Performance Simulation And Test Of The Full Hydraulic Braking System

The braking system is one of the most important systems in the composition of theloader’s systems and even off-highway vehicles’ systems. It relates to the primary issue-security issue in the actual engineering operation and the transition walking. Braking systemhas become the object of general concern in the construction machinery industry. The currentmainstream brake program is the air over hydraulic braking, and the application of the fullhydraulic braking with more superior braking performance is relatively few. On the one hand,due to the lack of in-depth understanding of the full hydraulic braking system performance, itbrings some trouble to the work of system matching. On the other hand, the full hydraulicbrake system adopts imported hydraulic components resulting in higher costs of application ofthe system. Based on the above two reasons, the research of characteristics of the fullhydraulic braking system is very important at this stage.The composition and working principle of hydraulic braking system was analyzed at first.The working of the hydraulic braking system includes two processes-charging process andbraking process. The charging process supplies oil to accumulators from an open centercircuit on demand at a preset rate, and within the preset pressure limits by accumulatorcharging valve. Braking process provides normal and emergency power-off braking throughthe braking pedal, on the one hand, the process is hydraulic drive by full hydraulic singlemedia, and braking response speed was increased substantially.The characteristics of key component-accumulator charging valve and brake valve of thefully hydraulic braking system were studied and the corresponding mathematical modelaccording to actual needs was established. The control forms of accumulator charging valvepressure range and dynamic characteristics the braking were analyzed.The HCD (Hydraulic Component Design) simulation model of key components wereestablished based on AMESim (Advanced Modeling Environment for performing Simulationsof engineering systems) The dynamic characteristics including charging characteristics;pressure characteristics, flow characteristics of charging process and the braking pressurecharacteristics; the dynamic response characteristics; safety of the braking process etc. weresimulated by AMESim.The experimental program of the hydraulic braking system was designed aimed atverifying the accuracy of the theoretical analysis and simulation results. The dynamicresponse of pressure of the charging process and braking process were tested. High similaritybetween the experimental results and simulation results verify the accuracy of the theoreticalanalysis and simulation model and excellent dynamic characteristics of the full hydraulicbraking system. According to the analysis of practical problems, the optimization for the full hydraulicbraking system was proposed and verified by simulation and experiment. The results shownthat the optimization correctly and effectively and the performances of braking system wereimproved effectively.