JP2003120298A - Double combustion engine and combustion method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the required combustion time in a combustion chamber by improving combustion modes not due to a propagation speed of flame or a required time for evaporating the fuel, and provide energy-saving, low pollution and high output engine by generating strong convection in a combustion chamber. SOLUTION: An annular protrusion 3 is formed on the top face of a piston 2, and an annular protrusion 4 is also formed on the face of a cylinder head 1 opposed to the protrusion 3, so as to form a small combustion chamber 6 overlaid only near the upper dead center of the piston 2. By the combustion in the small combustion chamber 6, a flame flow is emitted to generate strong convection in a main combustion chamber 5, so as to perform combustion. By improving combustion modes, a required combustion time is shortened and combustion efficiency is improved. Such an engine of large diameter more than 100 mm, which is a limit of a bore of a gasoline engine can be realized. By generation of strong convection, unburnt gas is reduced, and time lag for evaporating fuel is solved, so as to reduce exhaust of particulate matter such as black smoke, HC and other hazardous substances.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention improves energy saving, low pollution by improving the combustion mode of a reciprocating engine,
Related to providing a high power engine.

[0002]

2. Description of the Related Art At present, as a method for improving the combustion mode, a pentroof type combustion chamber engine for the purpose of shortening the combustion time and a stratified charge type having a sub combustion chamber such as Honda's CVCC engine are used. There are secondary combustion chamber systems for engines and diesel engines. In addition, as an attempt to generate an air flow in the combustion chamber for combustion, a measure is taken to generate an air flow in the main combustion chamber by utilizing the intake negative pressure or compression pressure by the piston to ensure good combustion. However, in the case of the above engine configuration, in a gasoline engine, the combustion speed in the combustion chamber is different from the distance from the ignition position to the farthest position on the outer peripheral portion, although the flame propagation speed varies depending on the fuel mixture ratio. It is determined by the flame propagation speed, and as the engine speed increases, the piston descending speed also increases proportionately, so the farthest position further increases, and the combustion time also increases proportionately. result,
The volume of the combustion chamber increases and the pressure generated by it also decreases proportionally. The combustion efficiency deteriorates that much, and when the piston rotates at a higher speed and the descending speed of the piston exceeds the flame propagation speed, unburned gas is generated, and harmful effects such as an increase in HC and other harmful emissions and a decrease in output occur. Occurs.

Since the flame propagation speed inevitably limits and determines the piston bore,
In the current gasoline engine, when using normal fuel, it is said that the bore 110 mm is the limit of use. Therefore, the engine of heavy-duty gasoline trucks is not currently used.

Further, the above-mentioned CVCC engine enables combustion close to the air-fuel ratio of 22: 1 which is the lean limit. However, when the engine is rotated at high speed, the piston is lowered to cause combustion in the combustion chamber. The volume increases, and the air-fuel ratio itself does not change, but the density changes greatly in the coarse direction. The flame propagation speed decreases in proportion to the change in the volume, and when the high speed rotation is performed in the lean region, the flame does not propagate at last.

In a diesel engine, since there is an ignition delay time lag between fuel injection and vaporization and combustion, abrupt explosion combustion occurs in proportion to the required time, and the pressure in the combustion chamber rises extremely. There is a problem of diesel knock that it does. Although improvements have been made by the secondary combustion method and squish flow, various problems caused by ignition delay are also fatal drawbacks of diesel engines. It is also the reason why diesel engines cannot be designed for high speed rotation. This is because the engine has to be designed by knocking and adjusting the fuel injection amount, so that the engine must run at low speed.

[0006] Further, since the particulate matter such as black smoke is discharged while the HC of the fuel is heated without reacting with oxygen, it is emitted as black smoke. In the current engine, air in the combustion chamber is exhausted. Flow is low and the reaction between oxygen and HC is insufficient, which is the cause of generation, but the solution has not been solved yet.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an annular projection provided in the central portion of the upper surface of the piston in the main combustion chamber of a reciprocating engine and an annular projection provided opposite thereto. The annular projection provided on the cylinder head surface is polymerized only near the top dead center of the piston to form a small combustion chamber having a space inside at the center of the main combustion chamber, and the small combustion chamber can be The small combustion chamber is burned by closing it for a certain period of time, and the generated pressure is maintained to eject a flame flow and a jet heat flow into the main combustion chamber to generate strong convection in the main combustion chamber. In order to provide an energy-saving, low-pollution, high-power engine by improving the combustion form by the measures described above without depending on the time required for combustion in the combustion chamber depending on the flame propagation speed and the time required for vaporization of fuel. It is the target.

