| 摘要 |
PROBLEM TO BE SOLVED: To provide a ventilator having superior opening and closing operability of an air capacity regulating valve, and having high air-tightness and water-tightness in a closed state.SOLUTION: The ventilator is composed of a wind tunnel 10 having an air inlet/outlet in communication with a building interior/exterior, the air capacity regulating valve 20 turning in the direction of fully opening the wind tunnel in a windless state and closing the wind tunnel on receival of wind, an abutting member 41 turning along with the air capacity regulating valve, a primary elastic body 32 urging the air capacity regulating valve in the direction of opening the wind tunnel to become turning resistance against turning of the air capacity regulating valve in the closing direction in a predetermined wind velocity or less, a secondary elastic body 42 contacting the abutting member and urging the air capacity regulating valve in the direction of opening the wind tunnel to become turning resistance against turning of the air capacity regulating valve in a direction of further closing the wind tunnel, and maintaining an air capacity passing through the wind tunnel at a certain amount by the primary elastic body and the secondary elastic body, and a closing mechanism turning the air capacity regulating valve and closing the wind tunnel by operation of an operation part and moving the secondary elastic body to a position not abutting on the abutting member. |
