Internal-combustion engines – Charge forming device – Fuel injection system
Reexamination Certificate
1999-05-13
2001-05-01
Argenbright, Tony M. (Department: 3747)
Internal-combustion engines
Charge forming device
Fuel injection system
C123S00100A, C123SDIG003
Reexamination Certificate
active
06223729
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an engine for a model equipped with a fuel injection apparatus and method therefor, and more particularly an engine for a model which is able to throttle fuel sufficiently at the time of low speed revolution to secure the stability of operation and a method therefor.
2. Description of the Prior Art
A carburettor has been conventionally used in a two-stroke cycle or four-stroke cycle globe engine as a means for regulating quantity of fuel supplied to a combustion chamber of the engine.
The present applicant has proposed an engine for a model equipped with a fuel injection apparatus instead of the carburettor. In this engine, air pressure generated in a crankcase is introduced into a combustion tank through a check valve and stored in the tank and fuel is pressurized to 20-100 kPa.
The pressure generated in the crankcase of the engine varies depending on number of revolutions, that is to say, it is high at the time of high speed revolution, and it is low at the time of low speed revolution. Therefore, the aforementioned fuel tank is constructed so that the maximum pressure can be stored therein. It is, however, difficult in practice to maintain stably a constant pressure, for example, at 30-40 kPa.
Therefore, a regulator has been conventionally used in order to control constantly the pressure of fuel supplied from the fuel tank to feed to a fuel injection apparatus. The regulator is an apparatus for passing only the fuel having a certain given pressure.
FIG. 5
is a block diagram of a fuel injection apparatus of a conventional engine for a model and
FIG. 6
is a view of timing for the same. A rotatory pulse is generated by a rotatory pulse detecting apparatus mounted to, for example, a crankshaft of an engine. This rotatory pulse is inputted into an injection timing generating circuit
100
. The injection timing generating circuit
100
outputs a timing signal which is delayed by time interval t with respect to the rotatory pulse into a fuel injection signal generating circuit
101
. An injection period signal proportional to open of a carburettor is inputted into a fuel period generating circuit
102
. The fuel period generating circuit
102
generates an actual injection period signal which is inputted into the fuel injection signal generating circuit
101
. The fuel injection signal generating circuit
101
generates a fuel injection signal as shown in
FIG. 6
which is given to a fuel injection apparatus driving circuit
103
. The fuel injection apparatus driving circuit
103
drives a fuel injection apparatus
104
on the basis of the signal.
In a conventional engine of a model which pressurizes the fuel by air pressure in a crankcase and injects the fuel by a fuel injection apparatus, it is premised that the pressure of the fuel is constant, and the supply of the fuel is controlled by injection period. That is to say, when the number of revolutions is low, the injection period is shortened to decrease the quantity of the fuel, and when the number of revolutions is high, the injection period is lengthened to increase the quantity of the fuel.
At the time of low speed, however, the pressure of the fuel rises since the quantity of the fuel used is small, and the fuel becomes dense. And, since the quantity of the fuel used per unit time is large at the time of high speed, the supply of the fuel is not sufficient, and the fuel becomes thin. Therefore, in the conventional engine for a model, the revolution of the engine is unstable and there is possibility in some instances that overheat takes place at the time of high speed and engine stop takes place at the time of low speed.
SUMMARY OF THE INVENTION
An object of this invention is to provide an engine for a model which is able to throttle fuel sufficiently at the time of low speed revolution to secure the stability of operation and a method for controlling an engine for a model.
According to a first aspect of this invention, there is provided a method of controlling an engine for a model characterized in that, in the method of controlling the engine for the model equipped with a fuel injection apparatus (
50
), when an amount of fuel per one cycle required for driving the engine is amount corresponding to an injection period falling below the minimum injection period controllable in the aforesaid fuel injection apparatus, according to corresponding relationship between a predetermined injection period and intermittent injection data (for example, an intermittent injection data table
65
), the aforesaid intermittent injection data is determined corresponding to the aforesaid injection period, and the fuel is intermittently injected into the aforesaid fuel injection apparatus for a controllable period for injection on the basis of the intermittent injection data.
According to a second aspect of this invention, there is provided a method of controlling an engine for a model characterized in that, in the method of controlling the engine (
1
) for the model equipped with a fuel injection apparatus (
50
), said method is characterized by comprising a first step of generating a fuel injection period corresponding to an amount of fuel per one cycle required for driving an engine, a second step of judging whether or not the aforesaid injection period falls below the controllable minimum injection period in the aforesaid fuel injection apparatus, a third step of, when a judgement is brought to be below at the second step, according to a corresponding relationship between a predetermined injection period and intermittent injection data (for example, an intermittent injection data table
65
), determining the aforesaid intermittent injection data corresponding to the aforesaid injection period, and a fourth step of injecting fuel intermittently into the aforesaid fuel injection apparatus (
50
) for a controllable injection period depending on the timing making use of the selected intermittent injection data.
According to a third aspect of this invention, there is provided a method of controlling an engine (
1
) for a model characterized in that, in the method of controlling the engine for the model of the second aspect of this invention, when a judgement is brought not to be below at the aforesaid second step, fuel is injected into the aforesaid fuel injection apparatus (
50
) by one cycle for the aforesaid injection period.
According to a fourth aspect of this invention, there is provided a method of controlling an engine for a model characterized in that, in the method of controlling the engine for the model of the second aspect of this invention, the controllable injection period at the aforesaid fourth step is minimum injection period of the aforesaid fuel injection apparatus.
According to a fifth aspect of this invention, there is provided a method of controlling an engine for a model characterized in that, in the method of controlling the engine for the model of the second aspect of this invention, the intermittent injection data comprises bit data showing number of revolutions corresponding to one cycle of intermittent injection.
According to a sixth aspect of this invention, there is provided a controlling apparatus for an engine for a model (an electronic controlling element) characterized by comprising, in the controlling apparatus for the engine (
1
) for the model equipped with a fuel injection apparatus (
50
), an injection period generating means (
60
) for generating an injection period of fuel according to an amount required for driving the engine, an intermittent injection judging means (
61
) for judging whether or not the aforesaid injection period falls below the controllable minimum injection period in the aforesaid fuel injection apparatus, a data table (an intermittent injection data table
65
) corresponding to the injection period and the intermittent injection data in the aforesaid fuel injection apparatus, an intermittent injection data selecting means (
62
) for selecting the aforesaid intermittent injection data corresponding to
Matsuda Norio
Tanaka Kazuyuki
Yamamoto Michio
Argenbright Tony M.
Futaba Denshi Kogyo Kabushiki Kaisha
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Vo Hieu T.
LandOfFree
Controlling apparatus for engine for model and controlling... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Controlling apparatus for engine for model and controlling..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Controlling apparatus for engine for model and controlling... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2564039