[0008]

The means of the present invention for achieving the above-mentioned object is to provide a cylinder head provided with an annular projection at the center of the upper surface of the piston in the main combustion chamber of a reciprocating gasoline engine and facing it. The annular projection containing the spark plug provided on the surface is polymerized only near the top dead center of the piston to form a small combustion chamber with a space inside at the center of the main combustion chamber. The combustion chamber is closed for an arbitrary time, only the small combustion chamber is burned to maintain the generated pressure, and a jet of jet flame and jet of heat are ejected from the small combustion chamber opened by the lowering of the piston into the main combustion chamber. The structure and method are for burning while generating strong convection in the main combustion chamber.

Further, an annular projection is provided at the center of the upper surface of the piston in the main combustion chamber of the reciprocating diesel engine, and the annular projection containing the fuel injection nozzle and the glow lamp provided on the cylinder head surface opposed to the piston is provided with the annular projection. The fuel is injected only into the small combustion chamber so that it is polymerized only near the top dead center, and the fuel is burned to maintain the generated pressure.The fuel is injected from the small combustion chamber opened by the lowering of the piston into the main combustion chamber. There is a structure and a method in which, while ejecting a flame flow or a jet heat flow, the jet flow is assisted, fuel is further injected, and the fuel is instantaneously vaporized and burned by the high temperature heat flow.

Further, an annular projection is provided at the center of the upper surface of the piston in the main combustion chamber of the reciprocating gasoline engine, and the lower end of the outer cylinder of the removable spark plug provided on the cylinder head surface opposite to this is located at the lower end of the main combustion chamber. A ring-shaped protrusion integrated with the spark plug that protrudes toward the main combustion chamber and is removable is designed to be polymerized only near the top dead center of the piston, A small combustion chamber having a space is formed in the center of the main combustion chamber, and the small combustion chamber is closed for an arbitrary time.
Burn only the small combustion chamber to maintain the generated pressure,
There is a structure and method for injecting a flame flow and a jet heat flow into a main combustion chamber from a small combustion chamber opened by lowering a piston to generate strong convection in the combustion chamber and perform combustion.

An annular projection is provided at the center of the upper surface of the piston in the main combustion chamber of the reciprocating diesel engine, and a detachable fuel injection nozzle and a glow lamp provided on the cylinder head surface opposed to the annular projection are integrated. By projecting the lower end of the outer cylinder part into the main combustion chamber, and as an annular projection integrating the fuel injection nozzle and the glow lamp, a detachable structure is polymerized only near the top dead center of the piston, A small combustion chamber having a space inside is formed in the main combustion chamber, and the small combustion chamber is closed for an arbitrary time to inject fuel into the small combustion chamber for combustion,
While maintaining the generated pressure and ejecting a flame flow and a jet heat flow into the main combustion chamber from the small combustion chamber opened by the lowering of the piston, assisting the jet flow, further injecting fuel and high heat flow. It is a structure and method for instantaneously vaporizing fuel and ejecting it into the main combustion chamber, and burning it while generating strong convection in the main combustion chamber.

[0012]

The dual-combustion engine of the present invention constructed as described above has the following actions. Combustion in a small combustion chamber formed only near the top dead center of the main combustion chamber of a reciprocating gasoline engine causes high-temperature and high-pressure combustion gas to form a flame flow and a jet heat flow from the small combustion chamber that opens as the piston descends. By ejecting into the main combustion chamber, strong convection is generated in the main combustion chamber and combustion is performed, and combustion in the main combustion chamber is made good. The pressure, temperature, and jet velocity generated by the combustion in the small combustion chamber vary depending on the mixing ratio of the fuel, the volume and structure of the small combustion chamber, but it is said to be 20 to 30 m / sec which is the flame propagation speed during combustion in the gasoline engine. It is ejected at a speed that is several times the speed and is proportional to the generated pressure, and the combustion time is shortened in proportion to the speed. Further, the combustion of unburned gas staying in the main combustion chamber is promoted by the generated convection. As a result, the combustion time is shortened, but the combustion form is mainly two-dimensional surface combustion due to flame propagation, and there is a three-dimensional area combustion due to self-ignition of fuel like the combustion form of a diesel engine. In contrast, the pressure rise in the combustion chamber does not show a vertical pressure rise, but shows a pressure gradient proportional to the fuel quantity.

