Proportional type electromagnetic valve
AssigneeHitachi, Ltd.
InventorsTorazo Nishimiya, Masamitsu Okumura, Seisaku Numakura
Life of this patent
Estimating the term…
Abstract
A proportional type electromagnetic valve comprises a flow rate control valve secured to a movable core which moves a stroke in proportion to the input current, and a valve seat portion cooperative with the flow rate control valve to control the flow rate. In addition to a bias spring providing for urging the flow rate control valve toward the valve seat portion, a second spring is disposed on the movable core for urging the flow rate control valve to release it from the valve seat portion. The resultant force of the two springs makes the stroke of the flow rate control valve proportional to the input current.
Claims6
A proportional type electromagnetic valve for controlling flow rate of fluid comprising, electromagnetic driving means having axially movable output shaft means whose moving stroke is in proportion to an input current fed to the electromagnetic driving means, a plurality of valve means mounted on the output shaft means for controlling flow rate of fluid in proportion to the stroke of the output shaft means, a first spring means biasing the output shaft means in a direction opposite to a direction of force applied to the output shaft means by the electromagnetic driving means, and a second spring means biasing said output shaft means in the same direction as the direction of force applied to said output shaft means by said electromagnetic driving means, each of said first and second spring means having a linear force-displacement characteristic such that the sum of the spring forces of said first and second spring means biasing said output shaft means is in linear proportion to the stroke of said output shaft means.
Dependencies are inferred from the claim text.