| 摘要 |
<p>The invention has its object to provide a valve device which drastically resolves an unexplored technical issue of simultaneously satisfying reduction of valve resistance loss and uniform contact at the time of valve seating, by means of a simple and reasonable construction based on a novel technical idea, is easy to design and manufacture, enables application of various materials such as all metallic materials and ceramics, endures high temperature, high pressure, slurry liquids and corrosive fluids, poses no problem when increased in size, and is of high performance and economical. In the valve device, a valve disc (4) is connected to an arm (5) through a valve disc supporting shaft (6) with a freedom in turning, and the arm (5) is connected to a body (1) through an opening and closing drive shaft (7) provided at a position separate from the valve disc supporting shaft (6), and is constantly biassed by an additional working force in a direction, in which a distance between a side of a valve disc end (4a) and a side of an arm end (5a) is lessened. With this arrangement, a torque is applied from outside to the opening and closing drive shaft (7) whereby upon full opening of the valve the valve disc (4) is positioned along streamlines of a flow passage to make a valve resistance loss small, and upon seating of the valve the valve disc (4) comes into close contact uniformly with a closing surface (3m) of a valve seat (3) to shut off the flow.</p> |
