System for controlling cooling water temperature for a water-cooled engine

In a system for controlling cooling water temperature of a water-cooled engine having an intake passage, a radiator, a water jacket having an inside water passage provided in said engine for cooling the engine, a water passage for communicating said inside water passage with said radiator, a thermostat provided in said water passage, and a pump causing the cooling water in said inside water passage to flow, said thermostat being so arranged as to open outside water passage when the water temperature exceeds a predetermined value, the improvement comprising

• a bypass connected between an outlet of said water jacket and an inlet of said pump;
• a circulation pipe connected between said outlet and inlet of said pump;
• changeover valve means provided for selectively connecting said outside water passage and said circulation pipe with said inlet;
• first actuator means for actuating said changeover valve;
• flow control valve means provided in said outside water passage for controlling flow rate of the water;
• second actuator means for actuating said flow control valve;
• thermo-switch means provided on the engine for operating said first actuator of said changeover valve for communicating said bypass with the inlet of said pump at a predetermined water temperature;
• means for detecting engine operation and for operating said second actuator of said flow control valve for controlling the flow rate of water at a water temperature higher than said predetermined water temperature.