug as ignition means and burned. The ideal cycle of such an SI engine is considered to be an Otto cycle (constant volume heating cycle), and the thermal efficiency can be improved by increasing the compression ratio and performing lean combustion. Further, in the case of the SI engine, there is a stratified air supply system as a lean combustion system which is effective in reducing exhaust gas and improving fuel efficiency due to a decrease in flame temperature, an improvement in cycle efficiency, a decrease in pumping loss, etc., particularly at a partial load. With the stratified charge system, a mixture that has an equivalence ratio within the combustion range where ignition is easy is created around the ignition plug, and a lean region where a mixture that is thinner than the mixture around the ignition plug exists outside the mixture. Then, first, an air-fuel mixture whose equivalence ratio is within the combustion range is ignited and burned, and the air-fuel mixture in the lean region is burned by the flame, thereby burning the lean air-fuel mixture as a whole. As an example of the stratified charge type combustion chamber structure, there is provided a fuel injection valve that directly injects fuel into the combustion chamber, and forms a combustible air-fuel mixture particularly near an ignition plug to stably burn by jetting the fuel into the combustion chamber. is there.

Further, in a diesel engine, fuel is injected by a fuel injection device into a high-temperature and high-pressure combustion chamber having a piston position near a top dead center position and self-ignited.
Ideally, it is configured to operate on a diesel cycle (constant pressure cycle). In the diesel cycle, as in the case of the SI engine, there is no occurrence of pressure oscillation, which is called knocking, caused by self-ignition of the final combustion portion (end gas) in the flame propagation in the combustion chamber, and the compression ratio is relatively high. As a result, the thermal efficiency can be improved.

[0005]

However, in the case where the efficiency is to be improved by directly injecting fuel into the combustion chamber as in the case of an SI engine or a diesel engine employing the above-described stratified charge system, the compression stroke is not sufficient. It is necessary to provide a complicated fuel injection device or the like for injecting fuel into a relatively high pressure combustion chamber. In particular, when the fuel is a gaseous fuel such as natural gas, it is difficult to sufficiently pressurize the gaseous fuel and directly inject it into the high-pressure combustion chamber, which requires a complicated and expensive fuel injection device.

Accordingly, the present invention has been made in view of the above circumstances,
It aims to realize a highly efficient engine with a high compression ratio by injecting fuel into the combustion chamber at high pressure without the need for complicated and expensive fuel injection equipment. It is an object of the present invention to provide a high-efficiency engine applicable to an engine to be used.

[0007]

According to a first aspect of the present invention, an engine according to the present invention includes a main chamber defined by a cylinder and a piston top surface, and a main chamber provided in a cylinder head. An engine comprising: a sub-chamber communicating with the sub-chamber through a communication passage; fuel supply means for supplying fuel to the sub-chamber; and ignition means for igniting the fuel in the sub-chamber.
A main chamber hole that opens to the main chamber of the communication passage is provided at a position protruding from the cylinder head into the main chamber, and an axial direction of the main chamber hole is in a direction along a radial direction of the cylinder. In addition, an oxygen-containing gas is supplied to the sub-chamber to which the fuel has been supplied by the fuel supply means, and a combustible region in which an air-fuel mixture having an equivalence ratio within a combustion range exists is provided on the ignition side of the sub-chamber. And an oxygen-containing gas supply means for forming an enriched region in which an air-fuel mixture having an equivalence ratio equal to or higher than the upper limit of combustion exists on the side of the sub-chamber opening of the sub-chamber in the communication passage of the sub-chamber. It is characterized by having.

