JPS5834258Y2 - How to use the latest information - Google Patents

Description

[Detailed description of the invention] This invention has a convex part on the top of the piston and the ceiling of the combustion chamber so that they fit together near top dead center and divide the combustion chamber into first and second combustion chambers. This invention relates to an improvement in a combustion device for an internal combustion engine in which a torch is ignited in the first combustion chamber and a torch is ignited in the second combustion chamber during the division period of the first and second eJn chambers. In addition to ensuring ignition in the first combustion chamber and flame propagation to the second combustion chamber,
By increasing the combustion speed in the second combustion chamber and ensuring complete combustion in the second combustion chamber, it is possible to improve output and reduce the weight of nitrogen oxides per horsepower in exhaust gas. The purpose is to provide a combustion device.

In order to achieve this objective, this invention provides a combustion device for an internal combustion engine as described above, in which a convex portion and a concave portion begin to fit together in a part of the circumferential direction of the portion where the first combustion chamber opens into the second combustion chamber. A communication passage is formed to communicate the first and second combustion chambers only within a predetermined range of the piston stroke on the fitting path, and the spark plug is located at a position farthest from the communication passage.

This invention will be explained in detail below based on the illustrated embodiments.

In the figure, reference numeral 1 denotes a piston that is slidably inserted into the cylinder 2, and a cylindrical sub-piston 3 is eccentrically formed as a convex portion at the top of the piston. It fits into a recess formed in the ceiling of a combustion chamber formed in the cylinder head 4 near the point, thereby dividing the combustion chamber into a first combustion chamber 5 and a second combustion chamber 6.

A spark plug I is installed in the first combustion chamber 5 at a position described later, and an intake valve 8 and an exhaust valve 9 are installed in the second combustion chamber 6.

and a portion where the first combustion chamber 5 opens into the second combustion chamber 6;
That is, the edge of the recess formed at the top of the combustion chamber of the cylinder head 4 is cut out, and a part of the circumferential direction of the first combustion chamber 5 is cut out so that the auxiliary piston 3 and the second combustion chamber 6 begin to fit together. A communication passage 11 is formed in the passageway for communicating the first and second combustion chambers 5°6 within a predetermined range of the stroke of the piston 1.

Further, a spark plug I is disposed at a position farthest from the communication path 11.

With the above structure, during the compression stroke in which the piston 1 moves upward, most of the first combustion chamber 5 is closed at the beginning when the auxiliary piston 3, which is a convex portion, fits into the recess forming the first combustion chamber 5. is divided, a part of which is in communication with the second combustion chamber 6 through the communication passage 11, and then the piston 1 further rises, so that the entire first combustion chamber 5 becomes divided.

In this state, the spark plug 7 causes the first combustion chamber 5 to
The mixture is ignited.

In addition, in the expansion stroke, in a predetermined range of the piston stroke on the fitting path between the auxiliary piston 3 and the first combustion chamber 5, the first and second combustion chambers 5 and 6 first communicate with each other only through the communication path 11, and then As the piston 1 further descends, the secondary piston 3
is drawn out from the first combustion chamber 5, and the entire circumference of the first combustion chamber 5 communicates with the second combustion chamber 6.

Therefore, when the air-fuel mixture in the first combustion chamber 5 ignites and burns and the piston 1 descends, the high-temperature, high-pressure gas flame is first injected into the second combustion chamber 6 only from the restricted communication passage 11. Ignition and initial combustion of the air-fuel mixture in the combustion chamber 6 are reliably performed, and flame is ejected from the entire circumference of the first combustion chamber 5 to every corner of the second combustion chamber 6 by the subsequent descent of the piston 1. In the second combustion chamber 6, the combustion speed is high and complete combustion occurs.

In addition, in the compression stroke, if there is a pressure difference between the first and second combustion chambers 5 and 6 within a predetermined range of the piston stroke at the beginning of the fitting of the auxiliary piston 3 with the first combustion chamber 5, the combustion chamber on the higher pressure side A strong directional airflow is generated from the air to the combustion chamber on the lower side through the communication passage 11, and this airflow causes turbulence in the first and second combustion chambers 5 and 6, causing the air-fuel mixture and residual burnt Mixing with the gas is performed well, and ignition in the first combustion chamber 5 and the second
Flame propagation within the combustion chamber 6 is ensured.

On the other hand, in the case where the communication passage as described above is not provided, the first combustion chamber is divided and communicated with the second combustion chamber at the same time, and the first combustion chamber during the expansion stroke is divided and communicated with the second combustion chamber at the same time. Since gas flame is not ejected from a part of the circumference and directional airflow is not generated during the compression stroke, combustion in the second combustion chamber is slow and combustion in the first combustion chamber is slow. A problem arises in that ignition is not reliable.

In this invention, in the above-mentioned embodiment, the spark plug I was installed at the farthest position from the communication passage 11, so that after the air-fuel mixture is ignited by the operation of the spark plug 7 in the first combustion chamber 5. , combustion in the first combustion chamber 5 is sufficiently achieved by the flame propagation up to the communication passage 11, and the communication passage 11
A flame is brought into the second combustion chamber 6 from there.

Immediately after that, the division by the sub piston 3 ends.

Therefore, the splitting effect of starting the second stage combustion after the first stage combustion is completed is accurately maintained.

Further, based on this idea, a concave portion is provided at the top of the piston, and a convex portion that fits into the concave portion is provided on the ceiling of the combustion chamber.
A combustion chamber may also be formed.

As explained above, according to this invention, by forming the communication passage with the above-mentioned structure, ignition in the first combustion chamber and the flow to the second combustion chamber are improved compared to the case without the communication passage. In addition to ensuring flame propagation, it improves combustion in the second combustion chamber to increase the combustion speed and achieve complete combustion, increasing output and reducing the weight of nitrogen oxides per horsepower in exhaust gas. This has the effect of further reducing the

And these effects are remarkable for those who burn dilute aiki.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of this invention, and FIG. 2 is a view taken along the line B--B in FIG. DESCRIPTION OF SYMBOLS 1...Piston, 2...Cylinder, 3...Sub-piston, 4...Cylinder head, 5...First combustion chamber,
6... Second combustion chamber, 7... Spark plug, 8... Intake valve, 9... Exhaust valve, 10... Boundary line, 11...
Communication path.

Claims (1)

[Scope of utility model registration request] The top of the piston and the ceiling of the combustion chamber are fitted together near top dead center to divide the combustion chamber into first and second combustion chambers.
A convex part and a concave part are respectively formed, and the first combustion chamber is ignited during the division period of the first combustion chamber, and the torch is ignited in the second combustion chamber. A communication passage that connects the first and second combustion chambers only at the beginning of the fitting between the convex portion and the concave portion and within a predetermined range of the piston stroke on the fitting path, in a part of the circumferential direction of the portion that opens into the second combustion chamber. A combustion device for an internal combustion engine, characterized in that a spark plug is installed in a first combustion chamber at a position farthest from the communication path.