BACKGROUND ART Generally, conventional fuel supply control system for automobiles is a system for generating power required to drive a car by supplying fuel into an engine of the car, which comprises a fuel tank for storing fuel, a fuel filter for filtering off impurities which exist in the fuel, a carburetor or a fuel injection device making mixed air and supplying the mixed air into the engine, a fuel pump sending the fuel into the carburetor or fuel injection device, and a fuel pipe connecting these above devices, etc.

U. S. Patent No. 4,491, 143 (issued to Nissan Motor company, Limited, Japan on January 1,1985) discloses such a fuel supply system for automobiles.

FIG. 1 shows a fuel supply system for internal combustion engines in accordance with the prior art.

In FIG. 1, fuel for the engine is delivered by the fuel injection pump 10 which draws fuel thereinto from the fuel

tank 12 through the fuel line 14 in which the water separator 30 is positioned. A fuel filter 90 is positioned in the fuel line 14 downstream of the water separator 30. The fuel filter 90 serves to prevent any contaminants from reaching the fuel injection pump 10. The fuel injection pump 10 delivers fuel under pressure to the fuel injectors 20 through which metered fuel is injected into the individual cylinders of the engine.

Superfluous fuel is discharged from the fuel injection pump 10 into the return line 22 to which the injector spill ports are connected.

Such a fuel supply system in accordance with the prior art injects fuel into each cylinder or intake manifold of the engine by the injectors 20 connected with each cylinder.

On this occasion, the amount of fuel inj ected by the inj ectors is controlled by an ECU (electronic control module) automatically, and the amount of fuel injected into each cylinder or intake manifold by the injectors is the same.

However, in the foregoing fuel control system in accordance with the prior art, since the amount of fuel injected into each cylinder or intake manifold of the engine is the same, it is difficult to control the amount of fuel injected by each injector when to save fuel by reducing the injection amount of each injector partially.

DISCLOSURE OF INVENTION The present invention is contrived to solve the above-mentioned problems. It is an object of the present

invention to provide a fuel supply system for automobiles, which can inject fuel differently according to the power of an engine.

In order to accomplish the above object of the present invention, the present invention provides a fuel supply control system for automobiles comprising a fuel storing means for storing fuel; a fuel pumping means for pumping fuel from the fuel storing means, which is connected with the fuel storing means ; a first fuel injection means injecting 60-80% of the optimum fuel injection amount required for maximum engine power, which is connected with the fuel pumping means and inject fuel pumped from the fuel pumping means into each cylinder head or intake manifold; a first control means for controlling the fuel amount injected from the first fuel inject ion means into each cylinder head or intake manifold, which is connected with the first fuel injection means electrically; a second fuel injection means injecting 20-40% of the optimum fuel injection amount required for maximum engine power, which is connected with the fuel pumping means and inject fuel pumped from the fuel pumping means into each cylinder head or intake manifoldmanually ; and a second control means for controlling whether the second fuel injection means injects fuel or not selectively, which is connected with the second fuel injection means electrically.

It is preferable that the first fuel injection means a primary injector injecting 65-75% of the optimum fuel injection amount required for mazimum engine power, and the second fuel inject ion means is an auxiliary injector injecting

25-35% of the optimum fuel injection amount required for maximum engine power.

Most preferably, the first fuel injection means can inject 70% of the optimum fuel injection amount required for maximum engine power, and the second fuel injection means inject 30% of the optimum fuel injection amount required for maximum engine power.

The second control means may be a switch installed so that it can be controlled on the driver's side.

The second fuel injection means is arranged in parallel pairs with the first fuel injection means.

The above-mentioned fuel control system for automobiles according to the preferred embodiment of the present invention switches off the second control means and does not operate the auxiliary injector under the condition that the high load is not necessary. If the auxiliary injector is not operated, 60-80% of the optimum fuel injection amount required for maximum engine power is injected by the only primary injector therefore fuel can be saved.

Further, in times of high-speed driving or high-load driving, 20-40% of the optimum fuel injection amount required for maximum engine power is injected additonally by operating the second fuel inj ection means manually by the second control means, and the power of the engine can be increased because the maximum amount of fuel required to provide the maximum engine power can be injected.

BRIEF DESCRIPTION OF DRAWINGS

Other features and advantages of the present invention will become more apparent from the following descriptions taken in connection with the accompanying drawings, wherein: FIG. 1 is a schematic view of the fuel supply system for automobiles in accordance with the prior art; FIG. 2 is a schematic view of the fuel supply system for automobiles in accordance with the preferred embodiment of the present invention; FIG. 3 is a sectional view showing an injector in accordance with the preferred embodiment of the present invention; and FIG. 4 is a schematic view showing a variation in accordance with the preferred embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION EMBODIMENTS Hereinafter, the fuel supply system for automobiles according to the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. The same elements refer to the same reference number, and the description of unnecessary elements about the preferred embodiment of the present invention is omitted.

