HYDRAULISCHES VENTIL

摘要

This invention relates to a valve device comprising a flow control valve (8; 8A-8G) including supply passages (11; 11a, 11b) connected to pressure oil supply sources (1, 2), load passages (12; 12a, 12b) connected to an actuator (4) and first meter-in variable throttle portions (14; 14a, 14b) disposed between the supply passages and the load passages for providing an opening in accordance with an operation quantity; first signal passages (18; 16a, 17a, 16b, 17b, 18) disposed downstream of the first variable throttle portion for detecting the load pressure of the actuator; tank passages (13; 13a, 13b) connected to a tank (56); exhaust passages (30; 16b, 17b, 16a, 17a) for connecting the first signal passage to the tank passage; and second variable throttle portions (21; 21a, 21b) disposed in the exhaust passages, for changing the degree of opening in accordance with the operation quantity of the flow regulation valve to generate a control pressure different from the loadd pressure in the first signal passage, wherein the control pressure of the first signal passage is transmitted to the oil pressure supply source through the second signal passage (19). Auxiliary throttle means (22; 22a, 22b) are disposed in the first signal passage (18; 16a, 17a, 16b, 17b, 18), the load pressure detected at the passage portion (15; 15a, 15b) of the first signal passage is reduced and a pressure lower than the load pressure is generated as the control pressure in the first signal passage.