| 摘要 |
PURPOSE:To eliminate any leakage in a spool valve as well as to make a distinct improvement in measuring accuracy, by making both sides of a cylinder part of the spool valve, where fuel flows in time of measuring, open to the atmosphere. CONSTITUTION:In time of measuring, both side parts of a cylinder chamber 50, where fuel oil in a spool valve 31 flows, are made to come into a state of being opened to the atmosphere. On the other hand, at the other side of a cylinder chamber 51, it is partitioned into a second piston part 37c and a third piston part 37c, while a cylinder chamber 52 interconnecting a fourth connecting port 40 is interconnected to a reflux passage 36 via the connecting port 40. Therefore, inside the cylinder chamber 50, high pressure fuel oil is in no case penetrated from both sides of it by way of each outer circumference of each of piston parts 37a and 37b. |
