JPH0614033Y2 - Combustion chamber of a sub-chamber internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to the shape of the main combustion chamber of an internal combustion engine of the auxiliary chamber type.

[Conventional technology]

 7 to 9 show a conventional combustion chamber shape.

In the figure, 1 is a main combustion chamber, 2 is a sub combustion chamber, 3 is a sub chamber injection port, 4 is a cylinder head, 5 is a fuel valve, 6 is a glow plug, 7 is a piston, 8 is a cylinder, 9 is a sub chamber base, 10 Is the top surface of the piston, and S is the vortex flow.

The sub-combustion chamber 2 is recessed in the cylinder head 4, and the sub-combustion chamber 2 is near the cylinder 8 located away from the cylinder center AA. As for the shape of this sub-combustion chamber 2, a glow plug 6 for preheating the inside of the sub-combustion chamber 2 at the upper portion and a lower portion for preheating the inside of the chamber 2 at the time of starting the engine are installed as required. The sub-combustion chamber 2 communicates with the main combustion chamber 1 including the piston top surface 10, the piston 7 cavity, the cylinder 8 wall surface, and the lower surface of the cylinder head 4 via the sub-chamber injection port 3 provided in the sub-chamber mouthpiece 9. There is.

Next, the operation of the conventional example will be described.

Air in the main combustion chamber 1 is compressed by the piston 7 in the compression stroke during engine operation, flows into the sub combustion chamber 2 through the sub chamber injection port 3, and generates a swirl S. The velocity of the vortex S increases as the piston 7 approaches the top dead center. When fuel is injected from the fuel valve 5 along the direction of the vortex S, the fuel swirls in the auxiliary combustion chamber 2 along with the vortex S and air Is mixed and formed, and the ignition starts from around the glow plug 6 and the combustion occurs.

Combustion gas and unburned gas in the sub-combustion chamber 2 pass through the sub-chamber injection port 3 due to the pressure difference between the main combustion chamber 1 and the sub-combustion chamber 2 (main combustion chamber <sub-combustion chamber) and the downward movement of the piston 7. Eject into the combustion chamber 1. The ejected gas acts on the piston 7 and at the same time mixes with the air in the main combustion 1 to further promote diffusion combustion.

[Problems to be solved by the invention]

However, the conventional sub-chamber engine has improved the performance by opening the sub-chamber nozzle to reduce the throttling loss. Connected, the mixture forming energy in the main chamber is attenuated,
Performance may be deteriorated due to slow combustion.

An object of the present invention is to provide a sub-chamber internal combustion engine which eliminates the drawbacks of the conventional device and does not restrict the nozzle opening of the sub-chamber, and further promotes combustion in the main chamber to improve and improve performance such as fuel consumption and smoke emission. It is located in the combustion chamber.

[Means for solving problems]

The combustion chamber of the sub-chamber internal combustion engine according to the present invention includes a main combustion chamber from the sub-combustion chamber 2 in a cavity near the main combustion chamber side opening end of the sub-chamber injection port 3 among the cavities of the main combustion chamber installed at the top of the piston. In the direction perpendicular to the gas ejected into the chamber 1, the upstream side region or one of the side wall portions of the cavity extends from the side wall in the direction perpendicular to the cylinder center line (A-A), and at the piston top portion 10. Pocket 11 that does not open
Is provided to achieve the above object.

[Action]

When the combustion gas in the sub-combustion chamber 2 is ejected into the main combustion chamber 1 at a high speed through the sub-chamber injection port 3, the jet gas is the air in the cavity side wall area of the piston upper surface or the air in the pocket portion 11 provided on the upstream side. It is accelerated more and more while getting involved. Therefore, the formation of the air-fuel mixture in the main combustion chamber 1 becomes active and combustion is promoted.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view of a combustion chamber according to the first embodiment of the present invention, and FIG.
The drawing is a piston top view, FIG. 3 is a sectional view taken along line III-III in FIG. 2, FIG. 4 is a piston top view of the second embodiment, and FIGS. 5 to 6 are VV and VI- in FIG. 4, respectively. FIG. 6 is a sectional view taken along line VI.

