To provide a hydraulic driving device capable of recovering potential energy of a lifting/lowering object while maintaining intended lowering speed of the lifting/lowering object.SOLUTION: A hydraulic driving device 1 includes: a main pump 8 for supplying working fluid to a lift cylinder 2; a variable displacement type sub pump 9; a working fluid regeneration flow passage 42 and a working fluid common flow passage 41 that connect a suction port 26 of the sub pump 9 with the lift cylinder 2; an operation valve 44 disposed in the working fluid common flow passage 41; an accumulator 52 for accumulating pressure of the working fluid discharged from a discharge port 27 of the sub pump 9; a swash plate angle control unit 38 for controlling the capacity of the sub pump 9; and a lowering control section 68 for determining target lowering speed of a fork 4 on the basis of operation amount of a lift operation lever 5, calculating necessary capacity of the sub pump 9 on the basis of the target lowering speed of the fork 4 and speed of an engine 11 and controlling the swash plate angle control unit 38 in accordance with the necessary capacity of the sub pump 9.SELECTED DRAWING: Figure 1
【課題】昇降物の所望の下降速度を維持しつつ、昇降物の位置エネルギーを回収することができる油圧駆動装置を提供する。【解決手段】油圧駆動装置1は、リフトシリンダ2に作動油を供給するメインポンプ8と、可変容量型のサブポンプ9と、サブポンプ9の吸込口26とリフトシリンダ2とを接続する作動油回生流路42及び作動油共通流路41と、作動油共通流路41に配設された操作弁44と、サブポンプ9の吐出口27から吐出された作動油を蓄圧するアキュムレータ52と、サブポンプ9の容量を制御する斜板角度制御ユニット38と、リフト操作レバー5の操作量に基づいてフォーク4の目標下降速度を決定し、フォーク4の目標下降速度とエンジン11の回転数とに基づいてサブポンプ9の必要容量を算出し、サブポンプ9の必要容量に応じて斜板角度制御ユニット38を制御する下降制御部68とを備える。【選択図】図1
HYDRAULIC DRIVING DEVICE
油圧駆動装置
2019-06-20
Patent
Electronic Resource
Japanese
IPC: | F15B SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL , Druckmittelbetriebene Systeme allgemein / B66F HOISTING, LIFTING, HAULING, OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD , Hub-, Verhol- oder Schubvorrichtungen, soweit nicht anderweitig vorgesehen, z.B. Vorrichtungen mit unmittelbarer Krafteinwirkung auf die Last |