Electromagnetically actuated directional valve

摘要

What is proposd is an electrohydraulic directional valve (11), the control slide (19) of which can be deflected into three positions (36, 38, 39) counter to a spring system (25) by one individual single-acting switching magnet (15). The spring system (25) has two springs (29, 32) which take effect in succession in a stroke-dependent manner and which lead to a force jump (63), assigned to a middle position (38), in the force characteristic of the spring system (25), the said force jump being intersected by the stroke/force characteristic (64) of the switching magnet (50) when a part current lower than the rated load flows through the latter. The directional valve (11) can be extended by means of a main valve (12) to form a fail-safe two-stage 4/3-switching valve (10). <IMAGE>