| 摘要 |
An object is to reduce a load acting on an engine upon starting up the engine such that the engine can be quickly started up to reliably feed pressure oil from a hydraulic pump to an accumulator. A hydraulic control system is provided with first accumulators (24,25) connected to a hydraulic pump (23) via a first line (28) and second accumulators (26,27) connected to a second line (29) branching from the first line (28), an on/off valve (32) arranged in the second line and interposed between the first line (28) and the second accumulators (26, 27), an operation detection device (41) for detecting whether or not a starter (22) is in an operation state, a rotational frequency detection device (a rotary encoder (47) and rotational frequency calculation device (43)) for detecting a rotational frequency of an engine (21), and a valve control device for, upon detection of the operation state of the starter (22) by the operation detection device (41), controlling a valve position of the on/off valve (32) at a closed position until the rotational frequency reaches an idling rotational frequency set beforehand but then controlling the valve position of the on/off valve (32) at a closed position. |