Further, in the reciprocating diesel engine, combustion gas in a small combustion chamber formed near the top dead center of the main combustion chamber causes combustion gas of high temperature and high pressure to be ejected from the small combustion chamber which opens as the piston descends. It becomes a hot air flow and ejects into the main combustion chamber. The jet flow is assisted to further inject fuel, which is instantly vaporized by the high heat flow and jetted into the main combustion chamber, where it is burned while causing strong convection. The heat generated by the combustion in the small combustion chamber changes depending on the volume of the small combustion chamber, the amount of fuel, and the like, but the temperature thereof is one thousand and several hundred degrees, which is a sufficient amount of heat to vaporize the injected fuel. As a result, the ignition delay of the fuel does not occur, and the combustion is immediately performed according to the injection amount of the fuel.

Further, a measure for forming a small combustion chamber to maintain the blockage for an arbitrary time is carried out by the degree of polymerization of the annular projection provided on the upper surface of the piston and the annular projection provided on the cylinder head surface. is there. The closing and opening are performed by the vertical movement of the piston.

80 mm bore and 80 m stroke
m, rotation speed 3000 rpm / min, small combustion chamber diameter 1
In an engine with specifications of 0 mm and an initial flame propagation speed at ignition of 10 m / sec, the required combustion time in the small combustion chamber is 0.0005 / sec. Due to the formation of the small combustion chamber, the ignition is advanced by ½ of the combustion time required to complete the combustion while the blockage is maintained (in the case of diesel, about 0 is taken as the time required for fuel vaporization). 1 in 0005 seconds
The fuel is injected by advancing by / 2) In this case, the number of advancing angles is 5 °. Blocking time and angle is 0.0005 seconds,
It is 10 °. The opening angle of the formed small combustion chamber is about 6 ° from the top dead center, and the time required from the top dead center is 0.0003.
Second, the time required for the main combustion chamber with a bore of 80 mm to burn while generating convection by the jet flow is ~ 0.001 second,
The crank angle is -18 °, and the volume of the main combustion chamber at the time of completion of combustion is 130% of the volume of the combustion chamber at top dead center. In the case of conventional engines of the same specifications, combustion is completed at a crank angle of around 50 °, so the volume of the main combustion chamber has expanded to 220% compared to that at top dead center. Even with the same amount of fuel, in the case of the double combustion system, the generated pressure can be obtained about twice as much.

[0016]

Embodiments of the dual combustion engine according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a reciprocating gasoline engine, which is a main combustion chamber 5 of the reciprocating gasoline engine.
Of the piston 2 is provided with an annular projection 3 at the center of the upper surface thereof, and a spark plug 7 is provided on the cylinder head surface opposite to the annular projection 3.
A small combustion chamber 6 having a space inside is formed in the central portion of the main combustion chamber 5 so that the annular projection 4 containing the above is polymerized only near the top dead center of the piston 2.
The small combustion chamber 6 is combusted only for an arbitrary time to maintain the generated pressure, and a flame flow and a jet heat flow are ejected into the main combustion chamber 5 to cause strong convection in the main combustion chamber 5. It is configured to burn while generating.

FIG. 2 shows an embodiment of a reciprocating diesel engine. An annular projection 3 is provided in the central portion of the upper surface of the piston 2 of the main combustion chamber 5 of the reciprocating diesel engine, and a cylinder head surface opposite to this is provided. The annular projection 4 including the fuel injection nozzle 9 and the glow lamp 10 provided therein is polymerized only near the top dead center of the piston 2 so that the fuel is injected only into the small combustion chamber 6 and burned to generate it. While ejecting a jet flow and a jet heat flow from the small combustion chamber 6 opened by lowering the piston 2 while maintaining the pressure to the main combustion chamber 5, the jet flow is assisted to further inject the fuel and the high temperature heat flow. The fuel is burned while being instantly vaporized.

Further, FIG. 3 shows that the outer cylinder portion 12 of the detachable spark plug 7 of the reciprocating gasoline engine is protruded so that the lower end of the outer cylinder portion thereof is opened toward the main combustion chamber 5 and the spark plug 7 and the annular shape. The projection 4 is integrated to form an annular plug 14 which is a spark plug integrated type that can be attached. FIG. 5 shows a reciprocating gasoline engine equipped with a spark plug-integrated annular protrusion 14, which is opposed to the annular protrusion 3 at the upper part of the piston 2 and is polymerized only near the top dead center of the piston 2 to have a space inside. The small combustion chamber 6 is formed in the central portion of the main combustion chamber 5 and has the same configuration as that of the above-mentioned embodiment of the reciprocating gasoline engine.