Referring to FIG. 2, the fuel supply system for automobiles according to the embodiment of the present invention provides a fuel supply control system for

automobiles comprising a fuel tank 110 for storing fuel; a fuel pump 120 for pumping fuel from the fuel tank 110, which is connected with the fuel tank 110; a primary injector 130 injecting 60-80% of the optimum fuel injection amount required for maximum engine power, which is connected with the fuel pump 120 and injects fuel pumped from the fuel pump 120 into each cylinder head or intake manifold of an engine; an ECU (Electronic Control Module) 140 for controlling the fuel amount injected from the primary injector 130 into each cylinder head or intake manifold, which is connected with the primary injector 130 electrically; an auxiliary injector 150 injecting 20-40% of the optimum fuel injection amount required for maximum engine power, which is connected with the fuel pump 120 and the injected fuel pumped from the fuel pump 120 into each cylinder head or intake manifold of the engine manually; and a control switch 160 for controlling whether the auxiliary injector 150 injects fuel or not selectively, which is connected with the auxiliary injector 150 electrically.

The fuel tank 110 is storing fuel appropriate to the kind of car engine, i. e. diesel engine or gasoline engine, and the fuel pump 120 pumps fuel stored in the fuel tank 110 and delivers it into the primary injector 130 and the auxiliary injector 150.

The primary injector 130 and the auxiliary injector 150 are injection nozzles, which have solenoid in the inside thereof, and once fuel is pumped from the fuel pump 120, they are inputted from the ECU 140 or the control switch

160, and inject fuel into the engine.

The general injector 130 for fuel supply control system is prepared numerously so that it can be connected with each cylinder of the engine, which commonly comprises multiple cylinders, and the supplied fuel is injected under the control of the ECU 140. Such an injector 130 may be mounted in a different way according to the kind of car engine.

It is preferable that for example, diesel engines, which can produce a large amount of horsepower by injecting fuel into a combustion chamber directly, are mounted on the cylinder head directly in order to inject fuel into the combustion chamber, and gasoline engines, which do not inject fuel into the combustion chamber directly but mix and deliver fuel with air and then ignite the mixture of fuel and air, are mounted so that they can be connected with the intake manifold gathering tubes in order to direct intake air.

The inj ector for the fuel supply control system according to the preferred embodiment of the present invention comprises the primary injector 130, which can inject 60-80% of the optimum fuel injection amount required for maximum engine power under the control of the ECU 140 and the auxiliary injector 150, which can inject 20-40% of the optimum fuel injection amount required for maximum engine power respectively as aforementioned.

Meanwhile, if the amount of fuel injection for the primary injector 130 is below the 65% of the optimum fuel injection amount required for maximum engine power, the power of engine is lowered, and if it is over the 75% of the optimum fuel

injection amount required for maximum engine power, a waste of fuel may be generated, therefore it is preferable that the primary injector 130 injects 65-75% of the optimum fuel injection amount required for maximum engine power, and the auxiliary injector 150 injects 25-35% of the optimum fuel injection amount required for maximum engine power.

Further, the most preferably, it is efficient that the primary injector 130 injects 70% of the optimum fuel injection amount required for maximum engine power, and the auxiliary injector 150 injects 30% of the optimum fuel injection amount required for maximum engine power.

For example, the amount of the fuel injection for common injectors used in a car engine, which an output of power is 2000cc (i. e. 4 cylinders having 500cc capacity respectively), is 180g/min (-. 23. 761b/hour) and the common <BR> <BR> injectorsinject180g (. 0. 41b) perminute. Howevertheamount of fuel injection for the primary injector 130 of the fuel supply control system according to the embodiment of the present invention is 126g/min (-16. 631b/hour), which corresponds to 70% of the fuel injection amount of the common injectors, and the amount of fuel injection for the auxiliary injector 150 is 54g/min (-7. 131b/hour), which corresponds to 30% of the fuel injection amount of the common injectors.

In normal driving conditions, only 70% of the optimum fuel injection amount required for maximum engine power is injected, consequently fuel can be saved, in the event of requiring a high output of power, 100% of the optimum fuel injection

amount required for maximum engine power is injected and maximum engine output is attained by operating the auxiliary injector 150 and injecting 30% of the optimum fuel injection amount required for maximum engine power additionally.

The amount of fuel injection of these primary injector 130 and auxiliary injector 150 can be changeable according to the capacity of the cylinders, etc.

