SHUT-OFF SAFETY VALVE UNIT

摘要

FIELD: hydraulic drives of on-board, timber loaders and construction manipulators. SUBSTANCE: unit contains two direct-acting controllable safety valves 1 with control channels, two check valves 3 forming two groups of valves together with safety valves 1 which are located in bore of housing 4. Housing 4 is provided with supply holes 5 and discharge holes 6. Inlet 7 of safety valve 1 and outlet 8 of check valve 3 are brought in communication and connected to respective discharge holes 6. Inlets 9 of check valves 3 are connected to supply holes 5. Inlet of two make-up valves 10 are connected to drain hole. Besides that unit is provided with boosters 13 mounted in bores of housing 4 for opening the shut-off members 14 of safety valves 1. Control chambers of boosters 13 are mounted in housing 4 and are brought in communication with supply holes 5 of valves of opposite group. Both groups of valve are located in one housing 4. Make-up valves 10 are mounted in bores of housing 4 which are perpendicular to bores of check valves 3 whose inlets 9 are brought in communication with outlets 15 of make-up valves 10 and outlets 16 of safety valves 1 are brought in communication with drain hole. EFFECT: enhanced reliability.