| 摘要 |
<p>PURPOSE: To hardly generate inertia and hysteresis by controlling flow passing through a first orifice to a forth channel when the coils are excited and ball armature is separated from a first seat. CONSTITUTION: When no current is supplied to coils 22, and the apparatus is initially corrected to have particular control pressure and supply pressure, flow to a chamber c is increased, pressure increase in the chamber side of a spool 90 is generated, ball armature 34 is separated from the exhaust seat orifice 68, and the armature 34 exhausts an excess flow supplied through orifice 100 of the spool 90, so the chamber c is kept under a stable pressure. When the current of the coils 22 is increased, the armature 34 is further separated from the exhaust seat 68, the flow area increases, pressure of the chamber c decreases, the spool 90 shifts toward low pressure direction, the rand 94 of the supply port 82 is controlled and closed until the feed back pressure is balanced to the vacuum pressure. By this manner, inertia and hysteresis are hardly generated.</p> |
