JPH0388927A - Control method for starting of engine with ultrasonic atomizer device - Google Patents

Abstract

PURPOSE:To enhance the low temp. starting characteristic of an engine by injecting the fuel from a main fuel supply valve when engine is in normal operation, and from an aux. fuel supply valve for a certain period at the time of engine starting. CONSTITUTION:The fuel supplied intermittently from a main fuel supply valve 5 is atomized and injected by an ultrasonic atomizing device 1, mixed with air stream, introduced to a combustion chamber 18 via a suction path 14 formed from a throttle valve 12 and suction manifold 13 and a suction valve 16, and combusted with spark ignition. Thus the power is transmitted to a piston 20 of a cylinder 19. At the time of engine starting, the fuel is injected from an aux. fuel supply valve 6 for a certain period to increase the amount of fuel supply, and thereby the starting characteristic is improved. To make this motion, the injection start timing set according to the point of inflammation of the fuel and the temp. of combustion chamber at the time of starting is turned into a map and a control table, and this table is reference at the time of starting to control the fuel injection timing. Thus the starting characteristic can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to automobiles, outboard motors, portable power a! The present invention relates to a start control method for an engine equipped with an ultrasonic atomizer used in a drive device of an f1 consumer heat pump, etc.

[Conventional technology]

Conventionally, for example, spark ignition engines in automobiles have used a vaporizer method in which fuel is sucked out with an air flow, atomized, and mixed with air, or a pressure-based method in which liquid fuel is pressurized and injected from a nozzle, atomized and mixed with air. Injection valve method is used,
The air-fuel mixture is transported to the combustion chamber using high-speed airflow, where it is ignited by a spark and combusted.

These air-fuel mixtures are a state in which atomized fuel particles are suspended in a high-speed air current, and some of the fuel is vaporized, but
Most of it adheres to the walls of the flow path and becomes liquid, and is sucked into the cylinder through the intake pipe while being pushed by the airflow. On the way, it is vaporized by heat from the flow path wall surface or heat inside the cylinder. be done.

In this way, since most of the fuel is transported and vaporized in the wall flow, the injected fuel is not quickly transported to the cylinders, and the responsiveness and combustion efficiency of the engine are not necessarily sufficient.

In contrast, in the ultrasonic atomization device proposed by the applicant, fuel is almost completely atomized during injection and mixed with air, and this air-fuel mixture is efficiently transported into the cylinder by airflow. Therefore, it is possible to increase the combustion efficiency and increase the responsiveness of the engine by performing fuel injection in pulses and changing the injection frequency or duty.

[Problem to be solved by the invention]

Incidentally, in recent years, regulations on exhaust emissions (HC, Co) from gasoline engines have become stricter, and attempts have been made to use alcohols such as methanol and ethanol as fuel. Although methanol and ethanol are superior in terms of environmental issues, their flash points are high at 11°C and 13°C, respectively, so if the engine is left for a long time, the combustion chamber temperature may drop below the flash point of these fuels. In such a case, the engine cannot be started, and even if an ultrasonic atomizer is used, low-temperature startability is poor.

The present invention is intended to solve the above problems, and an object of the present invention is to provide a start control method for an engine equipped with an ultrasonic atomizer, which can improve the low-temperature startability of the engine.

[Means to solve the problem]

The starting control method for an engine equipped with an ultrasonic atomizer according to the present invention includes arranging an ultrasonic atomizer 1 and a main fuel supply valve 5 upstream of a throttle valve, and arranging an auxiliary fuel supply valve 8 downstream of the throttle valve. In this spark ignition engine, during normal engine operation, fuel is injected from the main fuel supply valve 5, and when the engine is started, fuel is injected from the auxiliary fuel supply valve 6 for a predetermined period of time to increase the amount of fuel supplied. Features.

[Effect]

In the present invention, during normal operation, fuel is injected from the main fuel supply valve 5, and when starting the engine, fuel is injected from the auxiliary fuel supply valve 6 for a predetermined period of time to increase the amount of fuel supplied, thereby improving startability. Improve.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an engine equipped with an ultrasonic atomizer according to the present invention.

Figure 1 shows S P I (Single Point
2 shows an automobile engine of the Injector type. However, for convenience, the figure shows only one cylinder so that the fuel supply is perpendicular to the axis of the ultrasonic atomizer. In the figure, 1 is an ultrasonic atomizer, 5 is a main fuel supply valve, 6 is an auxiliary fuel supply valve, 12 is a throttle valve, 13 is an intake manifold, 14 is an intake path, 15 is an exhaust path, 16 is an intake valve, 17 is an exhaust valve, 18 is a combustion chamber, 19 is a cylinder, and 20 is a piston. The feature of the present invention is that an ultrasonic atomizer 1 and a main fuel supply valve 5 are disposed upstream of the throttle valve, and an auxiliary fuel supply valve 6 consisting of an ultrasonic atomizer is disposed downstream of the throttle valve. This is the point that was established.

Fuel intermittently supplied from the main fuel supply valve 5 is atomized and injected by the ultrasonic atomizer 1, mixed with the air flow, and is mixed with the throttle valve 12, the intake passage 14 formed by the intake manifold 13, and the intake valve 16. The fuel is guided to the combustion chamber 18 through the engine, where it is combusted by spark ignition, and power is transmitted to the piston 20 of the cylinder 19.

The burned gas is exhausted from the exhaust valve 17 through the exhaust path 15.

In the present invention, when starting the engine, starting performance is improved by injecting fuel from the auxiliary fuel supply valve 6 for a predetermined period of time to increase the amount of fuel supplied. In order to perform this operation, the injection start timing set according to the flash point of the fuel and the combustion chamber temperature at the time of startup is created as a map and used as a control table, and this table is referenced at the time of startup to control the fuel injection timing. This can improve starting performance.

Note that the auxiliary fuel supply valve 6 is disposed downstream of the throttle valve, and the reason and effect thereof will be explained. Existing S
In a PI type engine, a cold start injector, which corresponds to the auxiliary fuel supply valve 6, is installed upstream of the throttle valve and injects fuel into the engine's engine body during a cold start to improve startability. The injection angle is larger than that of the main injector. The reason why fuel is injected into the throttle body is to improve distribution among the cylinders by allowing the fuel to pass through the throttle body. In the present invention, by using an ultrasonic injection valve as the auxiliary fuel supply valve 6 to completely atomize the fuel and installing it downstream of the throttle valve, ignitability is improved and startability is improved.

〔Effect of the invention〕

As described above, according to the present invention, when starting the engine, fuel is injected from the auxiliary fuel supply valve for a predetermined period of time to increase the amount of fuel supplied, thereby improving startability. It is possible to improve low-temperature startability even with a fuel with a high score.

Furthermore, by using an ultrasonic injection valve as the auxiliary fuel supply valve to completely atomize the fuel and installing it downstream of the throttle valve, ignitability is improved and startability is improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an engine equipped with an ultrasonic atomizer according to the present invention. l... Ultrasonic atomization device, 5... Main fuel supply valve, 6.
... Auxiliary fuel supply valve, 12... Throttle valve. Tade rice map master destination

Claims (1)

[Claims] (1) In a spark ignition engine in which an ultrasonic atomizer and a main fuel supply valve are arranged upstream of a throttle valve and an auxiliary fuel supply valve is arranged downstream of the throttle valve, during normal engine operation, the main fuel is supplied A starting control method for an engine equipped with an ultrasonic atomizer, characterized in that fuel is injected from a valve, and when the engine is started, fuel is injected from the auxiliary fuel supply valve for a predetermined period of time to increase the amount of fuel supplied.