| 摘要 |
<p>PURPOSE: To set the specified setting position of a setting element regardlessly of the operating direction of the setting element so as to always generate desired control pressure at an outlet by moving a control piston in an opening direction just for a prescribed process while separating an inside valve seat from a valve closing member. CONSTITUTION: A separator 34 is operated in a short time at the beginning of operating movement to the pressure reduction direction of control pressure, and an inside valve seat 13 is forcedly separated from a valve closing member 14 more than proportional relation. Since a connection part between a control pressure chamber 18 and a pressure release chamber 33 is opened more than the proportional relation, pressure in the control pressure chamber 18 is reduced more than the proportional relation in an extremely short time. After the separator 34 stops operating as a result of pressure reduction, it is necessary to compensate a too much pressure loss inside the control pressure chamber 18, namely, since both valve seats 11 are not balanced, it is necessary to supply air into the control pressure chamber 18 again, and a pressure increase process is started. Therefore, even when a setting dial 30 is turned in the pressure reducing direction, both the valve seats 11 can be balanced by the pressure increase from the same direction like the case of turning the setting dial 30 in a pressure increasing direction.</p> |
