按输出力特性曲线设计凸轮轮廓曲线

针对以往设计断路器弹簧操动机构均是先确定满足动触头速度特性的输出力特性;再根据所需输出特性按照功或功率相等的等效原则计算动触头各行程下的凸轮轮廓半径;最后拟合出凸轮轮廓曲线。文中以设计真空断路器弹簧操动机构上配备的摆动滚子从动件盘形凸轮合闸行程中的轮廓曲线为模型,在以往的设计方法上提出了利用速度瞬心和微积分原理求得凸轮轮廓曲线的方法,该方法解决了传统设计方法繁琐的重复计算,不仅能方便的得到满足输出力特性曲线的凸轮轮廓,并能快速得到凸轮上各行程的压力角。用该方法得出的真空断路器合闸过程中的凸轮轮廓曲线与实际凸轮轮廓曲线进行对比,验证了方法的正确性,对设计弹簧操动机构中满足理想合闸特性的凸轮轮廓具有一定的借鉴意义。

Design of Cam Profile Curve Based on the Output Power Characteristic Curve

In the past,the circuit breaker spring operating mechanism was designed to first determine the output force characteristics satisfying the velocity characteristics of the moving contact,and then calculate the cam profile radius of the moving contact under each stroke according to the equivalent principle of equal work or power according to the required output characteristics.Finally,the cam profile curve is fitted.In this paper,the contour curve in the closing stroke of the wobbler-follower disc camshaft equipped on the spring operating mechanism of the vacuum breaker is designed as a model.In the previous design method,the principle of using the instantaneous center of the speed and calculus is proposed.The method of the cam profile curve solves the cumbersome repeat calculation of the conventional design method,and can not only easily obtain the cam profile satisfying the output force characteristic curve,but also quickly obtain the pressure angle of each stroke on the cam.The comparison of the cam profile curve and the actual cam profile curve during the closing process of the vacuum circuit breaker obtained by this method verifies the correctness of this method,and has a certain degree of design for the cam profile that meets the ideal closing characteristics in the spring operating mechanism.The design of the spring operating mechanism to meet the ideal closing characteristics of the cam profile has a certain reference value.