Integrated fuel control unit for gas-operated engines

Abstract

An integrated fuel control unit for gas-operated internal combustion engines that includes a base on which a primary diaphragm is secured to define a primary fuel chamber. A primary fuel orifice is carried by the base, as is a primary control lever that is coupled to the primary diaphragm for controlling flow of fuel through the primary orifice as a function of inlet fuel pressure and engine demand. A secondary diaphragm is also secured to the base to define a secondary fuel chamber. A secondary orifice is carried by the base between the primary and secondary chambers, and a secondary control lever is coupled to the secondary diaphragm for controlling flow of fuel through the secondary orifice as a function of engine demand. A heat exchange section in the body receives engine coolant or engine oil for heat exchange with fuel so as to heat and vaporize the fuel between the primary and secondary chambers. A high-pressure fuel lock-off is carried by the body, and includes a solenoid coil mounted on the body and a solenoid plunger within the coil for selectively closing an end of the primary orifice remote from the primary control lever. A fuel inlet filter is carried by the body for filtering fuel prior to passage to the primary orifice and the lock-off. The solenoid plunger is normally urged by fuel inlet pressure and by a plunger spring to close the primary orifice, and is withdrawn from the primary orifice against the force of the spring by energization of the solenoid coil when the engine is operating. This feature helps ensure that fuel will not flow to the engine when the engine is not operating.

Dependencies are inferred from the claim text.