JP2500172Y2 - Vortex chamber in diesel engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a swirl chamber in a diesel engine.

[Prior Art] A sub-combustion chamber of a diesel engine employs a swirl chamber to increase the mixing ratio of fuel injected from an injection nozzle and air sent from the main combustion chamber and to improve combustion efficiency. There is something. An example of this type of diesel engine is disclosed in Japanese Utility Model Laid-Open No. 63-119828. That is, as shown in FIG. 3, this sub-combustion chamber forms a swirl chamber 22 by press-fitting a cup-shaped partition member 21 into the space provided in the cylinder head.
The fuel injected from the injection nozzle 23 and the injection holes formed in the flange portion 25 of the partition member 21 from the main combustion chamber 26
A mixture is generated with the air sent through 27, and is heated by the glow plug 24 and burned at low temperature. Then, the combustion gas is injected from the injection holes 27 into the main combustion chamber 26.

[Problems to be Solved by the Invention] However, when the partition member 21 described above is unavoidable in manufacturing, a recess C is formed at the boundary between the flange portion 25 and the outer wall 28, and the partition member 21 is press-fitted into the space. This is a void
It becomes 29. Then, the air-fuel mixture in the swirl chamber 22 orbits along with the swirl flow, and a part thereof passes through a slight gap G between the partition member 21 and the wall surface surrounding the partition member 21 to reach the gap 29 and reaches here. Stay in. However, although the flame generated by the heating of the glow plug 24 rapidly burns the air-fuel mixture in the swirl chamber 22 due to the vortex, the flame becomes weaker while it enters the gap 29 through the gap G, and the mixture in the gap 29 is mixed. Qi is never completely burned.

Therefore, the air-fuel mixture staying in the gap 29, that is, the fuel cannot be effectively used, or the air-fuel mixture staying in the main combustion chamber 26 is sent after the main combustion chamber 26 finishes the combustion cycle, and The proportion of hydrocarbon (HC) components in exhaust gas increases with complete combustion.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a swirl chamber of a diesel engine capable of effectively using fuel and reducing HC components in exhaust gas. To provide.

[Means for Solving the Problem] In order to solve the above-mentioned object, the present invention press-fits a chamber partition member into a space of a cylinder head, and burns a combustion gas in a swirl chamber formed by the chamber partition member and the space. And a space through which combustion gas flows between the outer wall of the chamber partitioning member and the inner wall of the space is formed over the entire circumference of the swirl chamber and is formed on the outer wall of the chamber partitioning member. In a swirl chamber in a diesel engine, a gap generated between the hollow formed in the swirl and the inner wall of the space communicates with the gap, and combustion gas in the swirl chamber is retained in the gap through the gap. The gist of the invention is to provide the chamber partition member with a communication hole that allows the void to communicate with the swirl chamber and allows a flame to pass from the swirl chamber to the void.

[Operation] The flame in the swirl chamber passes through the communication hole, enters the space between the chamber partition member and the inner wall of the space, and burns the mixture remaining in the space.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to FIGS.

In FIG. 1, a fitting space 2 formed in a cylinder head on the upstream side of a main combustion chamber 1 of a diesel engine includes a lower large-diameter recess 3, a small-diameter recess 4 above the recess 3, and a hemispherical recess 5 above the small-diameter recess 4. It consists of A chamber partitioning member 6 is arranged in the fitting space 2, a flange portion 7 of the chamber partitioning member 6 is fitted and fixed in the large-diameter recessed portion 3, and a bowl-shaped portion 8 protruding upward from the flange portion 7.
The outer peripheral wall faces the inner peripheral wall of the small-diameter recess 4 with a slight gap G therebetween.

A swirl chamber 12 is formed by the bowl-shaped portion 8 of the partition member 6 and the hemispherical recess 5 of the fitting space 2. The swirl chamber 12 is formed in the flange portion 7 of the partition member 6 through the injection hole 16
Is communicated with the main combustion chamber 1 via. Then, after the compression process in the main combustion chamber 1, the air compressed by the piston is sent into the swirl chamber 12 through the injection holes 16 and spirals along the inner walls of the partition member 6 and the hemispherical recess 5 thereof. The flow of air flows in the swirl chamber 12.

