KR19980055437A - Combustion chamber structure of diesel engine - Google Patents

Abstract

The present invention relates to a combustion chamber structure of a direct injection diesel engine, to improve atomization of fuel injected into the combustion chamber, to maintain a good combustion state, to increase the output of the engine, and to reduce harmful components of the exhaust gas. In order to realize this, the present invention proposes a combustion chamber structure having an impact member 7 through which fuel injected from the injection nozzle 4 collides and diffuses. The impact member is installed on the combustion chamber 3 formed on the piston 1 head, and is installed by the support member 8 having one end fixed to the cylinder head 10 in front of the injection nozzle.

Description

Combustion chamber structure of diesel engine

The accompanying drawings are sectional views showing the combustion chamber structure of the diesel engine according to the present invention.

Explanation of symbols on the main parts of the drawings

1: piston 2: cylinder block

3: combustion chamber 4: spray nozzle

7: impact member 8: support member

10: cylinder head 11: volume part

Technical Field of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion chamber structure of a diesel engine. More specifically, by improving combustion chamber atomization injected into a combustion chamber, it is possible to maintain a good combustion state, increase engine output, and reduce harmful components of exhaust gas. It relates to a combustion chamber structure of a diesel engine having a fuel atomization means.

[Private Technology]

In general, in a gasoline engine, a mixer in which air is sufficiently mixed with fuel is sucked into a cylinder and combusted, but a diesel engine starts combustion after fuel injected from an injection nozzle reaches an ignition temperature by mixing with air. Combustion chambers of diesel engines are to have a good mix of injected fuel and air. For example, the combustion chamber may be specially shaped to cause strong vortex (i.e., vortex) at the end of compression, or to mix by using high pressure generated at the start of ignition.

The conditions required for such a combustion chamber include: A) complete injection of the injected fuel in the shortest possible time, B) high average effective pressure, C) low fuel consumption rate, and D) high speed rotation. Good combustion conditions, E) easy starting, F) low diesel rust.

In the combustion chamber of the diesel engine, the main combustion chamber is formed by the recesses formed in the cylinder head and the piston head, and a direct injection type in which fuel is directly injected, and a separate pre combustion chamber is provided above the main combustion chamber of the direct injection type. It is divided into pre-combustion chamber type, vortex chamber type, air chamber type, etc. to inject fuel.

Here, the structure of the direct injection combustion chamber, as is well known, consists of the space between the recessed portion of the piston and the bottom of the cylinder head. In addition, a fuel injection nozzle for injecting fuel into the combustion chamber is disposed in the cylinder head toward the center of the piston.

The combustion chamber typically has a piston head portion that is specifically shaped as a heart, hemispherical or spherical shape, and consists of a concave space.

In the direct injection combustion chamber configured as described above, air is sucked from the intake port during the intake stroke of the engine, the air is compressed in the combustion chamber according to the compression stroke, and the vortex motion is caused by the shape of the intake port and the combustion chamber.

In this state, the air is in a good mixing state with the fuel injected from the injection nozzles in all directions of the combustion chamber, and then combusts at a predetermined ignition temperature.

[Technical problem to be achieved]

The conventional direct injection combustion chamber described above is characterized in that the combustion chamber, which has the shape of the piston in its structure, is simple and its surface area is relatively small, so that the loss of heat is low and the thermal efficiency is high accordingly.

However, in comparison with other combustion chambers having a vortex chamber or the like, since the inflow air is compressed only by the heart-shaped combustion chamber, the vortex phenomenon in the combustion chamber is weakened, which causes a decrease in the utilization rate of the air in the combustion chamber. There is a problem that the mixing rate is reduced.

That is, according to the prior art, the atomization of fuel injected from the injection nozzle is reduced, incomplete combustion is performed, and unburned fuel is deposited on the inner wall of the combustion chamber or discharged into the atmosphere, so that harmful components (e.g., NO _X ) has the problem of increasing.

In addition, incomplete combustion of the mixer results in lowering and abnormal engine power.

In order to solve the problems of the prior art, the present invention achieves atomization of the fuel injected into the combustion chamber and improves the mixing ratio, thereby maintaining a good combustion state and increasing the output of the engine, and exhaust To reduce the harmful components of the gas.

[Configuration and Invention of the Invention]

As a means for realizing the above object, the present invention proposes a combustion chamber structure of a diesel engine having a configuration described below.

