| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect a piston malfunction and occurrence of delivery failure as an abnormality by means of a structure that fetches its piston's motion directly to the outside without damaging a direct-acting-type quantitative delivery function. SOLUTION: A piston 40 is formed with a front passage 50 having both an inlet 51 communicating with a feed inlet 21 and an intermediate outlet 52, a back passage 55 having both an intermediate inlet 56 opposite intermediate outlet 52 and an outlet 57 opened in an oil-storage chamber (R), and a communicating hole 58 opened in a storage chamber (S) to communicate with the intermediate outlet 52 and the intermediate inlet 56, and a valve body 70 is disposed between the intermediate outlet 52 and the intermediate inlet 56 so that during oil feed the intermediate inlet 56 is closed and oil is fed from the feed inlet 51 via the communicating hole 58 into the storage chamber (S), while during stop of oil feed the intermediate outlet 52 is closed and the oil in the storage chamber (S) is transferred from the communicating hole 58 via the back passage 55 into the oil-storage chamber (R), and the piston 40 is equipped with a detection pin 80 to detect the transference.</p> |
