DEVICE FOR RECOVERING PRESSURIZED OIL ENERGY FROM WORK MACHINE

摘要

There is provided a hydraulic fluid energy recovery apparatus for a work machine, which is capable of recovering energy efficiency while allowing the work machine to ensure operability equivalent to standard construction machines without making the energy recovery apparatus large in size. The hydraulic fluid energy recovery apparatus includes a fluid communication line for holding a bottom-side hydraulic fluid chamber and a rod-side hydraulic fluid chamber of a hydraulic cylinder in fluid communication with each other, a fluid communication valve connected to the fluid communication line for adjusting the pressure and/or flow rate of a hydraulic fluid passing through the fluid communication line in a manner that allows for adjustment of a degree of opening of the fluid communication valve, first pressure detecting means for detecting a signal indicative of pressure at the bottom-side hydraulic fluid chamber of the hydraulic cylinder, an amount-of-operation detecting means for detecting an amount of operation of the operating means, and a control device for capturing the signal of pressure at the bottom-side hydraulic fluid chamber of the hydraulic cylinder detected by the first pressure detecting means, and the amount of operation of the operating means detected by the amount-of-operation detecting means, calculating the speed of a piston rod of the hydraulic cylinder, and controlling the fluid communication valve responsive to the speed of the piston rod.