The Research Of Hydraulic Automatic Gearbox's Control System For ZL50 Loader

As the development of economic in our country, the domestic clients are demanding more with the performance and capacity of construction equipments such as the advanced technical, reliability, easement of operation, energy saving, environment protecting and competition of the price, thus, the pay loader which furnished with high capacity electronic controlled engine and auto-shift transmission case are more and more popular in the market. But as known to us, the study of electronic controlled auto-shit technology was just on the initial phase in China, and there're no applications of auto-shift system on the pay loader in our country. As we know, the shift parts is the basic components in the construction equipment, shifting technology is the core technology of construction equipment, that is the reason some international equipment manufactures such like CAT, VOLVO and KOMASTU have their own patent and factories to produce the shifting parts. Therefore, we should be pressured to intensify our study on auto-transmission case especially on the theory of shift-control system; control method and quality, and coming into being a shift-control technology with our own feature, which will let us remain invincible in the furious competition in the national and world market. It is stated in the 1st chapter that the development history of the auto-shift technology and the great significance of the research and study on the equipment auto-shift system at present, which are dissertated with the reference of the national and the foreign source regarding the auto-shift and control technology; equipment auto-shift strategy and quality control are introduced and analyzed in allusion to the development of the auto-control technology in this chapter; the main content of said chapter are the studies of the pay loader with model "ZL50"on design of the auto-control strategy and shift-rules with the related calculation of traction, while, the basic control function and liability are also validated base on the combination experiment of electronic control system and transmission case. In the following chapter, the wheeler type loader power transmission system and hydraulic-mechanical transmission case with model "YZX160D"have been introduced and analyzed base on the analyses of the working character of the loader, then, the scheme of electronic controlled auto-shift system is designed as the per function requirements of auto-shift system. In the 3rd chapter, method together with the step of design and affections on the equipments that caused by the shift rules are dissertated, through the analysis in the significance of shift-rules in the equipment auto-shift technology, finally, the shift rules of loader with model "ZL50"is designed resort to the result of engine and hydraulic matching computation and traction computation. On top of above-mentioned step, series circuitries such as keyboard display circuit, output signal processor, and CPU minimum system processor have been designed base on the study and analyses on the hardware component of the control system, meanwhile, the primary programme and module of the control software have been designed by dint of the modularized configuration method. It is emphasized in the 6th chapter that the corresponding experiments are very important which would be used to prove the reliability and validity of the control system. Conclusion of the task: (1) It is come true that the auto-shift control system can be applied to "ZL50"with good performance, which was designed manufactured base on the working character of the loader, the application of auto-shift control system on the loader is proved to be feasible.(2) Through analyzing the characters of C6121ZGO9F engine and YZXl60D hydraulic transmission gearbox, there are two cases depending on the working device's driving pump whether or net works. In every case, the matching calculation of engine and torque converter is carried out, including input characteristic calculation and output characteristic calculation, and then the traction force calculation of ZL50 loader is finished. Further, the design method of loader's shift rule is introduced and the shift rule of ZL50 loader is designed. (3) Then the automatic shift control strategy of loader is presented, and the functions of DSS and direct reversing are firstly applied to domestic loader according to characteristics of ZL50 loader. Moreover, the design and debugging of electronic control system's software are presented. (4) The function and reliability of the electronic control system are proved to meet the requirement resort to the combination test with auto-shift electronic control system of "ZL50"loader and hydraulic-mechanical transmission case model "YZX160D". Expectation for the future: (1) It is a pity that the test to determine the basic control function in this dissertation could only be done by method of electrical motor derived testing due to the limitation of time and condition, it is expected to be tested by the engine together with transmission to make further checking with the performance of the electronic control system if it is allowed. (2) It is expected to do more study and test for the design work of the shift-rules, and it's better to implement the field test to determine and modify the shift-rules (3) The quality control of shifting is important in the auto-shift technology, and itwill have more advantage if the process of the shifting is smooth and softness, but in this dissertation, only the buffering function of the torque converter is considered and utilized to produce the smooth shifting instead of considering the quality control of the shifting, which will put down the motivity and the economy of the equipment, hence, it is appealed to do more study on the quality control of the shift provided with sufficient conditions.