Low amperage electromagnetic apparatus and method for uniform rivet upset

摘要

A riveting apparatus and method wherein riveting upset force is provided by a solenoid operated plunger wherein the current provided to the coil of the solenoid is controlled such as by a servo-controller to achieve rivet upset time versatility whereby cracking may be minimized while maintaining high quality rivet upset uniformity. A condition such as plunger velocity or applied force during upset is sensed, and signals indicative of the condition are fed back to the servo-controller so that the condition may be instantaneously adjusted as the plunger is moved for rivet upset.