JPS587061Y2 - Engine altitude compensation device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an engine altitude compensation device that is mainly used in automobile engines and is useful for preventing exhaust gas pollution.

In conventional automobile engines, the efficiency of air intake into the combustion chamber is particularly poor due to the throttle valve.

Moreover, the ignition and combustibility of the engine are poor during idling operation and light load operation where the flow rate of intake air flowing into the combustion chamber is low.

Therefore, the deterioration in ignition and combustibility is generally solved by supplying a rich mixture with good combustibility, that is, a mixture with a low air-fuel ratio.

In this case, there are disadvantages such as an increase in fuel consumption and an increase in harmful unburned gases HC and CO in the exhaust gas.

Furthermore, recently, it has been proposed to burn a mixture that is sufficiently leaner than the stoichiometric mixture ratio, particularly for the purpose of reducing harmful NOx in exhaust gas.

It has also been proposed to extract part of the exhaust gas from the engine exhaust system and mix it into the mixture and burn it, but in either case, the ignitability and combustibility of the mixture decreases, so This had the disadvantage of deteriorating performance and fuel efficiency.

Based on this background, the primary purpose, ie.

■) Improving fuel efficiency.

2) It is possible to stably burn a lean mixture, which is difficult to operate stably with a normal engine, and as a result,
To reduce harmful components in exhaust gas.

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) Significant reduction in output and deterioration of drivability.

To stably burn a lean mixture or a mixture containing a large amount of recirculated exhaust gas without causing inconveniences such as deterioration of fuel efficiency.

5) To significantly reduce harmful components in exhaust gas compared to conventional conventional engines, especially in the idling and low-speed, low-load light-load operating ranges.

A technology for an engine with an injection chamber for a vehicle has been proposed for purposes such as the above, and the present invention relates to the application of this proposed technology.

In this engine technology with an injection chamber, combustion promoting flows such as laminar flow (swirl) and uneven flow (turbulence) are formed in the air-fuel mixture in the combustion chamber by energizing the gas flow. Now, to explain its structure 1 function, as shown in the left half of FIG.
An energizing gas ejection hole 4 is provided in the vicinity of the ignition plug 3, and the ignition plug 3 is energized by the ejected flow of the gas that scavenges the ignition plug 3.

It forms a combustion promoting flow S for the air-fuel mixture taken into the combustion chamber 2 from the intake port 5, and the energizing gas includes air taken in from an air cleaner or secondary air for an exhaust gas purification device. Alternatively, an appropriate gas such as exhaust gas (not shown) recirculated from the engine exhaust pipe 6 is used.

The gas passage 7 leading to the ejection hole 4 is provided with a gas intake valve 8 that opens and closes the passage.

This intake valve 8 has a camshaft 10 and a rocker arm shaft 11, as well as a valve operating mechanism 9 of an intake valve for air-fuel mixture (not shown).
It is driven by a valve train specially installed in the

That is, the intake valve 8 slides within the guide 12 and is normally lifted up by the spring 13 to close the passage during the required time period from the beginning of the intake stroke of the piston 14 to the beginning of the compression stroke.
It is driven and pushed down by the cam 16 via the rocker arm 15 to open the eye passage 17.

Furthermore, a gas passage 17 is provided upstream of the gas passage 7 and communicates with the gas supply mechanism.

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 simply communicated with the air cleaner through a passage with low flow resistance and air is used as the energizing gas.

In no-load or light-load operating conditions with a small throttle valve opening of the carburetor, the air-fuel mixture that is sucked into the combustion chamber 2 at negative pressure from the intake port 5 through the intake pipe 18 during the intake stroke of the piston 14 flows through the gas passage. While being sucked through 17°7,
It is energized by the air flow entering the combustion chamber 2 from the jet hole 4 to form a combustion promoting flow.

Therefore, since there is no path resistance comparable to the venturi, throttle valve, etc. of the carburetor 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 inside is strongly promoted.

Also, at this time. Since the spark plug 3 is scavenged by the high velocity air flow C, the burnt gas remaining near the plug gear is dissipated into the combustion chamber 2.

Note that the amount of air flowing into the combustion chamber 2 from the jet hole 4 is
This amounts to 10% to 30% of the total amount of intake air including air-fuel mixture.

Next, the piston 14 enters the compression stroke, 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 high flame propagation speed due to the combustion promoting flow, 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.

