| 摘要 |
<p>1521834 Hydraulic control circuits FICHTEL & SACHS AG 5 Aug 1976 [7 Aug 1975]. 32635/76 Heading F1P In a circuit, Fig. 1, in which a pump 31 supplies fluid under pressure sequentially to one or more hydraulic accumulators 33, 37 until they are fully charged, spring-loaded valves 32, 36 switch the fluid either to the accumulators or to a reservoir 30 and the valves are each loaded by a spring which has in its working range a load deflection curve section wherein the spring force is reduced as the deflection increases, Fig. 4. When the accumulator is not charged, a Bellville spring 8, Fig. 2 holds a slide valve 15 in the position shown. Fluid under pressure enters through a port 3 and passes through bores 18, 17 and a check-valve 20 to charge the accumulator. The spring 8 is pre-tensioned and when the pressure in the accumulator reaches the maximum spring pressure the slide valve 15 causes the spring to go over-centre and the fluid supply is switched through to port 4. A drain passage 24 is provided. If the return port 4 is to be pressurized, a seal 25, Fig. 5, and a drain 26 are provided. Fig. 6 shows an arrangement in which a ball-valve 27 provides connection between the ports 3, 4 and also acts as a pressure relief valve for the pump.</p> |
