Rolling stock ventilator and its control method

A railway rolling stock ventilator comprising:

• an air supply fan for intaking fresh air into a railway car;
• an exhaust fan for discharging air out of the car;
• an air supply control for controlling air feed pressure of said air supply fan and said exhaust fan, wherein said air supply fan and said exhaust fan are adapted to permit change of air supply pressure of said air supply fan and said exhaust fan;
• a tunnel detector for detecting that the car is entering a tunnel and for supplying a control input signal;
• flow path resistance changers installed in an air flow path connected to said air supply fan and said exhaust fan to control an air flow path area of the air flow path, and to change a flow path resistance of the air flow path and;
• a controller for supplying a control signal to said air supply control to raise an air feed pressure of said air supply fan and said exhaust fan in dependence upon the control input signal from said tunnel detector, and to supply said flow path resistance changers a control command to increase the flow path resistance;
• and
• wherein each flow resistance changer includes flow path restrictions, including check plates and stopper plates disposed in the air flow path, said check plates being arranged so as to interrupt flow of air through the air flow path and being provided with openings, said stopper plates being arranged so as to be movable toward said check plates so as to cover the opening in said check plates, the opening in said check plates including large opening and small openings, said stopper plates being arranged so as to close one of the large and small openings of the respective check plates, said check plates being provided with rotary shafts, said large openings and small openings being disposed around said rotary shaft, said stopper plates being mounted on the rotary shaft so as to rotate thereon, combinations of said check plates and said stopper plates being disposed in the direction of air flowing in the air flow path.