| 摘要 |
<p>1283994 Hydraulic motor control circuits ROBERT BOSCH GmbH 22 Sept 1970 [23 Sept 1969] 44977/70 Heading F1P A control device for effecting supply and return of hydraulic fluid to and from at least two actuators (not shown) selectively comprises a pressure fluid inlet 6, a return outlet 7 and a conduit 47 connected to each actuator and the device also comprises a spring-closed main valve 55 for each actuator open to a combined inflow and outflow passage 20, 48 and openable when one end 52 of a spool 51 carried thereby is subjected to hydraulic pressure at 58 controlled by spool valve 63 when displaced to the right by a single-stroke solenoid 62; the device also comprising an auxiliary valve 8 connected upstream of all the main valves and which in the open position shown connects inlet 6 with the upstream side of each valve 55 and when moved to the left by a solenoid 28 cuts off said supply inlet 6 from said passage 20, 48 and connects the latter to the return 7. The device also includes a throttle orifice 36 in a cup-member 34 which latter when solenoids 28, 62 are deenergized and valves 13, 61, 55 are in the positions shown becomes unseated to connect inlet 6 to return 7. On energizing one or other of solenoids 62 pressure fluid having passed through orifice 36 and passages 37, 67 is fed to chamber 58 and displaces spool 51 to open valve 55 thereby extending the associated actuator. If now solenoid 28 is energized the inlet 6 is isolated from passage 20, 48 and the latter is connected to return 6 to effect the return stroke of the actuator. The hydraulic actuators referred to are single acting but in a modified device the actuators are double acting.</p> |
