Optimization of electromagnetic impact actuator using a permanent magnet and spiral coils

Abstract

　When a momentary large current in opposite directions flows through the two opposing spiral coils, a momentary strong magnetic field in opposite directions is generated in the two coils. The strong magnetic field creates an impact force between the two coils. When a permanent magnet is placed under the spiral coils, the impact force of the actuator is enhanced because of the Lorentz force generated by the static magnetic field. In this paper, we introduce the principle of electromagnetic impact force generation and the calculation method of electromagnetic impact force. The magnetic fields generated by the spiral coil and the permanent magnet are analyzed by the finite element method. Then the electromagnetic impact force is derived from the current waveform and magnetic field. The shape of the spiral coil and permanent magnet is examined to maximize the electromagnet impact force.