Study on High Speed Operation in Harvesting by Multi-Crop Combine

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This study was performed concerning mechanical characteristics of crop stalks in harvesting in order to obtain fundamental design principles for high speed operation by Multi-crop Combine.At the beginning, an equation for large deflection of elastic beam were applied to solve the deflection problem of crop stalks (rice, wheat) caused by a reel operation. As a result, it was possible to presume a relationship between deflection and load acting on crop stalks simply. Further, Flexural rigidity values (EI) of tested crop stalks calculated from this equation were 2.25-2.75*10^4N・mm^2 (rice stalk, HINOHIKARI) and 2.65-3.25*10^4N・mm^2 (wheat stalk, NORIN 61).Next, the deflection characteristics of crop (rice, wheat) stalks was analyzed by Finite Element Method (FEM). As a result, deflection values and posture of crop stalks calculated by FEM almost coincided with measured values in case of using average values of EI at every knots of crop stalk. From this result, actual deflection characteri … More stics of crop stalks will be predicted accurately by FEM if correct values of EI are inputted.Further, a frequency response (amplitude ratio against a frequency) and a natural frequency of rice stalks were investigated. As a result, a frequency response indicated a typical characteristics which has a excellent peak in amplitude ratio, and natural frequency particularly varied depending on the values of EI.Moreover, natural frequency of tested rice were 1.37Hz and 1.13Hz.Finally, theoretical analysis of a natural frequency for bending vibration of rice stalks was performend by Rayleigh metod. Therefore, both methods of static deflection and dynamic deflection concerning Rayleigh metod were introduced to this analysis. As a result, in case of the static deflection method, error between experiment and analysis were 38.7% and 47.8%. In case of the dynamic deflection method, error were 7.3% and 11.5%. From this result, dynamic deflection metod will be available to estimate a natural frequency of rice stalks approximately. Less