Hydraulic control device for double work cylinder, esp steering appts. - controls both chambers of steering appts with proportional valve supplied by pressure source, and includes digital control circuit

摘要

The hydraulic control device has a proportional valve (12,61) connected to the work chambers (14,15) of the work cylinder (11) with no intermediate valve switch. The proportional valve is a 4-way 3-position valve which controls a regulator (42) for an electronic control circuit (22). The proportional valve (12) has a stored characteristic line which is used to linearise an off switch (12). The proportional valve (61) may alternatively be a 4-way 4-position valve driven by a proportional magnet (62). The electronic control circuit (22) is a digital circuit. ADVANTAGE - Safe operation, simple, compact.