[Effects] That is, in an engine provided with a main chamber and a sub-chamber in which the combustion chambers are communicated with each other by a communication passage, by providing the fuel supply means as in this configuration,
By this fuel supply means, for example, when the pressure in the main chamber and the sub-chamber is still in a low pressure state, in other words, in the case of a 4-cycle engine, at the beginning of the intake stroke or the compression stroke,
In the case of a two-cycle engine, a so-called fuel supply step of supplying fuel to the sub-chamber and forming an air-fuel mixture in the sub-chamber can be executed at the beginning of the scavenging stroke or the compression stroke. Further, a part of the fuel supplied to the sub chamber in this way flows out to the main chamber through the communication passage. However, as in this configuration, the main chamber hole that opens to the main chamber side of the communication passage is provided. Is provided at a position protruding into the main chamber, and furthermore, when the axial direction of the main chamber hole is in a direction along the radial direction of the cylinder, preferably in the radial direction of the cylinder, the fuel flows into the main chamber in the fuel supply step. The flow of the fuel that has flowed toward the top surface of the piston can be suppressed, and the fuel can be retained above the main chamber on the cylinder head side. Then, in the next compression stroke, when the piston rises and the main chamber is compressed, a so-called fresh air flow, in which gas in the main chamber flows into the sub-chamber through the communication passage, is generated. Due to the new airflow, the fuel staying above the main chamber flows into the sub-chamber satisfactorily. The equivalent ratio of the air-fuel mixture formed in the sub-chamber in this manner is equal to or higher than the upper limit of combustion, that is, the fuel, at least until air (an example of an oxygen-containing gas) is supplied to the sub-chamber by the oxygen-containing gas supply means described later. It is kept in a dense state.

Further, by providing the oxygen-containing gas supply means, the oxygen-containing gas supply means supplies fuel to the sub-chamber and forms an air-fuel mixture in the sub-chamber having an equivalent ratio equal to or higher than the upper limit of combustion. For example, in the early stage of the compression stroke, a so-called oxygen-containing gas supply step of supplying air to the sub chamber and forming the combustible region and the rich region in the sub chamber can be performed.

After the fuel supply step and the oxygen-containing gas supply step are sequentially performed, the engine of the present invention activates the ignition means provided in the sub-chamber in the latter stage of the compression stroke to operate the sub-chamber. The mixture in the combustible region is ignited and burned. Then, the pressure wave generated by the combustion in the combustible region of the sub-chamber is propagated to the rich region formed on the communication passage side, and the mixture having an equivalent ratio equal to or higher than the upper combustion limit of the rich region is ignited. Instead, the high pressure is injected into the main chamber through the communication passage.

Therefore, the engine of the present invention having the unique sub-chamber mechanism as described above uses a complicated and expensive fuel injection device, such as a conventional diesel engine, or a stratified charge system for directly injecting fuel into the combustion chamber. The fuel that has flowed out into the main chamber is returned to the sub-chamber well without the need for a fuel injection device, etc. Is formed, utilizing the pressure increase due to combustion in the combustible region of the sub chamber,
A unique operation method of injecting the fuel-rich mixture into the main chamber at a high pressure can be performed. The engine of the present invention is a diesel engine that injects air-fuel mixture into the main chamber at a high pressure and self-ignites even if the fuel is gaseous fuel, or an air-fuel mixture near the spark plug provided in the main chamber. And injects the mixture to ignite the mixture to burn the surrounding lean mixture, thereby enabling a stratified charge type SI engine to be constructed, thereby achieving higher efficiency.

[Structure 2] In the engine according to the present invention, as described in claim 2, in addition to the structure of the engine according to structure 1, a recess is formed in a top surface of the piston with respect to a portion where the main chamber hole projects. In the compression stroke, a flow toward the main chamber hole is formed in the main chamber.

[Operation and Effect] As in the present configuration, a recess is formed in the center of the top of the piston or the like, and when the piston is at the top dead center, the main chamber hole of the communication passage communicating the sub chamber and the main chamber. Is provided at a position protruding toward the concave side, and the shape of the piston top is formed so as to generate a squish flow or a tumble flow toward the main chamber hole during the compression stroke, so that the fuel supply In the process, the fuel flowing out to the main chamber can be satisfactorily pushed back to the sub-chamber side through the main chamber hole by the flow generated in the main chamber in the compression stroke.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the engine of the present invention will be described with reference to the drawings. An engine 100 according to the present invention shown in FIG. 1 includes a piston 2 and a cylinder 3 that houses the piston 2 and forms a main chamber 1 together with a top surface of the piston 2.
The piston 2 is reciprocated in the cylinder 3, and the intake valve 4 and the exhaust valve 5 are opened and closed to take in fresh air into the main chamber 1.
Various strokes of expansion and exhaust are performed, and reciprocating motion of the piston 2 is output as rotational motion of a crankshaft (not shown) by a connecting rod (not shown).
There is no difference from a normal four-stroke internal combustion engine.
Note that, in the engine 100 of the present embodiment, the cylinder 3
Has a bore diameter of 110 mm, the stroke length of the piston 2 is 106 mm, and the combustion when the position of the piston 2 is at the bottom dead center position with respect to the combustion chamber capacity when the position of the piston 2 is at the top dead center position. The compression ratio, which is the ratio of room volumes, is 17. Further, the engine 100 of the present embodiment is operated at a rotational speed of the crankshaft of 1200 rpm and operates at 15 kph.
An output of about W is obtained.

