Electrohydraulic servo steering valve - has valve body operated by force from magnet coil acting on ground plate

摘要

The electro hydraulically operated valve is esp. for servo assisted steering. Breakdowns caused by impurities in the hydraulic fluid are reduced with introduction of progressive input current/oil output flow characteristics instead of linear. The magnetic force is produced by a coil (3) with a ground plate (4) connected to the coil by a push rod (6) which operates in a cylindrical channel (5) and carries on its other end a valve body (10). The progressive characteristic is achieved by using a pot shaped magnet (1) instead of a permanent magnet. At a constant air gap (s) the magnet produces a force squarely proportional to the current through the coil.