(a) First embodiment In the cavity in the vicinity of the main combustion chamber side opening end of the sub chamber injection port 3, other than the shape of the main combustion chamber 1 shown in the figure, from the sub combustion chamber 2 to the main combustion chamber 1 In the cavity side wall portion on the upstream side of the jet gas, a pocket portion 11 extending from the side wall in a direction perpendicular to the cylinder center line (AA) is provided, and the pocket portion 11 is open to the piston top surface. Absent. The shape of the pocket 11 may be circular, elliptical, or polygonal in area, but a circular shape is shown here. The depth of the pocket portion may be shallower, the same or deeper than the deepest portion of one cavity of the main combustion chamber, but the depth is shown here.

Next, the operation of the first embodiment will be described.

Until the fuel and air are mixed, ignited and burned in the sub-combustion chamber 2, it is the same as before, but when the combustion gas in the sub-combustion chamber 2 is ejected through the sub-chamber injection port 3 into the main combustion chamber 1 at high speed. The jet gas (burnt gas, unburned gas) is further accelerated while entraining the air in the pocket 11 provided in the cavity of the main combustion chamber 1 and the air-fuel mixture is actively formed to promote combustion.

(b) Second embodiment Fig. 4 to Fig. 6 Although the embodiment is illustrated, it is the same as the conventional example (Figs. 7 to 9) except for the shape of the main combustion chamber 1.

In the cavity in the vicinity of the main combustion chamber side opening end of the sub chamber injection port 3, from the side chamber to the side wall of the cavity on both sides of the cavity in the direction perpendicular to the jet gas in the main chamber 1, the cylinder center line (A-
A pocket portion 11 extending in a direction perpendicular to A) is provided,
The shape of the pocket portion 11 may be circular, elliptical, polygonal or the like, but a circular example is shown here. The pocket portion 11 does not open to the piston top surface 10.
The depth of the pocket portion 11 may be shallower, the same or deeper than the deepest portion of the main chamber 1 cavity, but the shallow portion is illustrated here. Furthermore, the first and second
A combination of the pocket portions 11 of the embodiment at the same time can be realized.

The operational effect is the same as that of the first embodiment.

[Effect of device]

As described above, in the combustion chamber of the sub-chamber internal combustion engine according to the present invention, the air in the pocket portion is entrained by the high-speed jet gas flowing from the sub-combustion chamber to the main combustion chamber. Due to the introduction of the air, the jet gas is further accelerated and the energy for forming the air-fuel mixture in the main chamber is increased. Therefore, the air in the main chamber and the jet gas are actively mixed, the air utilization rate is increased, and combustion is further promoted. That is, the combustion time is shortened, the combustion efficiency is improved, and the performance such as fuel consumption and smoke emission can be achieved.

[Brief description of drawings]

FIG. 1 is a sectional view of a combustion chamber according to the first embodiment of the present invention, and FIG.
The drawing is a piston top view, FIG. 3 is a III-III sectional view of FIG. 2, FIG. 4 is a piston top view of the second embodiment, FIG. 5 is a VV sectional view of FIG. 4, and FIG. Is the VI-VI sectional view of FIG.
FIG. 7 is a sectional view of a conventional combustion chamber, FIG. 8 is a top view of a conventional piston, and FIG. 9 is a sectional view taken along line IX-IX of FIG. 1 ... Main (combustion) chamber, 2 ... Sub combustion chamber, 3 ... Sub chamber injection port, 10 ... Piston top surface, 11 ... Pocket part.

Claims (1)

[Scope of utility model registration request] 1. In the cavity of the main combustion chamber installed on the top surface of the piston of the sub chamber internal combustion engine, in the cavity near the main combustion chamber side opening end of the sub chamber nozzle, from the sub combustion chamber to the main combustion chamber. A pocket portion that extends in a direction perpendicular to the cylinder center line (AA) from the side wall and does not open to the top surface of the piston is provided on either or both of the cavity side wall portion on the upstream side and the direction perpendicular to the gas jet flow. A combustion chamber of an internal combustion engine, which is characterized in that it is provided.