The engine 100 is provided with a city gas (13
A) is used as fuel G. In the intake stroke, the intake valve 4 is opened, and only the air or fresh air I, which is a lean mixture of air and a small amount of fuel, is sucked into the main chamber 1,
In the compression stroke, the sucked fresh air I is compressed to produce fuel G
Is to burn.

Further, the cylinder head 9 of the engine 100 is provided with a sub-chamber 10 which is provided as a combustion chamber of the engine 100 like the main chamber 1 and communicates with the main chamber 1 through a communication passage 23. The structure of the sub chamber mechanism 20 having the sub chamber 10 will be described below. The sub chamber mechanism 20
The capacity of the sub-chamber 10 is 1/1 of the total combustion chamber capacity obtained by adding the capacity of the main chamber 1 when the position of the piston 2 is at the top dead center position.
It is about 0.

The communication passage 23 for communicating the sub-chamber 10 with the main chamber 1 has four main chamber holes 21 opening on the main chamber 1 side and one sub-chamber hole 22 opening on the sub-chamber 10 side. The main chamber hole 21 has an axial center in a direction perpendicular to the operation direction of the piston 2,
The auxiliary chamber holes 22 are arranged at equal intervals in the circumferential direction around the operation direction, while the sub chamber hole 22 has an axial center in an upward direction toward the air supply valve 31. The diameter of the communication passage 23 is 3
mm.

The main chamber hole 21 of the communication passage 23 is provided at a position protruding from the cylinder head 9 toward the main chamber 1.
The direction of the axis of the main chamber hole 21 intersects the direction of the axis of the cylinder 3, in other words, the sliding direction of the piston 2.
Preferably, it is at right angles.

The main chamber hole 21 on the top surface of the piston 2
A concave portion 2a is formed in the central portion where is provided,
The concave portion 2a is a deep dish type including a protruding portion that protrudes slightly upward at the center and a concave portion having a curved surface surrounding the protruding portion. The recess 2a as described above is formed on the top surface of the piston 2.
When the piston 2 rises during the compression stroke, it flows from the outer periphery of the top surface of the piston 2 to the center of the recess 2a, and from the center of the recess 2a to the outside along the curved surface of the recess 2a. Squish flowing to the air will occur.

A fuel supply valve 30 (an example of a fuel supply means) is provided above the sub-chamber 10. The fuel supply valve 30 supplies the fuel G to the sub-chamber at a supply pressure of 0.3 MPa (Gauge). 10.

Further, an air supply valve 31 (an example of an air supply means) is provided at a central portion above the sub-chamber 10, and the air supply valve 3 will be described in detail later.
1 is configured to supply air A (an example of an oxygen-containing gas) to the sub-chamber 10 at a supply pressure of 0.7 MPa (Gauge).

Further, an ignition plug 32 (an example of an ignition means) is provided above the sub-chamber 10, and the ignition plug 32 is configured to ignite the fuel G in the sub-chamber 10. .

Next, as an operation method of the engine 100 of this embodiment, an operation state in one cycle will be described with reference to the drawings. FIG. 2 shows the engine 1 of the present embodiment.
6 is a flowchart showing an operation state in one cycle of 00.

First, the engine 100 performs an intake stroke in which the intake valve 4 is opened, the piston 2 descends through the top dead center, and fresh air I is sucked into the main chamber 1. Later, the intake valve 4 is closed and the piston 2 rises, compressing fresh air I in the main chamber 1;
A so-called compression stroke is started.

