山核桃破壳机敲击臂凸轮机构的设计与试验

Design and test on cam mechanism of striking-arm for pecan shell breaker

根据敲击式山核桃破壳机的工作原理和作业要求,采用解析法对其核心部件——敲击臂凸轮机构进行了详细的设计与分析,以解决目前机具破壳作业不稳定、敲击臂摆动角度不精确的问题。根据破壳机构的结构尺寸及作业要求,采用能量法计算敲击臂摆角大小,选择从动件运动规律,通过压力角分析,对凸轮角度进行分配,进而得到凸轮实际轮廓曲线。在ADAMS环境下,建立凸轮模型并进行运动学仿真分析,制造了敲击式山核桃破壳样机。通过试验,验证了所设计凸轮能够准确实现敲击臂的预设摆动角度,运转平稳且不发生自锁现象,从而达到高破壳率、低果仁损伤率的作业要求。

By exploring the shortcomings and deficiencies of the existing cam mechanism used in the shell-breaking mechanism,it is not difficult to find that the mechanism suffers from such problems as unstable shell-breaking operation and inaccurate swing angle of the striking arm. To solve such problems,the cam mechanism is designed and studied with the aid of the analytic method. According to the structure dimensions and operating requirements,the energy method is employed,so as to calculate the swing angle of the striking arm. The motion law is employed,and the cam angle distribution is confirmed by means of the analysis of pressure angle. Based on this,the practical curve of the cam profile is obtained. The ADAMS software is applied to carry out the kinematics simulation analysis of virtual prototype. Then,a pecan shell-breaking physical prototype is made. By means of the test,it is verified that the designed cam can realize the preset swing angle in an accurate manner,and based on this,the machine runs smoothly without any self-locking.