Boom Hydraulic Circuit Transformer Based Hydraulic Excavators

Hydraulic excavator with high efficiency, good reliability, and othercharacteristics, but high energy consumption, emissions poor, environmentalpollution and other issues are also existed. Hydraulic excavator boom lift is veryfrequent in the course of its working, the potential drop process has not been togood use, but the cause of the heating system, increasing the installed capacityof the power system. Traditional hydraulic excavators are based on the throttlecontrol technology, so there will inevitably throttling losses, but the constantpressure rail hydrostatic transmission with secondary regulation technology is anew type of hydrostatic transmission technology based on pressure coupled,while the introduction of hydraulic transformer, can theoretically avoid throttlinglosses, and the hydraulic accumulator is used as the energy storage element.Therefore, the22T hydraulic excavator is chose for the object of study, thistechnology into the hydraulic excavator hydraulic system, and the loop of thehydraulic excavator boom based on hydraulic transformer is researched.The main work as follows:1、The significance of the hydraulic excavator for energy research has beenexplained, the current domestic and international development and applicationof hydraulic transformer, the home and abroad development of hydraulicexcavators saving research has been introduced respectively. Thus theimportance of hydraulic excavator boom saving research was led to.2、The working principle of the hydraulic transformer has been introduced,and the conditions of the hydraulic excavator was analyzed. And then valvecontrol loop of hydraulic excavator boom and loop of hydraulic excavator boombased on hydraulic transformer were carried out a detailed analysis, on this basis,a new loop of hydraulic excavator boom based on hydraulic transformer wasproposed, and its working principle、control strategies and the advantages wereexplained.3、The operating characteristics of the four quadrants of the hydraulictransformer was described, on this basis, the hydraulic transformer drive boom cylinder of four-quadrant operation range was analysed, and the “nose curve”has been was put forward. And the mathematical models of new loop ofhydraulic excavator boom based on hydraulic transformer were established, andkinetic analysis was carried out.4、A typical duty cycle of the hydraulic excavator was selected, and itsworking devices were simulated, the boom’s force curve was obtained in orderto simulate the actual load of the boom. The simulation model of valve controlloop of hydraulic excavator boom the simulation model of loop of hydraulicexcavator boom based on hydraulic transformer and the simulation model of thenew loop of hydraulic excavator boom based on hydraulic transformer wereestablished respectively, and they were simulated.