| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To optimize a seat diameter and a seat section shape according to actuator characteristics or the like in a pressure balance type control valve in a three-way valve structure used for a fuel injection valve. <P>SOLUTION: A valve needle 1 comprises a large-diameter valve section 11 and a sliding section 12, and the valve section 11 is selectively seated at a drain seat 14 at the side of a drain port 22 or a high-pressure seat 15 at the side of a high-pressure port 23 for increasing or decreasing control pressure. The valve needle 1 is in a relationship of drain seat diameter D1≥high-pressure seat diameter D2≥sliding diameter D3, sets each seat diameter to be equal to or slightly larger than the sliding diameter to stabilize operation. Contrarily, the drain seat diameter is set to be equal to or slightly larger than the high-pressure seat diameter to make the most of the characteristics of a piezo stack 51 as an actuator. Further, an angle formed by the valve section 11, and the drain seat 14 or the high-pressure seat 15 is set appropriately for avoiding wear by foreign matter. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
