Analysis And Simulation On Hydraulic Control System Of Mini Excavator

The mini hydraulic excavator replace the manpower work is mainly used in cabined area such as city, in the whole engineering machinery market, it belongs to one of maximum sales volume engineering machinery products. Considered the small working space, complex terrain, convenient operation and controllable of the mini excavator, it requests mini excavators possess the good compound movement, the simplification hydraulic system as well as superior fine work ability. The LUDV control system of BOSCH REXROTH Corporation is the single return route system and possesses characteristics of lower assembly expense, taking smaller space, compact system and so on, only one variable displacement pump can be used to satisfy all functional requirements, simultaneously various loads are approximate during the compound movements, the energy loss caused by the LUDV system is smaller than the large excavator.In the paper, based on the prototypical PZ70-7's research, design, manufacture and experiment, hydraulic control systems of the mini hydraulic excavator were studied. We adopt the BOSCH REXROTH LUDV control system in this prototype. Starting from the complete machine hydraulic system's design, the paper analyzed the operating principle of hydraulic system detailedly, then, LUDV control characteristics was analyzed from two aspects. Firstly, in terms of the theoretical analysis, the throttle control system, the LS control system and the LUDV control system were compared detailedly, the results show, in the flow unsaturated situation, the LS system and the LUDV system possess good control characteristics; On the other hand, the dynamic simulation of LS system and the LUDV system was carried on under the flow saturated situation using AMESim Software, the simulation results conform to the theoretical analysis and demonstrate that the LUDV system possess better speed rigidity than LS system. Then the LUDV model was consummated ulteriorly according to hydraulic schematic diagram of the prototype, the outside inputs were hypothesized according to the basis prototyping testing data, it obtains that the simulation results and the test results have good uniformity through the comparison. The theoretical analysis results, the AMESim simulation results and the prototyping testing results show the LUDV system adapt to the mini excavator. Because the simulation results conform to the results of the theoretical analysis and the test, it proves that the simulation models are accuracy and it provides design reference for modeling simulation of the complete machine hydraulic system and optimization of hydraulic system. Using the software of AMESim is propitious to design of hydraulic system and choice of hydraulic equipments and can also reduce the debug time fully. So the paper provides a design method of reducing the labor intensity and improving design efficiency.