JPH0458064A - Fuel supply method for internal combustion engine - Google Patents

Abstract

PURPOSE:To start an engine even with the use of fuel having a low startability and to reduce the mission of HC by feeding heated mixture into a catalyst device so as to produce an intermediate produce having a high volatility after fuel atomized by an ultrasonic atomizing device is burnt and then extinguished. CONSTITUTION:Fuel is fed from a fuel feed valve 10 to an ultrasonic vibrating member 11, and is atomized by an ultrasonic atomizing device 12 into fine droplets. Then, a part of the fuel is ignited and burnt by an ignition device 13. Thus formed flame is extinguished by an extinguisher 14, and heated mixture is led to a catalyst device 15 where aldehyde is created from, for example, methanol fuel by decomposition reaction, reforming reaction, partial oxidation or the like, or dimethyl ether or the like is created by dehydrated concentration reaction. Thus obtained intermediate product having a high volatility is fed into the engine 1 which can therefore, enhance its startability in a cold condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel supply method applied to an internal combustion engine using a fuel with low startability such as kerosene, alcohol, or a mixture of alcohol and gasoline.

[Prior Art] Conventionally, in order to improve the startability of internal combustion engines, spark ignition engines such as gasoline engines have been provided with a choke valve or a starting increase mechanism in systems using a carburetor fuel supply device, and In systems using fuel injection valves, the amount of fuel supplied at startup is increased by electronically controlling the injection valves.

[Problems to be solved by the invention] Although these measures ensure startability at normal temperatures, there are problems such as taking time to start at low outside temperatures and increasing HC emissions due to increased fuel volume. is occurring.

Furthermore, for low-volatile fuels other than gasoline, it is difficult to start at room temperature or low temperature even with the conventional method described above, and in the case of 100% methanol fuel, the low-temperature starting temperature is limited to about 5°C. For this reason, for example, in the case of methanol fuel, a method is adopted to improve startability by mixing about 15% gasoline at the time of starting, but the low starting temperature is -i
The temperature limit is approximately o'c to -15°C, which poses a problem in use in cold regions.

As a solution to this problem, an attempt was made to use an ultrasonic atomizer instead of a fuel injection valve to atomize the fuel using ultrasonic vibrations, promote evaporation of the fuel, and improve ignition, which improved startability to some extent. However, in the case of 100% methanol fuel, the low temperature starting temperature is on the O''CC level.

The reason for this is that the method of installing the ultrasonic atomizer in the intake pipe and the flow of the spray inside the combustion chamber are inappropriate, resulting in fuel adhering to the inner wall of the cylinder, and poor vaporization of the fuel, which prevents it from being sufficiently vaporized when the piston is compressed. and that it does not lead to ignition, and
Even if the fuel flows into the combustion chamber as a spray stream, sufficient vaporization may not occur and ignition may not occur due to the large latent heat of vaporization, such as alcohol fuel, or the high boiling point, such as kerosene.

An object of the present invention is to solve the above-mentioned problems, and to make it possible to start an engine using a fuel with low startability at a low temperature, shorten the starting time, and reduce HC emission. .

[Means for Solving the Problems] To this end, the fuel supply method for an internal combustion engine of the present invention provides an ultrasonic atomization device 12 disposed in the intake pipe 4 of the engine 1 in an engine that uses fuel with low startability. and a fuel injection valve 9, an ignition device 13, a flame extinguisher 14, and a catalyst device 15 disposed between the ultrasonic atomizer 12 and the fuel injection valve 9, and when starting the engine, the ultrasonic wave After burning and extinguishing the atomized fuel in the atomization device 12, the heated air-fuel mixture is supplied to the catalyst device 15 to generate a highly volatile intermediate product, and after the engine is started, the fuel injection valve 9 It is characterized by supplying fuel from

Note that the numbers added to the above configurations are for comparison with the drawings to facilitate understanding, and the configurations of the present invention are not limited thereby.

[Operations] In the present invention, as shown in FIG. 1, for example, when starting the engine, the ultrasonic vibration member 11 is
The ultrasonic atomizer 12 atomizes the fuel into fine droplets, a part of this fuel is ignited and burned by the ignition device 13, and the generated flame is extinguished by the extinguisher 14. The heated air-fuel mixture is introduced into the catalyst device 15, where, for example, in the case of methanol fuel, aldehyde is produced by decomposition reaction, reforming reaction, partial oxidation reaction, etc., or dimethyl ether etc. is produced by dehydration condensation reaction. . By supplying this highly volatile intermediate product to the engine 1, startability at low temperatures is improved.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the method for supplying fuel to an internal combustion engine according to the present invention.

In the present invention, it is most effective to use a fuel with low startability, such as kerosene, alcohol, or a mixed fuel of alcohol and gasoline.

