| 摘要 |
<p>PURPOSE:To carry out confluent control of both circuit systems while preventing a load pressure of a cylinder in one of the circuit systems from working on a regulator in the other circuit system even if a pressure of the cylinder in the other circuit system is increased up to a relief set pressure. CONSTITUTION:A load sensing line changeover valve 26 is disposed in one circuit system. The changeover valve 26 is changed over against a spring 28 when a load pressure of a cylinder 7 is increased up to a relief set pressure. If the changeover valve 26 is changed over in this way, the load pressure of the cylinder 7 cannot work on one pilot chamber 25a of a confluent control valve 25. Furthermore, even if the confluent control valve 25 is changed over, a high pressure of the cylinder 7 cannot work on a regulator 24 in the other circuit system.</p> |
