Hydraulic Excavators And Load Sensing System Simulation Studies And Energy Analysis

Hydraulic excavator is a kind of widely used construction equipment with the typical functions and complicated working conditions. In days of energy crisis and environment-friendly, energy saving of excavator is urgent and of higher development potential project. This paper takes hydraulic excavator load-sensing system as the object to research the energy-saving characteristic and controllability of excavator from the matching of pump and the load. The main work as follows:1) The working condition and duty cycle of hydraulic excavator is analyzed, the ways and reasons of hydraulic excavator energy waste is found out. The significance and development of energy-saving of hydraulic excavator in China and abroad are related. A load-sensing excavator system, which can easily get operating information and control, is designed for energy-saving research.2) The structure and principle of the main components of load-sensing hydraulic system are interpreted, and the AMESim model of the system is built. And many dynamic simulation researches are done on the models, the results show that load-sensing system can match the power of pump and load and presents well in energy-saving and control.3) Kinematic and dynamic analysis of excavator working device is done. Expression of bucket tip posture and the relationship between the manipulator rotation angle and cylinder distant are put out. Expression between load force and system pressure is established. And the AMESim model of excavator working device is built.4) An integrated hydraulic excavator model is established in the environment of AMESim, include hydraulic system model, kinematic and dynamic model of working device, to solve the imprecision of separated model.A typical excavator working cycle is simulated using the integrated model , the result show that load-sensing system has the best energy-saving characteristic and controllability among the traditional fixed-throttle system,negative control system and load-sensing system.5) A new type hydraulic system named electronic and hydraulic load-sensing system is presented. The energy-saving characteristic and controllability of load-sensing hydraulic system and the new type system is compared by simulation use the integrated hydraulic excavator model. The result prove that electronic and hydraulic load-sensing system performance better in energy-saving characteristic and controllability than the former system.6) The load-sensing excavator testing platform based on VPPM-PQC pump and BLS6 muti-way valve is built. The energy-saving characteristic and controllability of load-sensing hydraulic system is test on the testing platform. It is proved in experiment that load-sensing system presents well in energy-saving and control.