Hydromotor controller for crane - has safety valve in vent line responding to excessive pressure loading

摘要

The controller (S) for at least one hydromotor (H1,H2) has a flow regulator (Z) in the feed line (1) to a displacement slider (W). The slider is coupled to the hydromotors (H1,H2) via respective working lines (3,4), with load pressure sensor points (5,6) and control lines (9,10,11,12,13) providing a load-dependant control pressure. At least one safety valve (V1,V2,V3) is switched in response to a given load pressure or movement limit and lies in a section of the vent line (14,15,18,19,20). Pref. each safety valve (V2) acts as a pressure limiting valve. The other valves (V1,V3) comprise 2/2 way magnetic valves brought into the blocking position by energising a magnet (29). ADVANTAGE - Prevents excessive pressure loadings.