TWI743783B

According to the present invention, a gate valve comprises: a valve box having a first opening and a second opening; a valve main body positioned in a hollow portion inside the valve box; a rotational shaft supporting the valve main body; a rotation driving unit rotating the valve main body; a neutral valve unit connecting the valve main body to the rotational shaft; a driving valve frame installed in the valve main body; a valve case biasing unit connecting the neutral valve unit and the driving valve frame; a driving valve plate unit installed in the valve main body and enabling a position of the driving valve frame to be moved in a flow passage direction through a plate sliding seal unit; a valve plate biasing unit connecting the driving valve frame and the driving valve plate unit; a valve box biasing unit allowing the driving valve frame to be moved toward a valve closing position coming in contact with the periphery of a first opening; and a driving unit driving the valve box biasing unit. An inner peri