The Research Of Battery Solution Promotion System Design In High Powered Tractor

The common CF70 tractor hoist system was analyzed in this thesis in order to solve the existing system problems, a new type of hydraulic lifting system was designed with its main components - distributor, and a matching electro-hydraulic digital controller was also developed in order to achieve force and position integrated control. The new designed hydraulic lifting system and its electro-hydraulic control system were analyzed in both theoretical and experimental. The main contents of this thesis can be divided into two parts: design of hydraulic lifting system and development of electro-hydraulic control system. The main task of thesis is as follows:I. In the first chapter, the backgrounds and information of tractor hydraulic lifting system were reviewed at the beginning, and the overall system was established then; II. CF70 tractor hydraulic lifting system was taken as a research example, then the system was improved according to practical problems. And a new type of hydraulic lifting system was designed and its main components - distributor was also designed. There were three innovations in the new hydraulic lifting system:( i ) using a one-way valve instead of two one-way valves to reduce the cost and the leakage, to increase the reliability of the system;( ii ) the mechanical open method of one-way valve was changed to horizontal motion instead of vertical motion. Thus, the force and the motion were in the same direction which reduced the wear and tear on the main spool;( iii ) the descend speed regulating valve was abolished because the main spool had this ability. III. An electro-hydraulic digital control system which matched the new hydraulic lifting system was developed, including hardware design, control algorithm of continuous tracking stepping motor and software design.IV. Theory analysis of new type of tractor hydraulic lifting system and electro-hydraulic control system was done, and a related mathematical model was established by software Matlab, and the pressure– impact characteristics, response characteristics, closed loop control capabilities of system were simulated.V. Experimental platform for tractors was established to verify whether the hydraulic lifting system and electro-hydraulic digital control system meet the requirement or not, including experiment on tractor pressure - impact characteristics, response characteristics, closed loop control capabilities.