Numerical and Experimental Analysis of the Hydraulic Circuit for the Rear Hitch Control in Agricultural Tractors

This paper describes the mathematical modeling of a tractor rear hitch control valve (HCV). The HCV operates in two modes namely lifting and lowering. The lifting circuit incorporates a pressure compensated flow control valve, while the lowering circuit is gravity assisted. The HCV incorporates a load-sensing system; load-sensing systems and pressure compensated valves are classified as feedback systems. The objective of this study is to develop a complete mathematical model of the HCV. This would help to better understand its functionality and to quantify the energy losses across its components. This paper presents the first results of the study.