| 摘要 |
<p>PURPOSE:To reduce the numbers of pumps and pipings by using one of two pumps as a pilot pump, and feeding the confluent flow of both pumps into the cylinder of a service machine. CONSTITUTION:As a pump pressure is sent into the spring chamber of an unloading valve 6, the valve 6 staying in the unloaded state is forcedly turned into the on-load state, by the pressure in the second pump 2. The pressure in the first pump 1 is increased as well as the pressure in the second pump 2, flows from a branch point 63 through a piping 64 into the chamber 65, namely, the pump port of a main valve 17, forces a check valve 66 to be opened, runs through a chamber 49 and the narrow part 67 of a spool 18 which stays in the opened state, and is then mixed with the flow from the second pump 2. The confluent flow flows into the bottom part of a ripper cylinder 16 to expand it.</p> |
