蓖麻籽直筒式压榨侧向压力系数的理论研究

为建立蓖麻籽直筒式压榨侧向压力系数的理论公式，以便于合理地确定直筒式压榨机的榨筒参数，通过进行蓖麻籽直筒式单轴压榨试验，获取蓖麻籽压榨坯密度、侧向应力和轴向应力。试验建立的压榨坯密度与轴向应力的关系曲线和金属粉体压制曲线近似，由此利用金属粉体压制公式进行数据拟合，同时利用试验数据建立了侧向压力系数与轴向应力关系曲线。理论公式计算值与试验实测值的最大相对误差为24.74%，平均误差7.56%，证明了基于压榨塑性模型推导过程建立的侧向压力系数理论模型能较好地描述蓖麻籽侧向压力系数变化。

Theoretical Research on Lateral Pressure Coefficient in Castor Seeds Plunger Pressing

Through the process of deducing the plastic model and the density formula of the process of pressing metal powers, the theoretical formula of lateral pressure coefficient regarding to axial stress about castor seeds was created to legitimately determine the parameters of pressing cylinder. Through plunger type uniaxial pressing tests on castor seeds, density of compacted residues of castor seeds, lateral stress and axial stress were obtained. The relation curve about density of compacted residues and axial stress obtained by tests was approximate to the pressing curve of metal powders. Thus utilizing the density formula in the process of pressing metal powders to fit the data, and the relation curve about lateral pressure coefficient and axial stress obtained by tests was built. The maximum relative error of theoretical and measured value is 24.74% and the average error is 7.56%, which verifies that theoretical model of lateral pressure coefficient based on the process of deducing the plastic model can well describe the changes of lateral pressure coefficient of castor seeds.