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US 4,538,579 AGranted
Fuel supply control system
AssigneeDiesel Kiki Co., Ltd.
InventorsKouichi Moriya, Kouki Iwata
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AssigneeDiesel Kiki Co., Ltd.
InventorsKouichi Moriya, Kouki Iwata
Estimating the term…
A fuel supply control system for an internal combustion engine has a step motor driver for outputting excitation pulses to an excitation circuit for a step motor and a comparator supplied with a target step position of the step motor from a target step position memory and a present step position of the step motor from a current step position memory. The comparator is responsive to an output from a step motor speed setting unit which corresponds to a main power supply voltage detected by a voltage detector for comparing the target and present step positions. The step motor driver is responsive to an output from the comparator for issuing excitation pulses to the excitation circuit to turn the step motor by one step in one direction or the other until the present step position is equal to the target step position.
A fuel supply control system for controlling an amount of fuel supplied to an internal combustion engine by driving a step motor operatively coupled to fuel supply control means of the engine and having an excitation circuit, comprising:
Dependencies are inferred from the claim text.
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Characterised by non-mechanical control linkages, e.g. fluid control linkages or by control linkages with power drive or assistance: of the…
Electric control of rotation speed: controlling air supply
With positive ignition: with fuel-air mixture admission into cylinder
Characterised by the means for actuating the throttles: at least one throttle being moved only by an electric actuator
Term ended 3 Feb 2004 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to a fuel supply control system for controlling the amount of fuel supplied to an internal combustion engine, and more particularly to a fuel supply control system in which a fuel supply control means is driven by a step motor.
Fuel supply control means such as throttle valves in spark ignition engines and control levers in diesel engines have conventionally been driven by a step motor which is energized to a step position corresponding to a position to which an accelerator pedal is depressed for thereby effecting fuel supply control.
Prior fuel supply systems have been disadvantageous in that the torque generated by the step motor varies due to variations in a power supply voltage applied to a step motor exciting circuit, so that the step motor tends to fail to produce a torque necessary for actuating the fuel supply control means, resulting in a step-out. One solution has been to use a feedback potentiometer, for example, for detecting the position of the step motor rotor to achieve increased operation reliability.
FIG. 1 is a block diagram of a fuel supply control system according to an embodiment of the present invention;
FIG. 2 is a block diagmam showing a microcomputer and input and output devices which implement the fuel supply control system of the present invention;
FIG. 3 is a side elevational view of an accelerator pedal;
In the following embodiment of the present invention, a step motor for actuating a fuel supply control means such as a throttle valve, for example, is shown and described as comprising a four-phase step motor drivable for rotation with two phases excited at a time.
The present invention is applicable generally to internal combustion engines such as spark ignition engines and diesel engines.
FIG. 1 shows a fuel supply control system according to an embodiment of the present invention for controlling fuel supply to a spark ignition engine 1 such as a gasoline engine.