Development And Design Of Construction Machinery Transmission Control System

This paper briefly describes general situation of development of shift controlsystem in China and aboard, according to this application used in SDLG wheel loader,it emphatically describes the structure, work principle, the control strategy of theVRT200fixed-shaft power transmission developed by SDLG and VOLVO. Finally,analyzes shortcomings and suggests the trend of Electric Control Unit.Based on the working principle of the transmission, the structure of transmissiondetermines our control strategy within a certain extent, because the restriction ofcognitive and application in the development of transmission in China, which leads toa large impact in the process of shifting, so, the theoretical analysis and the formulacalculate are conducted to the process of power transmission. By analyzing theinternal structure of shift control valve, work principle, the control and resistance ofsolenoid valve to match the voltage and current of the output of the controller, andthe output can drive the solenoid valve rightly.On the design of shift control system, by analyzing the actual operating conditionand shifting control strategy of wheel loader, the factors which can affect the shiftingare thought over through the temperature, pressure, speed, sustained transfer of power,the research and design are carried out from the following two aspects:1. By way of analysis of the actual work condition and own characteristics ofshift control from the wheel loader, the control strategy is turned into reality，andthe algorithm is improved, in the same time, the installed test and user tracking trialare executed.The software of ECU shift control system is designed， includingKick-down function, change shifter time, acquisition and processing of input andoutput Signals, overload feedback.2. Test and application of the shift control system.Finally, supporting the problems in using of the whole shift control system,through analyzing and solving on that, the disadvantages are emphaticallysummarized against shift control system and associated components, personal point ofview and improved methods are suggested from the aspects of safety and protection.