The ECU 140 has various sensors in the inside thereof, and is inputted with information of the revolution number of engine, the amount of intake air and the starting signal, etc. from the aforementioned sensors. The ECU 140 inputted with these means of information orders the primary injector 130 to inject fuel automatically by calcuating the amount of optimum fuel injection with a predetermined program.

The control switch 160 may be installed so that it can be controlled from the driver's side.

The control switch 160 is connected with the auxiliary injector 150 electrically and installed near the driver's side, and the user can selectively decide whether the auxiliary injector 150 injects fuel or not, when he wants a large input.

In the mean time, the auxiliary injector 150 may be arranged in parallel pairs with the primary injector 130 according to the structure of the car's engine.

For example, in diesel engines, which inject fuel into the combustion chamber directly, the primary injector 130 and the auxiliary injector 150 may be installed in parallel pairs on the cylinder head.

Also, in gasoline engines, which do not inject fuel

into the combustion chamber directly, since there is no necessity for installing them on the cylinder head like diesel engines, they are installed in parallel pairs on the intake manifold. Such a structure is described in detail in the following.

Foregoing fuel supply control system according to the preferred embodiment of the present invention supplies fuel stored in the fuel tank 110 into the primary injector 130 and the auxiliary injector 150 by pumping fuel with the fuel pump 120. The primary injector 130 is controlled by the ECU 140 so that fuel can be injected into each cylinder head or intake manifold automatically, and whether the auxiliary injector 150 injects fuel or not is controlled by the control switch 160 according to the user's decision.

The primary injector 130 has the capacity for injecting only 65-75% of the optimum fuel injection amount required for maximum engine power therefore the primary injector 130 injects 65-75% of the optimum fuel injection amount required for maximum engine power.

The auxiliary injector 150 injects the remaining 25-35% of the optimum fuel injection amount required for maximum engine power, which is not injected by the primary injector 130, into each cylinder head or intake manifold of an engine manually according to the control of the control switch 160.

It is preferable not to turn on the control switch 160 in normal driving condition, e. g. in the event of driving at low speeds on level ground, as there is no need for a large output of power. In normal driving condition, only

65-75% of the optimum fuel injection amount required for maximum engine power is injected into each cylinder head or intake manifold by the primary injector 130, therefore 25-35% of the optimum fuel injection amount required for maximum engine power can be saved.

Consequently, in normal driving condition the user does not turn on the control switch 160 and can drive his car by using 65-75% of the optimum fuel injection amount required for maximum engine power, and in the event of requiring a large input, the user can turn on the control switch 160 and operate the auxiliary injector 150, therefore the engine output can be greater by injecting 25-35% of the optimum fuel injection amount required for maximum engine power additionally.

Referring to FIG. 3, the structure of the primary injector 13 0 of the fuel supply control systemaccording to the preferred embodiment of the present invention will be described in detail.

The primary injector 130 installs a solenoid 131 in the center thereof, and comprises a valve 133 for opening and closing a tip 132 of the injector, and a direct plate 134 which can set an injection shape in the lower end of the solenoid 131.

If the solenoid 131 is magnetized in the inside of the injector 130 by the ECU 140, the fuel injected on the upper end of the injector 130 passes through the valve 133 and is delivered into the direct plate 134 which is in the outlet side.

The direct plate 134 is connected with the injector tip 132 in which six mechanically processed holes are configured, and fuel is injected in a conical shape and supplied into the cyinder by the holes.

Because the injector 130 has a regular outlet 135 area and pressure of fuel, the amount of the fuel injection is settled by open time, i. e. , dwell time of the solenoid 131.

Accordingly the ECU 140 can increase and decease the amount of fuel injection by controlling the dwell time of the solenoid 131. The injector 130 of the fuel supply control system for automobiles according to the preferred embodiment of the present invention is controlled so that it can inject 65-75% of the optimum fuel injection amount required for maximum engine power.

A detailed description of the auxiliary injector 150 is omitted because the structure of it is the same, although its amount of fuel injection is different from that of the primary injector 130.

FIG. 4 shows a variation of the fuel supply control system for automobiles in accordance with the preferred embodiment of the present invention.

Referring to FIG. 4, the variation of the fuel supply control system for automobiles in accordance with the preferred embodiment of the present invention comprises a fuel tank 110 for storing fuel; a fuel pump 120 for pumping fuel from the fuel tank 110, which is connected with the fuel tank 110; a primary injector 130 injecting 60-80% of the optimum fuel injection amount required for maximum engine

power, which is connected with the fuel pump 120 and injects fuel pumped from the fuel pump 120 into each cylinder head or intake manifold of an engine; an ECU (Electronic Control Module) 140 for controlling the fuel amount injected from the primary injector 130 into each cylinder head or intake manifold, which is connected with the primary injector 130 electrically; an auxiliary injector 150 injecting 20-40% of the optimum fuel injection amount required for maximum engine power, which is connected with the fuel pump 120 and injects fuel pumped from the fuel pump 120 into each cylinder head or intake manifold of the engine manually; and a control switch 160 for selectively controlling whether the auxiliary injector 150 injects fuel or not, which is connected with the auxiliary injector 150 electrically.