FIG. 4 shows the injection nozzle 9 of the reciprocating diesel engine, and the detachable injection nozzle 9 and glow lamp 10 which are protruded so that the lower end of the outer cylinder is opened toward the main combustion chamber 5. 9 and the glow lamp 10 and the annular projection 4 are integrated, and the removal 6 is a reciprocating diesel engine equipped with an injection nozzle and an integrated annular projection 15 of the glow lamp. 2 has a structure similar to that of the embodiment of the reciprocating diesel engine in which a small combustion chamber 6 having a space inside is formed only in the vicinity of the top dead center and is formed in the center of the main combustion chamber 5. .

One of the annular projections 3 and 4 described above may be provided as a recess so that the annular projections 3 and 4 and the recess are polymerized only near the top dead center of the piston 2. Small combustion chamber 6 with a space inside
Is closed for an arbitrary time, only the small combustion chamber 6 is combusted to maintain its generated pressure, and the small combustion chamber 6 opened by the downward movement of the piston into the main combustion chamber 5 into the main combustion chamber 5. The flow is ejected to generate strong convection in the main combustion chamber 5 for combustion.

[0022]

As described above, in the dual combustion engine according to the present invention, an annular protrusion is provided on the center of the piston upper surface of the reciprocating engine, and the annular protrusion provided on the cylinder head surface opposite to this is provided on the piston. A small combustion chamber with a space inside is formed in the center of the main combustion chamber so that it is polymerized near the dead point, and the small combustion chamber is closed for an arbitrary time to burn only the small combustion chamber. The generated pressure is maintained, and a flame flow and a jet heat flow are ejected into the main combustion chamber to generate strong convection in the main combustion chamber for combustion, so the combustion mode is improved and the combustion in the combustion chamber is improved. The required time is not affected by the flame propagation speed, fuel vaporization, required time for ignition delay, etc., but the required time is shortened by the above-mentioned means, and combustion is performed while the combustion chamber volume is smaller. Complete To it can be. Further, it becomes possible to perform combustion in response to higher speed rotation. And, strong convection in the combustion chamber due to jet flow, jet heat flow, etc. reduces unburned gas, eliminates time lag by promoting vaporization of fuel, particulate matter such as black smoke, HC and other harmful emissions, etc. It is possible to improve the pollution problem. Furthermore, the fact that combustion is completed while the volume of the combustion chamber is small means that even if the air-fuel ratio is the same, the amount of fuel and oxygen per unit volume is large, and the density is dense, so the flame propagation speed is faster and easier. Become. Therefore, combustion with a thinner air-fuel ratio becomes possible.

Further, since the combustion speed does not depend on the propagation speed of the flame and combustion can be performed faster, the diameter of the piston of the reciprocating gasoline engine has hitherto been 110 mm in diameter when the normal fuel was used. It is said that this is because when the diameter increases, the high heat generated in the latter half of combustion causes the remaining fuel to self-ignite and knocking occurs, but it is possible to increase the combustion speed. This allows for larger diameter piston engines. Gasoline engines are not currently used in heavy-duty trucks, but heavy-duty trucks with gasoline engines are also possible. Furthermore, the insufficient vaporization of fuel, which is a problem of gasoline direct injection engines, will be solved. Then, the fuel is injected from the injector toward the small combustion chamber formed in the main combustion chamber, the small combustion chamber is rich, and the main combustion chamber has a low mixing ratio. It has special effects such as enabling combustion.

[Brief description of drawings]

FIG. 1 is a sectional view of a combustion chamber portion of a reciprocating gasoline engine.

FIG. 2 is a sectional view of a combustion chamber portion of a reciprocating diesel engine.

FIG. 3 is a cross-sectional view of a detachable annular protrusion having a built-in spark plug.

FIG. 4 is a cross-sectional view of an injection nozzle and a detachable annular protrusion having a built-in glow lamp.

FIG. 5 is a cross-sectional view of a reciprocating gasoline engine equipped with a detachable annular projection having a built-in spark plug.

FIG. 6 is a cross-sectional view of a reciprocating diesel engine equipped with an injection nozzle and a detachable annular projection having a built-in glow lamp.