A slanting groove 13a is provided on the peripheral wall of the hemispherical recess 5 of the fitting space 2, and fuel injected obliquely by the injection nozzle 13 is injected into the swirl chamber 12 from the inside of the slanting groove 13a. It is designed to meet and be mixed. Also,
Hemispherical recess 5 adjacent to the injection nozzle 13
A glow plug 15 is arranged in a vertical groove 14 which is transparently provided on the peripheral wall of the device, and a lower end portion of the glow plug 15 projects into the swirl chamber 12 to heat and burn the air-fuel mixture.

The partition member 6 is unavoidable during the manufacturing process,
The bowl-shaped portion 8 has a dent 9 at a location adjacent to the flange portion 7 on the outer peripheral surface.
Occurs. Then, in the state in which the partition member 6 is fitted in the fitting space 2, the portion of the recess 9 becomes the void 10, and this is the gap G.
Is in communication with

A pair of communication holes 17 are formed in the lower portion of the bowl-shaped portion 8 of the partition member 6 at two locations facing each other in the radial direction, and the swirl chamber 12 is connected to the void 10 by these communication holes 17. The communication hole 17 is set so as not to be parallel to the fuel injection direction of the injection nozzle 13 and the extending direction of the injection hole 16.

Now, the fuel obliquely injected from the injection nozzle 13 is sprayed on the inner wall of the swirl chamber 12 and then reflected, and rides on the high-speed swirl airflow in the swirl chamber 12 to circulate in the swirl chamber 12 and mix. Although the air-fuel mixture ratio is increased, a part of the air-fuel mixture enters the gap 10 through the gap G by the centrifugal force of the vortex flow.

In the swirl chamber 12, the air-fuel mixture is ignited by the heating of the glow plug 15, and the flame riding on the swirl orbits in the swirl chamber 12 to burn almost the entire air-fuel mixture. Then, the burned air-fuel mixture, that is, the combustion gas is injected into the main combustion chamber 1 through the injection holes 16 together with a small amount of the unburned air-fuel mixture, and the unburned air-fuel mixture is burned in the main combustion chamber 1.

Further, since the flame in the swirl chamber 12 weakens its heat when passing through the gap G, it cannot reach the void 10 through this gap G, but enters the void 10 through the communication hole 17, The air-fuel mixture that stays at is burned. Then, after the combustion gas passes through the gap G and returns to the swirl chamber 12,
It is injected from 16 into the main combustion chamber 1. Therefore, the air-fuel mixture in the void 10 is sent to the main combustion chamber 1 after being completely combusted.

Also, the flame that has entered the void 10 through the communication hole 17 is
The inside of the swirl chamber 12 is maintained at a high temperature by heating 12 from the outside. Therefore, the ignition delay of the fuel is eliminated in the swirl chamber 12, and the engine operates quietly by reducing the diesel knock.

Furthermore, since the penetration direction of the communication hole 17 of the swirl chamber 12 is not parallel to the fuel injection direction of the injection nozzle 13, the fuel injected from the injection nozzle 13 into the swirl chamber 12 directly communicates with the communication hole. It never crosses 17. Therefore, the fuel is prevented from entering the void 10 without being mixed with the compressed air.

Further, since the communication hole 17 of the swirl chamber 12 is provided so as not to be parallel to the extending direction of the injection hole 16, the main combustion chamber 1
The compressed air sent from the nozzles to the injection holes 16 does not directly pass through the communication holes 17 and hinder the generation of the vortex.

[Effect] As described in detail above, according to the present invention, it is possible to effectively use the fuel, reduce the HC component in the exhaust gas, and further exhibit the excellent effect of eliminating the ignition delay. To do.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the vortex type chamber of the present invention, FIG. 2 is a plane sectional view taken along line II-II, and FIG.
The drawing is a side sectional view showing a conventional swirl chamber. The fitting space 2 as a space portion, the chamber partition member 6, the swirl chamber 12, the void 10, the communication hole 17, and the gap G.

Claims (1)

(57) [Scope of utility model registration request] 1. A chamber partitioning member is press-fitted into a space of a cylinder head to generate combustion gas in a swirl chamber formed by the chamber partitioning member and the space, and an outer wall of the chamber partitioning member. A gap through which the combustion gas flows is formed between the inner wall of the space and the inner wall of the chamber, and a gap formed between the inner wall of the chamber and the recess formed in the outer wall of the chamber partitioning member. A swirl chamber in a diesel engine, wherein the combustion gas in the swirl chamber is retained in the void through the gap, the swirl chamber communicating the void with the swirl chamber, and A vortex flow chamber in a diesel engine in which a communication hole for passing a flame from a chamber to a space is provided in a chamber partition member.