The primary injector 130 can inject 65-75% of the optimum fuel injection amount required for maximum engine power, and the auxiliary injector 150 can inject 25-35% of the optimum fuel injection amount required for maximum engine power, and the most preferably, it is efficient that the primary injector 130 injects 70% of the optimum fuel injection amount required for maximum engine power, and the auxiliary injector 150 injects 30% of the optimum fuel injection amount required for maximum engine power.

The control switch 160 may be installed so that it can be controlled on the driver's side.

It is preferable that the control switch 160 is installed near the driver's side because the driver has to control the control switch 160 at his will and operate the auxiliary

injector 150 manually.

The primary injector 130 and the auxiliary injector 150 are installed in parallel pairs on the cylinder head.

Referring to FIG. 4, the primary injector 130 and the auxiliary injector 150 are installed in parallel pairs on the cylinder head or intake manifold of the car engine.

In the situation of diesel engines, the primary injector 130 and the auxiliary injector 150 can be installed in parallel pairs on the cylinder head. Further, in the situation of gasoline engines, since there is no necessity for installing them on the cylinder head like the diesel engines, they are installed in parallel pairs on the intake manifold.

The aforementioned fuel supply control system for automobiles further comprises a fuel supply line 171 for supplying fuel into the primary injector 130 and/or the auxiliary injector 150, which is connected with the fuel pump 120; a fuel distribution rail 172 for distributing fuel pumped from the fuel pump 120 to the primary injector 130 and/or the auxiliary injector 150; and a fuel return line 173 for returning fuel to the fuel tank 110 not distributed by the primary injector 130 and/or the auxiliary injector 150.

The fuel pumped from the fuel pump 120 is delivered into the fuel distribution rail 172 through the fuel supply line 171, and then it is distributed to each primary injector 130 and/or the auxiliary injector 150 within the fuel distribution rail 172, and injected into the cylinder head or intake manifold of the car engine, and the fuel not

distributed to the primary injector 130 and/or the auxiliary injector 150 is returned to the fuel tank 110 by the fuel return line 173.

Hereinafter, the operation of the variation of the fuel supply control system for automobiles according to the embodiment of the present invention will be described.

First fuel stored in the fuel tank 110 is pumped with the fuel pump 120. The pumped fuel is delivered to the fuel distribution rail 172 through the fuel supply line 172. The fuel distribution rail 172 distributes delivered fuel into each primary injector 130 and auxiliary injector 150.

On this occasion, the primary injector 130 has the capacity, which can inject 65-75% of the optimum fuel injection amount required for maximum engine power, and the auxiliary injector 150 has the capacity, which can inject 25-35% of the optimum fuel injection amount required for maximum engine power.

Accordingly, in normal driving conditions, e. g. , in the event of driving at low speeds on level ground, there is no need for a large output, therefore only 65-75% of the optimum fuel injection amount required for maximum engine power is injected into each cylinder head or intake manifold by the primary injector 130 if the control switch 160 is not turned on.

Not in normal driving conditions, but in the condition of requiring a large output of power, by turning on the control switch 160 and operating the auxiliary injector 150, a large output of power can be attained by injecting 25-35% of the

optimum fuel injection amount required for maximum engine power by the auxiliary injector 150 into each cylinder head or intake manifold additionally, besides the 65-75% of the optimum fuel injection amount required for maximum engine power.

As stated above, fuel distributed to the primary injector 130 and/or the auxiliary injector 150 is not distributed, but fuel beyond the predetermined pressure is returned to the fuel tank 110. This kind of fuel is delivered to the fuel tank 110 through the fuel return line 173.

The aforementioned fuel supply control system for automobiles according to the embodiment of the present invention comprises the primary injector which can inject 65-75% of the optimum fuel injection amount required for maximum engine power, the auxiliary injector which can inject 25-35% of the optimum fuel injection amount required for maximum engine power, and the control switch, thus the user can control the amount of fuel injection at will. Hence the amount injected into each cylinder head or intake manifold of the car engine can be controlled, under the user's necessity the user can use less fuel than the amount required for maximum engine power, therefore it has effectiveness in that fuel can be saved.

While the present invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be effected therein without departing from the spirit and scope of the invention as defined by the appended claims.