Further, when the sub-chamber 10 is in a low pressure state in the latter half of the intake stroke or the early stage of the compression stroke, a fuel supply step of supplying the fuel G to the sub-chamber 10 by the fuel supply valve 30 is performed as shown in FIG. Will be Part of the fuel G supplied to the sub-chamber 10 in this fuel supply step flows out of the main chamber hole 21 of the communication passage 23 to the main chamber 1. Is perpendicular to the axial direction of the main chamber 1, the fuel G flowing out into the main chamber 1 does not flow below the main chamber 1 but stays above the main chamber 1. Then, in the next compression stroke, the fuel G staying above the main chamber 1 is squished by the flow of the piston 2 having the concave portion 2a as described above, so that the fuel G stays in a favorable state near the main chamber hole 21. And flows into the sub-chamber 10 from the main chamber 1 through the communication passage 23 in the compression stroke (hereinafter, referred to as a fresh air flow).
Fuel G near the main chamber hole 21 is supplied to the sub-chamber 1 through the communication passage 23.
The mixture is pushed back to 0, and an air-fuel mixture is formed in the sub-chamber 10 in which the equivalent ratio is equal to or higher than the upper limit of combustion, that is, the fuel-rich mixture is maintained.

In the middle stage of the compression stroke, for example, when the crank angle is between 60 ° and 50 ° BTDC, as shown in FIG. An air supply step (oxygen-containing gas supply step) for supplying the sub chamber holes 22 from above to below the sub chamber holes 22 is performed. In the air supply step, the sub chamber 10
The air A immediately supplied to the sub-chamber 10 reaches the vicinity of the sub-chamber hole 22 of the sub-chamber 10.

However, in the compression stroke, the piston 2
As a result, the fresh air I of the main chamber 1 flows into the sub-chamber 10 through the communication passage 23, and a new air flow that flows upward from the sub-chamber hole 22 is generated in the sub-chamber 10. As shown in FIG. 5, in the air supply process,
The air A that has been supplied to the sub-chamber 10 and has reached the vicinity of the sub-chamber hole 22 is caused to flow above the sub-chamber 10 by the new airflow, that is, the so-called spark plug 32.
Will be pushed back to the side. That is, the air supply valve 31
Are generated in the sub-chamber 10 during the compression stroke.
The air A flows into the region of the fresh air flowing from
Means for supplying

Therefore, the air A is stored in the sub-chamber 10 in the fuel rich state.
By performing the above air supply step of supplying the equivalent ratio, as shown in FIG.
A combustible region X in which an air-fuel mixture of about 1.2) is formed on the side of the ignition plug 32 of the sub-chamber 10, and an air-fuel mixture having an equivalent ratio equal to or higher than the upper limit of combustion (for example, 1.2 or more) exists. The over-concentrated area Y is formed on the sub-chamber 10 side of the sub-chamber 10.

The engine 100 of the present embodiment
As shown in FIG. 6, in the vicinity of 20 ° BTDC, the ignition plug 32 is operated to cause the air-fuel mixture in the combustible region X to be ignited by spark ignition and burned. Then, the pressure wave generated by the combustion in the combustible region X of the sub-chamber 10 is propagated to the rich region Y formed on the sub-chamber hole 22 side, and the mixing ratio is equal to or higher than the upper combustion limit of the rich region Y. High-pressure air is injected from the main chamber hole 21 into the high-pressure and high-temperature main chamber 1 in the latter half of the compression stroke through the communication passage 23 without ignition.

In the engine 100, in the combustion / expansion stroke, the fuel-rich mixture injected into the main chamber 1 as described above is compressed into a main chamber having a compression ratio in the range of 16 to 18. Immediately after the fuel is injected into the main chamber 1, it self-ignites and burns using the oxygen of the fresh air I in the main chamber 1. Such a main room 1
Is in a state close to a so-called diesel cycle (constant pressure cycle), the compression ratio of the engine can be set high, and the thermal efficiency can be improved to, for example, about 40%. Further, in one cycle, the equivalent ratio φ of the air-fuel mixture burned in the entire combustion chamber of the main chamber 1 and the sub chamber 1 is, for example, 0.3.
Since lean combustion can be realized at about 5 to 0.5, preferably about 0.4, emission of NOx and the like can be reduced.

In the above embodiment, the main room 1
Does not have a spark plug, and a fuel-rich mixture formed in the sub-chamber 10 is ejected from the main chamber hole 21 to the main chamber 1 under high pressure, and reacts with the fresh air I in the main chamber 1 to burn. Although a configuration similar to a so-called diesel engine has been described, it is also possible to provide a spark plug in the main chamber 1 and separately ignite the air-fuel mixture jetted from the communication passage 23.

