Energy-saving device based on hydraulic energy recovery of four-way hydraulic transformer, for single-pump excavator

The invention discloses an energy-saving device based on the hydraulic energy recovery of a four-way hydraulic transformer, for a single-pump excavator. The energy-saving device comprises the four-way hydraulic transformer connected into the hydraulic system of the excavator, an energy accumulator, a normally-open electromagnetic valve, a normally-closed electromagnetic valve and a controller, and a working oil port, a pressure oil port and an oil return port are formed; and the controller switches over the four-way hydraulic transformer into a hydraulic loop needing to recover the hydraulic energy, the controller controls the corresponding normally-open electromagnetic valve and normally-closed electromagnetic valve to enable the inlet oil of the working oil port to flow in the four-way hydraulic transformer from a PA port, the hydraulic energy is recovered through the decompression of the four-way hydraulic transformer, and the recovered hydraulic energy is converged with the pressure oil port from a PO por