JPS5968518A - Combustion chamber for engine with pre-chamber - Google Patents

Abstract

PURPOSE:To improve the fuel economy and reduce the exhaust smoke by establishing a certain relationship between the minimum angle defined by the axis of a nozzle of a pre-chamber and a pre-chamber side surface of a separator wall and the minimum angle defined by the axis of the pre-chamber and a main chamber side surface of the separator wall. CONSTITUTION:A pre-chamber nozzle 2 connects a pre-chamber 1 and a main chamber 3. The minimum angle defined by the axis of the pre-chamber nozzle 2 and the pre-chamber bottom surface 1a is designated as Q2, and the minimum angle defined by the axis of the pre-chamber 2 and the main chamber side surface of the separator wall is designated as Q1. Part of the area surrounding the pre-chamber opening is inclined so Q2>Q1. As the gas flow from the pre-chamber 1 to the main chamber 3 becomes easy, a throttle loss is reduced, and at the same time there is no insufficiency of air. By this constitution, the fuel economy of the engine is improved, and the exhaust smoke is reduced.

Description

[Detailed description of the invention] The present invention relates to a combustion chamber of a pre-chamber engine.

The auxiliary combustion chamber (hereinafter referred to as the auxiliary chamber) of the conventional auxiliary chamber type engine is the first
As shown in the figure. In the figure, the auxiliary chamber 1 is recessed in the cylinder head 4, and its structure has a hemispherical upper part and a truncated conical or cylindrical lower part. show something The auxiliary chamber 1 is provided with a fuel injection valve 5 and a glow plug 6 for preheating the inside of the auxiliary chamber 1 when the engine is started, as necessary. Secondary, chamber 1 and top surface of piston 7, cylinder 8. A main combustion chamber (hereinafter referred to as the main chamber) 3 formed from the lower surface of the cylinder head 4 is divided by a partition wall at the bottom of the two nozzles 9, and is communicated with the sub-chamber nozzle 2 bored in the partition wall. There is. The end surface of the partition wall on the subchamber 1 side, that is, the subchamber bottom surface 9
a and the end face on the main chamber 3 side are perpendicular to the width chamber center line A-A, and the minimum angle between the sub-chamber bottom surface 9a and the axis of the sub-chamber nozzle 2 is θ.
2 and the minimum angle between the main chamber side end face and the axis of the sub chamber nozzle 2 is 01, then θ1-02.

During the compression stroke during engine operation, air in the main chamber 3 is compressed by the piston 7 and flows into the subchamber 1 through the subchamber nozzle 2 to generate a vortex S. Air flowing into the auxiliary chamber 1 and the fuel injection valve 5
Mixing with the fuel injected from the fuel is promoted by this vortex, and ignition occurs and combustion occurs.

Burnt and unburned gas in the pre-chamber 1 passes through the pre-chamber nozzle 2.

It is ejected into the main chamber 3, works on the piston, and simultaneously mixes with the air in the main chamber 3 and causes combustion.

However, the above method has the following drawbacks.

In order to reduce the fuel consumption and smoke emissions of pre-chamber engines.

The unburnt and burned gases in the auxiliary chamber 1 must quickly flow out into the main chamber 3 to promote mixing with the air in the main chamber 3 and combustion. In order to quickly drain out the unburned and burned gas in the subchamber 1, if the passage cross-sectional area of the subchamber nozzle 2 is increased, the main chamber 3
The injection speed of the gas inward decreases, and the mixing with the air in the main chamber 3 and therefore the combustion deteriorates. Also, the pre-chamber nozzle angle θ2
(=θ1), the unburned and burned gas in the subchamber 1 will more easily flow out to the main chamber 3, but the subchamber nozzle angle θ2(
= θ1) is large, the penetration of the jet flow in the main chamber 3 decreases, and the mixing with air and hence combustion deteriorates.

Smoke and fuel efficiency cannot be improved.

