Internal-combustion engines – Charge forming device – With fuel pump
Reexamination Certificate
2003-07-03
2004-10-26
Lo, Weilun (Department: 3747)
Internal-combustion engines
Charge forming device
With fuel pump
C123S490000, C123S406470, C123S179170
Reexamination Certificate
active
06807949
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention pertains to a fuel injection and ignition system for an internal combustion engine used for supplying fuel to and igniting the internal combustion engine.
BACKGROUND OF THE INVENTION
Many vehicles such as a snowmobile, an outboard motor and a small two-wheeled vehicle have no battery mounted thereon. Of late, even an internal combustion engine driving such a vehicle having no battery mounted thereon has an electronically controlled fuel injection system (EFI) used as means to supply fuel and an ignition system including a microprocessor used to precisely control an ignition timing to ignite the engine for the purpose of purifying the exhaust gas and improving the startability of the engine.
In the fuel injection and ignition system for the internal combustion engine for driving the vehicle having no battery mounted thereon, there has been employed a power source system for applying a power source voltage to an injector, a fuel pump, an ignition circuit and a controller to control them from a magneto generator driven by the engine, which is referred to as “MAG power system” hereinafter.
The internal combustion engine for driving such a small-sized vehicle using the MAG power source system is adapted to be generally started by a starter such as a rope starter or a kicking starter using human power.
Since the rotational speed of a crankshaft of the engine cannot get enough high when it starts using the human power starter such as the rope starter or the kicking starter, the generator driven by the engine cannot generate the high voltage. Thus, there are provided individual power source systems for applying the respective power source voltages to the injector, the fuel pump, the ignition circuit and the controller in order to start the engine by the limited electric power generated by the generator so that the output characteristics of the respective power source systems are made proper whereby the extremely low speed rotation when the engine starts causes no fault in which the injector cannot be driven due to shortage of the electric power for the controller and the fuel having the predetermined amount of injection cannot be injected due to the shortage of the fuel pressure caused by shortage of the driving electric power for the fuel pump even though the injector can be in the condition of being able to be driven and thus the startability of the engine is improved.
Such a prior art in which the electric powers from the individual power source systems are applied to the injector and the controller as aforementioned is disclosed in Japanese Utility Model No. 2573118 (JP2573118U). In this document, although power sources for the fuel pump and the ignition circuit are not described, the commercially available fuel injection and ignition system having the idea embodied has individual power source systems from which the power source voltages are applied to the fuel pump and the ignition circuit, respectively.
An example of the practically used power source system is shown in
FIG. 7. A
magneto generator
1
having a rotor mounted on a crankshaft of the internal combustion engine is provided on the side of a stator with a generation coil
1
a
for driving a fuel pump FP, a generation coil
1
b
for driving an injector INJ, a generation coil
1
c
for driving an ignition circuit, a generation coil
1
d
for driving a controller ECU and a generation coil
1
e
for driving a car body electric load
3
such as head lamps. These generation coils are wound on one pole (tooth) or a plural of poles of an armature core in accordance with the amount of electric power required for the load to which the electric power is supplied.
The outputs of the generation coils
1
a
through
1
e
are converted into DC voltages by respective power source circuits
2
a
through
2
e
including a voltage regulating rectifier circuit and a power source capacitor Cd connected across the output terminals thereof and supplied to the fuel pump FP, the injector INJ, the ignition circuit including an ignition coil IG, the controller ECU and the car body electric load
3
, respectively. The controller ECU comprises a microprocessor MPU for arithmetically operating the ignition timing and the amount of fuel injection and, in addition thereto, comprises a switch Qf to control the energization of the fuel pump FP, a switch Qj to control the energization of the injector INJ and a switch Qi to the energization of a primary coil of the ignition coil IG. In the illustrated example, the ignition circuit is constituted by the ignition coil IG and the switch Qi.
Although, in the example shown in
FIG. 7
, the power source circuits
2
a
through
2
e
are provided separately from the controller ECU, in some case, the power source circuits
2
a
through
2
e
may be collectively formed with the controller ECU so as to form a single unit.
With the construction shown in
FIG. 7
, the controller can be operated at the extremely low speed of the engine by getting the proper output characteristic of each of the power source circuits
2
a
through
2
e
so as to perform the fuel injection and the ignition, which causes the startability of the engine to be improved.
However, in the construction of
FIG. 7
, there are required many generation coils having different characteristics in the single generator so that the power source circuit is provided for each of the generation coils. This causes the following problems;
(a) Since the winding operation should be made while copper wire is changed for every generation coil, the winding operation of the generator is troublesome, which causes the higher manufacture cost of the generator.
(b) Since many generation coils require the respective terminal treatment, this needs a number of steps for the terminal treatment, which also causes the higher manufacture cost of the generator.
(c) Since the number of the wires of the wire harness led out from the generator increases, the laying operation of the wire harness gets troublesome.
(d) Since the number of the power source circuits increases, the cost of the power source section gets higher.
The vehicles such as the snowmobiles or ATVs (buggies) considered to be used in the out-of-the-way places or the vehicles such as the motorboats having a possible accident, which would occur if the engine stops, are preferably in the condition where the internal combustion engine can be operated even in the case where the batteries cannot be used.
The MAG power source system is the one excellently used for the case where the engine is laid under such a circumstance of extremely low temperature as cannot guarantee an output of a battery enough to enable the fuel injection system and the ignition system to be driven without relying on the battery after the engine starts and before it is steadily operated or the case where the engine is required to be operated even though the battery is deteriorated.
However, since the prior MAG power source system has a number of power source circuits as shown in
FIG. 7
, the system could be inevitably more expensive than the ordinary power source system having the battery used.
In Japanese Patent Application Laid-Open Publication No. 2002-21624 (JP2002-21624A), it is disclosed a start control system in which a power source section is so constructed that the fuel pump, the injector and the ignition system can be driven by a single power source circuit having a generator used as a power source and in which, when the engine starts, the fuel pump, the injector and the ignition system never serve simultaneously as the load to the power source circuit by stopping the operation of the fuel pump when the injector and the ignition system are driven in the course of starting the engine.
According to the start control system disclosed in JP2002-21624A, since the number of the power source circuits provided in the power source section can be decreased, the cost of the system can be reduced.
However, in this system, since the operation of the fuel pump stops when the fuel should be injected in
Kishibata Kazuyoshi
Kitagawa Yuichi
Sato Hiroyasu
Kokusan Denki Co. Ltd.
Lo Weilun
Pearne & Gordon LLP
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