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

Abstract

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 port for use or conveyed to the energy accumulator for storage. According to the energy-saving device, the transformer ratio of the transformer is adjusted through changing the control angle of the valve plate of the four-way hydraulic transformer, thereby realizing change on the pressure difference of the hydraulic recovery loop on the basis of no change on a load flow, that is, further recovering the hydraulic energy in the system under the condition of no influence on the maneuverability of the excavator.

Description

technical field [0001] The invention relates to an energy-saving device in a hydraulic transmission and control system, in particular to an energy-saving device for a single-pump excavator based on hydraulic energy recovery of a four-way hydraulic transformer. Background technique [0002] Some of the existing excavator hydraulic energy recovery devices adopt the power generation-energy storage-electric release method, the device is complicated, and the efficiency of the energy conversion link is low; most of the hydraulic recovery adopts the scheme of quantitative motor and variable pump pairing, with complex structure, Large volume, heavy weight, and high cost; and the use of a three-way hydraulic transformer cannot recover the differential pressure hydraulic energy of the load. [0003] Furthermore, the current liquid energy recovery device can only recover the energy of a single load in a certain working condition, such as the gravitational potential energy of the materi...

AI Technical Summary

Problems solved by technology

However, when the hydraulic excavator is in normal operation, its working conditions include: excavation, full bucket rotation, unloading, empty bucket rotation, etc., and the load includes boom cylinder, stick cylinder, bucket cylinder, swing motor, etc., and there are often more than two The loads work at the same time, and there is a large pressure difference between the loads supplied by the same main pump. The current research scheme does not consider the energy loss of this pressure difference

The recovered energy is first stored in the accumulator, and then used through the conversion of hydraulic energy-mechanical energy-hydraulic energy, which cannot be directly used. There are many conversion links and low efficiency

Most energy-saving devices use the scheme of recovering the energy of a certain load and using it for this load, and the recovered energy is not used flexibly

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