JPS5918096Y2 - Combined combustion chamber internal combustion engine - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an improvement in a pre-chamber internal combustion engine.

In conventional sub-chamber type engines, the main and sub-combustion chambers as well as the throttle section between them are always formed, resulting in large flow losses and heat losses at the throttle section during the compression and expansion strokes.

In addition, due to the pressure balance between the main and auxiliary combustion chambers, the combustion period in the auxiliary combustion chamber is inevitably long, and the combustion gas energy in the latter stage is not only not effectively used for the combustion work, but also
A portion of the burnt gas remains in the sub-combustion chamber, resulting in a disadvantage that the ignitability in the next stroke is reduced.

Furthermore, as the volume of the sub-combustion chamber increases, the air-fuel mixture formed during the ignition delay period is instantly combusted, which increases the maximum pressure and pressure rise rate within the sub-combustion chamber.
This is inconvenient in terms of vibration and noise.

The purpose of the present invention is to provide a composite combustion chamber type internal combustion engine that can eliminate the above-mentioned disadvantages of the pre-chamber type engine and take advantage of its advantages. It consists of a piston and a cylinder head that has a recessed chamber with a fuel injection device installed inside. Near the compression path, the protrusion of the screws enters the recessed chamber of the cylinder head, thereby opening the main and auxiliary combustion chambers. The combustion chamber is formed so that it exits from the recessed chamber near the beginning of the subsequent expansion stroke and becomes a single combustion chamber thereafter, and the main and auxiliary combustion chambers are connected to the recessed chamber wall or screw l.
- A depressed chamber wall on either or both of the top protrusions;
An inclined notch is provided on the side wall of the piston top surface protrusion to form a communicating hole.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1a is a cross-sectional view showing the main parts of an engine according to an embodiment of the present invention; FIG. 1A is a cross-sectional view showing the main parts of the engine of FIG. Figure C is a cross-sectional view of the piston in Figure 1 taken along line -■.

In the figure, 1 is the internal combustion engine main body, 2 is the cylinder liner, and the combustion chamber 3 has a cylindrical protrusion 4 with a notch 5 in a part.
It consists of a piston 6 provided with a cylindrical depression chamber and a cylinder head 7 provided with a cylindrical depression chamber.

In addition, the entrance area of the depression chamber should be 5% or more of the cross-sectional area of the screws (6) to (6).

10 is a fuel injection device. The operation in the case of the above configuration will be described.

In the early and middle stages of the compression stroke, the combustion chamber was a single combustion chamber, but in the latter stage near the end of the compression stroke, screws 1 to
The combustion chamber 3 is divided into an auxiliary combustion chamber 8 and a main combustion chamber 9 by the protrusion 4 of the cylinder entering the recessed chamber of the cylinder head 7 .

Thereafter, as the piston 6 rises, the air in the main combustion chamber 9 is compressed (the air in the sub-combustion chamber 8 is also compressed by the piston protrusion 4), and passes through the notch 5 of the piston protrusion into the sub-combustion chamber 8. It flows inside and forms a vortex.

The notch 5 serves as a communication hole between the main and auxiliary combustion chambers 8°9.

Near the end of compression, the fuel injection device 1 installed in the auxiliary combustion chamber 8
Fuel is injected from zero, and part of it is ignited and combusted in the sub-combustion chamber 8.

The combustion gas energy performs work on the piston 6, and at the same time injects the fuel and air-fuel mixture into the main combustion chamber 9, and is used to form the air-fuel mixture in the main combustion chamber 9 and partially ignite and burn it.

In order to improve the mixture formation in the main combustion chamber 9, the first
As shown in Figure C, a fan-shaped recess is provided on the top surface of the piston 6.

Thereafter, as the piston 6 descends, the combustion chamber becomes a single combustion chamber 3, the air-fuel mixture in the combustion chamber 3 is completely combusted, and the entire combustion energy is effectively used for piston work.

Focusing on the volume of the sub-combustion chamber and the area of the connecting hole throttle area,
Figure 2 a, l) shows these changes during the compression and expansion strokes.

That is, as shown in FIG. 2a, the main and auxiliary combustion chambers 8, 9
is formed at a certain time θ1 in the latter half of the compression stroke, and as compression progresses, the volume of the auxiliary combustion chamber gradually decreases, reaches a minimum at top dead center, and gradually increases in the expansion stroke, becoming a single combustion chamber at the end of the compression stroke.

