HYDRAULIC DEVICE IN BATTERY TYPE INDUSTRIAL VEHICLE

摘要

PURPOSE:To obtain a hydraulic circuit which provides energy saving by lowering a fork under a light load and stopping rotation of an electric motor when the electric motor is unable to make regeneration. CONSTITUTION:The output level of a hydraulic pump 1 functioning as a hydraulic motor by the return oil flowing through a hydraulic oil return passage from a lift cylinder 7 is detected by a detecting means and when a judging means judges the hydraulic pump 1 will not function as a hydraulic motor based on the difference between the above detected level and the command level by a speed command means, a controller 20 drives a changeover valve 8a serving as a selective changing means, thus changing the flowing direction of the return oil in the return passage of hydraulic oil to drain side and shutting down the driving source to an electric motor.