JPS59147819A - Stratified air feed combustion type internal-combustion engine - Google Patents

Abstract

PURPOSE:To make it easy to ignite atomized fuel in a combustion chamber, in an engine in which the combustion chamber is formed in a cylinder head below an exhaust valve, and is communicated with a main combustion chamber, by providing a fuel injection valve which is opened to the side part of the combustion chamber and in which an ignition plug is disposed. CONSTITUTION:A combustion chamber 4 formed in a concave shape in the lower section of a cylinder head 1 below an exhaust valve 2 fitted in the cylinder head 1, is communicated with a main combustion chamber 10 defined between the top of a piston 5 and the lower surface of the cylinder head 1. Further, a fuel injection valve 7 is arranged in the axial direction of a cylindrical ignition chamber 8 which is opened to the side part of the combustion chamber 4 and has an ignition plug 6 disposed therein. With this arrangement, the ignition plug 6 is laid at a substantially right angle to the injecting direction of the fuel injection valve 7, and is isolated from air stream in the combustion chamber 4, thereby atomized fuel is easily ignited by the discharge of the ignition plug 6.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a stratified charge combustion internal combustion engine having a combustion chamber communicating with a main combustion chamber, and in particular, a fuel injection valve and a spark plug for the combustion chamber can be used to easily ignite fuel spray. Items related to the invention placed in the position shown above are included.

There has been a lot of research into what is generally called a stratified charge combustion internal combustion engine, but it is known that among these engines, those that fall into the category of direct injection engines have multi-fuel properties. ing.

On the other hand, in order to burn a very wide range of fuel, it is best to use the part of the combustion chamber that tends to get hot as much as possible, so attention has been focused on internal combustion engines that have a combustion chamber under the exhaust valve. The inventions disclosed in Japanese Patent Publication No. 27-3258, Japanese Patent Publication No. 28-6353, and Japanese Patent Publication No. 29-4855 are known.

However, although these inventions provide a combustion chamber below the exhaust valve, they do not use a stratified charge combustion method (compression ignition method).

Also, Jitsugoku No. 49-37684 No. 1 and Assembly 1982-
In the invention of No. 2891 and the invention of Japanese Patent Publication No. 54-19923, the spark plug is directly mounted in the combustion chamber,
It is difficult to form an ignitable air-fuel mixture near the spark plug over the entire operating range.

Furthermore, the Special Publication No. 57 concerning a spark-ignition internal combustion engine having a main chamber and an auxiliary chamber, and equipped with a fuel injection valve and a spark plug in the auxiliary chamber.
- In the invention of No. 40329, the auxiliary chamber opens directly into the main combustion chamber, and it does not take into account that it is advantageous for multi-fuel engines to utilize the part of the combustion chamber that tends to become high temperature. .

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the conventional art. The stratified air combustion internal combustion engine of the present invention is aimed at facilitating the ignition of the spray.
In an internal combustion engine that has a combustion chamber that communicates with the main combustion chamber below the exhaust valve in the cylinder head, the combustion occurs through an ignition chamber that opens on the side of the combustion chamber and has a spark plug inside. The fuel injection valve is disposed in a position where fuel can be injected into the room, and the spark plug disposed inside the ignition chamber is oriented perpendicularly to the fuel injection direction of the fuel injection valve. This is a more preferable configuration.

Hereinafter, the present invention will be described in detail with reference to the drawings, in which the same parts in each embodiment are designated by the same part numbers.

FIG. 1 is a longitudinal cross-sectional view of the main part of the combustion chamber of a stratified air combustion internal combustion engine according to an embodiment of the present invention, and FIG. 2 is a partial cross-sectional view taken along the line AA in FIG. As shown in FIG. 1, this internal combustion engine has a main combustion chamber 10 between the upper part of the piston 5 and the lower surface of the cylinder head 1. A combustion chamber 4 formed by recessing the lower part of the cylinder head 1 is formed below the exhaust valve 2 between the intake valve 6 and the intake valve 6, and communicates with the main combustion chamber 10.

Next, a cylindrical ignition chamber 8 with an opening 1 and a spark plug 6 arranged therein as shown in FIG. 2 is provided in the side of this combustion chamber 4, and fuel is injected in the axial direction of this ignition chamber 8. A valve 7 is provided to enable fuel to be injected into the combustion chamber 4 via this ignition chamber 8.

Therefore, as shown in FIG. 2, the spark plug 6 is provided in the ignition chamber 8 at an intermediate portion between the fuel injection valve 7 and the combustion chamber 4, and is approximately parallel to the injection direction of the fuel injection valve 7. The ignition spark of the ignition plug B is disposed in the right angle direction, and the ignition spark of the ignition plug B is discharged in the ignition chamber 8, so that it is isolated from the strong air flow in the combustion chamber 4. Therefore, the fuel spray can be easily ignited by the discharge of the spark plug O.