The purpose of the present invention is to improve the fuel efficiency of a double-chamber engine by focusing on the above-mentioned points.
When the antechamber nozzle angle in the antechamber is increased to facilitate the outflow of gas from the antechamber to the main chamber as a smoke countermeasure, netting of the jet in the main chamber that occurs is worsened, resulting in mixing with air.
The purpose of the present invention is to provide a combustion chamber capable of preventing deterioration of combustion, and its feature is that a sub-chamber nozzle is provided in a partition wall that partitions the main chamber and the sub-chamber, and communicates the main chamber with the sub-chamber. In the pre-chamber type internal combustion engine, the minimum angle between the axis of the pre-chamber nozzle and the end surface of the partition wall on the sub-chamber side is represented by θ2, and the minimum angle between the axis of the pre-chamber nozzle and the end surface of the partition wall on the main chamber side When the minimum angle formed by the partition wall is θ1, at least a part of the end surface of the partition wall on the sub-chamber side around the opening of the sub-chamber nozzle is inclined so that θ2>θ1.

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

FIG. 2 is a sectional view showing the subchamber of the first embodiment of the present invention.

In the figure, 1 is the subchamber, 2 is the subchamber nozzle, 3 is the main chamber, and 4
is a cylinder head, 5 is a fuel injection valve, 6 is a glow plug, 7 is a piston, and 8 is a cylinder.

The auxiliary chamber nozzle 2 penetrates the partition wall between the auxiliary chamber 1 and the main chamber 3 to communicate the two chambers 1 and 3.

The auxiliary chamber 1 has a hemispherical upper structure, and the auxiliary chamber bottom surface 1a, which is the end surface of the partition wall on the side of the auxiliary chamber, is made thicker on the inner side of the partition wall and inclined as a whole, as shown in the figure.

That is, if the minimum angle between the axis of the sub-chamber nozzle 2 and the sub-chamber bottom surface 1a is θ2, and the minimum angle between the axis of the sub-chamber nozzle 2 and the end surface of the partition wall on the main chamber side is θ1, Due to the above-mentioned inclination, the angle θ2>θ1 is formed.

The functions and effects of the above configuration will be described.

If the sub-chamber bottom 1a is inclined as shown, gas can easily flow out from the sub-chamber 1 to the main chamber 3.

The throttling loss of the sub-chamber nozzle 2 is reduced, and at the same time, even if a large amount of fuel is injected into the sub-chamber 1 under high load, no air shortage occurs.

In addition, the penetration of the jet flow inside the main chamber 3 can be ensured,
Mixing of unburned gas and air is promoted and combustion is improved.

For the above reasons, the engine's fuel efficiency and smoke reduction can be achieved.

FIG. 3 is a sectional view showing the subchamber of the second embodiment of the present invention.

This is a case where a part of the bottom surface of the subchamber 1, that is, a portion 1b around the opening of the subchamber nozzle 2 is inclined so that θ2>θl,
Its action and effect are the same as in the embodiment described above.

A third embodiment of the present invention is as follows.

By tilting the center line A-A of the sub-chamber 1 of the first embodiment by θ2-θ1, the sub-chamber 1 is made axially symmetrical with respect to the center line A-A. In this case, the subchamber can be easily processed, and the effects and effects are the same as in the first embodiment.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the sub-chamber of a conventional sub-chamber type engine; FIG. 2 is a cross-sectional view showing the sub-chamber of a first embodiment of the present invention. The plan view and FIG. 3 are cross-sectional views showing the subchamber of the second embodiment of the present invention. 1... Sub-chamber, 2... Sub-chamber nozzle, 3... Main chamber, 1a
. 9a... Bottom of the sub-chamber, 1b... Part of the bottom of the sub-chamber. Fang 1 Figure / 〆One one□□Red ゝ-8 Thick 2) / ~8 Ko105- 5 f 2 5 -B

Claims (1)

[Claims] 1. In a sub-chamber type internal combustion engine having a sub-chamber nozzle that is bored in a partition wall that partitions a main chamber and a sub-chamber and communicates the main chamber and sub-chamber, the axial line of the sub-chamber nozzle and the line of the partition wall communicate with each other. When the minimum angle between the sub-chamber side end surface and the sub-chamber side end surface is represented by 02, and the minimum angle between the axial line of the sub-chamber nozzle and the main chamber-side end surface of the partition wall is θ1, at least the sub-chamber side end surface of the partition wall A combustion chamber for a pre-chamber type engine, characterized in that a part of the opening circumference of the pre-chamber nozzle is inclined so that θ2>θ1.