That is, according to the present invention, in the direct injection combustion chamber structure of the diesel engine, atomization means in which the fuel collides is provided in order to atomize the fuel injected from the injection nozzle. This atomization means is arranged in the center of the combustion chamber formed in the front part of the injection nozzle, ie, the head part of a piston, and consists of an impact member fixed to the cylinder head by a support member.

In this case, a volume part is formed in the cylinder head located directly above the impact member. In addition, the combustion chamber is composed of a re-entrant chamber to increase the diffusion effect after the collision of fuel.

In the combustion chamber structure of the diesel engine of the present invention configured as described above, the air introduced by the lowering of the piston during the intake stroke is introduced into the swirl and the squish by the combustion chamber during the compression stroke, and the impact member By smoothly mixing with more finely divided fuel through the, it is possible to optimally form the state of the mixer and improve the combustion efficiency.

Therefore, the present invention can increase the output of the engine while increasing the combustion efficiency, and can reduce harmful components of the exhaust gas.

EXAMPLE

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment for implementing this invention is demonstrated in detail based on an accompanying drawing.

The accompanying drawings are side sectional views showing the combustion chamber structure of the diesel engine according to the present embodiment.

Reference numeral 1 in the drawings refers to a piston. In the diesel engine of the present embodiment, the air introduced from the intake port 6 is compressed by a piston 1 having a reciprocating linear motion in the cylinder block 2 and the combustion chamber 3 formed in the head portion, thereby compressing a predetermined temperature. In the above case, the fuel injected at high pressure from the injection nozzle 4 is configured to self-ignite and burn.

The injection nozzle 4 is installed at the center of the cylinder head 10. In addition, an intake valve 5 for sucking air into the combustion chamber 3 and an exhaust valve 6 for discharging the combustion gas of the combustion chamber 3 to the outside are provided at both side portions of the injection nozzle 4. do.

Here, the combustion chamber structure according to the present embodiment is provided with atomization means in which the fuel impinges on the upper side of the combustion chamber 3, that is, the front part of the injection nozzle 4.

The atomizing means is provided with an impact member (7) in the front portion to which the fuel is injected, in order to further crush the fuel ejected from the injection nozzle (4), the impact member (7) is provided on the support member (8) It is made of a structure that is fixed to the bottom of the cylinder head (10) by.

In this case, the supporting member 8 for fixing the impact member 7 is fixed to the bottom of the cylinder head 10, and a plurality of support members 8 may be provided for firm fixing.

On the other hand, the combustion chamber 3 of this embodiment is comprised of a reentrant chamber to promote atomization of fuel impinging on and impacting the impact member 7.

In addition, the cylinder head 10 of the present embodiment has a structure in which a volume portion 11 is formed directly above the impact member 7, which volume portion 11 is formed to have the same diameter as the inlet diameter of the combustion chamber 3. do.

The combustion chamber of the present embodiment having the configuration as described above has the following function.

First, when the piston 1 built into the cylinder forms an intake stroke, air is introduced through the intake valve 5. When the piston 1 is raised in such a state and the compression stroke is executed, the squish phenomenon occurs at the end of the compression stroke due to the shape of the combustion chamber 3.

At this time, high pressure fuel is injected from the injection nozzle 4. The fuel is atomized by colliding with and spreading on the impact member 7 provided at the front part thereof. This atomized fuel achieves an optimal combustion state with the hot compressed air, and increases the engine output with the improvement of the combustion efficiency.

[Effects of the Invention]

Through the embodiments described above, it can be seen that the combustion chamber structure of the diesel engine according to the present invention further atomizes the fuel ejected from the injection nozzle.

Accordingly, the present invention ideally achieves ignition and combustion of fuel and air, and has an effect of improving the output of the engine and reducing harmful components of exhaust gas after combustion.

The combustion chamber structure of the present invention is not limited to the direct injection type combustion chamber according to the above embodiment, and can be applied to combustion chamber structures such as pre-chamber type, vortex chamber type and air chamber type.

On the other hand, the present invention is not limited to the above-described specific preferred embodiment, and any person having ordinary skill in the art to which the invention belongs without departing from the gist of the invention claimed in the claims, various modifications Would be possible.

Claims (1)

A combustion chamber formed in a space between the space formed concave in the piston head and the bottom surface of the cylinder head; A fuel injection nozzle injecting fuel into the combustion chamber and installed in the cylinder head; An impact member through which the fuel injected from the injection nozzle collides and diffuses; A combustion chamber structure of a diesel engine, characterized in that one end is fixed to the impact member, and the other end is formed of a support member fixed to the bottom of the cylinder head.