[Other Embodiments] <1> Next, another embodiment of the engine according to the present invention will be described with reference to the drawings. In the engine 200 shown in FIG. 7, the flow path diameter of the communication passage is 1.5 mm, the main chamber hole 21 has an axis in a direction perpendicular to the operation direction of the piston 2, and the operation direction is the axis. A sub-chamber mechanism 20 having the same configuration as that of the above-described embodiment is provided except for the eight main chamber holes 21 arranged at equal intervals in the circumferential direction, and detailed description of the sub-chamber mechanism 20 is omitted. .

The main chamber 1 side of the cylinder head 9 of the engine 200 is formed in a roof shape.
It has a roof shape corresponding to the shape of the cylinder head 9 on the main chamber side. Further, a recess 2a similar to that of the above embodiment is formed on the top surface of the piston 2, and the main chamber hole 21 of the communication passage 23 between the sub-chamber 10 and the main chamber 1 projects toward the recess 2a. It is provided in the position where it did. Due to the top surface of the piston 2 and the shape of the main chamber 1 configured as described above, when the piston 2 rises in the compression stroke, it flows from the outer peripheral portion of the top surface of the piston 2 to the upper main chamber hole 21 side, and furthermore, The main chamber hole 21 extends from the center of the recess 2a along the curved surface of the recess 2a.
A squish flowing to the side will occur.

The engine 200 is operated by the same operation method as that of the above embodiment. However, in the fuel supply step, the engine 200 flows out of the sub chamber 10 into the main chamber 1 through the communication passage 23, and Fuel G staying in the vicinity of the main chamber hole 21 of No. 1
Is collected in the vicinity of the main chamber hole 21 in a favorable state by the squish generated in the next compression stroke, and further, the fresh air I flowing from the main chamber 1 to the sub-chamber 10 through the communication passage 23 in the compression stroke. By the flow, the fuel G near the main chamber hole 21 is pushed back to the sub-chamber 10 via the communication passage 23, and the sub-chamber 10 is satisfactorily supplied with a fuel-fuel mixture in which the equivalent ratio is higher than the upper combustion limit. Can be formed.
The engine 200 configured as described above can improve the thermal efficiency to, for example, about 41%.

<2> In the engine of the present invention, the fuel G that has flowed out of the communication passage 23 into the main chamber 1 is not diffused widely in the main chamber 1, but as much as possible in the main chamber hole 21 protruding toward the recess 2 a side. In order to stay at a close position, it is preferable to set the volume of the concave portion 2a formed at the top of the piston 2 as small as possible. Further, the concave portion 2a is a deep dish type, and the concave portion 2a
It is preferable to make the other surfaces as large as possible so that the squish can be satisfactorily generated in the compression stroke. It can be pushed back into the chamber 10. Further, the fuel G flowing out to the main chamber 1 may be configured to flow to the main chamber 1 side by utilizing the flow of fresh air generated in the main chamber 1 other than the squish.

<3> In the above embodiment, the supply amount of the air A supplied from the air supply valve 31 to the sub-chamber 10 is fixed. The supply amount can be adjusted so that the equivalent ratio of the air-fuel mixture formed in the sub-chamber 10 can be adjusted or the range of the combustible region X formed in the sub-chamber 10 can be adjusted. For example,
When the engine is to be operated at a low load, as described in the above embodiment, the rich region Y is formed in the sub chamber 10 and
The mixture in the rich region Y is operated in a manner similar to a so-called diesel engine in which high-pressure injection into the main chamber 1 is performed through the communication passage 23 by using a pressure increase caused by combustion in the combustible region X. When a high-load operation is performed, a relatively high-concentration air-fuel mixture is sucked into the main chamber 1 as fresh air, and the supply amount of the air A supplied to the sub-chamber 10 is increased. To form the subchamber 10
The fuel-air mixture is ignited and burned, and a flame torch is injected into the main chamber 1 through the communication passage 23 to ignite the air-fuel mixture sucked into the main chamber 1. When such a high-load operation is performed, it is preferable that the compression ratio during the high-load operation be lower than that during the low-load operation in order to prevent knocking or the like during the high-load operation. Increases the difference between the closing timing of the intake valve 4 and the bottom dead center position at the end of the intake stroke, in other words,
The compression ratio can be reduced by increasing the degree of late closing or early closing of the intake valve 4 with respect to the bottom dead center position. Also, at the time of starting the engine, the same operation as the high-load operation can be performed, and the engine can be warmed up satisfactorily.