[Explanation of symbols]

1 Cylinder Head 2 Piston 3 Annular Projection on Top of Piston 4 Annular Projection on Cylinder Head 5 Main Combustion Chamber 5 Main Combustion Chamber 6 Small Combustion Chamber 7 Spark Plug 8 Cylinder 9 Injection Nozzle 10 Glow Lamp 11 Spark Plug 12 Outer cylinder portion 13 Space portion 14 Removable annular protrusion with built-in spark plug 15 Removable annular protrusion with built-in injection nozzle and glow lamp

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02F 3/26 F02F 3/26 B C F02M 57/00 F02M 57/00 61/16 61/16 QZ F02P 13/00 301 F02P 13/00 301A 302 302Z 19/00 19/00 BF term (reference) 3G019 KA01 KA12 KA15 KA16 KA21 KA26 3G023 AA04 AA06 AB03 AB05 AC05 AD12 AD13 AD26 AG02 3G066 AA02 AA07 AB02 BA12 BA26 BA16 CD26 DA09

Claims (5)

[Claims] 1. A reciprocal gasoline engine main combustion chamber is provided with an annular projection at the center of the upper surface of the piston, and an annular projection containing a spark plug provided on the cylinder head surface opposed to the piston is provided at the top dead center of the piston. A small combustion chamber with a space inside is formed in the central part of the main combustion chamber by polymerizing only in the vicinity, and only the small combustion chamber is burned by closing the small combustion chamber for the designated time. , The generated pressure is maintained, and a flame flow and a jet heat flow are ejected from the small combustion chamber opened by the lowering of the piston into the main combustion chamber to generate strong convection in the main combustion chamber for combustion. Dual combustion engine and combustion method 2. An annular projection is provided at the center of the upper surface of the piston in the main combustion chamber of a reciprocating diesel engine, and an annular projection is provided on the cylinder head surface opposed to the piston, and the annular projection encloses a fuel injection nozzle and a glow lamp. By polymerizing only near the top dead center of the piston, a small combustion chamber having a space inside is formed in the center of the main combustion chamber, and the small combustion chamber is closed for an arbitrary time.
Fuel is injected and burned only in the small combustion chamber, the generated pressure is maintained, and the jet stream and the jet heat flow are jetted from the small combustion chamber opened by the lowering of the piston into the main combustion chamber,
It is characterized by further injecting fuel by assisting the jet flow, instantaneously vaporizing the fuel by the high temperature heat flow and ejecting it into the main combustion chamber for combustion while generating strong convection in the main combustion chamber. Heavy combustion engine and combustion method. 3. An annular projection is provided at the center of the upper surface of the piston in the main combustion chamber of the reciprocating gasoline engine, and the lower end of the outer cylinder of the removable spark plug is provided as the main combustion chamber on the surface of the cylinder head opposite to the annular projection. The open structure that projects toward the combustion chamber and is detachable as an annular projection integrated with the spark plug is polymerized only near the top dead center of the piston to create a space inside. A small combustion chamber is formed in the center of the main combustion chamber, the small combustion chamber is closed for an arbitrary time, only the small combustion chamber is burned, the generated pressure is maintained, and the piston is lowered to open it. Double combustion with a detachable annular projection characterized by injecting a flame flow and a jet flow of heat from the small combustion chamber into the main combustion chamber to generate strong convection in the main combustion chamber while performing combustion. D Engine. 4. An annular projection is provided in the center of the upper surface of the piston in the main combustion chamber of a reciprocating diesel engine, and a detachable fuel injection nozzle provided on the cylinder head surface opposite to this is integrated with a glow lamp. The lower end of the outer cylinder is projected into the main combustion chamber to form an annular projection that integrates the fuel injection nozzle and glow lamp, and the detachable structure is polymerized only near the top dead center of the piston. A small combustion chamber with a space inside is formed in the center of the main combustion chamber, and the small combustion chamber is closed for an arbitrary time to inject fuel into the small combustion chamber for combustion and maintain its generated pressure. While ejecting a flame flow and jet heat flow into the main combustion chamber from the small combustion chamber opened by lowering the piston, the jet flow is assisted, and further fuel is ejected to generate fuel by high heat flow. A dual-combustion engine with a detachable annular projection characterized by instantaneously vaporizing and ejecting it into the main combustion chamber to generate strong convection in the main combustion chamber for combustion. 5. A ring-shaped projection provided on the center of the upper surface of the piston or a ring-shaped projection provided on the opposite cylinder head surface is used as a recess so that polymerization is performed only near the top dead center of the piston. Then, a small combustion chamber with a space inside is formed in the center of the main combustion chamber, and the small combustion chamber is closed for an arbitrary time to burn only the small combustion chamber and maintain its generated pressure. A double combustion engine characterized by ejecting a flame flow and a jet heat flow into the main combustion chamber from the small combustion chamber opened by the lowering of the piston to generate strong convection in the main combustion chamber for combustion. .