| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a hydraulic circuit of a winch for a crane capable of separately using a one-pump one-motor independent circuit system and a two-pump merging series circuit system according to content of work or the like. <P>SOLUTION: The hydraulic circuit of the winch for the crane makes the two-pump merging series circuit by merging a delivery pressure oil of the two hydraulic pump by two control valves according to operation of operation levers 21, 23 to feed it to the two hydraulic motors respectively. Further, the hydraulic circuit is provided with a pilot pressure control means 40 capable of retaining a second speed spool of the respective control valves to a neutral position regardless of operation of an operation lever by controlling a primary pressure or a secondary pressure of respective remote control valves 22, 24. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