<4> In the above embodiment, an engine using city gas has been described. However, the engine of the present invention exhibits excellent effects by configuring an engine using city gas or the like of gaseous fuel. Such gaseous fuels include C such as hydrogen and propane.
The O or H ₂ is gaseous fuels other than hydrocarbons mainly. Further, it is needless to say that a fuel other than the gaseous fuel can be used. For example, gasoline, alcohol, methanol, ethanol, or any fuel can be used.

<3> In the above embodiment, when changing the rotation speed or load of the engine of the present invention, a rotary valve or the like is provided in the flow path of fresh air I sucked into the cylinder, and The load or the rotation speed can be changed by changing the intake pressure according to the opening degree, changing the equivalence ratio of fresh air, the amount of fuel supplied to the sub chamber, and the like.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an engine according to the present invention.

FIG. 2 is a chart showing operation timings of the engine shown in FIG. 1;

FIG. 3 is a schematic configuration diagram showing an operating state of the engine shown in FIG. 1;

FIG. 4 is a schematic configuration diagram showing an operating state of the engine shown in FIG. 1;

FIG. 5 is a schematic configuration diagram showing an operating state of the engine shown in FIG. 1;

FIG. 6 is a schematic configuration diagram showing an operating state of the engine shown in FIG. 1;

FIG. 7 is a schematic view showing another embodiment of the engine according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 main chamber 2 piston 3 cylinder 10 sub-chamber 20 sub-chamber mechanism 21 main chamber hole 23 communication passage 30 fuel supply valve (fuel supply means) 31 air supply valve (oxygen-containing gas supply means) 32 spark plug X combustible area Y excess Rich area A Air (oxygen-containing gas) G Fuel I Fresh air

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F02F 3/26 F02F 3/26 C F02M 23/04 301 F02M 23/04 301A (72) Inventor Seiichi Ito Osaka-shi, Osaka Osaka Gas Co., Ltd. 4-1-2, Hirano-cho, Chuo-ku (72) Inventor Koji Moriya 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Prefecture F-term (reference) 3G023 AA01 AB02 AB03 AB06 AC05 AD08 AD12 AD14 AD27 AD28 AD30 AG01 3G092 AA01 AA07 AA09 AA11 AA16 AB07 AB08 AB09 DA01 DA08 DC07 EA03 EA04 FA16 FA31 FA50 GA01 GA06

Claims (3)

[Claims] 1. A main chamber defined by a cylinder and a piston top surface, a sub-chamber provided in a cylinder head and communicating with the main chamber via a communication passage, and fuel supply means for supplying fuel to the sub-chamber. And an ignition means for igniting the fuel in the sub-chamber, wherein a main chamber hole of the communication passage opening to the main chamber is provided at a position protruding from the cylinder head to the main chamber. The axial direction of the main chamber hole is a direction along the radial direction of the cylinder, and an oxygen-containing gas is supplied to the sub-chamber to which the fuel has been supplied by the fuel supply means, and a combustion range A combustible region in which an air-fuel mixture having an equivalence ratio is present is formed on the ignition means side of the sub-chamber, and an enriched region in which an air-fuel mixture having an equivalence ratio equal to or higher than the upper combustion limit exists in the sub-chamber. The passage is formed on the side of the sub-chamber hole that opens into the sub-chamber. Engine with an oxygen-containing gas supply means. 2. A recessed portion is formed in a top surface of the piston with respect to a portion where the main chamber hole protrudes, and a flow toward the main chamber hole is formed in the main chamber in a compression stroke. 2. The engine according to 1. 3. A sub-chamber provided in an engine having a main chamber defined by a cylinder and a piston top surface, the sub-chamber provided in a cylinder head and communicating with the main chamber via a communication passage, and a fuel in the sub-chamber. And a igniting means for igniting the fuel in the sub-chamber, wherein a main chamber opening in the main chamber of the communication passage extends from the cylinder head. The main chamber hole is provided at a position protruding from the main chamber, and the axial direction of the main chamber hole is a direction intersecting with the axial direction of the cylinder, and the sub chamber supplied with the fuel by the fuel supply unit. An oxygen-containing gas is supplied to form a combustible region on the ignition means side of the sub-chamber where an air-fuel mixture having an equivalence ratio within a combustion range is present, and an air-fuel mixture having an equivalence ratio equal to or higher than a combustion upper limit exists. The communication path of the sub-chamber with the rich area Sub-chamber mechanism provided with an oxygen-containing gas supply means formed on the sub-chamber hole side opening to the sub-chamber.