FLOW CONTROL VALVE, AND COOLING SYSTEM FOR INTERNAL COMBUSTION ENGINE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a flow control valve that can maintain a safe state of an internal combustion engine if the flow control valve or a control system fails while ensuring cooling water temperature control according to the operating state, and a cooling system for an internal combustion engine using the valve. SOLUTION: The flow control valve 1 comprises a valve element 20 for switching the flow rate of a cooling medium when turnably supported in a valve housing 10 having a first and a second fluid passage 11 and 12 for leading in the cooling medium and a third fluid passage 13 for leading it out, and a drive 30 for rotatively driving the valve element 20. When the drive 30 is out of operation, a return spring 50 urged against the valve element 20 fully opens either of the first and second fluid passages 11 and 12 to construct a normally open valve. The valve element 20 is driven via a reduction gear 40 to make the flow control valve 1 normally open.