PROBLEM TO BE SOLVED: To provide a hydraulic circuit of a crane capable of improving the operability of the crane when a heavy load is imposed thereon.SOLUTION: A hydraulic circuit of a crane includes: a flow-dividing valve 30 which is provided between a first hydraulic pump 1 and a derricking control valve 15 and makes fore-and-aft differential pressure of the derricking control valve constant while dividing a hydraulic oil fed from the first hydraulic pump into an upstream side and a downstream side of the derricking control valve; a series circuit which is provided between the derricking control valve and a first auxiliary control valve 11 and connects the derricking control valve and the first auxiliary control valve to the first hydraulic pump in series; and a switching valve 31 switching the hydraulic circuit to a parallel circuit in which the derricking control valve and the first auxiliary control valve are connected to the first hydraulic pump in parallel.SELECTED DRAWING: Figure 2
【課題】クレーンの高負荷時における操作性を改善できるクレーンの油圧回路を提供する。【解決手段】第1の油圧ポンプ(1)と起伏用制御弁(15)との間に設けられ、起伏用制御弁の前後差圧を一定にすると共に、第1の油圧ポンプからの圧油を起伏用制御弁の上流側と下流側とに分流する分流弁(30)と、起伏用制御弁と第1の補巻用制御弁(11)との間に設けられ、起伏用制御弁と第1の補巻用制御弁とを第1の油圧ポンプに対してシリーズに接続するシリーズ回路と、起伏用制御弁と第1の補巻用制御弁とを第1の油圧ポンプに対してパラレルに接続するパラレル回路とに油圧回路を切り換える切換弁(31)と、を有するクレーンの油圧回路。【選択図】図2
HYDRAULIC CIRCUIT OF CRANE
クレーンの油圧回路
2018-10-04
Patent
Electronic Resource
Japanese
IPC: | B66C Krane , CRANES |