Next, the internal combustion engine of the second embodiment shown in FIG. 3 has almost the same configuration and function as the first embodiment shown in FIG. In order to maintain an appropriate compression ratio in an internal combustion engine, it is necessary to adjust the diameter and height of the combustion chamber 4. It is necessary to lower the height and increase the diameter.

However, in that case, if the bore is made larger than the bore of the cylinder liner 9, problems such as gas sealing will occur.
The cylinder liner 9 has a large diameter and is provided so as to overhang the inner diameter of the cylinder liner 9 by a length, so that the connecting port to the main combustion chamber 10 at the lower end of the mouthpiece 11 is offset by a length l shown in FIG. It has a shape.

On the other hand, as described above, in the present invention, by providing the combustion chamber 4, the exhaust valve 2 is pushed upward, and there is a limit to the height of the cylinder head 1.
It is clear that if the exhaust port 12 is narrowed, the exhaust resistance will increase and the exhaust efficiency will deteriorate. In the third embodiment shown in the side sectional view, @W1 on the exhaust valve 2 side of the exhaust port 12 is made larger than @w2 on the outlet side, thereby reducing the dimension in the height direction near the exhaust valve 2 side. , so that the cross-sectional area of each cross-section within the exhaust port 12 does not change much.

Furthermore, as shown in FIG. 3, since the height of the exhaust boat 12 is limited, the length of the valve guide 16 of the exhaust valve 2 is inevitably shortened, and the contact between this valve guide 16 and the cylinder head 1 is reduced. If the length is too small, there is a risk that the valve guide 13 will fall off.

Therefore, as in the fourth embodiment shown in the side view of FIG. 6, in order to increase the insertion length H of the valve guide 16 into the cylinder head 1, a portion of the cylinder head 1 around the outside of the valve guide 16 is to the insertion length H
In this case, the upper end surface of the extension portion of the cylinder head 1 indicated by h is flush with the other upper end surface of the cylinder head 1.

Each example 2 shown in FIGS. 3 to 6 above,
3 and 4 are examples of embodiments in which a fuel injection valve 7 and a spark plug 6 similar to those in Embodiment 1 shown in FIG. 5 also shows an intake boat 14 having a shape called a helical port with a high swirl ratio, which is normally employed in direct injection internal combustion engines, for the combustion chamber 4 similar to that in FIG. 6. The swirl generated by the intake port 14 causes a strong air flow within the combustion chamber 4, promoting the mixing of fuel and air within the combustion chamber 4, thereby achieving a good result. It is made to burn easily.

Therefore, in the stratified air combustion internal combustion engine of the present invention, although the combustion chamber communicating with the main combustion chamber is provided at the lower part of the exhaust valve, the ignition of the fuel spray by the spark plug is prevented by the air flow. This is extremely effective in improving the combustion performance, as it is easy to carry out and the subsequent combustion is promoted by the air flow.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of the main part of the combustion chamber of a stratified charge combustion internal combustion engine according to Embodiment 1 of the present invention, and FIG. 2 is a line AA in FIG. 1.
3 to 7 show the main parts of the combustion chamber of the stratified air combustion internal combustion engine in each embodiment of the invention, and FIG. 2
4 is a plan sectional view of Embodiment 3, FIG. 5 is a side sectional view of FIG. 4, FIG. 6 is a side sectional view of Embodiment 4, and FIG. FIG. 5 is a plan cross-sectional view of Example 5. 1... Cylinder head, 2... Exhaust valve, 4...
Combustion chamber, 6... Spark plug, 7... Fuel injection valve, 8
...Ignition chamber, 10...Main combustion chamber. Agent: Patent Attorney Makoto Ogawa − Patent Attorney: Ken Noguchi Patent Attorney: Kazuhiko Saishita 113

Claims (1)

[Claims] 1. In an internal combustion engine in which a combustion chamber communicating with a main combustion chamber is provided at the lower part of an exhaust valve in a cylinder head, an ignition plug is opened at the side of the combustion chamber and a spark plug is disposed inside the combustion chamber. A stratified air combustion type internal combustion engine, characterized in that a fuel injection valve is disposed at a position where fuel can be injected into the combustion chamber via an ignition chamber. 2. The stratified air combustion internal combustion system according to claim 1, wherein the spark plug disposed inside the ignition chamber is disposed in a direction substantially perpendicular to the direction of the fuel injection valve. institution.