JPS6056247B2 - fuel injected engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection engine that is mainly used in automobile engines and is useful for preventing exhaust gas pollution.

In conventional automobile engines, the efficiency of the intake air into the combustion chamber is poor because it is throttled by the throttle valve, and the flow rate of the intake air flowing into the combustion chamber is low, especially during idling operation and light load operation. Bad sex.

Therefore, the deterioration of ignition and combustibility described above is generally solved by supplying a rich mixture with good flammability, that is, a mixture with a low air-fuel ratio, but in this case, the increase in fuel consumption There are disadvantages such as an increase in harmful unburned gases HC and Co in the exhaust gas.

In addition, recently, with the aim of particularly reducing harmful NOx in exhaust gas, it has been proposed to burn a mixture that is sufficiently leaner than the stoichiometric mixture ratio, and it has also been proposed to extract part of the exhaust gas from the engine exhaust system. It has also been proposed to mix the fuel into an air-fuel mixture and combust it, but in either case, the ignitability and combustibility of the air-fuel mixture are reduced, resulting in poor drivability and fuel consumption. Against this background,
The objectives are as follows: 1) To improve fuel efficiency.

(2) It is possible to burn a lean air-fuel mixture that is difficult to operate stably in a normal engine, and as a result, harmful components in exhaust gas are reduced.

(3) It is possible to stably burn a mixture containing a large amount of recirculated exhaust gas, which is difficult to operate stably in a normal engine, and as a result, NOx in the exhaust gas is reduced.

(4) To stably burn a lean mixture or a mixture containing a large amount of recirculated exhaust gas without causing inconveniences such as a large decrease in output, deterioration of drivability, and deterioration of fuel efficiency.

(5) Harmful components in exhaust gas should be significantly reduced compared to conventional conventional engines, especially in the light load operating range of idling and low speed and low load. A technology for an engine with an injection chamber for a vehicle has been proposed for the purpose of such purposes, and the present invention relates to the application of this proposed technology.

However, in the technology of this engine with an injection chamber, a combustion promoting flow such as a laminar flow (swirl) or spots (turbulence) is formed in the air-fuel mixture in the combustion chamber by energizing the gas flow. Here, to explain its structure and operation, as shown in FIG. Install, spark plug 3
The suction boat 5
This is to form a combustion promoting flow S for the air-fuel mixture sucked into the combustion chamber 2 from a
An appropriate gas such as secondary air or exhaust gas recirculated from the engine exhaust pipe 6 is used.

The gas passage 7 leading to the jet hole 4 is provided with a gas intake valve 8 that opens and closes the passage.
is driven by an operating valve mechanism specially disposed on a camshaft 10 and a rocker arm shaft 11, similar to the operating mechanism 9 of an air-fuel mixture suction valve (not shown).

That is, this air intake valve 8 slides within the guide 12 and is normally lifted up by the spring 13 to close the passage, but when the piston 14 is drawn in. During the required time period from the beginning of the air stroke to the beginning of the compression stroke, the cam 16 is
is driven and pushed down to open the passage 7. Furthermore, a gas passage 17 is provided upstream of the gas passage 7 and communicates with a gas supply mechanism (not shown). Next, the operation of the engine with the above configuration will be described. Here, the operation will be described when the gas passage 17 is communicated with the air cleaner and air is used as the energizing gas.

During the intake stroke of the piston 14, the air-fuel mixture is sucked under negative pressure from the suction boat 5 into the combustion chamber 2 through the intake pipe 18, and is sucked through the gas passages 17, 7, and enters the combustion chamber 2 through the jet hole 4. Forced by the airflow to form a combustion promoting flow.

Therefore, since there is no path resistance comparable to that of the carburetor's bench lily, throttle valve, etc. in the supply path of the energizing gas, the flow velocity of the ejected air is extremely higher than the intake flow velocity of the air-fuel mixture. The air-fuel mixture in the combustion chamber 2 is strongly promoted. Furthermore, at this time, the ignition plug 3 is scavenged by the high-velocity airflow, so the burnt gas remaining near the plug gap is dissipated into the combustion chamber 2. Note that the amount of air flowing into the combustion chamber 2 from the jet hole 4 reaches 10% to 30% of the total amount of intake air including the air-fuel mixture.
Next, the piston 14 enters the compression process, but due to its inertia, the accelerated flow of the mixture continues until the ignition timing of the cylinder, so when the spark plug 3 ignites at the end of compression, the nearby mixture is easily ignited. Furthermore, the combustion action spreads into the combustion chamber 2 at an extremely fast flame propagation speed to promote combustion, and thus the combustibility of the air-fuel mixture becomes extremely good.

