FLOW BRANCHING AND COLLECTING CONTROL VALVE EQUIPPED WITH PRESSURE ADJUSTING MECHANISM

摘要

PURPOSE:To reduce the loss of thermal energy by equalizing the hydraulic pressure in the internal chambers of both spools of a pressure control valve while increasing and decreasing the opening areas of both fixed throttles with unified axial shifting of said both spools when the load in a working cylinder varies. CONSTITUTION:Fixed throttles (a), (b) opened toward the intermediate chamber 15 of the piston 16 of a flow rate control valve are provided where the opening areas of the throttles change in response to the position of the piston. Further, a pressure control valve is arranged such that two spools 31, 32 are engaged with hooks 33, 34 within the prescribed limit, the fixed throttles (c) and (d) connected to connecting ports 45, 46 to both working cylinders are provided, and the both spools 31, 32 shift as one body in such a state that said spools get away from each other when the pressure oil flow is branched, and in such a state that they come near when the pressure oil flow is collected, allowing the change of the opening areas of the both throttles (c), (d) to be contrary to each other. In this way, the throttle opening area is changed in response to the increase and decrease of the amount of supplied pressure oil, so that the flow resistance is not increased. Accordingly, the occurrence of thermal energy loss can be prevented.