Hydraulic drive for vehicle folding roof

摘要

The folding roof or soft-top of the vehicle is operated by a number of hydraulic rams (1 to 4) connected to a common hydraulic feed by one of a number of control valves. The hydraulic circuit has a single pressure sensor (12). A processor control monitors the pressure changes when a ram is connected to the hydraulic circuit, with the pressure rise at the end of the drive sequence accurately indicating the end setting of the ram. The hydraulic system includes a temperature sensor (13) and the processor control (11) operates the rams sequentially, with the separate end positions indicated by the pressure characteristics. The separate hydraulic circuits are vented back to the sump by slow restrictions. The hydraulic supply system and the control valves are mounted in a common block (7).