Proportional solenoid-operated fluid metering device

摘要

A device for metering pressurized fluid in proportion to a supplied input signal to an electric solenoid providing non-proportional magnetic flex that is rectified by a piece-wise non-linear spring assembly. The solenoid, an electromagnetic coil and a movable armature which positions a metering valve as needed to allow the fluid to flow through the device at the desired rate. The non-linear spring assembly includes a pair of flexure springs with four pairs of independent spring fingers. The spring fingers supply a plurality of piece-wise forces opposing movement of the armature caused by magnetic flux generated by the coil so as to provide a non-proportional opposing force to the non-proportional force of the magnetic flux. This allows the metering valve to be moved, and thereby fluid metered, in proportion to the input signal supplied to the coil. A position transducer is mechanically coupled to an elongated axial rod attached to the armature to provide valve position feedback to an electronic control unit for correcting deviations in the actual position of the valve from that desired by the input signal.