Further, the amount of change in volume of the sub-combustion chamber from time θ1 to top dead center is 25 to 100% of the volume of the sub-combustion chamber at top dead center, and the amount of change is large.

In the case of the notch 5 indicated by the broken line in FIG. 1, the area of the connecting hole constriction portion is constant as shown by the broken line in FIG.

On the other hand, as shown in FIG. 1a, a part of the artificial end of the recessed chamber of the cylinder head has a notch 11. Alternatively, if an inclined notch as shown by the solid line is provided in the piston protrusion notch 5, a variable throttle is formed as shown by the solid line in FIG.

In the second embodiment, as shown in FIGS. 3A and 3L, a notch 5 is provided in the side wall of the depressed chamber, and the notch 5 is sloped to form a variable diaphragm.

Furthermore, as a third embodiment, as shown in FIG. 4, in a modification of the first embodiment, when the screws 1 to 1 are at the top dead center, the notch 5 is closed by the wrap part a. , the notch 5 has a slope.

In addition, in the case of a variable throttle, it is possible to maintain the passage area of the throttle part of the communication hole that adapts to the change in volume of the sub-combustion chamber 8, so the throttle loss due to air or combustion gas passing through the communication hole is minimized. The aperture area can be selected as follows.

Furthermore, the sub-combustion chamber 8 may be located not only at the periphery of the cylinder as shown in this embodiment, but also at the center.

As described above, the present invention has the following effects.

(1) By forming the main and auxiliary combustion chambers 8 and 9 only in the latter half of the compression stroke (near the end of compression) and using a variable throttle, flow loss and heat loss at the connecting hole throttle can be reduced.

(2) In addition, by forming the main and auxiliary combustion chambers 8 and 9 only at the beginning of the expansion stroke, and then forming a single combustion chamber, the combustion period in the auxiliary combustion chamber can be shortened, and the combustion gas energy can be reduced. is effectively used for piston work, the amount of residual burnt gas is reduced, and the amount of fresh air charged in the next compression stroke is increased, thereby improving ignition performance.

(3) At the same time, the combustion gas energy in the auxiliary combustion chamber is immediately used to perform piston work and inject the fuel mixture into the main combustion chamber, and the volume of the auxiliary combustion chamber gradually increases.
The maximum pressure and pressure rise rate in the sub-combustion chamber are also relatively low, reducing vibration and noise.

[Brief explanation of drawings]

FIG. 1a is a cross-sectional view showing the main parts of an engine according to an embodiment of the present invention; FIG. 1A is a cross-sectional view showing the main parts of the engine of FIG. Figure 1C is a cross-sectional view of the piston in Figure 1 taken along the I-■ line, Figure 2a is a diagram showing volume changes in the auxiliary combustion chamber during the compression and expansion strokes, and Figure 2 is a diagram showing the changes in volume within the auxiliary combustion chamber during the compression and expansion strokes. A diagram showing the change in the area of the connecting hole constriction part during the stroke, Fig. 3 a, t) is an explanatory diagram showing the second embodiment of the communicating hole, and Fig. 4 a, 1] is the third embodiment of the communicating hole. FIG.

Claims (1)

[Scope of utility model registration request] A recessed chamber is provided in the cylinder head and constitutes a part of the combustion chamber and is provided in the fuel injection device.A recessed chamber is provided on the top surface of the cylinder and is inserted into the recessed chamber only during the period when the piston passes near the top dead center. a protrusion that separates the combustion chamber into a main combustion chamber and an auxiliary combustion chamber formed by the recessed chamber; and a protrusion provided on either or both of the recessed chamber wall or the piston top surface protrusion, which separates the combustion chamber into a sub-combustion chamber formed by the main combustion chamber and the recessed chamber; The chamber is provided with a notch that communicates with the auxiliary combustion chamber, and after the piston top surface protrusion is inserted into the recessed chamber in the latter half of the compression stroke, the notch is inserted into the recessed chamber wall and the side wall of the screw top surface protrusion. The wall of the depressed chamber and the screws 1~
Composite combustion chamber type characterized by a top protrusion formed at an angle to the side wall.