| 摘要 |
<p>PROBLEM TO BE SOLVED: To magnify a ratio of maintaining an inching status in one working stroke of a valve driving means in an inching valve system. SOLUTION: A spool valve element 11 of a piston rod 10 as a valve drive shaft is slidably fitted in an axial direction within a specified range and provided with a piston 21 for energizing the spool valve element 11 in a valve closing direction by fluid pressure of the fluid introduced into a valve body 3, and a return spring 16 for energizing the spool valve element 11 in a valve closing direction is provided between the spool valve element 11 and a tip of the piston rod 10 such that the spool valve element 11 freely moves along the piston rod 10 within the preliminary defined range so as to balance the energizing force of the fluid pressure acted on the piston 21 with the energizing force of the return spring 16.</p> |
