关键词: 青皮核桃, 碰撞分析, 跌落, 接触力, 弹簧装置, 参数优化

Abstract: In order to study the contact force characteristics and determine the main parameters of green walnut falling and impact on the spring device, firstly, the material properties of “old walnut” varieties in Qingyang area were obtained through experiments. The threedimensional model and grid division of the spring pressing plate device of the green walnut peeling machine were established using an integrated method. Then, the green peel rupture of green peel walnut when falling from different heights was analyzed by drop tests, and the failure strain value of green peel with more cracks was obtained by numerical simulation. Finally, the collision process of green walnut falling from different heights and spring pressing plate devices with different stiffness was simulated. Through singlefactor analysis, the main factors affecting the contact stress and maximum effective stress during falling collision were determined. Combined with BoxBehnken Design, the response surface analysis was carried out to obtain the optimal solution of the key components of the peeling machine. The optimal parameters of the pressing plate structure were the spring wire diameter of 1 mm, the spring pitch diameter of 1185 mm, and the drop height of 1 000 mm. Through prototype testing, the peeling rate and walnut crushing rate were 97.08% and 1.6%, respectively, and the peeling effect was good.

Key words: green walnut, collision analysis, drop, contact force, spring device, parameter optimization