In the figure, a spark ignition engine 1 has a cylinder 2, a piston 3, an intake pipe 4, an exhaust pipe 5, an intake valve 6, and an exhaust valve 7. An ultrasonic atomizer 12 consisting of a fuel supply valve 10 and an ultrasonic vibration member 11 is installed upstream of the fuel pump 9 .

An atomization surface is formed at one end of the ultrasonic vibration member 11, and an electric/acoustic conversion element is provided at the other end. In addition,
The shape of the atomization surface may be a well-known shape such as a horn shape, a round shape, a bat shape, or the like.

Further, an ignition device 13, a flame extinguisher 14, and a catalyst device 15 are arranged between the fuel injection valve 9 and the ultrasonic atomization device 12.

The ignition device 13 is composed of a spark plug or a glow plug, and ignites and burns a portion of the fuel atomized by the ultrasonic atomization device 12. The flame extinguisher 14 is formed of a metal or ceramic porous plate or a nicum body, and extinguishes the flame generated by the ignition device 13 to prevent damage to the catalyst device 15 disposed downstream.

The catalyst device 15 has a carrier supporting a catalyst layer that reacts at low temperature or room temperature. For example, in the case of methanol, aldehyde is generated by a decomposition reaction, a reforming reaction, a partial oxidation reaction, etc., or a dehydration condensation reaction is performed. The reaction produces dimethyl ether, etc., and in short, it produces a highly volatile intermediate product.

The operation of the present invention having the above configuration will be explained.

When starting the engine, fuel is supplied from the fuel supply valve 10 to the ultrasonic vibration member 11, the fuel is atomized into fine droplets by the ultrasonic atomizer 12, and a portion of this fuel is ignited and combusted by the ignition device 13. let In this case, since all the starting fuel is not combusted, either control the amount of air flowing in to match the amount of air needed for combustion, or create a separate intake air hole on the downstream side to draw in only the combustion air. There are several possible methods.

The flame generated by the ignition device 13 is extinguished by the flame extinguisher 14, and the heated mixture is introduced into the catalyst device 15, where it effectively reacts with the catalyst layer. For example, in the case of methanol fuel, a decomposition reaction, Aldehyde is produced by a modification reaction, partial oxidation reaction, etc., or dimethyl ether etc. is produced by a dehydration condensation reaction. By supplying this highly volatile intermediate product to the engine 1, startability at low temperatures is improved. After starting the engine, the fuel supply is switched to from the fuel injection valve 9.

In the present invention, in the case of 100% methanol fuel, the low temperature starting temperature is -15°C or less, and methanol 8
5%, gun 9f15, the low temperature starting temperature could be improved to below -25°C.

Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, a nozzle, an A catalyst device 15 is provided.

In this embodiment, when starting the engine, the switching valve 16 causes air to flow into the bypass pipe 4a, and the ultrasonic atomizer 12, ignition device 13, flame extinguisher 14, and catalyst device After the product is generated and the engine is started, air flows into the intake pipe 4 through the switching valve 16, so that the durability of the catalyst device 15 can be improved.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made.

For example, the ultrasonic atomizer 12, the ignition device 13, the flame extinguisher 14, and the catalyst device 15 may be arranged as a set in a gathering part of the intake pipe, or they may be arranged in the intake pipe of each cylinder. You may also set it. Also, gasoline may be used as the fuel, and the engine is not limited to spark ignition engines.
It may also be applied to diesel engines.

[Effects of the Invention] As described above, according to the present invention, when starting an engine, after burning and extinguishing the fuel atomized by the ultrasonic atomizer,
The heated air-fuel mixture is supplied to the catalytic converter to generate highly volatile intermediate products, which enables low-temperature starting of engines that use fuel with low startability, shortens starting time, and improves HC.
Enables reduction of emission.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the fuel supply method for an internal combustion engine according to the present invention, and FIG. 2 is a partial cross-sectional view showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Engine, 4... Intake pipe, 9... Fuel injection valve, 12... Ultrasonic atomization device, 13... Ignition device,
14...Flame extinguisher, 15...Catalyst device. Applicant: Tonen Corporation (1 other person) Representative patent attorney: Hiroki Shirai (7 others) Figure 2

Claims (2)

[Claims] (1) In engines that use fuel with poor startability,
It includes an ultrasonic atomizer and a fuel injection valve disposed in an intake pipe of an engine, and an ignition device, a flame extinguisher, and a catalyst device disposed between the ultrasonic atomizer and the fuel injection valve. When starting the engine, the ultrasonic atomizer burns and extinguishes the atomized fuel, and then supplies the heated mixture to the catalyst device to generate a highly volatile intermediate product. A fuel supply method for an internal combustion engine, characterized in that fuel is supplied from the fuel injection valve. (2) The intake pipe is provided with a bypass pipe that can be switched by a switching valve, and the ultrasonic atomizer, the ignition device, the flame extinguisher, and the catalyst device are arranged in the bypass pipe. Method of fueling the internal combustion engine described.