As mentioned above, in the above-mentioned engine, by improving the combustibility of the mixture, the misfire limit of the leanness of the mixture increases,
Therefore, stable combustion operation can be obtained. Therefore, in this engine, it is possible to sufficiently suppress the generation of harmful components without reducing the drivability of the engine in any way. An object of the present invention is to apply the technology of the above-mentioned engine with an injection chamber to a fuel injection type engine, that is, the engine has good combustibility, and
An object of the present invention is to provide a fuel injection engine that generates low levels of harmful components.

The present invention will be explained below based on illustrated embodiments.

FIG. 2 is a cutaway view showing the main part of the engine of the first embodiment, that is, the vicinity of the combustion chamber 22 of the cylinder head 21, and is a schematic view showing the engine at a position where the intake boat 5 is removed. It is.

The aspect of each part other than the illustrated part is the same as each part of the engine shown in FIG.
Components with the same reference numerals as in the drawings are members having the same features as the members with the same numerals shown in FIG. 1, and the above-mentioned illustration method is also the same in FIG. 3 referred to in the following description. This first
In the engine of the embodiment, the intake boat 5 is connected to an intake pipe (not shown) that supplies only air, and the fuel is
It is supplied separately from the air by a fuel injection pump (not shown) located in place in the engine.

A spark plug 3 is attached to the wall of the combustion chamber 22, and an energizing gas jet hole 4 similar to that described above is also provided, and an injection pump is provided on the opposite side of the jet hole 4 from the spark plug 3. A jet nozzle 23 is attached to the head 21 with its tip 23a facing the wall surface.

The mounting position and mounting direction of the nozzle 23 are arranged such that the fuel injection flow merges with the energizing gas jet flow.

Therefore, the fuel particles injected from the nozzle tip 23a first collide with the air flow sucked in from the intake valve (not shown) to form an air-fuel mixture, and then the air-fuel mixture is further transferred to the ejection hole 4. After this merging, the air-fuel mixture is energized by the gas flow and enters the combustion chamber 22 into a combustion promoting flow S.
form.

In this way, the flow state of the mixture in this engine is not only similar to that in the proposed engine shown in Figure 1, but also the mixture produced by fuel injection has better atomization properties than the mixture produced by the carburetor. Therefore, the combustibility of the mixture is better than when using a carburetor. Next, the second embodiment shown in FIG. 3 will be explained. In this engine, the head 3
The tip 33a of the nozzle 33 attached to the nozzle 1 protrudes just in front of the intake valve 34 in the intake boat 5, and when the intake valve 34 is opened, fuel particles injected from the nozzle tip 33a mix with intake air. The air-fuel mixture flows out into the combustion chamber 32 through the valve opening space, and then forms a promoted flow S as in the case of the first embodiment.

Therefore, the combustibility of the air-fuel mixture in this engine is
This is the same as in the embodiment. As described above, according to the fuel injection engine of the present invention, the ejection hole for the energizing gas is provided between the fuel injection nozzle and the spark plug, and the energizing gas flow forms a combustion promoting flow in the air-fuel mixture. Therefore, the combustibility of the air-fuel mixture is extremely excellent, making it possible to dilute the concentration of the air-fuel mixture to the utmost.

As described above, this engine has excellent drivability and extremely low levels of generation of harmful components, and has great practical and pollution prevention effects.

``Brief explanation of the drawings Figure 1 is a schematic diagram of an engine with an injection chamber to which the present invention is applied, Figure 2 is a schematic diagram of main parts of a fuel injection type engine showing an embodiment of the present invention, and Figure 3 is a schematic diagram of an engine with an injection chamber to which the present invention is applied. FIG. 2 is a schematic diagram of main parts of an engine showing another embodiment.

Claims (1)

[Scope of Claims] 1. An energizing gas ejection hole that is bored near the spark plug on the wall of the cylinder head combustion chamber and that acts to energize a combustion promoting flow to the air-fuel mixture in the chamber, and a gas ejection hole in the ejection hole. A valve mechanism that is interposed in the passage and operates to open the gas passage at a predetermined time between the air supply stroke and the compression stroke in response to engine rotation, and a valve mechanism that is connected to the valve passage of the valve mechanism, In an engine equipped with a sub-air supply system consisting of a gas supply mechanism for supplying fuel gas, the intake port is connected to the intake pipe for air supply, and the fuel injection pump is disposed at an appropriate location, and the injection pump is connected to the intake pipe. 1. A fuel injection engine, characterized in that a nozzle is attached to a cylinder head, and its attachment position is set at such a position that the fuel injection flow joins the energizing gas jet flow. 2. The fuel injection engine according to claim 1, wherein the nozzle is mounted with the tip of the nozzle facing the wall surface of the combustion chamber. 3. The fuel injection type engine according to claim 1, wherein the nozzle is installed with the tip of the nozzle facing directly in front of the intake valve in the intake port.