However, when a vehicle equipped with this engine drives in a high mountain area, the air supply mass inevitably decreases due to a decrease in atmospheric pressure, that is, a decrease in air density. As shown in the fuel ratio characteristic graph, the air-fuel mixture becomes over-enriched, resulting in a decrease in drivability due to deterioration in engine combustion performance, and also has drawbacks such as an increase in the level of harmful components generated.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, namely, to provide an engine that maintains good combustibility and keeps the generation of harmful components at a low level even when the vehicle is traveling at high altitudes. An object of the present invention is to provide an altitude compensation device.

The present invention will be explained below based on one embodiment shown in the drawing.

The structure of the embodiment uses the above-described engine with an injection chamber, and the energizing gas passage 17 is connected to the air cleaner 22 above the carburetor 21 via an air pipe 20 as a gas supply passage, and further, There is an orifice 2 in the middle of the same pipe 20.
3 is interposed.

A bypass passage pipe 24 is attached to the downstream side of the orifice 23 in a branched manner, and the upstream end of the passage pipe 24 is connected to the air cleaner 22. A valve 25 is installed.

The valve shaft 26 of the operating valve 25 is driven by the moving end of the barometer-shaped bellows 28 via the lever 27 and slides, that is, in the direction of closing (opening) the valve passage due to an increase (decrease) in atmospheric pressure. The valve moves to the opening position corresponding to the atmospheric pressure value.

The opening degree of the operating valve 25 is set so that the bypass passage is closed at atmospheric pressure on a flat ground, and the bypass flow rate is gradually increased in response to a decrease in atmospheric pressure.

According to the engine configured in this way, when a vehicle equipped with the engine travels at a high altitude, the energizing air is supplied to the passage pipe 2.
Since a large amount of air-fuel mixture in the combustion chamber 2 is supplied to the nozzle hole 4 through the two-way pipes 0 and 24, the air-fuel mixture in the combustion chamber 2 is enriched due to the decrease in air density.

It is diluted by increasing energized air and restored to normal dilution.

Note that even when a fuel injection device is provided in place of the carburetor in the engine configuration, the same effect can be obtained by forming the compensation device in the same manner as described above.

As described above, according to the altitude compensator for a lean burn engine of the present invention, an operating valve is provided in the energizing gas supply passage to increase the gas flow rate when the atmospheric pressure drops, so that the engine is always maintained in good condition. It is possible to maintain a good combustion state, and even when driving at high altitudes, good combustibility and low levels of harmful components are maintained, which has practical and pollution prevention effects.

Furthermore, according to one invention, by installing an altitude compensation device, in addition to the conventional altitude compensation effect of preventing the enrichment of the air-fuel mixture,
It is possible to alleviate the general phenomenon that the combustion rate decreases as you go to higher altitudes where the atmospheric pressure decreases, resulting in a decrease in engine output.

In other words, due to the action of the altitude compensator, the amount of energizing gas increases relative to the total amount of intake air as the altitude increases, and accordingly, the combustion promoting flow in the combustion chamber is strengthened, thereby increasing the combustion speed. This prevents a decrease in engine output, and eliminates the need to change the ignition timing to match the altitude.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an engine altitude compensator showing an embodiment of the present invention, and FIG. 2 is a graph of air-fuel ratio characteristics. S: Combustion promoting flow, 1: Turinda head, 2: Combustion chamber, 3: Spark plug, 4: Nozzle hole. 7...Gas passage, 8...Intake valve as a valve mechanism. 17... Gas passage, 20... Piping as a supply passage, 23... Orifice 24...
...Bypass pipe. 25... Operating valve.

Claims (1)

[Scope of Claim for Utility Model Registration] An energizing gas nozzle that is opened near the spark plug on the wall of the cylinder head combustion chamber and is drilled in the cylinder head toward the vicinity of the plug gap of one spark plug, and a Fl nozzle. installed in the gas passage. In response to engine rotation, during the required time from the beginning of the intake stroke to the beginning of the compression stroke, the valve mechanism that opens the gas passage and the valve passage of the eye valve mechanism are energized with air, etc. Equipped with a sub-air supply system consisting of a gas supply mechanism that supplies gas,
The structure is configured such that energizing gas is strongly injected into the combustion chamber from the injection hole mainly due to the high negative pressure generated in the fuel chamber, and a combustion promoting flow is formed for the air-fuel mixture taken in from the main intake system. In the engine, an orifice is interposed in the middle of a gas supply passage connected to the valve passage, a bypass is provided to connect the upstream side of the orifice on the supply passage and the downstream side of the orifice, and furthermore, an orifice is provided in the middle of the gas supply passage connected to the valve passage. An altitude compensation device for an engine, characterized in that an operating valve that opens a flow path when the engine is lowered is interposed in the middle of the bypass.