| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a pneumatic valve which quickly reacts a direction of a reciprocal flow on pressure while maintaining substantially constant volume flow independent of pressure. SOLUTION: A pneumatic valve comprises a valve body 10, a control element 4 and a flow orifice 3. The valve body 10 has an inlet 11 and an outlet 12 for operation gas, a main connecting line 13 connecting the outlet and inlet, and transverse hole 14 intersecting with the main connecting line 13 crossing the valve body 10. A control element 4 is arranged in the transverse hole 14 so as to be movable inside the transverse hole 14. The effective area of a control opening 19a for operation gas is gradually reduced as the control element 4 moves from one end of the transverse hole 14 to the other end. The control element 4 is controlled to change the effective area of the control opening 19a according to the difference between gas pressures on the upstream and down stream sides of the orifice 3 through the medium of a juxtaposed reversing valve.</p> |
