Analisi del comportamento dei sollevatori idraulici montati sulle trattrici agricole. 1: Analisi cinetostatica.
1984
Monastero R.
Hydraulic draught control system is nearly always fitted out on agricultural tractors today. It is the most important mechanical unit of the 'tractor-implement-working soil' system: i.e. it works as a negative feed-back regulator and as such its behaviour allows the best efficiency in soil working both in a qualitative and quantitative way. We have now after the Ferguson system, some commercial devices with new structural arrangements but such a development comes from manufacturers' individual experience. Therefore it seems useful to investigate these different new devices in order to know their behaviour and performance concerning regulation. Dynamic analysis must be performed applying non-linear control systems theory because of particular non-linearities related with hydraulic unit. Nevertheless a behaviour steady-state analysis at equilibrium conditions has to come first: either the regulator itself or the external devices supplying the input signal may affect dynamic response (three-point linkage, implement, soil). This first paper presents the steady-state analysis of the top link sensing FIAT 450 draught control system; a mathematical model and a computer simulating program has been arranged in order to obtain system static response to different conditions and particularly to its own adjustments. Results show that the device may have effect in draught control when it works at a lower depth, and they also show it is important to make a correct choice of implement size and tie-rod length for optimum control conditions.
显示更多 [+] 显示较少 [-]