Walbro Corporation

James K Miller

Matthew L Werner

William C Eberline

Ralph G Hardwick

An automatic fuel enrichment system for cranking and warm-up of an internal combustion engine in which a solenoid valve is responsive to control electronics for selectively feeding enrichment fuel to the engine air intake manifold. The valve control electronics receives a signal from the engine ignition system and controls a solenoid valve as a function of engine speed. Specifically, the control electronics energizes the solenoid valve when engine speed exceeds a preset minimum cranking threshold until the engine reaches a preset idle speed threshold, at which point enrichment is terminated. In the event that the engine begins to stall during warm-up and engine speed declines to a preset intermediate threshold, the enrichment valve is again energized until the engine reaches idle speed.

Automatic engine fuel enrichment and ignition advance angle control

A fuel delivery system for purging air from the reservoir of a diaphragm carburetor on an internal combustion engine and for supplying priming fuel to the carburetor air intake. A pump is responsive to electrical signals from priming control circuitry to draw fuel through the carburetor reservoir and to fuel under pressure to a nozzle positioned at the carburetor air intake. The electronic control circuitry is responsive to an operator for initiating a priming operation and includes a temperature sensor coupled to the engine for controlling duration of the priming operation, and thus the quantity of engine priming fuel, as a function of engine temperature. A second timer is responsive to operator initiation of a priming operation for preventing regeneration of the priming control signal to the pump, and thereby preventing attempting repriming in the event of failure of the engine to start.

Cold-start engine priming and air purging system

A fuel delivery system for purging air from the reservoir of a diaphragm carburetor on an internal combustion engine and for supplying priming fuel to the carburetor air intake. A pump is responsive to electrical signals from priming control circuitry to draw fuel through the carburetor reservoir and to feed fuel under pressure to a nozzle positioned at the carburetor air intake. The electronic control circuitry is responsive to an oprator for initiating a priming operation and includes a temperature sensor coupled to the engine for controlling duration of the priming operation, and thus the quantity of engine priming fuel, as a function of engine temperature. A second timer is responsive to operator initiation of a priming operation for preventing regeneration of the priming control signal to the pump, and thereby preventing attempting repriming in the event of failure of the engine to start.

A fuel delivery system for purging air from the reservoir of a diaphragm carburetor on an internal combustion engine and for supplying priming fuel to the carburetor air intake. An manual pump has an inlet coupled by a fuel line through the carburetor reservoir to a fuel supply, and an outlet connected by the fuel line to a constant flow rate nozzle orifice positioned at the carburetor air intake. A pressure switch is connected in the fuel line between the pump and orifice and provides a signal, in the form of a switch closure, to priming control circuitry whenever fuel, as distinguished from air, is pumped through the orifice to the carburetor air intake. The control circuitry receives battery power through the pressure switch contacts, and includes an integrator for accumulating total time of fuel flow and thereby indirectly indicating the total quantity of priming fuel supplied through the constant-flow orifice. When the integrated time duration exceeds a selected threshold, an LED is driven by an oscillator to advise the operator to terminate the manual priming operation. Most preferably, the time-duration threshold is varied as a function of engine temperature.

An electromagnetic fuel atomizer for internal combustion engine applications which includes a generally C-shaped core of integral ferromagnetic construction having arms which form a pair of flat parallel surfaces spaced from each other to form a gap therebetween. The core structure is characterized by a fundamental resonant frequency determined in part by mass and elasticity of the core structure, and the ferromagnetic core is electromagnetically energized at such fundamental resonant frequency. Liquid fuel is supplied to the gap between the core arm surfaces, and standing waves are generated therein as the core arms vibrate with respect to each other. As amplitude of oscillations and such standing waves increase, fuel droplets break away from the standing wave nodes and are aspirated into the engine.

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Cass City, MI, United States of America

James K Miller