| 摘要 |
<P>PROBLEM TO BE SOLVED: To make leaking flow rate of suction air at a controlwise full close position small and to prevent biting when a taper surface of a valve element is abutted on a valve sheet. <P>SOLUTION: This invented flow rate control device makes the valve element 22 close to and separate from a valve seat 16 by converting regular and reverse motion of a stepping motor into reciprocating motion in an axial direction, controls flow rate of air flowing in a flow passage formed between the valve element 22 and the valve seat 16, and detects a position of the valve element 22 in relation to the valve seat 16 by control step indicating rotation angles of the stepping motor. The valve element 22 is provided with a tapered surface on the outer circumference. The control step is initialized at the full close position where the tapered surface of the valve element 22 abuts on the valve seat 16 from the axial direction. Inclination angles of the tapered surface in relation to an axial center of the valve element 22 is set to 8° or more and less than 25°. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
